Process for the production of ddr-type zeolite membranes

Abstract

A process for production of a DDR-type zeolite membrane, which comprises: both a seed crystal-forming step of immersing a porous substrate in a seed crystal-forming raw material solution which contains a DDR-type zeolite powder dispersed therein and performing hydrothermal synthesis to form plural DDR-type zeolite crystal particles on surface of the porous substrate, and a membrane-forming step of immersing the resulting porous substrate with DDR-type zeolite crystal particles on the surface in a membrane-forming raw material solution which is free from DDR-type zeolite powder and performing hydrothermal synthesis to form a DDR-type zeolite membrane on the surface of the porous substrate. According to the process, a dense DDR-type zeolite membrane can be formed, and the vessel used in the synthesis can be prevented from being damaged.

Dependencies are inferred from the claim text.