Date of Award
Master of Science
Materials Science and Engineering
Roberto S. Benson
David Harper, John Simpson
Superhydrophobicity is a property commonly seen in nature such as the lotus leaf. This unique property allows the surface of a material to exhibit water repellency and self-cleaning abilities. This effect is contributed by two important components: the rough surface topography and low surface free energy. Since the discovery of this unique property, several methods and various materials have been used to produce this effect and used in a wide variety of applications. However, the use of this type of effect on transparent surfaces is still being researched. I have proposed a method to develop a transparent superhydrophobic coating using a transparent polymer such as Polycarbonate (PC) as a matrix . Functionalized aerogel particles are broken down to nanosized particles by milling and sonication, and added into solution with PC. This solution is then applied on various substrates such as quartz and silicon wafers though a spin coating process. The film produced is transparent with a transmission of 92-93%. The increase in coating thickness showed only a slight reduction in the transmission; however, the transmission still exhibited an equal or higher transmission than observed for quartz glass without a coating. The superhydrophobic properties were obtained based on contact angle measurements of 150° or greater, which represent a combination of low surface free energy and nano-textured topography of the coating. Another important aspect to achieving a superhydrophobic coating is the addition of a rough surface topography. The SEM and AFM measurement indicates that the superhydrophobic polycarbonate coating (SHPC) coating exhibits the rough nano-textured topography for obtaining superhydrophobicity. The mechanical properties of the film indicated a decrease in hardness and modulus with the increase of the coating thickness, which is influenced by the substrate. This method has shown to be a simple and effective method that can be applied to a variety of substrates and can be expanded to being used for coating larger surfaces through different methods, such as spray coating. The coating has the potential to be used for various transparent applications, such as camera lenses, windows, and solar panels.
Loi, Gimgun, "Transparent Superhydrophobic Polycarbonate Coating. " Master's Thesis, University of Tennessee, 2015.