Gelation bath composition Permeance (GPU) Selectivity H2 N2 H2/N2 Pure deionized water 25.0 0.49 51.0 40 vol. % DMAc, 60 vol. % deionized water 12.1 0.34 35.6 80 vol.% DMAc, 20 vol. wt% deionized water 6.2 0.25 24.8 90 vol.% DMAc, 10 vol. wt% deionized water 3.7 0.20 18.5 Temperature: 25°C, feed pressure: 10 bar

Table 2: Gas permeance and H2/N2 selectivity through PSf/PDMS composite membranes (different gelation bath composition).