Molecular Rearrangement in a Zinc Stearate Langmuir Film Dependent on a Film Preparation Method Studied Using Polarization-Modulation Infrared Reflection Absorption Spectroscopy and X-ray Absorption F

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• 作者：Maiko Muro ; Makoto Harada ; Tetsuo Okada ; Takeshi Hasegawa
• 刊名：The Journal of Physical Chemistry B
• 出版年：2012
• 出版时间：March 15, 2012
• 年：2012
• 卷：116
• 期：10
• 页码：3148-3154
• 全文大小：404K
• 年卷期：v.116,no.10(March 15, 2012)
• ISSN：1520-5207

文摘

Molecular dynamic rearrangement in a Langmuir (L) film of zinc stearate in a cross section image has been analyzed by employing polarization modulation infrared reflection spectrometry (PM-IRRAS) and X-ray absorption fine structure (XAFS). The number of coordination on a zinc cation is evaluated by XAFS, and the coordination structure of the carboxylic group is revealed by the IR analysis. An L film prepared at a fixed area without using film-compression bar exhibits time-dependent change of the coordination structure about a zinc cation, and it attains a highly ordered coordination structure in the carboxylic group region. However, an L film prepared by the Langmuir technique using a compression bar exhibited ignorable spectral changes in both IR and X-ray analyses. The hydrocarbon chains in the compressed L film are better uniformed than the uncompressed film, but the uniformed molecular arrangement of the carboxylic group is restricted to be rearranged, and it does not attain a stable structure in terms of coordination on the zinc cation.