In situ gelation of aqueous sulfuric acid solution for fuel cells

Abstract

In situ polymerization with acrylamide (AM) as the monomer and divinylbenzene (DVB) as a crosslinker in aqueous sulfuric acid solution resulted in gel membranes applicable in fuel cells.

Mesomorphic Polymer Hydrogel Stabilizing Ionic Surfactant Self-Assembly for Fuel Cells

“…27 AM as the monomer was dissolved in the ImHS solution for the strong gelation ability under acid conditions. 28 Hydrophobic DVB was used as the rigid cross-linker to reinforce the polymeric network, which was distributed evenly in the aqueous solution by virtue of amphiphilic ImHS. Interestingly, the L α phase disappeared after AM and DVB were dispersed in the ImHS solution (Figure S1a).…”

Monoammonium salts of multiprotic acids as dopants for proton-conductive hydrogel membranes: the effects of anions

“…Like PAM hydrogels derived from H 2 SO 4 solution with different concentrations, PAM of HG-AHSO 4 exhibited a lower degradation temperature than that of HG-AH 2 PO 4 because of lower pH level. 13 After the two-step decomposition, the residues of the hydrogels remained approximately 10 wt%.…”

“…At 30 C, ionic conductivity of HG-AHSO 4 reached 225 mS cm À1 , which was higher than that of the 3.5 mol L À1 H 2 SO 4 -doped PAM hydrogel (184 mS cm À1 ). 13 Meanwhile, ionic conductivity of HG-AH 2 PO 4 (46 mS cm À1 ) was also superior to the 14.3 mol L À1 (85 wt%) H 3 PO 4 -doped PAM hydrogel (10 mS cm À1 ). 11 The higher conductivities of the hydrogels doped with the monoammonium salts were attributed to the protonated ammonium cation, which can enhance proton conduction via both forming hydrogen bond and acting as proton carrier.…”

“…which overtook P max obtained from the H 2 SO 4 -doped hydrogel with the same membrane thickness (74 mW cm À2 ). 13 The result conrmed the advantage of ammonium salts over corresponding inorganic acids for proton conduction. A lower P max (64 mW cm À2 ) was obtained from HG-AH 2 PO 4 due to the declined proton conductivity.…”

“…Radical polymerization of acrylamide (AM) as monomer and MBA as cross-linking agent in aqueous H 2 SO 4 or H 3 PO 4 solution gave acid hydrogels whose proton conductivities reached up to 10 mS cm À1 . 11,12 We prepared H 2 SO 4 -doped polyacrylamide (PAM) hydrogels using divinylbenzene (DVB) as cross-linking agent and promoted the conductivity to 187 mS cm À1 at 30 C. 13 Modestino et al fabricated ultra-thin proton-conductive hydrogel lms (thickness, <100 nm) for electrocatalyst interfaces by submerging thermally crosslinked poly(acrylic acid)-poly(vinyl alcohol) into H 2 SO 4 solution. 14 Despite the simplicity, dopants other than inorganic acids have hardly been employed to prepare proton-conductive hydrogels.…”