{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T11:46:50Z","timestamp":1792151210227,"version":"4.4.0"},"reference-count":53,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2020,2,18]],"date-time":"2020-02-18T00:00:00Z","timestamp":1581984000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Membranes"],"abstract":"<jats:p>Sulfonated polyphenylsulfone (SPPSU) with a high ion exchange capacity (IEC) was synthesized using commercially available polyphenylsulfone (PPSU), and a large-area (16 \u00d7 18 cm2) crosslinked sulfonated polyphenylsulfone (CSPPSU) membrane was prepared. In addition, we developed an activation process in which the membrane was treated with alkaline and acidic solutions to remove sulfur dioxide (SO2), which forms as a byproduct during heat treatment. CSPPSU membranes obtained using this activation method had high thermal, mechanical and chemical stabilities. In I-ViR free studies for fuel cell evaluation, high performances similar to those using Nafion were obtained. In addition, from the hydrogen (H2) gas crossover characteristics, the durability is much better than that of a Nafion212 membrane. In the studies evaluating the long-term stabilities by using a constant current method, a stability of 4000 h was obtained for the first time. These results indicate that the CSPPSU membrane obtained by using our activation method is promising as a polymer electrolyte membrane.<\/jats:p>","DOI":"10.3390\/membranes10020031","type":"journal-article","created":{"date-parts":[[2020,2,18]],"date-time":"2020-02-18T10:10:25Z","timestamp":1582020625000},"page":"31","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":31,"title":["Chemically Crosslinked Sulfonated Polyphenylsulfone (CSPPSU) Membranes for PEM Fuel Cells"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4301-1044","authenticated-orcid":false,"given":"Je-Deok","family":"Kim","sequence":"first","affiliation":[{"name":"Hydrogen Production Materials Group, Center for Green Research on Energy and Environmental Materials, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Akihiro","family":"Ohira","sequence":"additional","affiliation":[{"name":"Energy Storage Technology Group, Research Institute for Energy Conservation, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hidenobu","family":"Nakao","sequence":"additional","affiliation":[{"name":"Hydrogen Materials Engineering Group, Research Institute for Energy Conservation, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,2,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1016\/j.apcatb.2004.06.021","article-title":"Activity benchmarks and requirements for Pt, Pt-alloy, and non-Pt oxygen reduction catalysts for PEMFCs","volume":"56","author":"Gasteiger","year":"2005","journal-title":"Appl. Catal. B Environ."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1881","DOI":"10.1002\/cjce.21884","article-title":"Recent progress in non-precious metal catalysts for PEM fuel cell applications","volume":"91","author":"Higgins","year":"2013","journal-title":"Can. J. Chem. Eng."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"96","DOI":"10.1016\/j.jpowsour.2012.02.011","article-title":"Support materials for PEMFC and DMFC electrocatalysts\u2014A review","volume":"208","author":"Sharma","year":"2012","journal-title":"J. Power Sources"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"4535","DOI":"10.1021\/cr0207123","article-title":"State of understanding of Nafion","volume":"104","author":"Mauritz","year":"2004","journal-title":"Chem. Rev."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1149\/2.F05171if","article-title":"Increasing fuel cell efficiency by using ultra-low equivalent weight ionomers","volume":"26","author":"Yandrasits","year":"2017","journal-title":"Electrochem. Soc. Interface"},{"key":"ref_6","unstructured":"Savinell, R.F., and Litt, M.H. (1996). Proton Conducting Polymers Used as Membranes. (Number 5525436), US Patent."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1016\/S0167-2738(99)00181-2","article-title":"Synthesis and characterization of novel acid\u2014Base polymer blends for application in membrane fuel cells","volume":"125","author":"Kerres","year":"1999","journal-title":"Solid State Ion."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1016\/j.memsci.2009.10.052","article-title":"A simple heat treatment to prepare covalently crosslinked membranes from sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) for application in fuel cells","volume":"348","author":"Wu","year":"2010","journal-title":"J. Membr. Sci."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1189","DOI":"10.1021\/ma0523769","article-title":"Water stability of sulfonated polyimide membranes","volume":"39","author":"Yin","year":"2006","journal-title":"Macromolecules"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1762","DOI":"10.1021\/ja0571491","article-title":"Aliphatic\/aromatic polyimide ionomers as a proton conductive membrane for fuel cell applications","volume":"128","author":"Asano","year":"2006","journal-title":"J. Am. Chem. Soc."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"A1154","DOI":"10.1149\/1.2193334","article-title":"Durability of sulfonated polyimide membrane evaluated by long-term polymer electrolyte fuel cell operation","volume":"153","author":"Aoki","year":"2006","journal-title":"J. Electrochem. Soc."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1016\/j.jpowsour.2011.12.060","article-title":"Conductivity and hydration of sulfonated polyethersulfone in the range 70\u2013120 \u00b0C: Effect of temperature and relative humidity cycling","volume":"205","author":"Donnadio","year":"2012","journal-title":"J. Power Sources"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1517","DOI":"10.1016\/j.ijhydene.2012.10.110","article-title":"Crosslinked SPES-SPPSU membranes for high temperature PEMFCs","volume":"38","author":"Kim","year":"2013","journal-title":"Int. J. Hydrogen Energy"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1126\/sciadv.aao0476","article-title":"Design of flexible polyphenylene proton-conducting membrane for next-generation fuel cells","volume":"3","author":"Miyake","year":"2017","journal-title":"Sci. Adv."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"598","DOI":"10.1021\/ma062324z","article-title":"Sulfonated poly(phenylene sulfone) polymers as hydrolytically and thermooxidatively stable proton conducting ionomers","volume":"40","author":"Schuster","year":"2007","journal-title":"Macromolecules"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"43941","DOI":"10.1002\/app.43941","article-title":"Poly(ethylene glycol) crosslinked sulfonated polysulfone composite membranes for forward osmosis","volume":"133","author":"Ding","year":"2016","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1017","DOI":"10.1007\/s10853-009-4033-3","article-title":"Crosslinked sulfonated poly (bis-A)-sulfones as proton exchange membrane for PEM fuel cell application","volume":"45","author":"Yu","year":"2010","journal-title":"J. Mater. Sci."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"896","DOI":"10.1002\/1521-3927(20021001)23:15<896::AID-MARC896>3.0.CO;2-P","article-title":"Sulfophenylation of polysulfones for proton-conducting fuel cell membranes","volume":"23","author":"Lafitte","year":"2002","journal-title":"Macromol. Rapid Commun."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1016\/S0167-2738(01)00912-2","article-title":"Sulfonated polysulfone ionomer membranes for fuel cells","volume":"145","author":"Lufrano","year":"2001","journal-title":"Solid State Ion."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/S0376-7388(00)00631-1","article-title":"Development of ionomer membranes for fuel cells","volume":"185","author":"Kerres","year":"2001","journal-title":"J. Membr. Sci."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1250","DOI":"10.1002\/1097-4628(20000808)77:6<1250::AID-APP9>3.0.CO;2-R","article-title":"Sulfonated polysulfone as promising membranes for polymer electrolyte fuel cells","volume":"77","author":"Lufrano","year":"2000","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"8672","DOI":"10.1016\/j.ijhydene.2012.02.159","article-title":"High performance sulfonated aromatic ionomers by solvothermal macromolecular synthesis","volume":"37","author":"Alberti","year":"2012","journal-title":"Int. J. Hydrogen Energy"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"3674","DOI":"10.1007\/s10853-009-3490-z","article-title":"Long-term performance of polyetheretherketone-based polymer electrolyte membrane in fuel cells at 95 \u00b0C","volume":"44","author":"Chen","year":"2009","journal-title":"J. Mater. Sci."},{"key":"ref_24","first-page":"1","article-title":"Development of aromatic polymer electrolyte membrane with high conductivity and durability for fuel cell","volume":"116","author":"Goto","year":"2009","journal-title":"JSR Tech. Rev."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"7505","DOI":"10.1021\/jp9006679","article-title":"Analysis of temperature-promoted and solvent-assisted cross-linking in sulfonated poly (ether ether ketone)(SPEEK) proton-conducting membranes","volume":"113","author":"Sgreccia","year":"2009","journal-title":"J. Phys. Chem. B"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"4327","DOI":"10.1021\/cm800155r","article-title":"Composite proton-conducting hybrid polymers: Water sorption isotherms and mechanical properties of blends of sulfonated PEEK and substituted PPSU","volume":"20","author":"Sgreccia","year":"2008","journal-title":"Chem. Mater."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1021\/cm051546t","article-title":"A simple new route to covalent organic\/inorganic hybrid proton exchange polymeric membranes","volume":"18","author":"Marani","year":"2006","journal-title":"Chem. Mater."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"201","DOI":"10.1002\/fuce.200400084","article-title":"Poly(arylene ether sulfone) copolymers and related systems from disulfonated monomer building blocks: Synthesis, characterization, and performance\u2014A topical review","volume":"5","author":"Harrison","year":"2005","journal-title":"Fuel Cells"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"406","DOI":"10.1002\/fuce.200500089","article-title":"Characterization of sulfonated poly(etheretherketone)\/polytetrafluoroethylene composite membranes for fuel cell applications","volume":"5","author":"Xing","year":"2005","journal-title":"Fuel Cells"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/j.memsci.2003.09.019","article-title":"Synthesis and characterization of sulfonated poly(etheretherketone) for proton exchange membranes","volume":"229","author":"Xing","year":"2004","journal-title":"J. Membr. Sci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"93","DOI":"10.1016\/j.memsci.2004.01.004","article-title":"Proton conducting membranes based on cross-linked sulfonated poly(etheretherketone) (SPEEK)","volume":"233","author":"Mikhailenko","year":"2004","journal-title":"J. Membr. Sci."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1016\/j.memsci.2003.08.018","article-title":"Sulfonated poly(etheretherketon) membranes for direct methanol fuel cell","volume":"226","author":"Li","year":"2003","journal-title":"J. Membr. Sci."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"24527","DOI":"10.1021\/acsami.7b03720","article-title":"High-performance semicrystalline poly(ether ketone)-based proton exchange membrane","volume":"9","author":"Feng","year":"2017","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1016\/j.ssi.2017.12.033","article-title":"Organic solvent-free preparation of electrolyte membranes with high proton conductivity using aromatic hydrocarbon polymers and small cross-linker molecules","volume":"316","author":"Matsushita","year":"2018","journal-title":"Solid State Ion."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"221","DOI":"10.1016\/j.memsci.2017.09.076","article-title":"A novel ionically cross-linked sulfonated polyphenylsulfone (SPPSU) membrane for organic solvent nanofiltration (OSN)","volume":"545","author":"Tashvigh","year":"2018","journal-title":"J. Membr. Sci."},{"key":"ref_36","first-page":"1","article-title":"Effect of thermal crosslinking on the properties of sulfonated poly(phenylene sulfone)s as proton conductive membranes","volume":"44218","author":"Zhang","year":"2016","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"11794","DOI":"10.1016\/j.ijhydene.2016.02.084","article-title":"Annealing effect of highly sulfonated polyphenylsulfone polymer","volume":"41","author":"Kim","year":"2016","journal-title":"Int. J. Hydrogen Energy"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"221","DOI":"10.1016\/j.jpowsour.2015.07.001","article-title":"Hydrocarbon-based polymer electrolyte cerium composite membranes for improved proton exchange membrane fuel cell durability","volume":"295","author":"Lee","year":"2015","journal-title":"J. Power Sources"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1267","DOI":"10.1039\/C4PY01177E","article-title":"Hypersulfonated polyelectrolytes: Preparation, stability and conductivity","volume":"6","author":"Takamuku","year":"2015","journal-title":"Polym. Chem."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"174","DOI":"10.1016\/j.memsci.2013.12.020","article-title":"Locally confined membrane modification of sulfonated membranes for fuel cell application","volume":"454","author":"Krishnan","year":"2014","journal-title":"J. Membr. Sci."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"212","DOI":"10.1016\/j.memsci.2013.06.028","article-title":"Properties of sulfonated poly(arylene ether sulfone)\/electrospun nonwonen polyacrylonitrile composite membrane for proton exchange membrane fuel cells","volume":"446","author":"Yu","year":"2013","journal-title":"J. Membr. Sci."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1202","DOI":"10.1039\/c2py00611a","article-title":"Properties and degradation of hydrocarbon fuel cell membranes: A comparative study of sulfonated poly(arylene ether sulfone)s with different positions of the acid groups","volume":"3","author":"Takamuku","year":"2012","journal-title":"Polym. Chem."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"22242","DOI":"10.1039\/c2jm34372j","article-title":"Photocrosslinking of sulfonated poly(arylene ether sulfone) in a swollen state","volume":"22","author":"Wen","year":"2012","journal-title":"J. Mater. Chem."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"9946","DOI":"10.1016\/j.jpowsour.2011.08.091","article-title":"Cross-linked miscible blend membranes of sulfonated poly(arylene ether sulfone) and sulfonated polyimide for polymer electrolyte fuel cell applications","volume":"196","author":"Chen","year":"2011","journal-title":"J. Power Sources"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1016\/j.memsci.2009.02.034","article-title":"Synthesis and characterization of crosslinked sulfonated poly(arylene ether sulfone) membranes for DMFC applications","volume":"335","author":"Feng","year":"2009","journal-title":"J. Membr. Sci."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1074","DOI":"10.1016\/j.crci.2008.06.001","article-title":"Synthetic strategies for the preparation of proton-conducting hybrid polymers based on PEEK and PPSU for PEM fuel cells","volume":"11","author":"Luchetti","year":"2008","journal-title":"C. R. Chim."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"591","DOI":"10.1002\/pat.758","article-title":"Improved performance of sulfonated polyarylene ethers for proton exchange membrane fuel cells","volume":"17","author":"Xing","year":"2006","journal-title":"Polym. Adv. Technol."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"1939","DOI":"10.1016\/j.electacta.2004.09.003","article-title":"Polysulfone ionomers for proton-conducting fuel cell membranes 2. Sulfophenylated polysulfones and polyphenylsulfones","volume":"50","author":"Karlsson","year":"2005","journal-title":"Electrochim. Acta"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"2820","DOI":"10.1002\/app.11264","article-title":"Proton-conductive membranes of sulfonated polyphenylsulfone","volume":"86","author":"Dyck","year":"2002","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1016\/j.ssi.2014.12.012","article-title":"Cross-linked poly(arylene ether ketone) proton exchange membranes sulfonated on polymer backbone, pendant, and cross-linked sites for enhanced proton conductivity","volume":"270","author":"Nguyen","year":"2015","journal-title":"Solid State Ion."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"B729","DOI":"10.1149\/1.3116254","article-title":"Small-angle X-ray scattering and proton conductivity of anhydrous Nafion-Benzimidazole blend membranes","volume":"156","author":"Kim","year":"2009","journal-title":"J. Electrochem. Soc."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"943","DOI":"10.1149\/08513.0943ecst","article-title":"Annealing effect of Nafion-1,2,3-triazole membrane by autoclave solution processing","volume":"85","author":"Kim","year":"2018","journal-title":"ECS Trans."},{"key":"ref_53","first-page":"1","article-title":"In situ PEMFC fuel crossover & electrical short circuit measurement","volume":"8\u20139","author":"Cooper","year":"2008","journal-title":"Fuel Cell Mag."}],"container-title":["Membranes"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0375\/10\/2\/31\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T08:58:45Z","timestamp":1760173125000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0375\/10\/2\/31"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,2,18]]},"references-count":53,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2020,2]]}},"alternative-id":["membranes10020031"],"URL":"https:\/\/doi.org\/10.3390\/membranes10020031","relation":{},"ISSN":["2077-0375"],"issn-type":[{"value":"2077-0375","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,2,18]]}}}