Preparation of spray-coated surfaces from green-formulated superhydrophobic coatings

This study involves the fabrication of green-based superhydrophobic coatings, which can be applied to a surface via a simple spraying technique. The coating formulation is green as it utilizes silica extracted from rice husks (RHA) and silver particles reduced and capped by cabbage (CRS), both of which are readily available and environmentally-benign. 12.5 wt% loading of the RHA in the coating was found to yield the best superhydrophobic behavior via contact angle measurement. By further introducing CRS, which induces repulsive forces preventing particle agglomeration, the resulting RHA/CRS-coated surfaces exhibited better anti-wetting behavior and improved stability and durability. In addition, the coating was also shown to possess self-cleaning property, pH resistance, and insensitivity to any touches. All of these reveal the potential of the green-formulated RHA/CRS coating as a cheaper and friendlier alternative in the quest for superhydrophobicity.