Facile preparation of compact LTA molecular sieve membranes on polyethyleneimine modified substrates

A facile preparation strategy was proposed for preparation of compact zeolite LTA membranes on polyethyleneimine (PEI) modified substrates without seeding. Through the functionalization of substrates by using PEI, compact LTA membranes can be formed on various kinds of substrates. A well-intergrown and phase-pure LTA membrane with a thickness of about 3.0 mm is successfully prepared on the alpha-Al2O3 disk after crystallization for 24 h at 60 degrees C. Besides LTA membrane, wellintergrown zeolite FAU membranes can also be formed on PEI-modified alpha-Al2O3 substrates, suggesting the universality of this strategy. The zeolite LTA membranes synthesized on PEI-modified alpha-Al2O3 tubes were evaluated for the separation of alcohols/water mixture through pervaporation. The as-synthesized zeolite LTA membranes display high pervaporation performances. For the separation of 10 wt% isopropanol/water solution at 90 degrees C, a high separation factor of 44991 and a water flux of 1.73 kg m(-2) h(-1) are achieved. (C) 2020 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.

Automated summary

A facile strategy for preparing compact zeolite LTA membranes on PEI-modified substrates without seeding was proposed. By functionalizing the substrates with PEI, well-intergrown and phase-pure LTA membranes can be formed, which showed high pervaporation performances for alcohol/water mixtures separation. The universality and efficiency of this strategy were demonstrated by the successful formation of well-intergrown FAU zeolite membranes on the modified substrates.