Fig. 3: Structure characterization of 6FDA-TFDB-x precursor and CMS membranes.

a Liquid-state 19F NMR spectra of 6FDA-TFDB-x precursor. b Solid-state 19F NMR of 6FDA-TFDB-x CMS. c Solid-state ATR-FTIR spectra of 6FDA-TFDB-x precursors. d TGA-FTIR date of 6FDA-TFDB precursor. e TGA-FTIR date of 6FDA-TFDB-7 precursor. f TGA-FTIR date of 6FDA-TFDB-12 precursor.