Hydrophobic Polydimethylsiloxane Thin Films Prepared by Chemical Vapor Deposition: Application in Water Purification

화학적 증기 증착 방법을 통해 제조한 소수성 폴리디메틸실록산 박막: 수처리로의 응용

Han, Sang Wook;Kim, Kwang-Dae;Kim, Ju Hwan;Uhm, Sunghyun;Kim, Young Dok

  • Received : 2016.12.28
  • Accepted : 2017.01.20
  • Published : 2017.02.10


Polydimethylsiloxane (PDMS) can be deposited on various substrates using chemical vapor deposition process, which results in the formation of PDMS thin films with thickness below 5 nm. PDMS layers can be evenly deposited on surfaces of nanoparticles composed of various chemical compositions such as $SiO_2$, $TiO_2$, ZnO, C, Ni, and NiO, and the PDMS-coated surface becomes completely hydrophobic. These hydrophobic layers are highly resistant towards degradation under acidic and basic environments and UV-exposures. Nanoparticles coated with PDMS can be used in various environmental applications: hydrophobic silica nanoparticles can selectively interact with oil from oil/water mixture, suppressing fast diffusion of spill-oil on water and allowing more facile physical separation of spill-oil from the water. Upon heat-treatments of PDMS-coated $TiO_2$ under vacuum conditions, $TiO_2$ surface becomes completely hydrophilic, accompanying formation oxygen vacancies responsible for visible-light absorption. The post-annealed $PDMS-TiO_2$ shows enhanced photocatalytic activity with respect to the bare $TiO_2$ for decomposition of organic dyes in water under visible light illumination. We show that the simple PDMS-coating process presented here can be useful in a variety of field of environmental science and technology.


PDMS;hydrophobicity;hydrophilicity;water purification


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Supported by : Ministry of Environment