Stephen M. Ritchie, University of Alabama, Department of Chemical Engineering, Box 870203, Tuscaloosa, AL 35487-0203 and Simone Cowan, Chemical and Biological Engineering, University of Alabama, Department of Chemical Engineering, Box 870203, Tuscaloosa, AL 35487-0203.
Ultrafiltration membranes have been functionalized with sulfonated polystyrene grafts to enhance whey protein separation using single-stage ultrafiltration. The mechanism of enhanced selectivity was investigated using dextran, small molecule, and protein permeation studies. Experimental results will be compared to simulations based on pore size and distribution, diffusion, and electrostatic repulsion. The models show excellent correlation with experimental data, and demonstrate that selectivity is enhanced through a combination of size exclusion and electrostatic effects.