柿部 剛史

<p>自然エネルギーを安定に供給するため，蓄電システム（二次電池）の高性能化が重要視されている。特に性能の向上と共に安全性の向上や小型化の観点から固体電解質が注目されている。しかし，電解質の固体化は運動性の低下を意味し，固体でありながら高イオン伝導性を保持した電解質の設計が重要である。我々はマトリクスとしてナノレベルで相分離構造を形成するブロック共重合体を用い，イオン源として構造デザイン可能なイオン液体を用いることで，目的の相にイオンを高密度に選択配置させた固体高分子電解質を試作した。本研究では，固体高分子電解質のマトリクスとして30nm程度のラメラ構造を形成するp（MMA-bnBA-b-MMA）を用い，添加するイオン源としてイミダゾリウム型イオン液体を用いた。イオン液体の構造とマトリクスポリマーの親和性を調整することでイオンを選択的に配置させ，高イオン伝導体設計の指針を得た。</p>

DNA-heptyl viologen (HV) complexes were obtained as flexible films by adding ionic-liquid type copolymer. HVs were revealed to be well immobilized in the DNA groove without dimerization. Monomolecularly dispersed HV showed the maximum absorption at near 600 nm. The immobilized HVs showed reversible redox response without dimerization in the film. To increase their absorbance change, ionic-liquid type copolymer having hydrocarbon spacer between polymerizable group and imidazolium ring was added. The absorbance change certainly increased with the addition. However, excess amount of copolymer induced increase of HV dimers. Suitable amount of copolymer may keep large color change and suppress dimerization of HVs.

The DNA / Heptyl viologen (HV) complex solution was prepared and their redox behavior was estimated. From the results of solution system, HVs were revealed to be well immobilized in the DNA groove without dimerization. DNA/HV complexes were obtained as flexible films by adding copolymerized ionic liquids. Monomolecular dispersed HV showed the maximum visible absorption at 600 nm. The immobilized viologens showed reversible redox response without dimerization in the film. To improve electron transfer between viologens and electrode, ITO nano-particles were added. Thus prepared DNA/HV film showed faster response.

We prepared DNA / Heptyl viologen (HV) complex films and estimated electrochromic characteristics. DNA / HV complex were obtained as flexible films by adding ethylimidazolium tetrafluoroborate. DNA matrix was effective to prevent HV from dimerization due to specific interaction called groove binding. Mono molecularly dispersed HV showed the maximum visible absorption at 610 nm. Addition of ionic liquid was effective to improve the rate of redox response. The redox reaction of monomeric HV was improved by the ionic liquid addition.