摘要
Mesoporous SiO 2 aerogels are multi-functional porous materials with diverse applications. However, the fragile characteristics and low mechanical strength of mesoporous SiO 2 aerogels limits their development for use in industrial applications. The mechanical strength of SiO 2 aerogels can be greatly enhanced by the addition of tri-epoxy cross-linkers. Tri-epoxy cross-linked SiO 2 aerogels with tri-epoxy concentrations of 7.5%, 15%, 30% and 45% were coated on macroporous Al 2 O 3 membrane supports. The surface of the tri-epoxy cross-linked SiO 2 aerogel membranes became superhydrophobic after fluoroalkylsilane (FAS) modification. Compared to native SiO 2 aerogel membranes in the absence of tri-epoxy cross-linker, the pore size of the tri-epoxy cross-linked SiO 2 aerogel membranes with tri-epoxy concentrations of 15% and 30% increased to approximately 6 nm, resulting in an increase in the CO 2 absorption flux. The highest CO 2 absorption flux of 1.4 mmol/m 2 s was reached for the tri-epoxy cross-linked SiO 2 aerogel membrane with a tri-epoxy concentration of 15%. The durability of the as-prepared SiO 2 aerogel membranes for CO 2 absorption is also demonstrated in this work. Consequently, the mechanically robust tri-epoxy cross-linked SiO 2 aerogel membranes have potential applications in membrane contactor systems for CO 2 capture.