Abstract:Through reasonable coating structural design, polydimethylsiloxane(PDMS)/Sm2O3 composite coating with superhydrophobic property was prepared by scratch coating method using nano-SiO2, PDMS and Sm2O3 particles as micro-nano structural modifier, adhesives and functional pigments, respectively. The effects of the ratio of PDMS to Sm2O3, the addition amount of nano-SiO2 and the surface micro-nano structural layer on the coating properties were discussed. The results show that the ratio of PDMS to Sm2O3 (mass ratio) has an important effect on the coating properties. When m(PDMS):m(Sm2O3)=6:4, the reflectance of the coating to the 1.06 μm near-infrared light can be as low as 58.8%. The water contact angle can reach 113°, which is significantly higher than the conventional polyurethane-based near-infrared absorption coatings. The superhydrophobic property of the coating can be achieved by coating a PDMS/SiO2 micro-nano structural layer with a distinct papillary structure on the surface of the PDMS/Sm2O3 composite coating. After the surface of PDMS/Sm2O3 composite coating is coated by PDMS/SiO2 micro-nano structural layer with SiO2 mass fraction of 30%, the water contact angle can be increased to 158°, the roll angle can be as low as 4°, and has lower reflectance (61.4%) to the 1.06 μm near-infrared light.