Synthesis of Macroporous Minerals with Highly Ordered Three-Dimensional Arrays of Spheroidal Voids

Abstract

Titania, zirconia, and alumina samples with periodic three-dimensional arrays of macropores were synthesized from the corresponding metal alkoxides, using latex spheres as templates. In a fast, single-step reaction, the monomeric alkoxide precursors permeate the array of bulk polystyrene spheres and condense in air at room temperature. Close packed, open-pore structures with 320- to 360-nanometer voids are obtained after calcination of the organic component at 575 degreesC. The examples presented demonstrate the compositional diversity possible with this technique. The resulting highly structured ceramics could have applications in areas ranging from quantum electronics to photocatalysis to battery materials.

Nanocatalysis I: Synthesis of Metal and Bimetallic Nanoparticles and Porous Oxides and Their Catalytic Reaction Studies

“…The solids result in inverse replicas of the template or inverse opals with highly ordered arrays of spherical voids. Because hard template spheres were formed in a micrometer size (*100 nm), the resulting solids have macropores in general [47]. By applying the microspheres to the synthetic method of mesoporous materials, bimodal porous materials incorporating two distinct pore networks can be generated [48,49].…”

Self-assembly of shape-controlled nanocrystals and their in-situ thermodynamic properties

“…The structure is ordered on the length-scale of the template spheres and the pore sizes are in submicron to micron range. Alternatively, ordered porous silica with much smaller pore sizes in nanosize range ( B 30 nm), produced deliberately by introducing surfactant, has also been processed [20,21], in which the porosity is created by surfactants. This is the so-called mesoporous structure.…”

“…The other is the ordered porous structures. Here the ordered hollow structure of titania is taken as an example [20,21]. The ordered hollow structure was made through a template-assisted technique, in which selfassembly of size selective polystyrene spheres creates an ordered template.…”

Hierarchically structured meso-macroporous aluminosilicates with high tetrahedral aluminium content in acid catalysed esterification of fatty acids

“…These strategies can be summarised into two categories. One concerns the use of templates such as polymeric beads and silica opals [14][15][16], soft sacrificial template [17], foam [18,19], emulsions [20,21], ice crystals [22], natural structures [23] such as bacterial threads [24] with the combination of amphiphilic molecules or zeolite crystal seeds [25][26][27][28]. Other one is related to post-synthesis treatments [29].…”