Colloid-Polymer Systems: Statics and Dynamics

William Marsh Rice University, Houston TX

Investigators

Abstract

Marc A. Robert William Marsh Rice University "Colloid-Polymer Systems: Statics and Dynamics" Phase equilibria, static and dynamic microstructures, and diffusion properties of mixtures of colloidal particles and soluble non-adsorbing polymers will be investigated. The systems are either bulk three-dimensional ones, or they are confined to two-dimensional films, slit pores, and one- and quasi one-dimensional channels. The largest possible range of polymer-to-colloid size ratios will be investigated, from deep into the "colloid limit" of small polymer and large colloid, to deep into the "protein limit" of large polymer and small colloid. The colloid-polymer systems to be investigated consist of colloidal particles which are hard-sphere like (neutral or charged with a highly screened interaction), and of polymer which is soluble and non-adsorbing in the colloidal suspensions. A combination of the most efficient computer simulation methods developed by mathematicians and physicists and based on histogram reweighting and finite-size scaling, of theory (statistical thermodynamics) and of experiment (lithography, video microscopy, fluorescence microscopy, image analysis) will be used. Intellectual Merit of the Proposed Activity The problems that will be studied are challenging fundamental ones which require expertise in statistical thermodynamics, computer simulations, theoretical and experimental physical chemistry, and condensed matter physics. In particular, the powerful computer simulations proposed in this project will lead to significant understanding at a molecular level of the subtle key issues of soluble polymer-induced forces between neutral colloidal particles, which theory and experiment alone have not been able to resolve. Professor Panagiotopoulos (Princeton University) has agreed to collaborate with the PI on computer simulations at no cost to the project. Broader Impacts Resulting from the Proposed Activity In addition to graduate students, a large number of undergraduate students will take part in the proposed activity, and several will make presentations at national and regional scientific meetings and become co-authors of publications. The PI will be involved in several outreach programs of Rice University, in which he will discuss this proposed activity in understandable terms with middle- and high school teachers and students, in predominantly African-American and Hispanic public schools of Houston, those most largely underrepresented in academia. The PI will also host several middle-school students in the summer to visit his laboratory for one week. The project is supported by two CTS programs: Interfacial, Transport, and Thermodynamics sub-program; Particulate and Multiphase Processes.