title: Imaging individual proton-conducting spots on sulfonated multiblock-copolymer membrane under controlled hydrogen atmosphere by current-sensing atomic force microscopy.
abstract: The proton-conductive spots on the membrane surface of sulfonated poly(arylene ether) multiblock copolymer were successfully imaged by current-sensing atomic force microscopy under hydrogen atmosphere at various temperatures and humidities. These spots should be connected to the proton-conductive paths inside the membrane. The average diameter of the spots was approximately 12 nm, consistent with the size of hydrophilic domains observed by transmission electron microscopy. The size of the proton-conducting spots was almost unchanged regardless of the temperature and humidity, whereas the number of the spots increased at higher humidity; the total area of the proton-conducting spots increased accordingly on the membrane surface. This increase in the conducting area at high humidity should be related to the bulk ionic conductivity measured by impedance spectroscopy.
authors.affiliation: Fuel Cell Nanomaterials Center, University of Yamanashi, 6-43 Miyamae, Kofu, Yamanashi 400-0021, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Hara
authors.forename: Daiki
authors.initials: D
authors.lastname: Hattori
authors.forename: Junji
authors.initials: J
authors.lastname: Inukai
authors.forename: Byungchan
authors.initials: B
authors.lastname: Bae
authors.forename: Takayuki
authors.initials: T
authors.lastname: Hoshi
authors.forename: Masaya
authors.initials: M
authors.lastname: Hara
authors.forename: Kenji
authors.initials: K
authors.lastname: Miyatake
authors.forename: Masahiro
authors.initials: M
authors.lastname: Watanabe
mesh_terms: D004553:Electric Conductivity; D055664:Electrochemical Techniques; D005740:Gases; D006813:Humidity; D006859:Hydrogen; D008567:Membranes, Artificial; D018625:Microscopy, Atomic Force / Q000379:methods*; D057054:Molecular Imaging / Q000379:methods*; D011108:Polymers / Q000737:chemistry*; D011522:Protons; D013696:Temperature
chemical_list: D005740:Gases; D008567:Membranes, Artificial; D011108:Polymers; D011522:Protons; D006859:Hydrogen