2023 Fiscal Year Final Research Report
Revealing of chiral factors in cellulosic liquid crystal toward the design and development of new functional materials
| Project/Area Number |
21K05706
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Review Section |
Basic Section 40020:Wood science-related
|
|---|
| Research Institution | Kyoto University |
|---|
Principal Investigator |
|
|---|
| Project Period (FY) |
2021-04-01 – 2024-03-31
|
| Keywords | セルロース系液晶 / コレステリック構造 / 分子キラリティー / 掌性反転 / 位置選択置換 / 包接錯体 / 液晶デバイス |
|---|
| Outline of Final Research Achievements |
The effects of the molecular structure (e.g., side-chain group and its degree of substitution) and environmental factors (polymer concentration, temperature, etc.) on the liquid crystallinity of ethyl cellulose (EC) and (hydroxypropyl)cellulose (HPC) derivatives were evaluated. Regioselectively substituted EC derivatives were synthesized via regioselective protection of cellulose. It was revealed that the wavelength of maximal reflectance λmax of their lyotropic solutions in chloroform shifted to longer wavelength by selective acetylation at the O-6 position. In addition, bulky adamantoyl group was introduced as a substituent on HPC, and the effects of the degree of adamantoyl substitution, polymer concentration, and temperature on the chiroptical properties of HPC lyotropic were investigated. Optical measurements revealed that the hydrophilicity/hydrophobicity of the HPC molecule strongly affects the cholesteric liquid-crystalline structure.
|
| Free Research Field |
生物材料機能学
|
| Academic Significance and Societal Importance of the Research Achievements |
代表的な液晶性セルロース誘導体であるエチルセルロースECとヒドロキシプロピルセルロースHPCが濃厚溶液中で形成するコレステリック液晶について、そのラセン周期（ピッチP）と旋回方向（センス）に及ぼす分子構造・環境因子を解明した本研究成果により、コレステリック液晶の反射波長と偏光状態のコントロールが可能な先進的光学機能材料の設計開発に向け、有益な指針を獲得できた。さらに、セルロース分子鎖のキラリティーに関する学術研究の一助となり、近年議論が活発なセルロースナノ繊維におけるキラリティー起源の解明に繋がる。
|
