Sulfonated poly(ether ether ketone)/poly(styrene-divinylbenzene) (SPEEK/PSt-DVB) semi-interpenetrating polymer networks (semi-IPNs) were prepared to be used as proton exchange membranes (PEMs) for direct methanol fuel cells (DMFCs) applications. The morphologies of the membranes were investigated using field emission scanning electron microscopy. The ion-exchange capacity, water uptake, proton conductivity, methanol permeability, mechanical properties, and the thermal stability were characterized for each of the various semi-IPN membranes and evaluated for DMFC suitability. The semi-IPN SPEEK/PSt-DVB structure provided better dimensional stability, thermal stability, and mechanical integrity than the pristine SPEEK membrane. The methanol diffusion coefficient of the SPEEK/PSt-DVB-30% was reduced approximately by 70% when compared to the value of Nafion-117 at 30°C. The maximum selectivity of the semi-IPN membranes was 9.27 × 104 S s cm−3 for the SPEEK/PSt-DVB-20%, which was nearly 2.1 times higher than that of the Nafion-117 membrane. The improved properties of the SPEEK/PSt-DVB membranes were attributed to the homogeneous semi-IPN structure and to the hydrophobic molecular chains of PSt-DVB.
LiYLiTYaoM. Metal-free nitrogen-doped hollow carbon spheres synthesized by thermal treatment of poly(o-phenylenediamine) for oxygen reduction reaction in direct methanol fuel cell applications. J Mater Chem2012; 22(21): 10911–10917.
3.
GuptaDChoudharyV. Sulfonated poly(ether ether ketone)/ethylene glycol/polyhedral oligosilsesquioxane hybrid membranes for fuel cell applications. Int J Hydrogen Energy2012; 37(7): 5979–5991.
4.
BakanguraEWuLGeL. Mixed matrix proton exchange membranes for fuel cells: State of the art and perspectives. Prog Polym Sci2016; 57: 103–152.
5.
SteeleBCHHeinzelA. Materials for fuel-cell technologies. Nature2001; 414(6861): 345–352.
6.
FengPJLiuZLiuSY. Novel sulfonated poly(ether ether ketone)/polybenzimidazole blends for proton exchange membranes. High Perform Polym2013; 25(6): 697–704.
7.
AbdrashitovEFKritskayaDABokunVC. Synthesis and properties of stretched polytetrafluoroethylene-sulfonated polystyrene nanocomposite membranes. Solid State Ionics2016; 286: 35–140.
8.
HsuCYKuoMHKuoPL. Preparation, characterization, and properties of poly(styrene-b-sulfonated isoprene)s membranes for proton exchange membrane fuel cells (PEMFCs). J Membr Sci2015; 484: 146–153.
9.
VarnadoCDZhaoXOrtizM. Pyridine- and pyrimidine-functionalized poly(sulfone)s: performance-enhancing crosslinkers for acid/base blend proton exchange membranes used in direct methanol fuel cells. RSC Adv2014; 4(5): 2167–2176.
VengatesanSSanthiSSozhanG. Novel cross-linked anion exchange membrane based on hexaminium functionalized poly(vinylbenzyl chloride). RSC Adv2015; 5(35): 27365–27371.
12.
ZhouSKimJKimD. Cross-linked poly(ether ether ketone) membranes with pendant sulfonic acid groups for fuel cell applications. J Membr Sci2010; 348(1-2): 319–325.
13.
LuuDXKimD. Semi-interpenetrating polymer network electrolyte membranes composed of sulfonated poly(ether ether ketone) and organosiloxane-based hybrid network. J Power Sources2011; 196(24): 10584–10590.
14.
SongJMShinJSohnJY. Preparation and characterization of SPEEK membranes crosslinked by electron beam irradiation. Macromol Res2011; 19(10): 1082–1089.
15.
MikhailenkoSDWangKKaliaguineS. Proton conducting membranes based on cross-linked sulfonated poly(ether ether ketone) (SPEEK). J Membr Sci2004; 233(1-2): 93–99.
16.
HouHPoliniRDi VonaML. Thermal crosslinked and nanodiamond reinforced SPEEK composite membrane for PEMFC. Int J Hydrogen Energy2013; 38(8): 3346–3351.
17.
ZhuYZierenSManthiramA. Novel crosslinked membranes based on sulfonated poly(ether ether ketone) for direct methanol fuel cells. Chem Commun2011; 47(26): 7410–7412.
18.
MalikRSVermaPChoudharyV. A study of new anhydrous, conducting membranes based on composites of aprotic ionic liquid and cross-linked SPEEK for fuel cell application. Electrochim Acta2015; 152: 352–359.
ZhaoCXHeDLiYT. High-performance proton exchange membranes for direct methanol fuel cells based on a SPEEK/polybenzoxazine crosslinked structure. RSC Adv2015; 5(59): 47284–47293.
21.
WangJJiangSZhangH. Enhancing proton conduction and methanol barrier performance of sulfonated poly(ether ether ketone) membrane by incorporated polymer carboxylic acid spheres. J Power Sources2010; 364(1-2): 253–262.
22.
De AlmeidaNEEastonEB. Nafion/sulfonated silica composite membranes for PEM fuel cells. J Electrochem Soc2010; 28(27): 29–38.
23.
CelsoFMikhailenkoSDRodriguesMAS. Electrical conductivity of sulfonated poly(ether ether ketone) based composite membranes containing sulfonated polyhedral oligosilsesquioxane. J Power Sources2016; 305: 54–63.
DuLYanXHeG. SPEEK proton exchange membranes modified with silica sulfuric acid nanoparticles. Int J Hydrogen Energy2012; 37(16): 11853–11861.
26.
LiuXHeSSongG. Proton conductivity improvement of sulfonated poly(ether ether ketone) nanocomposite membranes with sulfonated halloysite nanotubes prepared via dopamine-initiated atom transfer radical polymerization. J Membr Sci2016; 504: 206–219.
27.
HeoYImHKimJ. The effect of sulfonated graphene oxide on sulfonated poly(ether ether ketone) membrane for direct methanol fuel cells. J Membr Sci2013; 425-426: 11–22.
SongMLuXLiZ. Compatible ionic crosslinking composite membranes based on SPEEK and PBI for high temperature proton exchange membranes. Int J Hydrogen Energy2016; 41(28): 12069–12081.
30.
XingPRobertsonGPGuiverMD. Synthesis and characterization of sulfonated poly(ether ether ketone) for proton exchange membranes. J Membr Sci2004; 229(1-2): 95–106.
31.
MossayebiZSaririchiTRowshanzamirS. Investigation and optimization of physicochemical properties of sulfated zirconia/sulfonated poly(ether ether ketone) nanocomposite membranes for medium temperature proton exchange membrane fuel cells. Int J Hydrogen Energy2016; 41(28): 12293–12306.
32.
SngESSunY. Fully crosslinked poly(styrene-co-divinylbenzene) microspheres by precipitation polymerization and their superior thermal properties. J Polym Sci Part A: Polym Chem2004; 42: 835–845.
33.
PeeraSGMeenakshiSGopiKH. Impact on the ionic channels of sulfonated poly(ether ether ketone) due to the incorporation of polyphosphazene: a case study in direct methanol fuel cells. RSC Adv2013; 3(33): 14048–14056.
34.
YaoBYanXDingY. Synthesis of sulfonic acid-containing polybenzoxazine for proton exchange membrane in direct methanol fuel cells. Macromolecules2014; 47(3): 1039–1045.
