Department of Polymer Chemistry, Kyoto University, Nishikyo, Kyoto, Japan.
Langmuir. 2012 Oct 2;28(39):13871-6. doi: 10.1021/la302513c. Epub 2012 Sep 17.
The conformation of poly(methyl methacrylate) (PMMA) chains in a thin film after the rubbing process was investigated through the direct observation of the single chains by scanning near-field optical microscopy (SNOM) and excitation polarization modulation microscopy (EPMM). The rubbing at room temperature hardly changed the dimension on the whole chain scale in spite of the increase in orientational order on the segmental scale. The increase in the chain dimension along the rubbing direction was observed in the film rubbed at the higher temperature, which showed a surface morphology with fine groove. The extension ratio of the whole chain in the rubbed film was much smaller than that in the uniaxially stretched film. This indicates that the rubbing process mainly induces the conformational change on the length scale of the monomer unit rather than for the whole chain.
通过扫描近场光学显微镜 (SNOM) 和激发偏振调制显微镜 (EPMM) 直接观察单链，研究了在摩擦过程后薄膜中聚甲基丙烯酸甲酯 (PMMA) 链的构象。尽管在链段尺度上的取向有序性增加，但室温下的摩擦几乎没有改变整个链尺度上的尺寸。在较高温度下摩擦的薄膜中观察到沿摩擦方向的链尺寸增加，这显示出具有精细凹槽的表面形貌。在摩擦薄膜中整个链的拉伸比远小于单向拉伸薄膜中的拉伸比。这表明摩擦过程主要引起单体单元长度尺度上的构象变化，而不是整个链。
