Fabrication of free-standing non-close-packed opal films

This article reports an approach to the fabrication of free-standing non-close-packed opal films. In this approach a chemical vapor deposition technique was employed to deposit a layer of silica on the interior surface of a silica inverse opal, thus the sizes of the air spheres and connections of the inverse opal were reduced to yield a non-close-packed inverse opal. After infiltration of styrene monomer with subsequent polymerization, followed by removal of the silica framework, a non-close-packed polystyrene opal film consisting of polystyrene spheres connected by polystyrene cylinders was obtained. The sizes of the spheres and the cylinders can be tuned by changing the thickness of the silica layer deposited earlier on the inverse opal, allowing one to control the structure of the non-close-packed polystyrene opal film.