Preparation and characterization of triptycene-based microporous poly(benzimidazole) networks

We demonstrate the synthesis of two triptycene-based microporous poly(benzimidazole) networks through condensation of triptycene-hexone with dialdehyde in refluxing glacial acetic acid containing ammonium acetate. The benzimidazole-linkage in the resulting polymers is confirmed by Fourier transform infrared and solid-state C-13 CP/MAS NMR spectroscopy. The spindle-shaped morphology of the obtained polymers was also observed through scanning electron microscopy. The materials, with Brunauer-Emmet-Teller (BET) specific surface area over 600 m(2) g(-1), possess a good hydrogen storage capacity (up to 1.57 wt% at 77 K and 1.0 bar) and a high carbon dioxide uptake (up to 14.0 wt% at 273 K and 1.0 bar). These excellent performances would probably make them promising candidates for gas-selective adsorption, heterogeneous catalysis, and proton-exchange membrane fuel cells.