FTIR Studies of C30 Self-Assembled Monolayers on Silica, Titania, and Zirconia

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• 作者：Gokulakrishnan Srinivasan ; Matthias Pursch ; Lane C. Sander ; and Klaus Mü ; ller
• 刊名：Langmuir
• 出版年：2004
• 出版时间：March 2, 2004
• 年：2004
• 卷：20
• 期：5
• 页码：1746 - 1752
• 全文大小：140K
• 年卷期：v.20,no.5(March 2, 2004)
• ISSN：1520-5827

文摘

The conformational order of alkyl chains in four different C₃₀ self-assembled monolayers (SAMs) hasbeen examined using Fourier transform infrared spectroscopy. The C₃₀ SAMs used in the present studywere prepared by reacting C₃₀H₆₁SiCl₃ with the humidified surfaces of zirconia, titania, and two differentsilica gels. The conformational order of the alkyl chains that are attached to the solid substrates is derivedfrom the analysis of well-known conformation-sensitive IR regions, that is, CH₂ symmetric and antisymmetricstretching modes as well as CH₂ wagging bands. The CH₂ symmetric and antisymmetric stretching bandpositions provide a qualitative measure of the conformational order. The CH₂ wagging bands are used todetermine the relative amounts, that is, integral values over the whole chains of kink/gauche-trans-gauche, double-gauche, and end-gauche conformers in the alkyl chain regions. The results derived fromthe present IR data analysis demonstrate that the substrate plays an important role for the conformationalorder of alkyl chains that are attached to inorganic oxide surfaces. C₃₀ SAMs on titania are found to possessa higher degree of conformational order as compared to C₃₀ SAMs on zirconia and silica.