Synthesis of D-A liquid crystalline electrochromic compounds and development of their electrochromic devices

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K05826
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Functional solid state chemistry
• Research Institution: Saitama University
• Principal Investigator: Yasutake Mikio 埼玉大学, 研究機構, 講師 (70361392)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: エレクトロクロミズム材料 / 液晶材料 / 電子ドナー / 電子アクセプター / オリゴチオフェン / キノン類

Outline of Final Research Achievements

We were designed four kinds of liquid crystal materials having pyrendithione and bithiophene moieties and synthesized. And their liquid crystalline properties were also investigated. Furthermore, we investigated the electrochromic properties of PQBTs in the solutions. After, the electrochromic　devices using PQBTs were formed, and this was also examined. In particular, the electrochemical properties of PQBTs in solution were better than those previously reported and showed electrochromic properties over a wide range of potentials. In addition, the PQBTs devices showed electrochromic characteristics of three colors. In addition, we also investigated the switching speeds of these and examined their repeatability.

Free Research Field

有機化学

Academic Significance and Societal Importance of the Research Achievements

エレクトロクロミック素子に用いられる材料のほとんどはポリマー構造のものが多く報告されており,それらは剛直で加工性等に乏しい。その点，流動性と秩序性を併せ持つ液晶材料は，均一な薄膜形成ができる点では優位性を持つ。本研究で提案している分子構造のものは電子アクセプター部位とドナー部位に加え,電解質部位をあわせ持つため電解質なしでのエレクトロクロミック素子の形成と言う点では独創的である。これらのことは，エレクトロクロミック素子の観点から見れば今まで白黒の表示であったものが，フルカラー電子ペーパーへの期待，学術的には液晶相におけるラジカル種やイオン種の安定性について議論できる。