Defects of Zeolite Membranes: Characterization, Modification and Post-treatment Techniques

Characterization of zeolite membrane defects including SEM, dye permeation, bubble point and permporometry methods are presented. Experimental setup, governing equations and step by step procedure for obtaining pore sizes are discussed for the most useful method, i.e., the permporometry. A complete review on the techniques for elimination of defects including chemical vapor and liquid depositions, coke deposition, surface coatings, and hydrothermal treatments is presented. For each method, experimental setup, various modification conditions as well as performance enhancement of the membranes are comprehensively discussed. Finally, comparison between different methods is performed to find the more efficient techniques.