液晶ブロック共オリゴマーの素早く光学的に変化する順序変異
Changyeon Lee1, Dennis Ndaya2,3, Reuben Bosire2,3
1Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
Journal of the American Chemical Society
|December 28, 2021
まとめ
アゾベンゼンメソゲンのブロックコオリゴーマーには,室温で紫外線を用いて,秩序ある状態と無秩序な状態の間で迅速に切り替えられる. この光学制御は,材料の構造と性質の迅速で可逆的な変化を可能にします.
科学分野:
- 材料科学
- ポリマー化学
- ナノテクノロジー
背景:
- 大分子における光学的に誘導される順序転換は,運動学によって制限されます.
- アゾベンゼン (Azo) メソゲンは光異性化を受け,光に反応する材料の可能性を秘めている.
研究 の 目的:
- ブロックコオリゴーマー (BCO) を開発し,自己組み立てに迅速かつ可逆的な光学制御を行う.
- 化学構造が光スイッチング運動と結果のナノ構造に及ぼす影響を調査する.
主な方法:
- アゾベンゼンメソゲンとシロキサン鎖によるトライブロックコオリゴマーの合成
- 現場顕微鏡検査とX線測定で,自己組み立てと相変化を研究する.
- アゾベンゼンのイソメリゼーション運動を監視するためのUV-Visスペクトロスコーピー.
主要な成果:
- BCOは,紫外線照明と除去時に,迅速かつ可逆的な秩序と乱れ (液化/固化) を表した.
- メソゲン末端グループ (NO2,CN) とスペーサー長 (0C,12C) を含む化学構造は,自己組み立てと光スイッチに大きく影響した.
- 12Cスペーサーは,持続的なラメラーシートを持つ階層的順序 (ラメラ内のスメクティック層) を導入した.
- 電子を取り除くグループによって促進された熱的リラックスにより,紫外線を除去した際のリオーダリング運動は極めて迅速 (< 5秒) であった.
結論:
- ナノ構造の形成と溶解を迅速に光学的に制御する光学的に変換可能なBCOを開発した.
- フォトスイッチングの効率と階層的な自己組み立てを規定する,実証された構造-特性関係.
- 先進的な材料の応用のために,オーダーされたナノ構造を光学的に書き込み,消去する可能性を高めました.
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