Journal of Coatings Technology and Research

, Volume 13, Issue 5, pp 735–751 | Cite as

Surface degradation and nanoparticle release of a commercial nanosilica/polyurethane coating under UV exposure

  • Deborah S. JacobsEmail author
  • Sin-Ru Huang
  • Yu-Lun Cheng
  • Savelas A. Rabb
  • Justin M. Gorham
  • Peter J. Krommenhoek
  • Lee L. Yu
  • Tinh Nguyen
  • Lipiin Sung


Many coating properties such as mechanical, electrical, and ultraviolet (UV) resistance are greatly enhanced by the addition of nanoparticles, which can potentially increase the use of nanocoatings for many outdoor applications. However, because polymers used in all coatings are susceptible to degradation by weathering, nanoparticles in a coating may be brought to the surface and released into the environment during the life cycle of a nanocoating. Therefore, the goal of this study is to investigate the process and mechanism of surface degradation and potential particle release from a commercial nanosilica/polyurethane coating under accelerated UV exposure. Recent research at the National Institute of Standards and Technology (NIST) has shown that the matrix in an epoxy nanocomposite undergoes photodegradation during exposure to UV radiation, resulting in surface accumulation of nanoparticles and subsequent release from the composite. In this study, specimens of a commercial polyurethane (PU) coating, to which a 5 mass% surface-treated silica nanoparticle solution was added, were exposed to well-controlled, accelerated UV environments. The nanocoating surface morphological changes and surface accumulation of nanoparticles as a function of UV exposure were measured, along with chemical change and mass loss using a variety of techniques. Particles from the surface of the coating were collected using a simulated rain process developed at NIST, and the collected runoff specimens were measured using inductively coupled plasma optical emission spectroscopy to determine the amount of silicon released from the nanocoatings. The results demonstrated that the added silica nanoparticle solution decreased the photodegradation rate (i.e., stabilization) of the commercial PU nanocoating. Although the degradation was slower than the previous nanosilica epoxy model system, the degradation of the PU matrix resulted in accumulation of silica nanoparticles on the nanocoating surface and release to the environment by simulated rain. These experimental data are valuable for developing models to predict the long-term release of nanosilica from commercial PU nanocoatings used outdoors and, therefore, are essential for assessing the health and environmental risks during the service life of exterior PU nanocoatings.


Atomic force microscopy Nanocomposite Particle release Peak force QNM AFM SEM UV degradation 


  1. 1.
    McNally, T, Pötschke, P (eds.), Polymer-Carbon Nanotube Composites, Preparation, Properties, and Applications. Woodhead, Philadelphia (2011)Google Scholar
  2. 2.
    Potts, JR, Dreyer, DR, Bielawski, CW, Ruoff, RS, “Graphene-Based Polymer Nanocomposites.” Polymer, 52 5–25 (2011)CrossRefGoogle Scholar
  3. 3.
    Li, B, Zhong, WH, “Review on Polymer/Graphite Nanoplatelet Nanocomposites.” J. Mater. Sci., 46 5595–5614 (2011)CrossRefGoogle Scholar
  4. 4.
    Pavlidou, S, Papaspyrides, CD, “A Review on Polymer-Layered Silicate Nanocomposites.” Prog. Polym. Sci, 33 1119–1198 (2008)CrossRefGoogle Scholar
  5. 5.
    Zou, H, Wu, SS, Shen, J, “Polymer/Silica Nanocomposites: Preparation, Characterization, Properties, and Applications.” Chem. Rev., 108 3893–3957 (2008)CrossRefGoogle Scholar
  6. 6.
    “Nanomaterials in Plastics and Advanced Polymers.” Market Report #52, Future Markets, Inc., April (2012)Google Scholar
  7. 7.
    Froggett, SJ, Clancy, SF, Boverhof, DR, Canady, RA, “A Review and Perspective of Existing Research on the Release of Nanomaterials from Solid Nanocomposites.” Part. Fibre Toxicol., 11 (1) 17 (2014)CrossRefGoogle Scholar
  8. 8.
    Duncan, TV, “Release of Engineered Nanomaterials from Polymer Nanocomposites: The Effect of Matrix Degradation.” ACS Appl. Mater. Interfaces, 7 20–39 (2015)CrossRefGoogle Scholar
  9. 9.
    Nowack, B, David, RM, Fissan, H, Morris, H, Shatkin, JA, Stintz, M, Zepp, R, Brouwer, D, “Potential Release Scenarios for Carbon Nanotubes Used in Composites.” Environ. Int., 59 1–11 (2013)CrossRefGoogle Scholar
  10. 10.
    Lee, J, Mahendra, S, Alvarez, PJ, “Nanomaterials in the Construction Industry: A Review of Their Applications and Environmental Health and Safety Considerations.” ACS Nano, 4 3580–3589 (2010)CrossRefGoogle Scholar
  11. 11.
    Nowack, B, Ranville, JF, Diamond, S, Gallego-Urrea, JA, Metcalfe, C, Rose, J, Horne, N, Koelmans, AA, Klaine, SJ, “Potential Scenarios for Nanomaterial Release and Subsequent Alteration in the Environment.” Environ. Toxicol. Chem., 31 50–59 (2012)CrossRefGoogle Scholar
  12. 12.
    Rabek, JF, Polymer Photodegradation—Mechanisms and Experimental Methods, Vol. 4. Chapman & Hall, New York (1995)Google Scholar
  13. 13.
    Nel, A, Xia, T, Mädler, L, Li, N, “Toxic Potential Of Materials at the Nanolevel.” Science, 311 622–627 (2006)CrossRefGoogle Scholar
  14. 14.
    Poland, C, Duffin, R, Kinloch, I, Maynard, A, Wallace, WAH, Seaton, A, Stone, V, Brown, S, MacNee, W, Donaldson, K, “Carbon Nanotubes Introduced into the Abdominal Cavity of Mice Show Asbestos-Like Pathogenicity in a Pilot Study.” Nat. Nanotechnol., 3 423–428 (2008)CrossRefGoogle Scholar
  15. 15.
    Maynard, AD, “Nanotechnology: Assessing the Risks.” Nano Today, 2 22–33 (2006)CrossRefGoogle Scholar
  16. 16.
    Aschberger, K, Johnson, HJ, Stone, V, Aitken, RJ, Hankin, SM, Peters, SA, Tran, CL, Christensen, FM, “Review of Carbon Nanotubes Toxicity and Exposure—Appraisal of Human Health Risk Assessment Based on Open Literature.” Crit. Rev. Toxicol., 40 (9) 759–790 (2010)CrossRefGoogle Scholar
  17. 17.
    Handy, RD, Henry, TB, Scown, TM, Johnston, BD, Tyler, CR, “Manufactured Nanoparticles: Their Uptake and Effects on Fish-A Mechanistic Analysis.” Ecotoxicology, 17 396–409 (2008)CrossRefGoogle Scholar
  18. 18.
    Nguyen, T, Wohlleben, W, Sung, L, Mechanisms of Aging and Release from Weathered Nanocomposites, in Nanomaterials Throughout Their Lifecycle: Human Exposure, Hazard, Safety, pp. 315–334. Taylor & Francis, New York (2014)Google Scholar
  19. 19.
    Wohlleben, W, Vilar, G, Fernandez-Rosas, E, Gonzalez-Galvez, D, Gabriel, C, Hirth, A, Frechen, T, Stanley, D, Gorham, J, Sung, L, Hsueh, H-C, Chuang, Y-F, Nguyen, T, Vazquez-Campos, S, “A Pilot Interlaboratory Comparison of Protocols That Simulate Aging of Nanocomposites and Detect Released Fragments.” Environ. Chem., 11 (4) 402–418 (2014)CrossRefGoogle Scholar
  20. 20.
    Chin, J, Byrd, E, Embree, N, Garver, J, Dickens, B, Finn, T, Martin, J, “Accelerated UV Weathering Device Based on Integrating Sphere Technology.” Rev. Sci. Instrum., 75 4951–4959 (2004)CrossRefGoogle Scholar
  21. 21.
    Sung, L, Stanley, D, Gorham, JM, Rabb, SA, Gu, X, Yu, LL, Nguyen, T, “A Quantitative Study of Nanoparticle Release from Nanocoatings Exposed to UV Radiation.” J. Coat. Technol. Res., 12 (1) 121–135 (2015)CrossRefGoogle Scholar
  22. 22.
    Petersen, E, Lam, T, Gorham, JM, Scott, K, Long, C, Stanley, D, Sharma, R, Liddle, J, Pellegrin, B, Nguyen, T, “Methods to Assess the Impact of UV Irradiation on the Surface Chemistry and Structure of Multiwall Carbon Nanotube Epoxy Nanocomposites.” Carbon, 69 194–205 (2014)CrossRefGoogle Scholar
  23. 23.
    Nguyen, T, Pellegrin, B, Bernard, C, Gu, X, Gorham, JM, Stutzman, P, Stanley, D, Shapiro, A, Byrd, E, Hettenhouser, R, Chin, J, “Fate of Nanoparticles During Life Cycle of Polymer Nanocomposites.” J. Phys.: Conf. Ser., 304 012060 (2011)Google Scholar
  24. 24.
    Gorham, JM, Nguyen, T, Bernard, C, Stanley, D, Holbrook, RD, “Photo-Induced Surface Transformations of Silica Nanocomposites.” Surf. Interface Anal., 44 1572–1581 (2012)CrossRefGoogle Scholar
  25. 25.
    Nguyen, T, Pellegrin, B, Bernard, C, Rabb, S, Stuztman, P, Gorham, JM, Gu, X, Yu, LL, Chin, J, “Characterization of Surface Accumulation and Release of Nanosilica During Irradiation of Polymer Nanocomposites by Ultraviolet Light.” J. Nanosci. Nanotechnol., 12 6202–6215 (2012)CrossRefGoogle Scholar
  26. 26.
    Pittenger, B, Erina, N, Su, C, “Quantitative Mechanical Property Mapping at the Nanoscale with PeakForce QNM” Veeco Instruments Inc. AN128, A0 (2010)Google Scholar
  27. 27.
    Skoog, DA, Holler, FJ, Nieman, TA (eds.), Principles of Instrumental Analysis, 5th ed. Brooks/Cole, Belmont (1998)Google Scholar
  28. 28.
    Gu, X, Chen, G, Zhao, M, Watson, SS, Nguyen, T, Chin, JW, Martin, JW, “Critical Role of Particle/Polymer Interface in Photostability of Nano-filled Polymeric Coatings.” J. Coat. Technol. Res., 9 (6) 251–267 (2012)CrossRefGoogle Scholar
  29. 29.
    Watson, SS, Forster, AL, Tseng, I, Sung, L, “Investigating Pigment Photoreactivity for Coatings Applications: Methods Development.” In: Martin, J, Ryntz, R, Chin, J, Dickie, R (eds.) Service Life Prediction for Polymeric Materials: Global Perspectives. Springer, Berlin (2008)Google Scholar
  30. 30.
    Pang, Y, Watson, SS, Forster, AM, Sung, L, “Correlating Nanoparticle Dispersion to Surface Mechanical Properties of TiO2/Polymer Composites.” Mater. Res. Soc. Symp. Proc., 1224 Materials Research Society, 1224-FF10-16 (2010)Google Scholar
  31. 31.
    Hu, H, Zhang, C, Han, CC, Zhao, J, Wei, Y, Sung, L, Gu, X, Clerici, C, “Dispersion of Particles in the Coatings Characterized by Laser Scanning Confocal Microscopy (LSCM) I: Vertical Dispersion of Particles in the Coatings and the Weathering Property Studied by Orthogonal Analysis Method of LSCM.” Sci. China Ser. E, 53 (8) 2247–2251 (2010)CrossRefGoogle Scholar
  32. 32.
    Krommenhoek, PJ, Tracy, JB, “Magnetic Field-Directed Self-assembly of Magnetic Nanoparticle Chains in Bulk Polymers.” Part. Syst. Charact., 30 759–763 (2013)CrossRefGoogle Scholar
  33. 33.
    Lemaire, J, Siampiringue, N, “Prediction of Coating Lifetime Based on FTIR Microspectrophotometric Analysis of Chemical Evolutions,” In: Bauer, D, Martin, JW (eds.) “Service Life Prediction of Organic Coatings—A System Approach.”, vol. 722, pp. 246–256. American Chemical Society Series, Oxford (1999)Google Scholar
  34. 34.
    Harrick, NJ, Internal Reflection Spectroscopy, 2nd ed., pp. 30–31. Harrick Scientific Corporation, Ossining, NY (1979)Google Scholar
  35. 35.
    Vella, D, Mahadevan, L, “The ‘Cheerios Effect’.” Am. J. Phys., 73 817 (2005)CrossRefGoogle Scholar

Copyright information

© American Coatings Association (Outside USA) 2016

Authors and Affiliations

  • Deborah S. Jacobs
    • 1
    Email author
  • Sin-Ru Huang
    • 1
  • Yu-Lun Cheng
    • 1
  • Savelas A. Rabb
    • 2
  • Justin M. Gorham
    • 3
  • Peter J. Krommenhoek
    • 1
  • Lee L. Yu
    • 2
  • Tinh Nguyen
    • 1
  • Lipiin Sung
    • 1
  1. 1.Materials and Structural Systems Division, Engineering LaboratoryNational Institute of Standards and TechnologyGaithersburgUSA
  2. 2.Chemical Sciences Division, Material Measurement LaboratoryNational Institute of Standards and TechnologyGaithersburgUSA
  3. 3.Materials Measurement Science Division, Material Measurement LaboratoryNational Institute of Standards and TechnologyGaithersburgUSA

Personalised recommendations