Difference between revisions of "Colloidal self-assembly at an interface"
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where <math>R</math> is the particle radius, <math>\gamma_{OW}</math> is the energy per unit area of the liquid-liquid interface, and <math>\theta_C</math> is the contact angle. The contact angle is related to the energy per unit area of the various interfaces through: | where <math>R</math> is the particle radius, <math>\gamma_{OW}</math> is the energy per unit area of the liquid-liquid interface, and <math>\theta_C</math> is the contact angle. The contact angle is related to the energy per unit area of the various interfaces through: | ||
<math>\cos\theta_C=(\gamma_{PO}-\gamma_{PW})/\gamma_{OW}</math>, | <math>\cos\theta_C=(\gamma_{PO}-\gamma_{PW})/\gamma_{OW}</math>, | ||
| − | where <math>\gamma_{PO}</math> is at the particle-oil interface, and <math>\ | + | where <math>\gamma_{PO}</math> is at the particle-oil interface, and <math>\gamma_{PW}</math> is at the particle-water interface. |
The paper focuses on how to control the assembly of colloidal particles at liquid-liquid interfaces. The control methods are divided into two categories: | The paper focuses on how to control the assembly of colloidal particles at liquid-liquid interfaces. The control methods are divided into two categories: | ||
Revision as of 04:34, 20 September 2010
Edited by Qichao Hu
September 19th, 2010
reference: [1]
It is well known that colloidal particles can form at the interfaces between liquids. This phenomenon can be used to self-assemble colloidal particles and ultimately to synthesize new materials.
The colloidal particles' ability to bind to liquid and stabilize emulsion is guided by the need to minimize interfacial energy. When a particle moves from a liquid to a liquid-liquid interface, the change in free energy is
<math>\Delta G=-\pi R^2\gamma_{OW} (1-\cos\theta_C)^2</math>
where <math>R</math> is the particle radius, <math>\gamma_{OW}</math> is the energy per unit area of the liquid-liquid interface, and <math>\theta_C</math> is the contact angle. The contact angle is related to the energy per unit area of the various interfaces through: <math>\cos\theta_C=(\gamma_{PO}-\gamma_{PW})/\gamma_{OW}</math>, where <math>\gamma_{PO}</math> is at the particle-oil interface, and <math>\gamma_{PW}</math> is at the particle-water interface.
The paper focuses on how to control the assembly of colloidal particles at liquid-liquid interfaces. The control methods are divided into two categories:
1) controlling the geometry at the interface
2) controlling the particle-particle interaction at the interface
