Antireflection Films Based on Large-Area 2D Hollow SiO2 Spheres Monolayer Opals

Hollow SiO 2 spheres are synthesized by using various sizes of PS spheres as sacrified templates followed removal of the PS core by calcination. Large-area 2D monolayer SiO 2 hollow spheres opals are fabricated through gas–liquid–solid interface self-assembly route base on core–shell PS@SiO 2 as structural bricks which is a simple, fast and easily large-area-fabricated. In this route, proper ratio of alcohol to water plays important role on the synthesis of core–shell PS@SiO 2 composite spheres while,the hydrophobic treatment of core–shell PS@SiO 2 composite spheres is found primarily to realize opal films floating on water surface and further to be compacted into well ordered large monolayer films. Scanning electron microscopy and transmission electron microscopy demonstrate the obtained hollow SiO 2 spheres opals are well dispersed and well-ordered into two dimensional arrays. ultraviolet–visible–near infrared (UV–vis–NIR) spectroscopy shows that transmission in visible light range increases with the added size of hollow SiO 2 spheres. In contrast to solid SiO 2 spheres opal, hollow SiO 2 spheres opals demonstrates their improved transmission due to their high porosity.