SEMINAR

Speaker

Srinivasa R. Raghavan Department of Chemical & Biomolecular Engineering, University of Maryland

Topic

Adventures with Self- and Directed Assembly: Light-Switchable Fluids, Swimming Microcapsules and Hemostatic Biomaterials

Date

23 December, 2013 (Monday)

Place

L-3, Lecture Hall Complex

Time

4.00 PM - 5.00 PM
   

ABSTRACT

Our laboratory seeks to engineer the assembly of "building blocks" such as polymers, surfactants, or colloids into higher-order materials. When such assembly is induced spontaneously by thermodynamic driving forces, it is called self-assembly. Alternately, when assembly is directed by bringing materials into contact at interfaces or around predefined templates, it is termed directed assembly. Both processes have their analogs in biology and nature, and both are of great technological interest.

This talk will provide illustrative examples of our work with self- and directed assembly. We have created assemblies that respond to stimuli such as temperature, pH or light; an example of the latter are fluids whose viscosity can be varied million-fold by irradiation with light. Also, we have used microfluidic techniques to create microcapsules of biopolymers, which we have endowed with self-propulsive capabilities in the presence of a chemical fuel. We have also developed self-assembling biopolymers that have the ability to convert liquid blood into a gel; thereby, the materials can stop bleeding from serious injuries. A startup company has been established to commercialize these "hemostatic" materials for military and civilian use.

References:

  • A. M. Ketner, S. R. Raghavan, et al. J. Am. Chem. Soc., 129, 1553 (2007)

  • H. Oh, S. R. Raghavan, et al. Soft Matter, 9, 5025 (2013)

  • K. Q. Jiang, D. L. DeVoe, S. R. Raghavan, et al. Small, 7, 2470 (2011)

  • A. X. Lu, D. L. DeVoe, S. R. Raghavan, et al. Langmuir, in press (2013)

  • M. B. Dowling, S. R. Raghavan, et al. Biomaterials, 32, 3351 (2011)

ABOUT THE SPEAKER

Prof. Srinivasa R. Raghavan did his B.Tech. from IIT Madras in 1992 in Chemical Engineering followed by Ph.D. in North Carolina State University in 1998 in Chemical Engineering. After spending three years as a Post-Doc in University of Delaware he joined Department of Chemical & Biomolecular Engineering, University of Maryland where he presently an Associate chair and Patrick & Marguerite Sung Professor. Prof. Raghavan works on variety of topics including self assembled systems, drug delivery, Polymeric and colloidal gels, and rheology.