The conformation of terminally anchored chains is of importance in applications such as chromatography with reversed phases, ceramic-supported polymer membranes, biocompatible surface, rheology, composites, chemical sensors and lubrication. Of particular interest in this project is the conformation of such chains subjected to shear and elongational flows. Experimental studies have been conducted with terminally anchored chains and adsorbed polymers in which the hydrodynamic response of the chains was studied. Brownian-dynamics models that account for the detailed motion of model terminally anchored chains have been developed. Current work is focusing on developing a modeling framework to account for the interaction of surface chains. Flow-induced deformation of tethered chains can be harnessed in numerous applications. for example, pore screening in membranes can provide for an additional control of membrane rejection. Current work is focusing on developing a modeling framework to account for the interaction of surface chains. The aim of this study is to determine the effect of flow on such end grafted chains and to predict the physical parameters such as Diffusivity and solvation for various flow and solvent conditions. Advanced simulation tools such as Brownian dynamics, Monte Carlo and Biased Monte Carlo are being explored.

References:

• Castro, Robert P., Harold G. Monbouquette and Yoram Cohen, "Shear-induced permeability changes in a polymer grafted silica membrane," J. Membrane Sci., 179, 207-220 (2000).
• Cohen, Y., R.S. Falbish and M. Rovira-Bru, "Polymer-Modified Silica Resins for Aqueous Size Exclusion Chromatography," pp. 263-310, in Interfacial Phenomena in Chromatography, Pefferkorn, E. (Ed.), Marcel-Dekker, New York, (1999).
• Parnas, R. and Y. Cohen, "A Terminally Anchored Polymer Chain in Laminar Shear Flow: Hydrodynamic Interactions," Rheologica Acta, 33, 485-505 (1994).
• Eisenberg, P., M. Chaimberg and Yoram Cohen, "Permeability of Graft Polymerized Polyvinylpyrrolidone-Silica Resin in Packed Columns," J.Colloid and Interface Science, 148, 580-586 (1992).
• Parnas, R. S. and Yoram Cohen, "The Response of a Terminally Anchored Polymer Chain to Simple Shear Flows," Macromolecules, 24, 4646-4656 (1991).