Effect of SBA-15 texture on the gas separation characteristics of SBA-15/polymer multilayer mixed matrix membrane

The authors previously synthesized a SBA-15/PPO multilayer mixed matrix membranes (MMMs) and demonstrated that the SBA-15 filler itself may create additional passageway for gas pass through. The objectives of this work were to investigate the effect of texture of SBA-15, including pore sizes, pore volume, and external surface area, on the structure of MMMs and gas permeation performance. To obtain different textures of mesoporous silica, various SBA-15 were prepared under different aging temperatures to modify the crystalline structure. Results show that selectivity for H2/N2 and H2/CH4 separation through the SBA-15/PPO MMM increased remarkably from 90 to 110 °C in SBA-15 aging temperature, with values at 49.7–102.9 and 63.3–140.4, respectively. This indicates that blocking and reducing the mobility of polymer chains by mixing a PPO matrix with SBA-15 of 110 °C aging temperature may significantly improve the gas separation performance of the MMM. The increments of glass transition temperature of the MMM suggest that the integration of larger SBA-15 crystals aged at 110 °C causes the polymer chains to become rigid.

Research highlights▶ High gas separation performance of SBA-15/PPO mixed matrix membrane was prepared. ▶ The texture of SBA-15 was modified by different aging temperature. ▶ SBA-15 with large surface area and pore volume could be formed at high temperature. ▶ Polymer chains can penetrate into the pores of SBA-15 and lead to chain rigidity.