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) ultrafiltration membranes. The flux through these polymer-based composite membranes is known to be proportional to the inorganic-filler content. Image analysis of skin surface micrographs revealed the skin surface pore characteristics to be almost unchanged over a wide range of compositions. The inorganic filler was found to be present in the skin layer, where it modifies the polymer network and locally reduces the skin thickness. This latter effect might be able to account for the observed flux behaviour.