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Author
Gu, X. | Sung, L. P. | Kidah, B. | Oudina, M. | Martin, D. | Rezig, Z. | Stanley, D. | Jean, J. Y. C. | Nguyen, T. | Martin, J. W.
Title
Relating Gloss Loss to Nanoscale/Microscale Topographical Change for a Polymer Coating Exposed to UV Radiation.
Coporate
National Institute of Standards and Technology, Gaithersburg, MD University of Missouri at Kansas City, Kansas City, MO
Report
ACS Symposium Series 1008; Chapter 16,
Book or Conf
Nanotechnology Applications in Coatings. American Chemical Society (ACS) Symposium Series 1008. Chapter 16, American Chemical Society, Washington, DC, Fernando, R. H.; Sung, L. P., Editors, 328-348 p., 2009
Keywords
coatings | nanotechnology | ultraviolet radiation | topography | exposure | microscopy | lasers | scaling | exposure time
Identifiers
Tomic Force Microscopy (AFM); Laser Scanning Confocal Miscroscopy (LSCM); Root Mean Square (RMS); outdoor UV exposure; gloss measurement; surface topography; surface roughness and scaling factor; gloss retention and its relationship to surface roughness
Abstract
Surface topography and gloss are two important and highly related properties affecting the appearance of a coated surface. Upon exposure to ultraviolet (UV) radiation, the surface roughness generally increases and, correspondingly, its gloss decreases. However, the surface factors affecting gloss are difficult to ascertain. In this paper, atomic force microscopy (AFM) and laser scanning confocal microscopy (LSCM) measurements of a polymer coating exposed to UV radiation have been performed, and the relationship between changes in surface toughness and gloss has been analyzed. The root mean square (RMS) roughness of the coating is related to nanoscale and microscale morphological changes in the surface of a coating as well as to gloss retention. A near-linear dependence of RMS roughness with the measurement length scale (L) is found on a double logarithmic scale, i.e., RMS ~ Lf. The scaling factor, f, decreases with exposure time. A general relationship between surface topography, on nano- to microscales, and gloss loss is observed. Future work on using optical scattering technique for appearance measurement will be discussed.