(417c) Active Layer Brush Membranes for Pervaporation: A New Class of Synthetic Membranes

Performance and characterization of a new class of synthetic membranes are presented. These membranes are based on a brush-like active layer and were created through graft polymerization of vinyl monomers from light active porous poly(ether sulfone) supports. The grafted material or active layer is the rate limiting barrier to species transport and endows the membrane with selectivity, and are collectively known as polymer brushes. Various grafted polymer brushes were tested with an emphasis on those synthesized from hydrophobic monomers. Irradiation and reduction-oxidation methods were used to graft the polymer brush layers. The membranes were tested for their transport properties (selectivity and permeability) and characterized for polymer morphology, grafting density and solvent effects on mean brush height. Several techniques, including Attenuated Total Reflectance â?? Fourier Transform Infrared Spectroscopy (ATR-FTIR), X-Ray Photoelectron Spectroscopy (XPS), Time of Flight â?? Secondary Ion Mass Spectroscopy (TOF-SIMS), Atomic Force Microscopy (AFM), and Scanning Electron Microscopy (SEM) were used. The membranes were tested for recovery of small organics (e.g. acetic acid, isobutanol) from aqueous mixtures with pervaporation. An attractive feature of these brush skinned membranes are their ease and low cost of manufacture.