Abstract
The dynamic motion of a water droplet on an inclined hydrophobic surface is analyzed with and without environmental dust particles on the surface. Solution crystallization of a polycarbonate surface is carried out to generate a hydrophobic surface with hierarchical texture composed of micro/nanosize spheroids and fibrils. Functionalized nanosize silica particles are deposited on the textured surface to reduce contact angle hysteresis. Environmental dust particles are collected and characterized using analytical tools prior to the experiments. The droplet motion on the hydrophobic surface is assessed using high-speed camera data, and then, the motion characteristics are compared with the corresponding analytical results. The influence of dust particles on the water droplet motion and the amount of dust particles picked up from the hydrophobic surface by the moving droplet is evaluated experimentally. A 40 μL droplet was observed to roll on the hydrophobic surface with and without dust particles, and the droplet slip velocity was lower than the rotational velocity. The rolling droplet removes almost all dust particles from the surface, and the mechanism for the removal of dust particles from the surface was determined to be water cloaking of the dust particles.
Highlights
Many research studies have examined surface hydrophobicity and related characteristics
To reduce the contact angle hysteresis, functionalized silica nanoparticles were deposited on the textured surface, which results in superhydrophobic surfaces with low contact angle hysteresis
Water droplet movement on the resulting inclined surface with and without environmental dust particles was analyzed in relation to self-cleaning applications
Summary
The droplet transition dynamics on a hydrophobic surface are pertinent to environmental dust removal from the surface. Some of the smaller dust particles, which are in the sub-micrometer range, attach to the surfaces of the larger dust particles The bright areas, which are typically observed for the smaller particles, are indicative of electron charging during SEM analysis. This indicates that the small particles are charged prior to SEM analysis. The geometric features of the dust particles can be characterized by the shape factor and the aspect orraaftttiihooe3i7sd. The relationship between the particle size and the aspect ratio or the shape factor is complicated due to the irregular shapes and varying sizes of the dust particles.
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call