Salvinia inspired fluroine free superhydrophobic coatings

Highlights: • Salvinia inspired fluorine free superhydrophobic coatings were prepared by incorporating as-prepared metal silcates. • WCA increased to 156.8° for pigment incorporated coating compared to that of 93.5° for pristine resin. • Multiscale roughness along with pinning effect Swas created by utilizing nanopigments and as prepared metal silicates. • This study paves new dimensions for making underwater air retaining superhydrophobic coatings. In this work, Salvinia inspired fluorine free superhydrophobic coatings were prepared by incorporating as-prepared metal silicates in silicone resin along with nanosilica, nanotitania and aluminium stearate. Coatings with different composition were prepared and applied by air spray method over precleaned mild steel panel. The superhydrophobicity and stability of coatings were studied. The pristine resin with no pigments and additives showed hydrophobic behaviour with water contact angle (WCA) of 93.5° and tilting angle (TA) of 60°. The WCA increased to 156.8° and TA to 28° with incorporation of metal silicates. Other properties like abrasion, adhesion, water uptake and water vapour permeation were also evaluated.