COMPARATIVE-STUDY OF MICRO- AND ULTRAFILTRATION MEMBRANES USING STM, AFM AND SEM TECHNIQUES

In this work, Nuclepore ultrafiltration membranes are studied by various techniques (STM, AFM and SEM), in order to determine the method best suited for the study considered. AFM allows direct measurement of pore density and turns out to be highly reliable. However, in terms of surface corrugation, this technique remains limited at high magnifications. Despite the conductor film deposition needed for achieving a tunnel effect, STM yields the best resolution for defining surface corrugation. With respect to the study of ultrafiltration membranes, the resolution obtained from STM or AFM is much better than that of SEM whose electron beam also damages the polymer surface, These results are confirmed by the STM study of organic sulphonated polysulphone membranes.