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Improvement of Polycarbonate Properties by Coating of TiO2 and SiO2 Thin Film

TiO2/SiO2 박막 코팅에 의한 폴리카보네이트 특성 개선

  • Won, Dong So (Department of Chemical Engineering, Kangwon National University) ;
  • Lee, Won Gyu (Department of Chemical Engineering, Kangwon National University)
  • 원동수 (강원대학교 화학공학과) ;
  • 이원규 (강원대학교 화학공학과)
  • Received : 2013.08.23
  • Accepted : 2013.10.22
  • Published : 2014.02.10

Abstract

The property improvement of polycarbonate coated with a multilayer film composed of an inorganic $SiO_2$ film and a photocatalytic $TiO_2$ film was studied. The $SiO_2$ film as a binder had an excellent light transmission characteristic. After the treatment with atmospheric pressure plasma, the surface of $SiO_2$ film showed the hydrophilicity, which increased the film coating uniformity with a $TiO_2$-containing aqueous solution. When $TiO_2$ film was over 200 nm thick, the absorption effect of UV rays in the range of 180~400 nm suppressed the yellowing phenomena of polycarbonate substrate. The inorganic film improved the heat resistance of polycarbonate substrates. $TiO_2$ film in the outmost under the exposure of UV rays promotes the catalytic oxidation characteristics and yields the capability to the decomposition of organic contaminants, and also increases the self-cleaning properties due to the increase of hydrophilicity. Structural stability of the polycarbonate substrate coated with inorganic $TiO_2$ and $SiO_2$ film was shown. The role of $SiO_2$ film between $TiO_2$ and polycarbonate substrate suppressed the peeling of $TiO_2$ film by inhibiting the photocatalytic oxidation effect of $TiO_2$ film on the polycarbonate substrate.

폴리카보네이트의 표면에 무기계 $SiO_2$ 박막을 바인더로 코팅한 후 광촉매 특성을 갖는 $TiO_2$ 박막을 추가로 형성하여 모재의 특성을 향상시키는 연구가 수행되었다. 바인더로 사용되는 $SiO_2$ 박막은 광투과 특성이 우수하며, 상압플라즈마처리를 통한 친수성의 증가로 $TiO_2$ 함유 수용액의 도포성을 향상시켜 균일한 박막을 형성시킬 수 있었다. 약 200 nm이상으로 코팅된 $TiO_2$ 박막은 180~400 nm의 자외선을 차단하여 폴리카보네이트의 황변현상을 억제하고 내열성을 크게 향상하는데 기여하였다. 최외층에 형성된 $TiO_2$ 박막은 자외선의 흡수로 활성화되는 표면산화특성으로 유기 오염물의 분해반응 촉진과 표면의 친수성의 증가에 따른 자기세정특성을 나타내었다. $TiO_2$ 박막과 폴리카보네이트 기재 사이에 $SiO_2$ 박막의 적용은 기재의 부식에 의한 코팅된 $TiO_2$ 층의 박리를 억제하여 구조 안정성을 유지할 수 있었다.

Keywords

References

  1. T. Tatsuma, S. Tachibana, and A. Fujishima, Remote oxidation of organic compounds by UV-irradiated $TiO_2$ via the gas phase, J. Phys. Chem. B, 105, 6987-6992 (2001). https://doi.org/10.1021/jp011108j
  2. A. Fujishima, T. N. Rao, and D. A. Tryk, Titanium dioxide photocatalysis, J. Photochem. Photobiol. C, 1, 1-21 (2000). https://doi.org/10.1016/S1389-5567(00)00002-2
  3. K. Guan, Relationship between photocatalytic activity, hydrophilicity and self-cleaning effect of $TiO_2/SiO_2$ films, Surf. Coat. Technol., 191, 155-160 (2005). https://doi.org/10.1016/j.surfcoat.2004.02.022
  4. A. Hozumi and O. Takai, Effect of hydrolysis groups in fluoro- alkyl silanes on water repellency of transparent two-layer hard coatings, Appl. Surf. Sci., 103, 431-441 (1996). https://doi.org/10.1016/S0169-4332(96)00534-X
  5. A. Moustaghfir, E. Tomasella, A. Rivaton, B. Mailhot, M. Jacquet, J. L. Gardette, and J. Cellier, Sputtered zinc oxide coatings : structural study and application to te photoprotection of the polycarbonate, Surf. Coat. Technol., 180/181, 642-645 (2004). https://doi.org/10.1016/j.surfcoat.2003.10.109
  6. W. Jia and X. Chen, Effect of polymer-filler interactions on PTC behaviors of LDPE/EPDM blends filled with carbon blacks, J. Appl. Polym. Sci., 66, 1885-1890 (1997). https://doi.org/10.1002/(SICI)1097-4628(19971205)66:10<1885::AID-APP5>3.0.CO;2-J
  7. S. J. Park and J. S. Kim, Modifications produced by electrochemical treatments on carbon blacks : Microstructures and mechanical interfacial properties, Carbon, 39, 2011-2016 (2001). https://doi.org/10.1016/S0008-6223(01)00015-X
  8. E. T. Kang, K. L. Tan, K. Kato, Y. Uyama, and Y. Ikada, Surface modification and functionalization of polytetrafluoroethylene films, Macromolecules, 29, 6872-6879 (1996). https://doi.org/10.1021/ma960161g
  9. J. R. Chen and T. Wakida, Studies on the surface free energy and surface structures of PTFE film treated with low temperature plasma, J. Appl. Polym. Sci., 63, 1733-1739 (1997). https://doi.org/10.1002/(SICI)1097-4628(19970328)63:13<1733::AID-APP4>3.0.CO;2-H
  10. D. K. Hwang, J. H. Moon, Y. G. Shul, K. T. Jung, D. H. Kim, and D. W. Lee, Scratch resistant and transparent UV-protective coating on polycarbonate, J. Sol-Gel. Sci. & Technol., 26, 783-787 (2003). https://doi.org/10.1023/A:1020774927773
  11. H. Yaghoubi, N. Taghavinia, and E. K. Alamdrari, Self cleaning $TiO_2$ on polycarbonate : Surface treatment, photocatalytic and nanomechanical properties, Surf. Coat. Technol., 204, 1562-1568 (2010). https://doi.org/10.1016/j.surfcoat.2009.09.085
  12. H. Anma, Y. Yoshimoto, M. Tanaka, H. Takatsuma, and Y. Hatanaka, Preparation of ZnO thin films deposited by plasma chemical vapor deposition for application to ultraviolet-cut coating, Jap. J. Appl. Phys., 40, 6099-6103 (2001). https://doi.org/10.1143/JJAP.40.6099
  13. J. F. Rabek, Polymer Photodegradation-Mechanisms and Experimental Methods, Chapman Hall, Cambridge (1995).