Preparation and application of silicalite-1 micromembranes on laser-perforated stainless steel sheets

Silicalite-1 micromembranes of approximately 80 μm in diameter have been prepared by synthesizing the zeolite material inside a network of perforations created by using a Nd–YAG laser on 75 μm thick stainless steel sheets. Several strategies have been introduced here to reduce the thickness of the micromembranes synthesized; among these the most successful involved using a polyamide filling to reduce the volume of the microperforations accessible to the synthesis solution. The density of microperforations could be tailored to prepare arrays of micromembranes of different overall porosity (1.8, 3.7, 6.6 and 7.7%). The micromembranes performed well in the propane/N2 separation, showing a maximum propane/N2 separation factor of 46, at a propane permeance of about 5 × 10−6 mol/(m2 s Pa).