The Effect of Dust Hygroscopicity on Soiling and Self-Cleaning Processes in a Condensing Environment

Dew promotes chemical interactions between soilants and glass that lead to increased soiling rates and cleaning costs. Anti-soiling coatings have been developed to address these issues, and prior experiments have quantified the soiling impact of several categories of particle chemistries. In this paper, the impact that the hygroscopicity of a soilant has on soiling and cleaning values was measured on hydrophobic coated glass and compared to bare glass samples. Results will be presented from UV -visible direct transmittance and optical image processing measurements to characterize soiling and self-cleaning of surfaces as a function of particle hygroscopicity in a condensing environment, mimicking natural dew conditions.