CHARACTERIZATION OF ANISOTROPIC UF-MEMBRANES - TOP LAYER THICKNESS AND PORE STRUCTURE

Anisotropic poly(2,6-dimethyl-, 1,4-phenylene oxide) (PPO) ultrafiltration membranes are characterized by means of two techniques. A new method for the determination of skin thicknesses, the gold sol method, is introduced and applied to these membranes. The membranes appeared to have a well-defined skin with a thickness of 0.2-mu-m. The results were combined with permporometry, a method that measures the size of the active pores that are actually responsible for the membrane performance. By following this approach it is possible to calculate the porosity of the skin layer and to obtain a suitable prediction of the pure water flux.