Design of a highly ordered and uniform porous structure with multisized pores in film and particle forms using a template-driven self-assembly technique

A highly ordered arrangement of pores with multiple sizes in film and particle forms was successfully prepared using the dip-coating and spray-drying methods, respectively. The template-driven self-assembly technique was effective when a combination of 5 nm silica (as a model of an inorganic nanoparticle) and two different sizes of monodispersed polystyrene (PS) spheres (as models of the template) were self-assembled to produce a composite silica/PS template. Heat treatment was then used to remove the PS, which produced the porous particle. A material with spherical pores in an art-design organization was produced. The size of the pores (large pore: 100-1000 nm; small pore: 30-200 nm) could be controlled simply by adjusting the PS size. Sufficient numbers of large/small pores made it possible to produce a material of ultralow density with an ultralow refractive index, because the multiple pores allocated free space, all of which was confirmed by calculation. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.