Fabrication Of Solvent-free, Hardness, Superhydrophobic Coating

Superhydrophobic coating with hard,transparent and durable properties are widely used in practical applications,especially in anti-icing,self-cleaning,oil-water separation and optical devices.However,there are various difficulties in the development,such as environmental pollution,expensive equipment,complicated process,which limited the development of superhydrophobic coating and its large-area application.In this paper,a solvent-free environment-friendly siloxane coating was designed based on the lotus leaf,and a rough surface structure was prepared simply by combining it with nanoparticles in different ways to obtain a superhydrophobic coating.A new-style siloxane coating with excellent optical transparency,mechanical properties,hydrophobicity and good adhesion was prepared based on the reaction of an epoxy group and primary amine group as well as the co-hydrolysis/condensation reaction of DTDA.The structural,morphological,mechanical and optical properties were tested of the siloxane coating,The results showed that the increase of GPTS and DTDA is beneficial to the improvement of mechanical properties and optical transmittance of the coating.Moreover,the increase of PFTS is beneficial to the improvement of the hydrophobic performance of the coating.The as-prepared siloxane coating owns high hardness(pencil hardness: 8 H),transmittance(95.2 %)excellent adhesion to the substrate(5 B),CA of 107° and weather resistance.The transparent superhydrophobic hybrid coating with excellent mechanical strength and durability which is based on the spin coating process was prepared by mixing siloxane coating prepared by sol-gel and the modified nano-silica suspension(Hs).The contact angle and UV-vis-NUR test show that the hydrophobic property of the hybrid coating increased and the optical transmittance decreased with the increase of the proportion of Hs and concentration of Hs.Also,mechanical stability and durability tests show that the coating own good properties and the coating could be used for selfcleaning and oil-water separation.The superhydrophobic coating was prepared by spraying the modified nano-silica suspension(Hs)on the substrate which coated the siloxane coating prepared by sol-gel.The effects of curing time and spraying time on coating properties were investigated.Contact angle and UV-vis-NIR tests show that the increase of curing time and spraying time is beneficial to the improvement of the hydrophobic property but the transmittance.In addition,the mechanical stability test shows that the proper curing time and spraying time are beneficial to the improvement of its stability.