Fluorinated Porous Poly(spirobifluorene) Via Direct C-H Arylation: Characterization, Porosity, and Gas Uptake

Considering intrinsic properties of conjugated polyfluorenes and special functions of porous polymers, synthesis of fluorinated porous poly(spirobifluorene) via direct C-H arylation polycondensation is explored. Owing to the contorted structure and cross-linking nature, the obtained polymer FPSBF shows permanent porosities with Brunauer-Emmett-Teller specific surface area up to 700m(2) g(-1) and exhibits a narrow pore size distribution with the dominant pore size at about 0.63nm, which is more suitable for adsorption of small gas molecules. Based on the measured gas physisorption isotherms with pressure up to 1.13 bar, the obtained polymer shows good uptaking capacities for hydrogen (1.30wt% at 1.0 bar and 77K) and methane (4.80wt% 1.0 bar and 273K). Moreover, FPSBF has significant adsorption selectivity for CH4 against N-2 and the estimated ideal adsorption selectivity ratio is up to 30/1 at 1.0 bar and 273K, which makes the material possess potential application in gas separation.