Effect of heat diffusivity for driving chain stitching of dual-type hybrid organosilica-derived membranes

Abstract

In this study, the usage of dual hybrid organosilica is proposed for discussing the influence of thermal-driven chain stitching on the organosilica membrane structure for the first time. The influence of the gas thermal diffusivity on the hybrid organosilica membrane for separating H2 from CH4, C2H6, and C3H8, is discussed in detail. The characterization and permeation tests revealed that the optimal condition of the organosilica membrane fabrication is the usage of nitrogen as calcination atmosphere owing to the mild reaction. In addition, it is found that when N2 is used as the calcining gas and calcination is performed at a lower temperature, it is beneficial for the separation of small-molecule gases. However, calcination at higher temperatures is beneficial to the separation of gas pairs with a big difference in kinetic diameter. The as-prepared M−N2−300 exhibited the maximum selectivity of 37.32 for CO2/N2, 82.37 for CO2/CH4, 47.51 for H2/N4, and 109.28 for H2/CH4, and ideal H2 permeance of 2.24 × 10−8 mol/(m2sPa). Moreover, the as-prepared M−N2−500 exhibited the maximum selectivity for the following gases: 438.99 and 301.47 toward H2/C2H6 and H2/C3H8, respectively, at the ambient environment, and satisfactory H2 permeance of 5.14 × 10−8 mol/(m2sPa). This shows the potential and industrial relevance for gas-separation concerning applications like H2 energy production and olefins/paraffins recovery.