Surface characterization by FTIR-ATR spectroscopy of polyethersulfone membranes-unmodified, modified and protein fouled

Polyethersulfone (PES) ultrafiltration membranes were modified by radical g rafting with the aid of redox initiators to create new functional groups on the surface. Methacrylate-based monomers were used. The modified membrane surfaces were characterized by FTIR-ATR spectroscopy to detect chemical cha nges during modification. In addition to the common adsorption bands of car bonyl groups typical for all grafted polymers, the FTIR spectrum displayed new absorption bands in the region of aliphatic stretching vibration of the modified PES membrane (2921-2875 cm(-1)), a region lacking absorption band s in the spectrum of the original membrane. It was also shown that the ATR technique enables recognition of the adsorption of albumin on the surface o f the membranes. Preliminary results indicate, that spectral techniques suc h as subtracting and deconvolution could be applied in order to recognize t he conformation of the adsorbed albumin. (C) 2000 Elsevier Science B.V. All rights reserved.