“…Due to the preparation of PFEP molecule, three new peak components at 290.2 eV, 291.3 eV, and 294.2 eV are clearly observed, as shown in spectrum 7a. The three peaks originate from the -CF 2 -CH 2 -, -CF 2 -CF 2 -, and CF 3 -CF 2 -groups, respectively [50,51]. The CF 3 and CF 2 components could be clearly resolved from the other components because of fluorine's great electronegativity.…”