Journal of Coatings Technology and Research

, Volume 15, Issue 5, pp 1025–1034 | Cite as

Extended hydrophobicity and self-cleaning performance of waterborne PDMS/TiO2 nanocomposite coatings under accelerated laboratory and outdoor exposure testing

  • Fei Xu
  • Tao Wang
  • James Bohling
  • Alvin M. Maurice
  • HongYu Chen
  • Limin Wu
  • Shuxue ZhouEmail author


It has been shown that incorporation of TiO2 nanoparticles into hydrophobic coatings can show self-cleaning performance. Accelerated laboratory testing indicated that the coats retain their hydrophobic nature for an extended time period. In this paper, hydrophobic polydimethylsiloxane (PDMS)/TiO2 nanocomposite coatings with a TiO2 content of 0–40% were fabricated by simple blending of a PDMS dispersion with an aqueous TiO2 nanoparticle dispersion. Their long-term hydrophobicity and self-cleaning performance were investigated both in laboratory and real-world outdoor testing. As expected, TiO2 nanoparticle-based coatings exhibited better self-cleaning relative to the TiO2-free PDMS control coating as measured by methylene blue degradation testing. Excellent long-term hydrophobicity was observed in accelerated weathering testing when they contained the appropriate levels of TiO2 nanoparticles (i.e., 0–30%). However, the same PDMS/TiO2 coatings did not show self-cleaning performance, and instead, exhibited improved dirt pickup resistance, in outdoor exposure testing. Sustained hydrophobicity was observed in outdoor exposure testing for the clear films except when TiO2 levels were at 40%. The hysteresis of water contact angle (HWCA) significantly increased for the PDMS control coating, and water beading was lost as the film surface picked up dirt. In contrast, the TiO2-based coatings with appropriate TiO2 levels maintained a relatively low HWCA after outdoor exposure and no water sheeting on rainy days was observed. This result demonstrates that while photocatalytic TiO2 nanoparticles can maintain coating hydrophobicity upon outdoor exposure, long-term self-cleaning performance in polluted environments has not yet been achieved with this type of coating under real-world conditions.


TiO2 nanoparticles Self-cleaning Hydrophobicity Outdoor performance PDMS 



This work was financially supported by The Dow Chemical Company.

Supplementary material

11998_2017_37_MOESM1_ESM.docx (169 kb)
Supplementary material 1 (DOCX 168 kb)


  1. 1.
    Hu, Z, Zhang, X, Liu, Z, Huo, K, Chu, PK, Zhai, J, Jiang, L, “Regulating Water Adhesion on Superhydrophobic TiO2 Nanotube Arrays.” Adv. Funct. Mater., 24 (40) 6381–6388 (2014)CrossRefGoogle Scholar
  2. 2.
    Pang, H, Zhou, S, Gu, G, Wu, L, “Long-Term Hydrophobicity and Ice Adhesion Strength of Latex Paints Containing Silicone Oil Microcapsules.” J. Adhes. Sci. Technol., 27 (1) 46–57 (2013)CrossRefGoogle Scholar
  3. 3.
    Gao, S-H, Lei, M-K, Liu, Y, Wen, L-S, “CF4 Radio Frequency Plasma Surface Modification of Silicone Rubber for Use as Outdoor Insulations.” Appl. Surf. Sci., 255 (11) 6017–6023 (2009)CrossRefGoogle Scholar
  4. 4.
    Qing, Y, Yang, C, Sun, Y, Zheng, Y, Wang, X, Shang, Y, Wang, L, Liu, C, “Facile Fabrication of Superhydrophobic Surfaces with Corrosion Resistance by Nanocomposite Coating of TiO2 and Polydimethylsiloxane.” Colloids Surf. A: Physicochem. Eng. Aspects, 484 471–477 (2015)CrossRefGoogle Scholar
  5. 5.
    Ragesh, P, Anand Ganesh, V, Nair, SV, Nair, AS, “A Review on ‘Self-Cleaning and Multifunctional Materials’.” J. Mater. Chem. A, 2 (36) 14773–14797 (2014)CrossRefGoogle Scholar
  6. 6.
    Tung, WS, Daoud, WA, “Self-Cleaning Fibers via Nanotechnology: A Virtual Reality.” J. Mater. Chem., 21 (22) 7858–7869 (2011)CrossRefGoogle Scholar
  7. 7.
    Ganesh, VA, Raut, HK, Nair, AS, Ramakrishna, S, “A Review on Self-Cleaning Coatings.” J. Mater. Chem., 21 (41) 16304–16322 (2011)CrossRefGoogle Scholar
  8. 8.
    Teisala, H, Tuominen, M, Kuusipalo, J, “Superhydrophobic Coatings on Cellulose-Based Materials: Fabrication, Properties, and Applications.” Adv. Mater. Interfaces, 1 (1) 1–20 (2014)CrossRefGoogle Scholar
  9. 9.
    Sahoo, BN, Kandasubramanian, B, “Recent Progress in Fabrication and Characterisation of Hierarchical Biomimetic Superhydrophobic Structures.” RSC Adv., 4 (42) 22053–22093 (2014)CrossRefGoogle Scholar
  10. 10.
    Mahadik, SA, Pedraza, F, Vhatkar, RS, “Silica Based Superhydrophobic Coating for Long-Term Industrial and Domestic Applications.” J. Alloys Compd., 663 487–493 (2016)CrossRefGoogle Scholar
  11. 11.
    Li, S, Gu, G, Zhou, S, Wu, L, “Dependence of Dirt Resistance of Steel Topcoats on Their Surface Characteristics.” J. Coat. Technol. Res., 10 (3) 339–346 (2012)CrossRefGoogle Scholar
  12. 12.
    Wooh, S, Encinas, N, Vollmer, D, Butt, HJ, “Stable Hydrophobic Metal-Oxide Photocatalysts via Grafting Polydimethylsiloxane Brush.” Adv. Mater., 29 (16) 1–7 (2017)CrossRefGoogle Scholar
  13. 13.
    Ding, X, Zhou, S, Gu, G, Wu, L, “A Facile and Large-Area Fabrication Method of Superhydrophobic Self-Cleaning Fluorinated Polysiloxane/TiO2 Nanocomposite Coatings with Long-Term Durability.” J. Mater. Chem., 21 (17) 6161–6164 (2011)CrossRefGoogle Scholar
  14. 14.
    Chen, K, Zhou, S, Yang, S, Wu, L, “Fabrication of All-Water-Based Self-Repairing Superhydrophobic Coatings Based on UV-Responsive Microcapsules.” Adv. Funct. Mater., 25 (7) 1035–1041 (2015)CrossRefGoogle Scholar
  15. 15.
    Peter, G, “Modified Silica Sols: Titania Dispersants and Co-binders for Silicate Paints.” Pigment Resin Technol., 39 (6) 315–321 (2010)CrossRefGoogle Scholar
  16. 16.
    Wada, T, Inui, K, Uragami, T, “Properties of Organic–Inorganic Composite Materials Prepared from Acrylic Resin Emulsions and Colloidal Silicas.” J. Appl. Polym. Sci., 101 (3) 2051–2056 (2006)CrossRefGoogle Scholar
  17. 17.
    Zhang, S, Zhou, S, You, B, Wu, L, “Fabrication of Ordered Porous Polymer Film via a One-Step Strategy and Its Formation Mechanism.” Macromolecules, 42 (10) 3591–3597 (2009)CrossRefGoogle Scholar
  18. 18.
    You, B, Wen, N, Zhou, S, Wu, L, Zhao, D, “Facile Method for Fabrication of Nanocomposite Films with Ordered Porous Surface.” J. Phys. Chem. B, 112 7706–7712 (2008)CrossRefGoogle Scholar
  19. 19.
    Yang, L, Zhou, S, Gu, G, Wu, L, “Film-Forming Behavior and Mechanical Properties of Colloidal Silica/Polymer Latex Blends with High Silica Load.” J. Appl. Polym. Sci., 129 (3) 1434–1445 (2013)CrossRefGoogle Scholar
  20. 20.
    Novotná, P, Zita, J, Krýsa, J, Kalousek, V, Rathouský, J, “Two-Component Transparent TiO2/SiO2 and TiO2/PDMS Films as Efficient Photocatalysts for Environmental Cleaning.” Appl. Catal. B: Environ., 79 (2) 179–185 (2008)CrossRefGoogle Scholar
  21. 21.
    Wang, R, Hashimoto, K, Fujishima, A, “Light-Induced Amphiphilic Surfaces.” Nature, 388 (6641) 431–432 (1997)CrossRefGoogle Scholar
  22. 22.
    Li, Y-F, Wu, C-J, Sheng, Y-J, Tsao, H-K, “Facile Manipulation of Receding Contact Angles of a Substrate by Roughening and Fluorination.” Appl. Surf. Sci., 355 127–132 (2015)CrossRefGoogle Scholar

Copyright information

© American Coatings Association 2018

Authors and Affiliations

  1. 1.Department of Materials Science, State Key Laboratory of Molecular Engineering of Polymers, Advanced Coatings Research Center of Ministry of Education of ChinaFudan UniversityShanghaiChina
  2. 2.Dow Chemical CompanyShanghaiChina
  3. 3.Dow Chemical CompanyCollegevilleUSA

Personalised recommendations