Fabrication, permeation, and corrosion stability measurements of silica membranes for HI decomposition in the thermochemical iodine-sulfur process

Myagmarjav, O.; Shibata, Ai*; Tanaka, Nobuyuki; Noguchi, Hiroki; Kubo, Shinji; Nomura, Mikihiro*; Takegami, Hiroaki

International Journal of Hydrogen Energy, 46(56), p.28435 - 28449, 2021/08

https://doi.org/10.1016/j.ijhydene.2021.06.079

Imidazolium cation based anion-conducting electrolyte membranes prepared by radiation induced grafting for direct hydrazine hydrate fuel cells

Yoshimura, Kimio; Koshikawa, Hiroshi; Yamaki, Tetsuya; Shishitani, Hideyuki*; Yamamoto, Kazuya*; Yamaguchi, Susumu*; Tanaka, Hirohisa*; Maekawa, Yasunari

Journal of the Electrochemical Society, 161(9), p.F889 - F893, 2014/06

https://doi.org/10.1149/2.0511409jes

Graft-type anion-conducting electrolyte membranes (AEMs) with imidazolium cations on graft polymers were synthesized through radiation-induced graft polymerization of -vinylimidazole (NVIm) on poly(ethylene-co-tetrafluoroethylene) (ETFE) films, followed by -propylation and ion-exchange reactions. The -propylation proceeded quantitatively, whereas the ion-exchange reactions in 1 M KOH at 60C were accompanied by partial -elimination of the imidazolium cations(AEM2), which exhibited an ion-exchange capacity (IEC) of 0.85 mmol g and ionic conductivity of 10 mS cm. AEM2 showed alkaline stability at 60C but it gradually degraded at 80C for ca. 150 h. The copolymer-type AEM (AEM3) with an IEC of 1.20 mmol g was prepared through the copolymerization of NVIm with styrene on ETFE films, followed by the same -propylation and ion-exchange reactions. AEM3 was shown higher alkaline durability in 1 M KOH at 80C. As a result, it exhibited higher conductivity (10 mS cm) for 250 h. Therefore, alkylimidazolium cations in copolymer grafts are a promising anion conducting group for alkaline-durable AEMs. A maximum power density of 75 mW cm is obtained for AEM3 in a direct hydrazine hydrate fuel cell.

Simulation study on the catalytic decomposition of hydrogen iodide in a membrane reactor with a silica membrane for the thermochemical water-splitting IS process

Hwang, G.; Onuki, Kaoru

Journal of Membrane Science, 194(2), p.207 - 215, 2001/12

https://doi.org/10.1016/S0376-7388(01)00540-3

no abstracts in English

Studies on hydrogen separation membrane for IS process; Membrane preparation with porous -alumina tube

Hwang, G.*; Onuki, Kaoru; Shimizu, Saburo

JAERI-Research 98-002, 8 Pages, 1998/01

JAERI-Research-98-002.pdf:0.53MB

no abstracts in English

Preparation of metal nano-needles using ion-track membranes

Koshikawa, Hiroshi; Yamamoto, Shunya; Sugimoto, Masaki; Kitamura, Akane; Sawada, Shinichi; Yamaki, Tetsuya

no journal, , 

Chemical etching of polymer films irradiated with heavy ions leads to the formation of ion-track membranes with nanoscale pores in different shapes. Particularly, conically-shaped pores are expected to have a potential to create metallic nanoneedles by combination of vapor-deposition and electroplating methods. In this study, we prepared copper nanoneedles inside the conical pores of polyimide (PI)-based ion-track membranes and investigated their morphology. The PI films were irradiated with Ar ions. The irradiated films were etched in a sodium hypochlorite solution at 60C for 0.5 h, leading to the formation of conical pores with a surface diameter of ca. 500 nm. A very thin Au layer was deposited on this pore side of the ion-track membranes; then, it was used as a cathode for electroplating copper into the pores. After dissolving the PI templates, we obtained the copper needles ca. 500 nm in base diameter and 1.2 m in height on copper plates.