Four Simple Structure Carbazole-Based Conjugated Microporous Polymers with Different Soft Connected Chains

Four carbazole-spacer-carbazole polymers PCz-Cn-Cz (n = 3-6) with the similar topological model structures are designed and prepared by FeCl3 oxidative coupling polymerization. The Brunauer-Emmett-Teller (BET) specific surface areas of polymers are 862, 870, 768 and 785 m(2) g(-1), respectively. Interestingly, there are no obvious differences in the domain pore width (centered at 0.5 nm) and the pore size distribution among four polymers, although they have different length soft alkylene chains to interlink same rigid backbone carbazole. Gas adsorption isotherms show that H-2 storage of polymers can be up to 1.33 wt% at 1.0 bar and 77 K, the uptake capacity for CO2 can reach 16.8 wt% at 1.0 bar and 273 K, CH4 uptake can reach 2.11 wt% at 1.0 bar and 273 K, and the CO uptake performance can be up to 1.37 wt% at 298 K and 1.0 bar. Selective adsorption of CO2/N-2 and CO2/CH4 calculated using the initial gas uptake slopes shows that these networks display good selectivity with a maximum value of 47.7 (33.8) and 14 (7.3) at 273 K (298 K). The high selective adsorption performances make these materials potential candidates for gas separation and other environmental applications.