Dust mitigation by rolling water droplets from hydrophobic surfaces

Abstract Environmental dust mitigation from hydrophobic surfaces by rolling water droplets is considered and the dust particle removal mechanism by rolling droplet fluid is examined. The dust particles are analyzed evaluating elemental composition, shapes, and sizes. The solubility of some dust compounds in the droplet fluid is also assessed. Glass surfaces are hydrophobized through deposition of the functionalized nano-size silica particles using the dip coating method. A high speed recording system is utilized monitoring and tracking of the droplet liquid infusion (cloaking) on the dust particle surfaces. Similarly, the droplet motion on the inclined dusty hydrophobic surface is monitored and tracked. The findings reveal that dust possess various elements and alkaline and alkaline earth metal compounds can dissolve in water while forming a chemically active solution, which can damage the dusty surfaces. The droplet liquid infusion (cloaking) on the surface of the dust particles remains essential for removing dust from the hydrophobic surfaces by rolling water droplets. The droplet liquid spreading ceases for low surface energy dust particles. This prevents the droplet fluid spreading onto the surface of the dust particles; hence, these particles remain as dust residues on the surface. Rolling water droplet cleans the dusty hydrophobic surface and improves the optical transmittance of the surface.