Mueller Kerstin, Yang Xiujuan, Paulite Melissa, Fakhraai Zahra, Gunari Nikhil, Walker Gilbert C
Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada.
Langmuir. 2008 Jun 1;24(13):6946-51. doi: 10.1021/la703406d. Epub 2008 Jun 6.
The nanoscale chemical composition variations of the surfaces of thin films of polystyrene- b-poly(methyl methacrylate) (PS- b-PMMA) diblock copolymers are investigated using apertureless near-field IR microscopy. The scattering of the incident infrared beam from a modulated atomic force microscopy (AFM) tip is probed using homodyne detection and demodulation at the tip oscillation frequency. An increase in the IR attenuation is observed in the PMMA-rich domains with a wavenumber dependence that is consistent with the bulk absorption spectrum. The results indicate that even though a small topography-induced artifact can be observed in the near-field images, the chemical signature of the sample is detected clearly.
使用无孔近场红外显微镜研究了聚苯乙烯- b-聚（甲基丙烯酸甲酯）（PS- b-PMMA）二嵌段共聚物薄膜表面的纳米级化学成分变化。使用零差检测并在尖端振荡频率下进行解调，探测来自调制原子力显微镜（AFM）尖端的入射红外光束的散射。在富含PMMA的区域中观察到红外衰减增加，其波数依赖性与本体吸收光谱一致。结果表明，尽管在近场图像中可以观察到由形貌引起的小伪影，但样品的化学特征仍能被清晰检测到。
