Fundamental studies of a new series of anion exchange membranes: membrane preparation and characterization

Alkali resistant and conductive guanidinium-based anion-exchange membranes for alkaline polymer electrolyte fuel cells

“…2a), the signals with chemical shifts δ = 6.4-6.5 were assigned to aromatic hydrogens, while the signals at δ = 2.0-2.1 were assigned to the benzyl (-CH 3 ) hydrogens [18]. The spectrum for BPPO-0.54 (Fig.…”

“…The ion-exchange capacities were measured as in previous studies [18]. The AAEM sample was dried to a constant mass and then converted to the Cl -anion form by immersion in aqueous NaCl (1 mol …”

“…Gravimmetric water uptakes (W R ) were measured according to our previous work as an empirical measure of the hydrophilicity of the GPPO-X membranes [18]. The samples were dried in vacuum at 80°C until a constant weight m dry was attained.…”

“…The spectrum for BPPO-0.54 (Fig. 2b) exhibited new signals at δ = 4.0-5.0, which were assigned to the hydrogens of benzyl bromide (-CH 2 Br) [18]; these signals were used to calculate the X values of the BPPO-X (summarized in Table 1). …”

“…Therefore, AEMs were prepared with pendant guanidinium groups attached to poly(2,6-dimethyl-1,4-phenylene oxide) (PPO), a system that, to the best of our knowledge, has not been studied to date. According to our extensive previous work, brominated PPO (BPPO) can be easily formed using simple bromination reactions and as such allows the avoidance of the use of chloromethyl methyl ethers [18].…”