SoL-gel Preparation of Superhydrophilic Silica Coating-materials with Low Refractive Index

Porous silica coatings with low refractive index and superhydrophilicity property were prepared via a base-catalysed sol-gel process. Precursor sols were prepared based on a base-catalysed sol-gel process, followed by etching of silica particles in sols with acid fluoride ( HF) . Then , low refractive index films were prepared by dip-coating process. It was found that the refractive index of coating reduce to 1. 101 after etching with 3% HF, the static contact angle of the films reduced to 3 degrees and anti-fogging performance of the coatings is improved significantly.