Synthesis of highly c-oriented AFI membranes by epitaxial growth

The growth behavior between the two isomorphs of AFI type zeolite molecular sieves, AlPO-5 and SAPO-5 was studied. It was found that epitaxial growth of AlPO-5 from SAPO-5 seed layers led to preferential growth along the in-plane directions. Based on this interest finding, compact and highly c-oriented AFI membranes were successfully synthesized through a modified seeded growth procedure. The membrane quality was inspected by DC polarization test.