Preparation of polyacrylamide-silica organic-inorganic hybrid membranes for carbon dioxide separation via in-situ polymerization

Polyacrylamide (PAAm)-silica organic-inorganic hybrid membranes for carbon dioxide (CO2) separation were prepared via in-situ polymerization. Formation of silica and PAAm via sol-gel method and in-situ polymerization was confirmed by IR spectroscopy. Single gas permeances through the membranes were measured at 298, 373 and 423 K using CO2, He and N-2. The ideal separation factor (the ratio of the permeances) of CO2/N-2 through the AAm10 membrane (starting solution composition; tetraethoxysilane: methyltriethoxysilane: distilled water: hydrochloric acid: ethanol: acrylamide: dimethyl 2,2'-azobis(isobutyrate) = 0.4: 0.6: 2: 0.01: 20: 1.0: 0.1 in molar ratio) was 25.4 at 298 K. This value was thirty times higher than the theoretical Knudsen value (CO2/N-2 = 0.8). Binary gas permeation at 298 K was also investigated using a gas mixture of 50%CO2-50%N-2. The ideal separation factor (the ratio of the permeances) of CO2/N-2 through the membrane was 24.9. This value was the same as the ideal separation factor of CO2/N-2 calculated from the single gas measurement. Such a high CO2 selectivity in 50%CO2-50%N-2 feed gas was also found even at high temperature for this membrane. [GRAPHICS] .

Automated summary

Polyacrylamide (PAAm)-silica organic-inorganic hybrid membranes were prepared for carbon dioxide (CO2) separation. The membranes showed high ideal separation factor for CO2/N-2 at 298 K, and also exhibited high CO2 selectivity in a gas mixture of 50%CO2-50%N-2.