Preparation and gas sensing of ionic conductors based on semiclathrate hydrates containing guest quaternary onium salts

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K05412
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 32020:Functional solid state chemistry-related
• Research Institution: Wakayama National College of Technology
• Principal Investigator: Tsunashima Katsuhiko 和歌山工業高等専門学校, 生物応用化学科, 教授 (90550070)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 準包接水和物 / オニウム塩 / イオン伝導 / 交流インピーダンス法 / ガスセンシング

Outline of Final Research Achievements

Semiclathrate hydrates containing guest quaternary onium salts and host water cages have been examined by ac impedance spectrometry as ion conductors used for gas sensors. The phosphonium salts as well as ammonium salts were employed as guest quaternary onium salts. We have already designed and synthesized a new class of phosphonium cations based on a carbon-carbon unsaturated bond and cycloalkyl groups, investigating their phase equilibrium behaviors and crystal structures to collect the basic physicochemical property data. It was found that the electrical conductivity response of the single crystals of semiclathrate hydrates were observed at ac impedance spectrometry measurements, which indicates that the semiclathrate hydrate crystals could be regarded as potential candidates of novel ionic conduction materials for gas sensors.

Free Research Field

電気化学

Academic Significance and Societal Importance of the Research Achievements

四級オニウム塩型準包接水和物は潜熱蓄熱材料として応用されることが多いが、センサーよしての応用についてはこれまでほとんど事例がなかった。また、このたびデザインして合成した不飽和結合や環状構造を側鎖に有するホスホニウム塩をゲストとして用いる試みも当該学術分野においても先例がなく、新しい準包接水和物の一群を提案できたと考えている。また準包接水和物をイオン伝導体として用いるセンサーへの応用についても新しい切り口の研究であり、準包接水和物の電気化学および導電材料としての新たな応用が拓けたとも考えられる。