With the objective of improving water uptake and proton conductivity, silica sulfonic acid (SSA) nanoparticles were successfully prepared via the sulfonation of silica (SiO2) with sulfuryl chloride and a series of branched sulfonated poly(ether ether ketone) (BSPEEK)-based hybrid membranes with varying contents of SSA were fabricated by the solution-casting method as proton electrolyte materials. The hybrid membranes exhibited improved water uptake, excellent thermal stability, and enhanced mechanical strength. Compared with the methanol permeability, with the incorporation of SSA particles, the proton conductivity enhanced more significantly. The selectivity of the hybrid membranes increased with the increasing SSA contents, and the highest value was 8.2 × 105 S s cm−3, which was 2.6 times higher than that of Nafion 117. Therefore, these BSPEEK-SSA hybrid membranes could be considered as promising materials for direct methanol fuel cell applications.
ParkCHLeeCHCuiverMD. Sulfonated hydrocarbon membranes for medium-temperature and low-humidity proton exchange membrane fuel cells. Prog Polym Sci2011; 36: 1443–1498.
4.
ChenBKWuTYKuoCW. 4,4′-Oxydianiline (ODA) containing sulfonated polyimide/protic ionic liquid composite membranes for anhydrous proton conduction. Int J Hydrogen Energ2013; 38: 11321–11330.
5.
WangSZhaoCJMaWJ. Silane-cross-linked polybenzimidazole with improved conductivity for high temperature proton exchange membrane fuel cells. J Mater Chem A2013; 1: 621–629.
6.
WonJHLeeHJLimJM. Anomalous behavior of proton transport and dimensional stability of sulfonated poly(arylene ether sulfone) nonwoven/silicate composite proton exchange membrane with dual phase co-continuous morphology. J Membr Sci2014; 450: 235–241.
7.
LiYLiZLLuXF. Composite membranes based on sulfonated poly(aryl ether ketone)s containing the hexafluoroisopropylidene diphenyl moiety and poly(amic acid) for proton exchange membrane fuel cell application. Int J Hydrogen Energy2011; 36: 14622–14631.
8.
HaraREndoNHigaM. Polymer electrolyte fuel cell performance of poly(arylene ether ketone)-graft-crosslinked-poly(sulfonatedarylene ethe sulfone). J Power Sources2014; 247: 932–938.
9.
WangHPangJZhouF. Synthesis and preparation of sulfonated hyperbranched poly(aryl ether ketone)-sulfonated linear poly(aryl ether ketone) blend membranes for proton exchange membranes. High Perform Polym2013; 25: 759–768.
10.
LiSTomoyaHMitsuruU. Poly(arylene ether ether nitrile)s containing flexible alkylsulfonated side chains for polymer electrolyte membranes. J Polym Sci A Polym Chem2014; 52: 21–29.
KimYSEinslaBSankirM. Structure property performance relationships of sulfonated poly(arylene ether sulfone)s as a polymer electrolyte for fuel cell applications. Polymer2006; 47: 4026–4035.
14.
SakaguchiYKajiAKitamuraK. Polymer electrolyte membranes derived from novel fluorine-containing poly(arylene ether ketone)s by controlled posted-sulfonation. Polymer2012; 53: 4388–4398.
15.
LinCKTsaiJC. The effect of the side-chain ratio on main-chain-type and side-chain-type sulfonated poly(ether ether ketone) for direct methanol fuel cell applications. J Mater Chem2012; 22: 9244–9252.
16.
ParkHSSeoDWChoiSW. Preparation and characterization of branched and linear sulfonated poly(ether ketone sulfone) proton exchange membranes for fuel cell applications. J Polym Sci A Polym Chem2008; 46: 1792–1799.
17.
MatsumuraSHlilARDuNY. Ionomers for proton exchange membrane fuel cells with sulfonic acid groups on the end groups: novel branched poly(ether-ketone)s with 3,6-ditrityl-9H-carbazole end groups. J Polym Sci A Polym Chem2008; 46: 3860–3868.
18.
WangLLiKZhuGM. Preparation and properties of highly branched sulfonated poly(ether ether ketone)s doped with antioxidant 1010 as proton exchange membranes. J Membr Sci2011; 379: 440–448.
19.
ThanganathanUNogamiM. Synthesis of mixed composite membranes based polymer/HPA: electrochemical performances on low temperature PEMFCs. J Membr Sci2012; 411–412: 109–116.
20.
RenJZhangSWangQ. Novel hybrid acid–base membranes based on sulfonated poly(arylene ether sulfone), tetraethoxysilane and (3-aminopropyl)triethoxysilane for fuel cell application. High Perform Polym2013; 25: 188–197.
21.
FuTCuiZZhongS. Sulfonated poly(ether ether ketone)/clay-SO3H hybrid proton exchange membranes for direct methanol fuel cells. J Power Sources2008; 185: 32–39.
22.
LeiMWangYJLiangC. Prositron annihilation lifetime study of Nafion/titanium dioxide nano-composite membranes. J Power Sources2014; 246: 762–766.
23.
WangJTZhengXHWuH. Effect of zeolites on chitosan/zeolite hybrid membranes for direct methanol fuel cell. J Power Sources2008; 178: 9–19.
24.
KannanRKagalwalaHNChaudhariHD. Improved performance of phosphonated carbon nanotube-polybenzimidazole composite membranes in proton exchange membrane fuel cells. J Mater Chem2011; 21: 7223–7231.
25.
RodgersMPShiZHoldcroftS. Transport properties of composite membranes containing silicon dioxide and Nafion. J Membr Sci2008; 325: 346–356.
26.
TsaiCHLinHJTsaiHM. Characterization and PEMFC application of a mesoporous sulfonated silica prepared form two precursors, tetraethoxyslicane and phenyltriethoxysilane. Int J Hydrogen Energy2011; 36: 9831–9841.
27.
LiYXieMWangXT. Novel branched sulfonated poly(ether ether ketone)s membranes for direct methanol fuel cells. Int J Hydrogen Energy2013; 38: 12060–12068.
28.
KreuerKD. Proton conductivity: materials and applications. Chem Mater1996; 8: 610–641.
29.
KimDSLiuBJGuiverMD. Influence of silica content in sulfonated poly(arylene ether ether ketone ketone) hybrid membranes on properties for fuel cell application. Polymer2006; 47: 7871–7880.
30.
ZhangYZhangGWanY. Synthesis and characterization of poly(arylene ether ketone)s bearing pendant sulfonic acid groups for proton exchange membrane materials. J Polym Sci A Polym Chem2010; 48: 5824–5832.
