CeO2 Nanocrystals from Supercritical Alcohols: New Opportunities for Versatile Functionalizations?

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• 作者：Cedric Slostowski ; Samuel Marre ; Odile Babot ; Thierry Toupance ; Cyril Aymonier
• 刊名：Langmuir
• 出版年：2014
• 出版时间：May 27, 2014
• 年：2014
• 卷：30
• 期：20
• 页码：5965-5972
• 全文大小：370K
• 年卷期：v.30,no.20(May 27, 2014)
• ISSN：1520-5827

文摘

The fast and controlled synthesis of surface-modified cerium oxide nanoparticles was carried out in supercritical {ethanol + alcohol derivative} mixtures. The newly found ability of supercritical alcohols to graft onto cerium oxide nanocrystals (CeO₂ NCs) during their synthesis was exploited to control their surface chemistry via the addition of three aminoalcohols: ethanolamine, 3-amino-1-propanol and 6-amino-1-hexanol. Although the ethanol to aminoalcohol ratio was consistent (285:1), the successful grafting of these alcohol derivatives onto CeO₂ NCs was identified based on Fourier transform infrared (FTIR) and thermogravimetric analysis鈥搈ass spectrometry (TGA-MS) measurements. Smaller crystallite size of CeO₂ NCs synthesized in the presence of aminoalcohols, compared to those synthesized in supercritical ethanol alone, were also noticed and attributed to a possible intervention of amine groups helping the grafting of the alcohols, allowing one to stop the growth of the CeO₂ NCs faster. The use of supercritical alcohol mixture鈥攅thanol with hexanol, dodecanol, or octadecanol, with a 285:1 ratio鈥攚as also investigated. Such mixtures allow accessing a finer control in CeO₂ NCs crystallite size compared to pure alcohols, according to calculation made from X-ray diffraction measurements. Finally, fluorescent molecules (fluorescein isothiocyanate) were grafted onto amine-modified CeO₂ NCs. The powders displayed a fluorescent behavior under UV light, confirming the suitability and interest of CeO₂ NCs surface modification by such technique.