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

Creation of polymer electrolyte membranes for fuel cell applications by quantum beam technology

八巻 徹也

Yamaki, Tetsuya

本研究では、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。講演では、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、イオンビームによるナノ構造制御電解質膜の作製、中性子小角散乱法による膜構造解析への展開などをトピックに、著者らが行った研究をレビューする。

This paper describes the versatile application of quantum beam-based technology to the development of proton exchange membranes (PEMs) for fuel-cell applications. The -ray or electron-beam induced radiation grafting offers a way to prepare PEMs; typically, the radical-initiated polymerization of a styreneor styrene-derivative monomer on a base polymer is followed by a sulfonation step. The bombardment of heavy ions accelerated to MeV or higher energies produces a continuous trail of excited and ionized molecules in polymers, which is known as a latent track. The approach using this ion-track technology 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 PEM was found to have perfect one-dimensional proton-conductive pathways parallel to its thickness direction. The hierarchical structures of the PEMs, ranging from nanometers to micrometers, were revealed by small-angle neutron scattering experiments using a coldor thermal neutron beam. The information led to a deep insight into the dynamic properties inside the PEM from a molecular to macroscopic level.