8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Thu 811:10-14:00P7.19Non-equilibrium molecular dynamics simulations ofmodel membrane permeabilityPeter Daivis 11 RMIT University, School of Applied Sciences, RMIT University, GPO Box 2476 3001,Melbourne, AustraliaFlow through a simplified model polymer membrane is simulated by non-equilibrium moleculardynamics methods. We use an external field in the microscopic equations of motion to drive thesolvent flow, and compute the flux as a function of the driving field. The relationship betweenthe external field and the membrane permeability coefficient is derived. We find that the flux isdirectly proportional to the field, yielding a permeability coefficient. The solvent permeabilitycoefficient is computed as a function of the membrane thickness and density. We also compute thesolute permeability for various solute particle sizes and different values of the solute-membraneinteraction parameters. Membrane fouling is studied by including a polymeric solute, and the effectof cross-flow is simulated by including a component of the external field parallel to the membranesurface. These results show that this method constitutes a viable and well-defined technique forstudying polymer membrane permeability.19