Applied Chemistry for Engineering (공업화학)

The Korean Society of Industrial and Engineering Chemistry (한국공업화학회)
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Electrohydrodynamic Instability at Surface of Block Copolymer/Titania Nanorods Thin Film

타이타니아 나노막대가 포함된 블록 공중합체 박막 표면의 전기장하에서의 불안정성 거동 연구

  • Bae, Joonwon (Department of Applied Chemistry, Dongduk Women's University)
  • 배준원 (동덕여자대학교 응용화학과)
  • Received : 2016.02.18
  • Accepted : 2016.03.26
  • Published : 2016.04.10
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Abstract

The influence of titania nanorods with an average diameter of 10 nm and an average length of 30 nm on the electrohydrodynamic instability of block copolymer (polystyrene-b-poly(2-vinylpyridine)) thin film was investigated in this article. The presence of titania nanorods increased the dielectric constant of the film, which resulted in a systematic reduction in the wavelength of the surface instability. Cross-sectional transmission electron microscopy analysis indicated that the migration/aggregation of titania nanorods did not occur as a result of the applied electric field. This work can provide a simple route to the pattern formation using electrohydrodynamic instability with an aid of nanoparticles.

특정 온도(대부분의 고분자의 경우는 유리 전이 온도) 이상에서 균일한 전기장 내부에 존재하는 고분자 박막의 표면에는 전기장에 의한 힘이 작용하기 때문에, 표면은 항상 불안정성을 나타낸다. 즉, 고분자 박막의 표면에 전기장을 가하면 표면이 울퉁불퉁한 형태를 띄고, 이 정도가 심해져서 막대 형태로 성장하게 된다. 본 연구에서는, 타이타니아 나노막대를 포함한 블록 공중합체 박막의 표면에 나타나는 전기장에 의한 불안정성 형태에 대해서 고찰해 보고자 한다. 평균 직경 10 nm를 갖는 30 nm 길이의 타이타니아 나노막대를 제조한 뒤, 블록 공중합체(폴리스티렌-폴리(2-비닐피리딘))와 혼합한 뒤에 스핀코팅을 통해서 박막을 형성시킨다. 이 박막을 균일한 전기장 속에 넣고 공중합 고분자의 유리 전이 온도 이상에서 일정 시간 동안 유지시킨 뒤 다양한 방법으로 관찰한다. 타이타니아 나노막대의 높은 유전상수는 필름 전체의 유전상수를 증가시켜 표면 불안정성 패턴의 크기를 감소시키고, 박막의 내부에서는 타이타니아 나노막대의 엔트로피적인 이동 현상은 고찰되지 않는 것으로 밝혀졌다. 이 연구는 향후 나노입자를 적용한 박막의 전기장하에서 표면 불안정성 패턴 형성에 도움이 될 것으로 사료된다.

Keywords

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  1. 공중합체/나노입자 복합체 박막 내 미세구조의 전기장 하에서의 거동 vol.28, pp.3, 2016, https://doi.org/10.14478/ace.2017.1010