Fabrication of a superhydrophobic mixed matrix PVDF-SiO2-HDTMS hollow fiber membrane for membrane contact carbon dioxide absorption

In order to obtain high performance polyvinylidene fluoride (PVDF) hollow fiber membrane for post combustion carbon dioxide (CO 2 ) capture from flue gas by membrane contact absorption technology, a novel mixed matrix membrane fabrication process was proposed in this study. The mixed matrix PVDF-SiO 2 (silicon dioxide)-HDTMS (hexadecyltrimethoxysilane) hollow fiber membranes fabricated via this process exhibit super-hydrophobicity on the outer surface and high mechanical strength. Among the membranes, the PVDF-SiO 2 (1.5)-HDTMS membrane exhibited the highest CO 2 absorption performance, which was due to its excellent properties. It had water and diethanolamine (DEA, 1 mol/L) contact angles of 159.3° and 157.5°, respectively. Tensile strength, elongation at break, and LEP W (liquid entry pressure of water) of it were 3.2 × 10 6  Pa, 35.0%, and 9.0 × 10 5  Pa, respectively. The CO 2 absorption flux of PVDF-SiO 2 (1.5)-HDTMS membrane attained 2.39 × 10 −3  mol‧m −2 ‧s −1 , which was 7.2% and 141.4% higher than that of the PVDF-HDTMS-1.5 and PVDF membranes, respectively. Moreover, CO 2 absorption flux of the PVDF-SiO 2 (1.5)-HDTMS membrane decreased only 3% after twenty days of continuous operation. Highlighted by the outstanding performance in membrane contact CO 2 absorption, the PVDF-SiO 2 (1.5)-HDTMS membrane shows great potential in the application of membrane contact absorption for post-combustion CO 2 capture.