Development of simultaneous control system for photopolymerization and photoalignment

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H01983
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 35010:Polymer chemistry-related
• Research Institution: Nagoya University
• Principal Investigator: Seki Takahiro 名古屋大学, 工学研究科, 名誉教授 (40163084)
• Co-Investigator(Kenkyū-buntansha): 原 光生 名古屋大学, 工学研究科, 助教 (10631971)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 光配向 / 光重合 / RAFT重合 / 液晶

Outline of Final Research Achievements

This project was undertaken to create a photoresponsive polymerization system that simultaneously applies photoalignment by combining the recently developed methods of photopolymerization and photoaliginment of liquid crystalline (LC) materials.
A fluorine moiety was introduced into a commercially available RAFT agent, the RAFT agent was mixed with a LC monomer, surface segregation, and photopolymerization conditions were examined in the presence of a photocatalyst of an iridium complex, and the structure was evaluated. In addition, we succeeded in monitoring the process of polymerization from the free surface using fluorine and sulfur atoms introduced into the RAFT agent by XPS spectroscopy. It has not yet reached the point of demonstrating that the simultaneous photoalignment, which was the original target, and it remains a continuing issue in the future.

Free Research Field

高分子化学

Academic Significance and Societal Importance of the Research Achievements

RAFT重合の研究はここ数年での発展が著しい。基板表面からのグラフト重合も報告されているが、本研究で行った空気界面からの液晶物質のRAFT重合は初めての試みであり、新たな薄膜重合系の提案である。モノマー薄膜からの光重合系の実施について多くの知見を得た。高分子薄膜での重合プロセスにおける新たな手法提案となるとともに、高分子表面加工法が開発される可能性もある。当初期待していなかった結果として、RAFT剤の片方の部位を空気側に留まるフロロカーボンを導入して、膜の深さ方向の元素分布を重合時にモニターすることにより、モノマーがジチオエステル部分に挿入され重合していく様子をとらえることに成功した。