PERMPOROMETRY STUDY ON THE SIZE DISTRIBUTION OF ACTIVE PORES IN POROUS CERAMIC MEMBRANES

Permporometry as well as nitrogen adsorption-desorption techniques hav e been applied to study the pore size distribution in gamma-alumina me mbranes with a pore radius ranging from about 2 nm to 10 nm. The permp orometry technique measures the active pores only, while nitrogen adso rption-desorption measures the active as well as the passive pores. Th e pore size distribution in the porous ceramic membrane supported with an alpha-alumina substrate (supported membrane) was determined by usi ng permporometry, while the membrane without a supporting substrate (u nsupported membrane) was characterized by nitrogen adsorption-desorpti on. The experimental results of permporometry and nitrogen adsorption- desorption indicate that the size distribution of the active pores in the supported membranes is similar to that of the active and passive p ores in the unsupported membranes. The alpha-alumina supporting substr ate seems to have no detectable influence on the size distribution of the active pores of the ceramic membranes studied.