"Entropically driven self-assembly and interaction in suspension"

Arjun G. Yodh

Department of Physics & Astronomy
University of Pennsylvania

Abstract

The addition of small macromolecules (particles) to a suspension of large particles causes an entropic attraction to arise between the large particles. The origin of this attractive force is an increase in volume (i.e. entropy) available to the smaller particles that arises when the large particles are moved close together. We review this effect and experimentally explore its manifestations near walls, wall-structures, within vesicles, and in suspensions of polymeric DNA. Light force microscopies to measure colloidal particle interaction and dynamics are introduced and experimentally demonstrated in some of these systems. Finally, entropically driven nucleation and assembly on grating surface templates is demonstrated.