Preparation of antireflection coatings with novel cationic–nonionic PU‐SiO₂ core–shell particle dispersions

Abstract

A novel polyurethane (PU)-SiO 2 core-shell particle dispersion was prepared by an acid-catalyzed sol-gel process using cationic-nonionic PU particle as template. Results of average sizes, polydispersity index, and transmission electron microscope indicated that tetramethylorthosilicate were first diffused to the surface of PU particles, then occurring hydrolysis-condensation reaction to form core-shell particles. Antireflection coating formulation was prepared by as-prepared core-shell particle dispersion and SiO 2 sol binder. After dip-coating in the formulation, antireflection coating was formed on glass surface by calcination. Scanning electron microscopy images showed that pores had been formed inside coating after removing PU template particles, and the coating surface could be almost fully closed. In addition, ultraviolet-visible spectrophotometer analysis showed that the maximum transmittance of antireflection glasses can be as high as 98.6% at 548 nm.