Finely tuning the microporosity in phosphoric acid doped triptycene-containing polybenzimidazole membranes for highly permselective helium and hydrogen recovery

Evidence Snippet

Additionally, under mixed-gas conditions at 150 ◦C, the TPBI-(H3PO4)0.98 membrane displays a H2 permeability of 46.7 Barrer and a H2/CO2 selectivity of 16, far beyond the Robeson’s 2008 upper bound for H2/CO2 separation. The TPBI-PA composite membranes were fabricated by immersing the TPBI films (~25 μm) in PA/methanol solutions. Dense TPBI membranes were obtained by the solution casting method. Specifically, 0.6 g of TPBI was entirely dissolved in 10 mL DMAc and filtered with a 0.45 μm syringe filter to eliminate any undissolved polymers or dust. The solution was cast onto a clean and predried glass plate and heated using an infrared lamp at 60 ◦C for 14 h. The isotropic film was obtained and peeled off from the glass plate, and the film was further dried under vacuum at 170 ◦C for 4 h to evaporate the residual solvent completely. The solution was stirred for 20 h and then dried in a vacuum oven at 110 ◦C for 4 h.