Difference between revisions of "Highly-Ordered Selective Self-Assembly of a Trimeric Cationic Surfactant on a Mica Surface"

From Soft-Matter
Jump to: navigation, search
(Soft matter discussion)
(Soft matter discussion)
Line 13: Line 13:
 
[[Image:DTAD.jpg|500px|thumb|left| Chemical structure of DTAD.  Notice its trimeric cation structure.]]
 
[[Image:DTAD.jpg|500px|thumb|left| Chemical structure of DTAD.  Notice its trimeric cation structure.]]
  
[[Image:Stripes.jpg|500px|thumb|right| The top two photos show the silicon template used to create the PUA nanofibrilsBelow that is finished PUA nanofibrilsBelow that show the two shape tuned nanofibrils, the left is the stooped fibril structure, while the right is the crispated fibril structure.]]
+
[[Image:Stripes.jpg|500px|thumb|right| The top photo shows the parallel stripes with a few islandsThe next photo shows more stripes that are longerThe final image shows stripes that are both longer and thicker.]]
  
  
 
Future devices may have a need for nanoscale structures, so research in this area is booming even without direct applications in mind.  To create these structures, many scientists have already noticed that surfactant molecules can self assemble in unique ways; much research has been done on single tailed, or two tailed surfactants.  The people in this study however, have used a trimeric structure, DTAD, pictured left.
 
Future devices may have a need for nanoscale structures, so research in this area is booming even without direct applications in mind.  To create these structures, many scientists have already noticed that surfactant molecules can self assemble in unique ways; much research has been done on single tailed, or two tailed surfactants.  The people in this study however, have used a trimeric structure, DTAD, pictured left.
  
The researchers used the critical concentration to create micelles from DTAD, 0.29mM,  as a basis for their study.  They
+
The researchers used the critical concentration to create micelles from DTAD, 0.29mM,  as a basis for their study.  They added concentrations of 0.08, 2, 10, and 20 mM, corresponding to 0.2, 5, 25, and 50 times its cmc, respectively to a mica surface.  At the lowest concentration typical islands were observed, then as the CMC was passed, parallel stripes began forming.  As the concentration was then increased the islands gave way to longer and thicker parallel stripes.  These can be seen in the figure on the right.

Revision as of 01:42, 29 September 2009

Original entry: William Bonificio, AP 225, Fall 2009

Information

Highly-Ordered Selective Self-Assembly of a Trimeric Cationic Surfactant on a Mica Surface Yanbo Hou, Meiwen Cao, Manli Deng, Yilin Wang Langmuir 2008 24 (19), 10572-10574

Soft matter keywords

micelle, surfactant, DTAD, bilayer, hydrophobic, hydrophilic

Summary

The purpose of this study was to investigate a novel self assembly on a mica surface. When the researchers allowed (dodecyldimethylammonioacetoxy)diethyltriamine trichloride (DTAD) to assemble on a mica surface nanoscaled parallel stripes formed. This interesting formation is quite unique compared to islands that form on normal surfaces. A suggested mechanism for this ordering was also proposed that draws on many different forces including hydrophbicity and lattice matching.

Soft matter discussion

Chemical structure of DTAD. Notice its trimeric cation structure.
The top photo shows the parallel stripes with a few islands. The next photo shows more stripes that are longer. The final image shows stripes that are both longer and thicker.


Future devices may have a need for nanoscale structures, so research in this area is booming even without direct applications in mind. To create these structures, many scientists have already noticed that surfactant molecules can self assemble in unique ways; much research has been done on single tailed, or two tailed surfactants. The people in this study however, have used a trimeric structure, DTAD, pictured left.

The researchers used the critical concentration to create micelles from DTAD, 0.29mM, as a basis for their study. They added concentrations of 0.08, 2, 10, and 20 mM, corresponding to 0.2, 5, 25, and 50 times its cmc, respectively to a mica surface. At the lowest concentration typical islands were observed, then as the CMC was passed, parallel stripes began forming. As the concentration was then increased the islands gave way to longer and thicker parallel stripes. These can be seen in the figure on the right.