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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
한상욱;김광대;김주환;엄성현;김영독

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

Abstract

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.

Keywords

PDMS;hydrophobicity;hydrophilicity;water purification

References

  1. D. Bracho, V. N. Dougnac, H. Palza, and R. Quijada, Functionalization of silica nanoparticles for polypropylene nanocomposite applications, J. Nanomater., 2012, 263915 (2012).
  2. W. Gao, B. Zhou, Y. H. Liu, X. Y. Ma, Y. Liu, Z. C. Wang, and Y. C. Zhu, The influence of surface modification on the structure and properties of a zinc oxide-filled poly(ethylene terephthalate), Polym. Int., 62, 432-438 (2013). https://doi.org/10.1002/pi.4328
  3. B. Bhushan and Y. C. Jung, Wetting, adhesion and friction of superhydrophobic and hydrophilic leaves and fabricated micro/nanopatterned surfaces, J. Phys. Condens. Matter, 20, 225010 (2008). https://doi.org/10.1088/0953-8984/20/22/225010
  4. M.-G. Jeong, H. O. Seo, K.-D. Kim, D. H. Kim, Y. D. Kim, and D. C. Lim, Quenching of photocatalytic activity and enhancement of photostability of ZnO particles by polydimethysiloxane coating, J. Mater. Sci., 47, 5190-5196 (2012). https://doi.org/10.1007/s10853-012-6402-6
  5. Y. C. Jung and B. Bhushan, Mechanically durable carbon nanotube-composite hierarchical structures with superhydrophobicity, self-cleaning, and low-drag, ACS Nano, 3, 4155-4163 (2009). https://doi.org/10.1021/nn901509r
  6. K.-D. Kim, E. J. Park, H. O. Seo, M.-G. Jeong, Y. D. Kim, and D. C. Lim, Effect of thin hydrophobic films for toluene adsorption and desorption behavior on activated carbon fiber under dry and humid conditions, Chem. Eng. J., 200, 133-139 (2012).
  7. K.-D. Kim, H. O. Seo, C. W. Sim, M.-G. Jeong, Y. D. Kim, and D. C. Lim, Preparation of highly stable superhydrophobic $TiO_2$ surfaces with completely suppressed photocatalytic activity, Prog. Org. Coat., 76, 596-600 (2013). https://doi.org/10.1016/j.porgcoat.2012.11.010
  8. W. Li and A. Amirfazli, Hierarchical structures for natural superhydrophobic surfaces, Soft Matter, 4, 462-466 (2008). https://doi.org/10.1039/B715731B
  9. E. J. Park, J. K. Sim, M.-G. Jeong, H. O. Seo, and Y. D. Kim, Transparent and superhydrophobic films prepared with polydimethylsiloxane-coated silica nanoparticles, RSC Adv., 3, 12571-12576 (2013). https://doi.org/10.1039/c3ra42402b
  10. N. A. Patankar, Mimicking the lotus effect: influence of double roughness structures and slender pillars, Langmuir, 20, 8209-8213 (2004). https://doi.org/10.1021/la048629t
  11. H. O. Seo, M.-G. Jung, K.-D. Kim, Y. D. Kim, D. C. Lim, and K. H. Lee, Characterization of stable hydrophobic carbon coating and its application in removing organic pollutants, Curr. Appl. Phys., 13, 31-36 (2013). https://doi.org/10.1016/j.cap.2012.06.008
  12. J. Bravo, L. Zhai, Z. Wu, R. E. Cohen, and M. F. Rubner, Transparent superhydrophobic films based on silica nanoparticles, Langmuir, 23, 7293-7298 (2007). https://doi.org/10.1021/la070159q
  13. M. Hikita, K. Tanaka, T. Nakamura, T. Kajiyama, and A. Takahara, Super-liquid-repellent surfaces prepared by colloidal silica nanoparticles covered with fluoroalkyl groups, Langmuir, 21, 7299-7302 (2005). https://doi.org/10.1021/la050901r
  14. E. J. Park, B. R. Kim, D. K. Park, S. W. Han, D. H. Kim, W. S. Yun, and Y. D. Kim, Fabrication of superhydrophobic thin films on various substrates using $SiO_2$ nanoparticles coated with polydimethylsiloxane: towards the development of shielding layers for gas sensors, RSC Adv., 5, 40595-40602 (2015). https://doi.org/10.1039/C5RA05470B
  15. E. J. Park, K.-D. Kim, H. S. Yoon, M.-G. Jeong, D. H. Kim, D. C. Lim, Y. H. Kim, and Y. D. Kim, Fabrication of conductive, transparent and superhydrophobic thin films consisting of multi-walled carbon nanotubes, RSC Adv., 4, 30368-30374 (2014). https://doi.org/10.1039/C4RA04272G
  16. Y.-C. Sheen, W.-H. Chang, W.-C. Chen, Y.-H. Chang, Y.-C. Huang, and F.-C. Chang, Non-fluorinated superamphiphobic surfaces through sol-gel processing of methyltriethoxysilane and tetraethoxysilane, Mater. Chem. Phys., 114, 63-68 (2009). https://doi.org/10.1016/j.matchemphys.2008.07.132
  17. C.-F. Wang, Y.-T. Wang, P.-H. Tung, S.-W. Kuo, C.-H. Lin, Y.-C. Sheen, and F.-C. Chang, Stable superhydrophobic polybenzoxazine surfaces over a wide pH range, Langmuir, 22, 8289-8292 (2006). https://doi.org/10.1021/la061480w
  18. H. Zhou, H. Wang, H. Niu, A. Gestos, X. Wang, and T. Lin, Fluoroalkyl silane modified silicone rubber/nanoparticle composite: a super durable, robust superhydrophobic fabric coating, Adv. Mater., 24, 2409-2412 (2012). https://doi.org/10.1002/adma.201200184
  19. S. Chen, X. Li, Y. Li, and J. Sun, Intumescent flame-retardant and self-healing superhydrophobic coatings on cotton fabric, ACS Nano, 9, 4070-4076 (2015). https://doi.org/10.1021/acsnano.5b00121
  20. X. Deng, L. Mammen, H.-J. Butt, and D. Vollmer, Candle soot as a template for a transparent robust superamphiphobic coating, Science, 335, 67-70 (2012). https://doi.org/10.1126/science.1207115
  21. L. Mishchenko, B. Hatton, V. Bahadur, J. A. Taylor, T. Krupenkin, and J. Aizenberg, Design of ice-free nanostructured surfaces based on repulsion of impacting water droplets, ACS Nano, 4, 7699-7707 (2010). https://doi.org/10.1021/nn102557p
  22. T. Verho, C. Bower, P. Andrew, S. Franssila, O. Ikkala, and R. H. Ras, Mechanically durable superhydrophobic surfaces, Adv. Mater., 23, 673-678 (2011). https://doi.org/10.1002/adma.201003129
  23. F. Xia and L. Jiang, Bio-inspired, smart, multiscale interfacial materials, Adv. Mater., 20, 2842-2858 (2008). https://doi.org/10.1002/adma.200800836
  24. X. Zhang, F. Shi, J. Niu, Y. Jiang, and Z. Wang, Superhydrophobic surfaces: from structural control to functional application, J. Mater. Chem., 18, 621-633 (2008). https://doi.org/10.1039/B711226B
  25. Y. K. Cho, E. J. Park, and Y. D. Kim, Removal of oil by gelation using hydrophobic silica nanoparticles, J. Ind. Eng. Chem., 20, 1231-1235 (2014). https://doi.org/10.1016/j.jiec.2013.08.005
  26. A. M. Atta, W. Brostow, H. E. H. Lobland, A. R. M. Hasan, and J. M. Perez, Porous polymer oil sorbents based on PET fibers with crosslinked copolymer coatings, RSC Adv., 3, 25849-25857 (2013). https://doi.org/10.1039/c3ra44759f
  27. X. Gui, Z. Zeng, Z. Lin, Q. Gan, R. Xiang, Y. Zhu, A. Cao, and Z. Tang, Magnetic and highly recyclable macroporous carbon nanotubes for spilled oil sorption and separation, ACS Appl. Mater. Interfaces, 5, 5845-5850 (2013). https://doi.org/10.1021/am4015007
  28. J. K. Yuan, X. G. Liu, O. Akbulut, J. Q. Hu, S. L. Suib, J. Kong, and F. Stellacci, Superwetting nanowire membranes for selective absorption, Nat. Nanotechnol., 3, 332-336 (2008). https://doi.org/10.1038/nnano.2008.136
  29. A. Zhang, M. Chen, C. Du, H. Guo, H. Bai, and L. Li, Poly(dimethylsiloxane) oil absorbent with a three-dimensionally interconnected porous structure and swellable skeleton, ACS Appl. Mater. Interfaces, 5, 10201-10206 (2013). https://doi.org/10.1021/am4029203
  30. E. J. Park, B. Jeong, M.-G. Jeong, and Y. D. Kim, Synergetic effects of hydrophilic surface modification and N-doping for visible light response on photocatalytic activity of $TiO_2$, Curr. Appl. Phys., 14, 300-305 (2014). https://doi.org/10.1016/j.cap.2013.12.004

Acknowledgement

Supported by : Ministry of Environment