Self- and Directed Assembly of Soft Matter: Photorheological Fluids, Magnetic Microchains and Hemostatic Biomaterials

Srinivasa R. Raghavan, University of Maryland, College Park

Our group seeks to engineer the assembly of building blocks such as polymers, surfactants, or nanoparticles into higher-order materials. Such assembly can be induced spontaneously, guided by thermodynamic driving forces – a process that is termed self-assembly. Alternately, assembly can be directed in specific ways, e.g., by contacting fluids at interfaces or around predefined templates – and this can be 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 photorheological fluids. Also, we have used microfluidic techniques to create magnetic microcapsules of biopolymers, which we have then assembled into flexible microchains. We have also developed self-assembling biopolymers that have the ability to gel blood cells and thereby serve as effective hemostatic dressings for both military and civilian use.