Fig. 2: Synthesis and characterization of membranes.
a Schematic diagram and molecular model of a rigid and contorted PIM polymer chain with negatively charged sulfonate groups. b Synthetic route of sPIM-SBF polymers. c IEC and skeletal density of PIMs as a function of molar equivalent of TMSCS over PIM-SBF. Error bars are standard deviations derived from three IEC measurements based on three different samples, or a series of ten skeletal density measurements based on the same samples. d N2 adsorption isotherms at 77 K. e Pore size distribution derived from CO2 sorption based on DFT calculations. f Water vapor uptake isotherms at 298 K. g 1 nm-thick cross sections of the simulated polymer models in dry state. Purple shading highlights the isosurface of the polymer chain and light blue corresponding to the free volume. Sulfur atoms are colored in red and the polymer backbone in green. h Photograph of the PIM-SBF and sPIM-SBF membranes that corresponding to the modeling cell above each sample.
