Tuesday, 02/24/2004
4:00 PM
Steinman Hall, Room #312
(Chemical Engineering Conference Room)

Dr. Anand Yethiraj
University of British Columbia
Department of Chemistry

"Controlling Self Assembly in Colloids: From Crystallization and Melting to the Design of Novel Photonic Materials"


Self assembly is the formation of ordered structures (from simple ones, such as opals, to rather complex biological ones, such as ourselves) in a remarkably non-energy-intensive way. Model spherical colloids exhibit a thermodynamic phase behaviour analogous to that in atomic fluids and solids, and provide a wonderful medium to control self-assembly, by controlling colloidal interactions using external fields, solvent electrochemistry, and bounding surfaces.

Self-assembly in these simple model systems provides a basis for the understanding of colloidal interactions in more complex colloidal systems in biology. It also provides a pragmatic way of designing large-area photonic band-gap materials: materials with a periodic modulation of the dielectric constant that produces a potential for photons analagous to the atomic potential for electrons in semiconductors.

I will describe quantitative confocal microscopy studies of the rich phase behaviour that arises from an unprecedented control of interactions and present studies of phase transitions, crystallization, melting, and applications to novel photonic crystal structures.

  • BSc, St. Xavier's College, Bombay, Physics, 1988.
  • MS, U. Houston, Physics, 1991.
  • PhD, Simon Fraser University (Canada), Physics, 1999. NMR spectroscopy studies of the nematic-smectic-A phase transition in liquid crystals.
  • Post-doctoral Research Scientist, Physics department, Utrecht U., and FOM
  • Institute for Atomic and Molecular Physics, the Netherlands, 1999-2002. Electric-field induced structure and dynamics in colloidal suspensions.
  • Post-doctoral Research Scientist, Chemistry Department, U. British Columbia, since 2002. NMR studies of anisotropic diffusion and relaxation in lyotropic liquid crystals and complex fluid (micro-)emulsions.