単一壁の炭素ナノチューブバンドルの高温変換の実験熱力学
Daniele Gozzi1, Alessandro Latini, Laura Lazzarini
1Dipartimento di Chimica, SAPIENZA Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy. daniele.gozzi@uniroma1.it
Journal of the American Chemical Society
|August 7, 2009
まとめ
グラファイトに変換する単一壁の炭素ナノチューブ (SWCNTs) の熱力学的性質が測定されました. 高圧下でのバンドル構造の変化は,これらの熱力学的量に影響します.
科学分野:
- マテリアルサイエンス 材料科学
- 熱力学は熱力学である.
- 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 (SWCNTs) は,ユニークな性質を持つ炭素の重要なアロトロップです.
- SWCNTsのグラファイトへの変換を理解することは,材料科学のアプリケーションにとって非常に重要です.
- 異なる条件下でのSWCNTの熱力学的振る舞いは,詳細な調査を必要とします.
研究 の 目的:
- SWCNTバンドルの炭素をグラファイットの炭素に変換する熱力学的数値を決定する.
- この変換の温度依存性と可逆性を調査する.
- SWCNTバンドルの構造変化を熱力学データと相関させるため.
主な方法:
- CaF2固体電解質のガルバニックセルを使用して,750〜1015Kの測定を行いました.
- 構造分析のために,低角X線微分法 (XRD),マイクロラーマン光譜法,および高解像度伝送電子顕微鏡法 (HR-TEM) を採用した.
- 標準エンタルピーとエントロピーの変化を計算するために,細胞の電動力を分析しました.
主要な成果:
- ガルバン電池の電気運動力は,強い温度依存性と可逆性を示した.
- 標準エンタルピーとエントロピーの変化は,異なる温度 (778,883,および975 K) で定量化されました.
- 構造分析は,内部圧力によるバンドルの変形と安定した相互変換のバンドル状態の形成を確認した.
結論:
- SWCNTのグラファイトへの変換は,SWCNTバンドル内の温度に依存する構造的再配置の影響を受けます.
- 熱膨張の制約によって発生する高い内部圧力は,チューブの形状と格子に重大な変形をもたらします.
- この研究は,SWCNTバンドルの構造的安定性に関する貴重な熱力学データと洞察を提供します.
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