EVALUATION OF SELECTED METHODS FOR THE CHARACTERIZATION OF CERAMIC MEMBRANES

Defect-free surface layers with narrow pore size distributions and opt imal porosity of support and supporting layers are desirable propertie s of ceramic membranes. When fouling, concentration polarisation and i nteractions of molecules with pore walls are negligible, the permeabil ity in ceramic membranes and the efficiency of the separation process are determined mainly by the membrane pore structure. That is why the porous structure of ceramic membranes must be reliably tested. Ceramic membranes are often tested by mercury porosimetry. Other suitable met hods - Coulter porosimetry and permeation - are relative new. A compar ison of the possibilities and limitations of these methods and an expl anation of the differences in the obtained results are discussed. Prob lems connected with the preparation of membrane samples for measuremen t are also embraced.