Journal of the Korean Vacuum Society (한국진공학회지)

The Korean Vacuum Society (한국진공학회)
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Polymer surfaces studied by sum-frequency vibrational spectroscopy

  • Kim, D. (Department of Physics, Sogang University) ;
  • J. Sung (Department of Physics, Sogang University) ;
  • H. M. Cheong (Department of Physics, Sogang University) ;
  • C. N. Whang (Department of Physics, Yonsei University) ;
  • Y. Ouchi (Department of Chemistry, Nagoya University) ;
  • T. limori (Department of Chemistry, Nagoya University) ;
  • N. Matsuie (Department of Chemistry, Nagoya University) ;
  • K. Seki (Department of Chemistry, Nagoya University)
  • Published : 2003.10.01
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Abstract

Sum-frequency vibrational spectroscopy has recently been used to investigate the surface of the various polymers and was able to find the chemical compositions and structures specific to the surface. Here we report our studies on two specific polymer samples to demonstrate its capability. Polyimide thin films were made by spin coating on fused quartz and $CaF_2$ substrates. The sum-frequency signal originating mainly from the air/polymer interface showed markedly different spectra, indicating the structural change of the polymer surface depending on the underlying substrate. Various polyethylene surfaces were also investigated by sum-frequency vibrational spectroscopy. The surface of polyethylene samples in the CH-region showed different sum-frequency spectra, presumably due to the trace amount of additives having much higher concentration at the air/polymer interface. These examples demonstrate the surface and interface of the polymer could have different structure and chemical composition from those of a bulk, which can be studied effectively by surface nonlinear optical spectroscopy.

Keywords

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