US Patent 7381461 - Zeolite nanocrystal antireflective film

http://www.freepatentsonline.com/7381461.html

In order to prevent glare for displays and other optical devices anti-reflective films are often used. These anti-reflective films usually employ either multilayer films having thicknesses selected for destructive interference of any reflection or films having a graded index of refraction to achieve the same effect. This patent teaches an alternative solution using graded porosity of a zeolite nanocrystal film. Claim 1 reads:

1. An antireflective transparent zeolite hardcoat, comprising a zeolite nanostructure made of zeolite nanocrystals vertically stacked into a porous structure on a substrate, wherein the porosity increases with structure height, thereby providing a smooth refractive index transition.