Characterization and theoretical analysis of isoporous cycloaliphatic polyurethane membrane for water treatment

A narrow pore size distribution is critical for most membrane separation processes even though it is difficult to achieve through conventional methods of membrane synthesis such as phase inversion. Although various technologies have been proposed for the preparation of isoporous membranes, few technologies are available for use in water treatment applications. In our previous works, we have prepared isoporous membranes using a novel technique based on soft lithography. A micro pattern of pyramid shape was applied to produce uniform pores. In this work, we aimed at the characterization of these isoporous membranes using both experimental and theoretical methods. The pore size distributions of the membranes were characterized by scanning electron microscopy image analysis. Using this image analysis technique, the pore size ranging from 2.2 to 21.4 μm could be identified. A simple theoretical model was developed to determine the pore size, porosity, and membrane resistance of the isoporous membranes. A preliminary filtration test was also carried out to examine the fundamental properties of the isoporous membranes.