Fig. 4: The structure characterization of the CTF film.

a FT-IR spectra of the CTF films. b ¹³C-NMR spectra of the CTF films. c Raman spectra of monomers and CTF films. d, e X-ray photoelectron spectrum of the CTF films. f N₂ adsorption and desorption isotherms (77 K); insert: the pore size distributions.