http://soft-matter.seas.harvard.edu/api.php?action=feedcontributions&user=Tkodger226&feedformat=atomSoft-Matter - User contributions [en]2022-12-07T01:08:04ZUser contributionsMediaWiki 1.24.2http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6801Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:19:14Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N} \sum_{k=1}^{N_j}e^{i6\theta_{jk}}</math><br />
<br />
where &theta;<sub>jk</sub> is the angle between r<sub>jk</sub>=r<sub>j</sub>-r<sub>k</sub>. As seen in Fig.1 the order parameter varies from 0 to 1, with 1 having 6 perfect nearest neighbors. In Fig.1, the increasing gray scale shows increasing crystallinity. The authors then extend this parameterization into the z-dimension by defining,<br />
<br />
<math>\psi^{(6)}(z)=\left \langle | \psi_j^{(6)} \right | \rangle_{\Delta z}</math><br />
<br />
By employing this layerwise crystallinity analysis, the authors were able to quantitatively study the crystallization process on an entire layer basis. What they found is graphically represented in Fig. 2. If a flat surface is used, the first two layers crystallize at approximately the same density <math>N/\sigma^2</math>, while with the templated surface the layers crystalize in a sequential fashion Fig.2(b). These results match recent colloidal particle simulations {Ref.1,2}<br />
<br />
==References==<br />
<br />
[1] J. Hoogenboom, P. Vergeer, and A. v. Blaaderen, ''J. Chem. Phys.'' 119, 3371 (2003).<br />
<br />
[2] M. Marechal and M. Dijkstra, ''Phys. Rev. E'' 75, 061404 (2007).</div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6800Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:19:01Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N} \sum_{k=1}^{N_j}e^{i6\theta_{jk}}</math><br />
<br />
where &theta;<sub>jk</sub> is the angle between r<sub>jk</sub>=r<sub>j</sub>-r<sub>k</sub>. As seen in Fig.1 the order parameter varies from 0 to 1, with 1 having 6 perfect nearest neighbors. In Fig.1, the increasing gray scale shows increasing crystallinity. The authors then extend this parameterization into the z-dimension by defining,<br />
<br />
<math>\psi^{(6)}(z)=\left \langle | \psi_j^{(6)} \right | \rangle_{\Delta z}</math><br />
<br />
By employing this layerwise crystallinity analysis, the authors were able to quantitatively study the crystallization process on an entire layer basis. What they found is graphically represented in Fig. 2. If a flat surface is used, the first two layers crystallize at approximately the same density <math>N/\sigma^2</math>, while with the templated surface the layers crystalize in a sequential fashion Fig.2(b). These results match recent colloidal particle simulations {Ref.1,2}<br />
<br />
==References==<br />
<br />
[1] J. Hoogenboom, P. Vergeer, and A. v. Blaaderen, ''J. Chem. Phys.'' 119, 3371 �(2003�).<br />
<br />
[2] M. Marechal and M. Dijkstra, ''Phys. Rev. E'' 75, 061404 (�2007�).</div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=User:Tkodger226&diff=6799User:Tkodger2262009-04-20T04:16:43Z<p>Tkodger226: </p>
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[[Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces]]</div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6798Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:16:15Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N} \sum_{k=1}^{N_j}e^{i6\theta_{jk}}</math><br />
<br />
where &theta;<sub>jk</sub> is the angle between r<sub>jk</sub>=r<sub>j</sub>-r<sub>k</sub>. As seen in Fig.1 the order parameter varies from 0 to 1, with 1 having 6 perfect nearest neighbors. In Fig.1, the increasing gray scale shows increasing crystallinity. The authors then extend this parameterization into the z-dimension by defining,<br />
<br />
<math>\psi^{(6)}(z)=\left \langle | \psi_j^{(6)} \right | \rangle_{\Delta z}</math><br />
<br />
By employing this layerwise crystallinity analysis, the authors were able to quantitatively study the crystallization process on an entire layer basis. What they found is graphically represented in Fig. 2. If a flat surface is used, the first two layers crystallize at approximately the same density <math>N/\sigma^2</math>, while with the templated surface the layers crystalize in a sequential fashion Fig.2(b). These results match recent colloidal particle simulations {Ref.1,2}<br />
<br />
==References==</div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6797Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:10:51Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N} \sum_{k=1}^{N_j}e^{i6\theta_{jk}}</math><br />
<br />
where &theta;<sub>jk</sub> is the angle between r<sub>jk</sub>=r<sub>j</sub>-r<sub>k</sub>. As seen in Fig.1 the order parameter varies from 0 to 1, with 1 having 6 perfect nearest neighbors. In Fig.1, the increasing gray scale shows increasing crystallinity. The authors then extend this parameterization into the z-dimension by defining,<br />
<br />
<math>\psi^{(6)}(z)=\left \langle | \psi_j^{(6)} \right | \rangle_{\Delta z}</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6796Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:10:35Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N} \sum_{k=1}^{N_j}e^{i6\theta_{jk}}</math><br />
<br />
where &theta;<sub>jk</sub> is the angle between r<sub>jk</sub>=r<sub>j</sub>-r<sub>k</sub>. As seen in Fig.1 the order parameter varies from 0 to 1, with 1 having 6 perfect nearest neighbors. In Fig.1, the increasing gray scale shows increasing crystallinity. The authors then extend this parameterization into the z-dimension by defining,<br />
<br />
<math>\psi^{(6)}(z)=\left \langle | \psi_j^{(6)} \right \vert \rangle_{\Delta z}</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6795Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:09:07Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N} \sum_{k=1}^{N_j}e^{i6\theta_{jk}}</math><br />
<br />
where &theta;<sub>jk</sub> is the angle between r<sub>jk</sub>=r<sub>j</sub>-r<sub>k</sub>. As seen in Fig.1 the order parameter varies from 0 to 1, with 1 having 6 perfect nearest neighbors. In Fig.1, the increasing gray scale shows increasing crystallinity. The authors then extend this parameterization into the z-dimension by defining,<br />
<br />
<math>\psi^{(6)}(z)=\langle\left\psi_j^{(6)}</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6794Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:08:52Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N} \sum_{k=1}^{N_j}e^{i6\theta_{jk}}</math><br />
<br />
where &theta;<sub>jk</sub> is the angle between r<sub>jk</sub>=r<sub>j</sub>-r<sub>k</sub>. As seen in Fig.1 the order parameter varies from 0 to 1, with 1 having 6 perfect nearest neighbors. In Fig.1, the increasing gray scale shows increasing crystallinity. The authors then extend this parameterization into the z-dimension by defining,<br />
<br />
<math>\psi^{(6)}(z)=</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6793Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:08:36Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N} \sum_{k=1}^{N_j}e^{i6\theta_{jk}}</math><br />
<br />
where &theta;<sub>jk</sub> is the angle between r<sub>jk</sub>=r<sub>j</sub>-r<sub>k</sub>. As seen in Fig.1 the order parameter varies from 0 to 1, with 1 having 6 perfect nearest neighbors. In Fig.1, the increasing gray scale shows increasing crystallinity. The authors then extend this parameterization into the z-dimension by defining,<br />
<br />
<math>\psi^{(6)}(z)=\langle\left\psi_j^{(6)}\right\rangle</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6792Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:08:04Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N} \sum_{k=1}^{N_j}e^{i6\theta_{jk}}</math><br />
<br />
where &theta;<sub>jk</sub> is the angle between r<sub>jk</sub>=r<sub>j</sub>-r<sub>k</sub>. As seen in Fig.1 the order parameter varies from 0 to 1, with 1 having 6 perfect nearest neighbors. In Fig.1, the increasing gray scale shows increasing crystallinity. The authors then extend this parameterization into the z-dimension by defining,<br />
<br />
<math>\psi^{(6)}(z)=\langle\left\psi_j^{(6)}\right\rangle_{\Delta z}</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6791Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:07:45Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N} \sum_{k=1}^{N_j}e^{i6\theta_{jk}}</math><br />
<br />
where &theta;<sub>jk</sub> is the angle between r<sub>jk</sub>=r<sub>j</sub>-r<sub>k</sub>. As seen in Fig.1 the order parameter varies from 0 to 1, with 1 having 6 perfect nearest neighbors. In Fig.1, the increasing gray scale shows increasing crystallinity. The authors then extend this parameterization into the z-dimension by defining,<br />
<br />
<math>\psi^{(6)}(z)=\lange\left\psi_j^{(6)}\right\rangle_{\Delta z}</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6790Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:03:16Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N} \sum_{k=1}^{N_j}e^{i6\theta_{jk}}</math><br />
<br />
where &theta;<sub>jk</sub> is the angle between r<sub>jk</sub>=r<sub>j</sub>-r<sub>k</sub></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6789Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:01:53Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N} \sum_{k=1}^{N_j}e^{i6\theta_{jk}}</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6788Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:01:43Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N} \sum_{k=1}^{N_j} </math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6787Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:01:31Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N} \sum_{k=1}^N_j </math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6786Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:01:16Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N} \sum_{k=1}^N_je^{i6\theta_{jk}}</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6785Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:00:53Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N} \sum_{k=1}</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6784Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:00:28Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N}</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6783Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:00:11Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N}\sum_{k=1}^\N_j</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6782Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T04:00:00Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N}\sum_{k=1}^\N_je^{i6\theta_{jk}}</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6781Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:59:17Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}=\frac{1}{N}\sum_{k=1}^\N_j e^{i6\theta_{jk}}</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6780Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:57:26Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^{(6)}</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6779Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:56:04Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses. On a technical basis, the crystallization kinetics of sedimenting and templated colloidal sized particles is critical toward inexpensive photonic crystals.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;m. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]<br />
<br />
The authors define a 6th-order bond parameter to define crystalline particles as such,<br />
<br />
<math>\psi_j^(6)</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6778Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:51:32Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a [111] template.]]</div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6777Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:51:17Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density for the first five layers sedimenting (a) onto a flat surface and (b) onto a {111} template/]]</div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6776Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:50:45Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density �see text� for the first five layers sedimenting �a� onto a flat surface and �b� onto a �111� template/]]</div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=File:Bond_order_parameters.jpg&diff=6775File:Bond order parameters.jpg2009-04-20T03:50:21Z<p>Tkodger226: </p>
<hr />
<div></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6774Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:50:13Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;. Density profiles and bond order parameters are measured with time.<br />
<br />
[[Image:Bond_order_parameters.jpg|frame|left|Fig. 2. Mean order parameter as a function of the projected particle density �see text� for the first five layers sedimenting �a� onto a flat surface and �b� onto a �111� template/]</div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6773Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:47:17Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres (1.55&mu;m) at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm/h</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.<br />
<br />
The particles are sedimented at the slow rate described above onto either a flat or templated substrate. The substrate is templated with a [111] oriented single crystal, made with reactive ion etching. A Leica SP5 confocal is used to observe the particles while they sediment slowly approximately every ~15sec per z-stack. The 3D dimensions are 93 X 93 X 16&mu;. Density profiles and bond order parameters are measured with time.</div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6772Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:43:02Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <br />
<math>g^*=m^*g\sigma/k_B T \approx 7</math> <br />
where <math>m^*=(\frac{1}{3}\pi\sigma^2)\Delta\rho</math> is the relative particle mass.</div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6771Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:42:34Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm</math><br />
<br />
The authors index match using DMSO, to minimize van der Waals. As a result the inverse gravitational length, <math>g^*=m^*g\sigma/k_B T \approx 7</math> where <math>m^*=(\frac{1}{3}\pi\sigma^2)\delta\rho</math> is the relative particle mass.</div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6770Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:39:36Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, except for basic sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6769Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:39:05Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, despite applying sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \approx 4.7mm</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6768Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:38:33Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, despite applying sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \prop 4.7mm</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6767Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:37:19Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, despite applying sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta \asymp 4.7mm</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6766Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:36:31Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, despite applying sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<math>u_0=\frac{1}{18}\sigma^2\Delta\rho g/\eta</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6765Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:35:55Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, despite applying sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<math>u_0=\frac{1}{18}\sigma</math><br />
<math>u_0=\frac{1}{18} &sigma; ^2 &Delta; &rho; g/&eta; </math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6764Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:35:34Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, despite applying sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<math>u_0=\frac{1}{18}sigma</math><br />
<math>u_0=\frac{1}{18} &sigma; ^2 &Delta; &rho; g/&eta; </math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6763Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:34:27Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, despite applying sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<math>u_0=\frac{1}{18} &sigma; </math><br />
<math>u_0=\frac{1}{18} &sigma; ^2 &Delta; &rho; g/&eta; </math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6762Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:34:16Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, despite applying sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<math>u_0=\frac{1}{18}&sigma;</math><br />
<math>u_0=\frac{1}{18}&sigma; ^2 &Delta; &rho; g/&eta; </math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6761Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:33:49Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, despite applying sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<math>u_0=\frac{1}{18}&sigma;</math><br />
<math>u_0=\frac{1}{18}&sigma;^2&Delta;&rho;g/&eta;</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6760Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:33:35Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, despite applying sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<math>u_0=\frac{1}{18}</math><br />
<math>u_0=\frac{1}{18}&sigma;^2&Delta;&rho;g/&eta;</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6759Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:33:11Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, despite applying sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<math>u</math><br />
<math>u_0=\frac{1}{18}&sigma;^2&Delta;&rho;g/&eta;</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6758Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:32:33Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, despite applying sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<math>u_0=&sigma;^2&Delta;&rho;g/&eta;</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6757Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:32:19Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, despite applying sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<math>u=\frac{1}{18}&sigma;^2&Delta;&rho;g/&eta;</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6756Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:32:05Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, despite applying sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<math>u_0=\frac{1}{18}&sigma;^2</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6755Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:31:51Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, despite applying sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<math>u_0=\frac{1}{18}&Delta;&rho;g/&eta;</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6754Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:31:26Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, despite applying sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<math>u_0=\frac{1}{18}&sigma;^2&Delta;&rho;g/&eta;</math><br />
<math>x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6753Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:29:25Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, despite applying sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <br />
<math>u_0 = \frac{1}{18}&sigma;^2&del;&rho;g/&eta;</math></div>Tkodger226http://soft-matter.seas.harvard.edu/index.php?title=Experimental_observation_of_the_crystallization_of_hard_sphere_colloidal_particles_by_sedimentation_onto_flat_patterned_surfaces&diff=6752Experimental observation of the crystallization of hard sphere colloidal particles by sedimentation onto flat patterned surfaces2009-04-20T03:29:08Z<p>Tkodger226: </p>
<hr />
<div>by Tom Kodger<br />
----<br />
<br />
== Reference ==<br />
<br />
I.B. Ramsteiner, K.E. Jensen, D.A. Weitz, F. Spaepen. ''PRE'' '''79''', 011403 (2009);<br />
<br />
== Keywords ==<br />
<br />
Colloidal crystal, patterned substrate, bond order parameter, template<br />
<br />
== Abstract ==<br />
We present a confocal microscopy study of 1.55 &mu;m monodisperse silica hard spheres as they sediment and crystallize at the bottom wall of a container. If the particles sediment onto a feature less flat wall, the two bottom layers crystallize simultaneously and layerwise growth follows. If the wall is replaced by a hexagonal template, only layerwise growth occurs. Our results complement earlier numerical simulations and experiments on other colloidal systems.<br />
<br />
== Capillarity In Action ==<br />
[[Image:Colloidal_crystal_template.jpg|frame|FIG. 1. Selected snapshots of the first three sedimented layers for four different area densities labels on top. Darker particles have higher-order parameters.]]<br />
<br />
While this paper contains very little capillarity, despite applying sedimentation concepts, the paper contains several useful experimental approaches, such as a bond order parameter, that could be used in other capillarity analyses.<br />
<br />
Briefly, the experiment system contains monodispersed silica spheres at low volume fraction in a fluorescent DMSO/water solution. Due to a density difference between the 2 components, these spheres slowly sediment according to, <math>/u_0 = \frac{1}{18}&sigma;^2&del;&rho;g/&eta;</math></div>Tkodger226