Preparation and Property of Superhydrophobic Antireflective Film with Gradient Refractive Index

Abstract

Gradient refractive index antireflection film achieves antireflective performance in wider spectrum band at larger incident of angle. In this study, solid silica nanometer particles (SiO2) sol and hollow silica nanometer particles (H-SiO2) sol were synthesized by Sol-Gel method, while hollow rod-shaped magnesium fluoride nanometer particles (MgF2) sol was prepared by solvothermal method. Then, the SiO2/H-SiO2/MgF2 gradient refractive index antireflection film was successfully coated on double sides of borosilicate glass by dip-coating method. The experimental results show that in the wavelength range of 380~1600 nm, when light is incident vertically, the transmittance of the coated glass reaches 99.88%; when the light is at the incident angle of 0°~45°, with the average transmittance higher than 97.85%. And the light is even at the incident angle of 75°, its maximum transmittance is still as high as 95.51%. After modified by hexadecyl trimethoxysilane (HDTMOS) the contact angle of the coated glass is up to 150.6°, showing good hydrophobic self-cleaning performance.