Soft colloidal assemblies: Overpacked crystals and glasses

PHYS 149

L. Andrew Lyon, ll62@mail.gatech.edu1, Ashlee N St. John, ashlee.stjohn@chemistry.gatech.edu1, Zhiyong Meng1, Victor Breedveld, victor.breedveld@chbe.gatech.edu2, and Jae Kyu Cho2. (1) School of Chemistry and Biochemistry & Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 901 Atlantic Drive, Atlanta, GA 30332-0400, (2) School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, GA 30332-0100
The packing of spheres is a problem that has fascinated mathematicians, and natural scientists since before the time of Kepler. What began as a pursuit driven purely by curiosity has now grown into numerous fields that depend upon a deep understanding of how geometric building blocks assemble into structured materials. This lecture will introduce the audience to these issues in the context of colloidal microparticle and nanoparticle self assembly. Traditional hard sphere packing, such as that present in gemstone opals, will then be contrasted with the more complex problem of soft sphere packing. By using well-defined, stimuli-sensitive, hydrogel microparticle building blocks for the assembly of colloidal gels, glasses, and crystals, we have discovered that the interplay of the colloidal packing physics with the polymer chemistry and physics gives rise to incredibly rich phase behavior. An example of how the lessons learned from these studies are enabling the design and synthesis of "photonic paints" will be presented.
 

Emergence of Function in Molecular Assemblies
1:20 PM-5:00 PM, Monday, August 20, 2007 BCEC -- 159, Oral

Division of Physical Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007