量子ビームを利用した燃料電池用高分子電解質膜の創製に関する研究

Development of polymer electrolyte membranes for fuel cells using quantum beam technology

八巻 徹也

Yamaki, Tetsuya

日本原子力研究開発機構では、独自の量子ビーム技術を駆使して、燃料電池に応用可能な高分子電解質膜の開発を進めている。本論文では、発表者らによるその活動について、(1)線・電子線による架橋・グラフト反応を利用した電解質膜の作製、(2)イオンビームによるナノ構造制御電解質膜の作製、(3)中性子小角散乱法による膜構造解析への展開、などのトピックをレビューする。

This paper reviews the application of our quantum beam-based technology to the development of polymer electrolyte membranes for fuel-cell applications. The -ray or electron-beam induced graft polymerization is known to offer a way to prepare membranes. We previously combined this process with the radiation crosslinking method and thus obtained the nove "multiply-crosslinked" membranes, in which both the main and grafted chains have covalently bridged structures leading to a high durability. The approach using heavy ions accelerated to MeV or higher energies is based on the chemical etching and/or modification of each track with diameters of tens to hundreds of nanometers. The resulting "nano-structure controlled" membrane was found to have perfect one-dimensional proton-conductive pathways parallel to its thickness direction. We revealed the hierarchical structures of the membranes, ranging from nanometers to micrometers, by small-angle neutron scattering experiments using a cold or thermal neutron beam. Concludingly, it is important to understand that every quantum beam is different, thereby making the right beam choice.