Anti-icing and antibacterial super-hydrophobic poly(dimethyl siloxane) coatings modified with silica, TiO2, Ag3PO4, and CuO nanoparticles

Abstract

Functional coatings with high performance in special environments or harsh conditions have gained high attention in recent years. The aim of this work is to develop super-hydrophobic poly(dimethyl siloxane) (PDMS) coatings by incorporating silica nanoparticles prepared from rice husk (PDMS-SiO2) as a green florin free method by using non-toxic materials. Additionally, titanium dioxide, silver phosphate, and copper (II) oxide nanoparticles (X), as simple and non-toxic additives are separately added in PDMS-SiO2 coatings (PDMS-SiO2-X) to impart antibacterial properties. Results revealed the synergetic effects of silica and antibacterial additives on each other functionality. Silica nanoparticles, silver phosphate, and copper (II) oxide nanoparticles were successfully synthesized. Ceramic substrates were coated with PDMS formulations containing varying percentages of additives. Scanning electron microscopy (SEM) and surface topography analysis revealed increased coating surface roughness upon incorporating additives. Evaluation of the surface wettability demonstrated that the PDMS coatings containing various percents of SiO2 and X nanoparticles (X = Ag3PO4, TiO2, or CuO) exhibit super-hydrophobic characteristics, with a significantly high-water contact angle surpassing 150° and a low sliding angle of less than 10°. The findings reveale low surface energy and an optimal surface roughness profile for modified nanocomposite coatings. Anti-icing investigations of the PDMS-SiO2-X coatings reveale a threefold increase in the icing time of water droplets on the super-hydrophobic PDMS-SiO2-X coatings compared to ceramic bare substrates. Moreover, the PDMS-SiO2-X surfaces exhibit robust antibacterial properties. Additionally, the results substantiate the long-term chemical stability of PDMS-SiO2-X coatings in harsh environmental conditions, as these coatings maintained their desired slippery properties even after prolonged exposure to such conditions. Consequently, the prepared high-performance coatings, exhibiting exceptional resistance to icing and antibacterial capabilities, hold immense potential for widespread application across various industries, including marine, medical, and flooring sectors.