SURFACE CHARACTERISTICS OF ZIRFON(R) COMPOSITE ULTRAFILTRATION MEMBRANES

This paper presents the first high-resolution field emission scanning electron micrographs of the skin layers of a series of Zirfon(R) ultra filtration membranes. The flux through these polymer-based composite m embranes is known to be proportional to the inorganic-filler content. Image analysis of skin surface micrographs revealed the skin surface p ore characteristics to be almost unchanged over a wide range of compos itions. The inorganic filler was found to be present in the skin layer , where it modifies the polymer network and locally reduces the skin t hickness. This latter effect might be able to account for the observed flux behaviour.