ZSM-5 Zeolite Membrane Preparation, A Review

Over the last decade, much attention has been focused on the development of continuous zeolite-based separations processes. For such purposes, the natural configuration of the zeolite material is in the form of a thin film or membrane supported on, or deposited in, a porous substrate. ZSM-5 type zeolite membranes have shown promise for molecular sieving applications that require high chemical and thermal stability. ZSM-5 type zeolite membranes were prepared by template-free seeded growth method in order to minimize defects and/or intercrystalline gaps that form during the calcination step required for template removal. In many cases, microwave synthesis has proven to remarkably reduce the synthesis time. In addition, microwave synthesis could also result in different membrane morphology, orientation, composition, and thus the different permeation characteristics as compared with those synthesized by conventional heating.