Durable superhydrophobic coating based on inorganic/organic double-network polysiloxane and functionalized nanoparticles

The poor durability of superhydrophobic coating is one of the most important reasons that limit its wide application. In this research, a superhydrophobic coating with excellent mechanical properties was prepared using a facile reaction. The inorganic/organic polysiloxane double networks were introduced to immobilize fluorinated nanoparticles (NPs) in order to provide superhydrophobicity and durability. In the first step, three functional groups, the double bond, hydroxyl group and fluorocarbon chain were grafted on SiO2 NPs, while in the second step, the inorganic networks were prepared by co-hydrolysis of methyltriethoxysilane (MTES) with the hydroxyl group on SiO2 NPs. This was followed by synthesized of organic networks by hydrosilylation of the double bond on SiO2 NPs and the polymethylhydrosiloxane (PMHS). Both networks rendered excellent properties to the superhydrophobic coatings. After 350 times of friction cycles under the condition of 200 g loads, the water contact angle (WCA) of the coating was kept above 145 degrees. Furthermore, the coating still maintained superhydrophobic property for dozens of hours in the acidic and alkaline condition. In addition, the effect of superhydrophobic did not recede significantly under strong ultraviolet or serious dust pollution environment.