Cross-linked polymer particles showing light-induced shape change

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05621
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 35020:Polymer materials-related
• Research Institution: Ehime University
• Principal Investigator: Itoh Tomomichi 愛媛大学, 理工学研究科(工学系), 講師 (40363254)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 高分子微粒子 / 架橋 / アゾベンゼン / 光応答 / 変形 / 乳化剤

Outline of Final Research Achievements

Crosslinked azobenzene polymer particles were developed to achieve light-responsiveness, recoverability, and reusability. Precipitation polymerization and dispersion polymerization of an azobenzene monomer bearing asymmetric divinyl groups successfully endowed crosslinked azobenzene polymer particles with a unique oblate shape and narrow size distribution. Polarized optical microscopy studies indicated that the azobenzene groups were aligned in the particles and had a bipolar configuration. The particles exhibited recoverable light-responsive shape changes upon irradiation with ultraviolet and white light. The precipitation-polymerized and dispersion-polymerized particles produced water-in-oil and oil-in-water Pickering emulsions, respectively, both of which were reversibly destabilized and restabilized by irradiation with ultraviolet and white light. Furthermore, the reusability of the particles in light-responsive liquid marbles was achieved.

Free Research Field

高分子材料化学

Academic Significance and Societal Importance of the Research Achievements

温和な光刺激で変形や親水性の変化を示すアゾベンゼン含有微粒子は、微細構造の構築や制御への応用が期待されているものの、再利用が困難であったため、持続して利用が可能な材料ではなかった。本研究では分子設計、合成、分子の集積構造の構築、巨視的な形状の形成に至る分野を横断した考察を経ることで光応答性微粒子に可逆性、再利用性をもたせることに成功しており、材料としての用途開拓への道が拓け、たとえばセルギャップの光制御、微小液滴の輸送や放出、油水混合物の分離などに繰り返し使用できる高機能な材料として提案することができた。