Education B.A. 1964, Southern Illinois Ph.D. 1969, Georgetown A.P. Sloan Foundation Fellow 1974-78 Visiting Scientist, Bell Laboratories 1975-76

Physical Chemistry

My field of research is equilibrium statistical mechanics, which I use to study the relationship between molecular structure and interactions and the stability and properties of various liquid crystalline phases or mesophases. At present, I am concentrating on two classes of mesophases that are found in systems of rodlike molecules: nematic mesophases, in which the only long-range order present is the orientational alignment of the molecular long axes, and smectic A mesophases, in which the rodlike molecules are orientationally ordered and arranged in two-dimensional liquid layers. Some time ago, a student and I developed a lattice model for molecules with rigid rodlike central "cores" and two semiflexible pendent "tails" and used this model quite successfully to investigate the roles of molecular packing, intermolecular attractions, and molecular flexibility in stabilizing nematic and smectic A mesophases. A modification of this lattice model is currently being used to study systems with reentrant smectic and nematic phases; i.e., systems in which the unexpected sequence of phases nematic - smectic A - nematic - smectic A ... occurs with decreasing temperature.