Hypercrosslinked microporous organic polymer networks derived from silole-containing building blocks

Abstract

Three silole-containing hypercrosslinked microporous organic polymer networks were designed and synthesized via Friedel–Crafts alkylation promoted by anhydrous FeCl3. The results demonstrated that the substitution of methyl group connected with silicon atom by benzene has negligible effect on the surface area and gas uptake ability of the polymer networks. The network-1 produced from 1,1-dimethyl-2,3,4,5-tetraphenylsilole shows a surface area up to 1236 m2 g−1 with the hydrogen uptake ability of 1.33 wt% (77.3 K/1.13 bar) and a carbon dioxide capture capacity of 2.94 mmol g−1 at 273 K/1.13 bar. The isosteric heats of carbon dioxide sorption for all of the polymer networks exceed 25 kJ/mol at the zero coverage because the introduction of silicon atom into the polymer skeleton enhanced the binding affinity between the adsorbent and CO2 molecules. In addition, the selectivity of the polymer networks for CO2/N2 and CO2/CH4 were found to be around 35 and 6 at 273 K, respectively. These results show that these materials are potential candidates for applications in post-combustion CO2 capture and separation.