Novel approach to the fabrication of macroporous polymers and their use as a template for crystalline titania nanorings

This paper presents a novel method for fabricating two- and three-dimensional (2D/3D) polymer macroporous structures and demonstrates their use as templates for the production of crystalline titania nanorings. 2D honeycomb and 3D inverse opal structures were fabricated with a linear shrinkage of about 1% by means of the selective dissolution of a sintered colloid crystal. In this novel method, the conventional infiltration step that introduces a polymer precursor prior to selective dissolution is not required. Honeycomb or isolated polymer rings can also be produced using this approach, depending on the sintering conditions. The resulting macroporous structures were used in this study as templates for the formation of isolated or interconnected crystalline titania nanorings via the calcination of titanium alkoxide deposited on the templates. The resulting titania nanorings exhibited a robust, undisrupted rutile phase.