Developing bagasse towards superhydrophobic coatings

Superhydrophobic surfaces have attracted great attention due to their interesting properties. The ever-increasing environmental concern accelerated the development of bio-based superhydrophobic coating materials. As a high-yield agricultural waste, bagasse is cheap, ready available, renewable and biodegradable. It would be an ideal raw material for the preparation of bio-based superhydrophobic coatings to further improve its application value. Although the hydrophobization of bagasse have been reported, the according works mainly focus on the reaction mechanism and/or their oil-absorption properties. As far as we know, the design of bagasse-based superhydrophobic coatings has been uncovered. Herein, mechanically pretreated bagasse was esterified with stearoyl chloride. Spray-coating the suspension of as-synthesized bagasse esters onto various substrates (glass slide, aluminum flake and filter paper), superhydrophobic surfaces were generated. SEM images in combination with the high-resolution C1s XPS deconvolution spectra implied that nano-structured bagasse esters were deposited on the synthesized micro-scaled esters, which was necessary for their superhydrophobicity. The as-prepared superhydrophobic surfaces exhibited good anti-fouling, oil absorption performance and high time/temperature/pH stability. This research would provide a novel perspective for the design of other bio-based superhydrophobic coatings. Graphic abstract