強い酸の単一壁の炭素ナノチューブのイソトロピク-ネマティック相変化
Pradeep K Rai1, Robert A Pinnick, A Nicholas G Parra-Vasquez
1Carbon Nanotechnology Laboratory, Center for Nanoscale Science and Technology, Rice University, Houston, Texas 77005, USA.
Journal of the American Chemical Society
|January 13, 2006
まとめ
この研究では,ブロンステッド・ローリー酸の同位相における単壁炭素ナノチューブ (SWNT) の最大濃度が定量化されています. このイソトロピク・ネマティック・トランジションの重要な濃度は,酸の強度とともに増加し,サイドウォールのプロトネーション機構をサポートします.
科学分野:
- マテリアルサイエンス 材料科学
- 物理化学 物理化学
- ナノテクノロジー ナノテクノロジー
背景:
- 単一壁の炭素ナノチューブ (SWNT) は,溶液中の液晶相を形成することができます.
- 酸性介質におけるSWNTの相行動を理解することは,その処理と応用にとって極めて重要です.
- ブロンステッド・ローリー酸は,サイドウォールプロトネーションによるSWNTの分散に有効な溶媒である.
研究 の 目的:
- ブロンステッド=ローリー酸の同位相におけるSWNTの最大濃度を定量的に決定する.
- 強い酸のSWNTのイソトロピー・ネマティック・フェーズ・トランジションの臨界濃度を特定する.
- 酸性強度とこの臨界濃度との関係を調査する.
主な方法:
- SWNT分散の同otropicとnematicフェーズを分離するために遠心分離技術を使用しました.
- 紫外線対近赤外線 (nIR) のスペクトロスコピーを用いて,SWNT濃度を定量化しました.
- 超酸性 (400-1400 nm範囲) のSWNTの確立されたビールの法則の校正曲線.
主要な成果:
- 同位体相におけるSWNTの最大濃度 (Cmax) を数値化しました.
- Cmaxがイソトロピク-ネマティック変異の臨界濃度であることを示した.
- スーパアシドで200ppm未満のSWNT濃度と吸収率の間の線形関係が観察されました.
- 酸の強度が増加するにつれて,臨界濃度が増加することを発見した.
結論:
- この研究は,酸におけるSWNT同位体相限界の最初の定量的な評価を提供する.
- この発見は,SWNTの酸性分散の基礎として,サイドウォールプロトネーションメカニズムを支持する.
- この結果は,SWNT液晶の形成と処理を制御するための貴重なデータを提供します.
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