シリカ表面でのアルコキシシラン組成を再考:溶液中のホモコンデンセーション対接
Yannick Millot1, Antoine Hervier1, Jihed Ayari1
1Sorbonne Université, CNRS, Laboratoire de Réactivité de Surface (LRS), 4 place Jussieu, F-75005 Paris, France.
Journal of the American Chemical Society
|March 17, 2023
まとめ
アミノプロピルトリエトキシシラン (APTES) は,主にホモコンデンサーションによるシリカに物理吸収されたネットワークを形成し,接ぎ木ではありません. これは,シリカとシリケートのAPTES表面組成の一般的な理解に挑戦しています.
科学分野:
- 材料科学
- 表面化学
- ナノテクノロジー
背景:
- シリカ表面機能化は,通常,表面シラノールによるシラン凝縮を使用します.
- アミノプロピルトリエトキシシラン (APTES) は,そのアミン群によって触媒化されたヘテロ凝縮によって,シリカ表面に容易に接着すると広く考えられている.
研究 の 目的:
- シリカとシリケートの表面にAPTESの組み立てメカニズムを定量的に調査する.
- APTES 移植 (ヘテロコンデンサ) と,物理的に吸収されたポリコンデンサを導くホモコンデンサを区別する.
- シアノプロピルトリクロロシラン (CPTCS) とのAPTESアセンブリをシリカで比較する.
主な方法:
- 定量分析には固体29Si NMRスペクトロシーを使用した.
- 分析は,シラン (T種) とシリカ (Q種) のシリコン信号の比率に焦点を当てた.
- T-O-T/Q-O-Tシロキサンブリッジの比率は,移植対ホモコンデンサを推定するために使用されました.
主要な成果:
- シアノプロピルトリクロロシラン (CPTCS) は,シリカ表面への接ぎ木の明確な証拠を示した.
- アミノプロピルトリエトキシシラン (APTES) はシラノール群の最小消費を示し,限られた移植を示した.
- シリカとシリケート表面のAPTESの大部分はホモコンデンスのネットワークとして存在し,主にフィジソルブされ,6%未満の直接のシルアノールアンカリングがあります.
結論:
- シリカとシリケートにAPTESを組み立てる一般的なメカニズムは,直接接合ではなく,フィジソルブネットワークを形成するホモコンデンサスです.
- ヘテロコンデンサーションによるAPTES移植に関する確立された見解は,見直す必要がある.
- APTESによる表面機能化は,主に表面シラノールとの直接相互作用が限られているシランの自己凝縮を含みます.
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