Ordered macroporous titania photonic balls by micrometer-scale spherical assembly templating

Abstract

Highly ordered macroporous photonic balls (i.e. inverse opaline structure) composed of titania frameworks were fabricated by using a titania precursor templated around polystyrene spheres which had been assembled into polymer photonic balls (i.e. opaline structure). Narrow disperse polymer photonic balls consisting of monodisperse surface-modified polystyrene (PS) latex particles were prepared by utilizing a suspension system. The diameters of the opaline balls can be controlled in a range of a few or a few tens of micrometers. The macroporous titania structure made by this method was well-defined because the PS spheres making up the polymer photonic balls were close-packed and ordered in three-dimensions. Furthermore, crystalline types of titania (anatase or rutile) were readily adjusted through tuning the calcination temperatures, so the macroporous titania inverse opaline balls composed of anatase or rutile can be used for various applications.