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Chen, J.; Li, D.*; Asano, Masaharu; Maekawa, Yasunari; Yoshida, Masaru
no journal, ,
To meet the request of direct methanol fuel cells (DMFC), a highly thermal engineering aromatic polymer, polyetheretherketone (PEEK) film, was used as the base film to develop the polymer electrolyte membrane by radiation-grafting method. However, because of the low grafting activity of the PEEK chains, the styrenesulfonic ethyl ester (ETSS) monomer was difficult to directly graft to the PEEK film with request amounts. In this study, we first grafted a divinylbenzene (DVB) monomer into the PEEK film to form the radiation-active sites, through which ETSS can be easily grafted to the PEEK during the second radiation grafting step. As a result, new polymer electrolyte membranes with high proton conductivity and low methanol permeability were successfully developed. The new polymer electrolyte membrane was tested in a DMFC, showing a high power density.
Yamaki, Tetsuya; Koshikawa, Hiroshi; Hasegawa, Shin; Asano, Masaharu; Maekawa, Yasunari; Voss, K.-O.*; Trautmann, C.*; Neumann, R.*
no journal, ,
Poly(vinylidene fluoride) (PVDF) thin films were irradiated with different kinds of ion beams and then exposed to a 9 M KOH aqueous solution. Based on the results of SEM observations and conductometric analyses, the heating at 120
C was found to enhance the etch rate in the latent track without changing that in the non-irradiated part, thereby enabling us to obtain very high etching sensitivity for the preparation of nano-sized pores. The formation of oxidized species during this pretreatment should facilitate the introduction of the etching agent to improve etchability. Additionally, the irradiation with higher-mass ions was preferable to achieve high sensitivity of the etching.