Experimental and theoretical XPS study of model molecules for poly(methyl methacrylate)
Experimental and theoretical XPS study of model molecules for poly(methyl methacrylate)
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DOI：
10.1002/sia.740170205
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发表时间：
1991-02
影响因子：
1.7
通讯作者：
A. N. D. Brito;M. P. Keane;N. Correia;S. Svensson;U. Gelius;B. Lindberg
中科院分区：
文献类型：
--
作者：
A. N. D. Brito;M. P. Keane;N. Correia;S. Svensson;U. Gelius;B. Lindberg
本文研究了异丁酸甲酯、甲基丙烯酸甲酯、丙烯酸甲酯、乙酸和甲酸作为固体聚甲基丙烯酸甲酯（PMMA）模型化合物的高分辨率C - is和O - is气相光电子能谱。二级化学位移，变化的峰形状和强度的不同的核心线被观察到。结果表明，要正确分析固体聚合物光谱，必须考虑各组分峰的不对称性和线宽差异。由于不同的振荡/振荡概率，气相光谱中不同的c1s和ois峰的观测强度不遵循化学计量比。气相核心电子结合能与从头算ΔSCF计算进行了比较，其中包括核心-空穴态的弛豫。利用基团位移理论，讨论了气相模型分子位移与固体PMMA位移之间的关系，并将其应用于PMMA光谱的分析。
High-resolution C is and O is gas-phase X-ray photoelectron spectra of methyl isobutyrate, methyl methacrylate, methyl acrylate, acrylic acid, acetic acid and formic acid have been investigated as model compounds for solid poly(methyl methacrylate) (PMMA). Secondary chemical shifts, variations in peak shapes and intensities for the different core lines were observed. It is shown that asymmetries and differences in line widths of the component peaks should be considered for a correct analysis of the solid polymer spectra. The observed intensities of the different C 1s and O is peaks in the gas-phase spectra do not follow stoichiometric ratios owing to different shake-off/shake-up probabilities. The gas-phase core electron binding energies have been compared with ab initio ΔSCF calculations where the relaxation of the core-hole state was included. Using a group shift argument, the relationship between the gas-phase model molecule shifts and the solid PMMA shifts have been discussed and applied to the analysis of the PMMA spectra.