John Dahler is supported by a grant from the Theoretical and Computational Chemistry Program to continue his theoretical statistical mechanical research on suspensions, polymers, and chemically reactive and non-uniform fluids. Four specific areas of research are being pursued: 1) Statistical mechanical studies of non-uniform systems that seek to extend a new theory of non-uniform but static thermodynamic field variables to incorporate fluxes and rates of relaxation and reaction in terms of well-defined correlation integrals of microdynamic variables; 2) An extension of a theory of colloidal dispersions and applications to studies of frequency-dependent viscoelastic moduli and of sedimentation and light scattering; 3) Studies involving a theory of chemically reactive fluids to examine density fluctuations caused by size changes of the species involved in reactions and the effects of chemical reaction on collective modes of the fluid such as those associated with ordinary and fast sound; and 4) Studies of the equilibrium properties of ideal polymer chains to incorporate the effects of excluded volume interactions. A number of commercially important products are derived from colloidal dispersions and solutions of polymers. Dahler's research is focused on a molecular level understanding of the physical properties of such complex fluid systems. A deeper understanding of these systems may lead to improved materials properties and new commercial applications.
