title: Aerosol-assisted controlled packing of silica nanocolloids: templateless synthesis of mesoporous silicates with structural tunability and complexity.
abstract: A template-free synthesis method for mesoporous and macro-/mesoporous hierarchically porous silicates with remarkable structural tunability and complexity is presented. SiO2 nanocolloids having diameters of 3.0-29 nm were prepared as a primary building block by using extended Stöber synthesis, and they were subsequently assembled by an aerosol-assisted drying. The silica pore structure can be rationally controlled depending on the initial diameter of SiO2 colloids and the aerosol-assembly temperature that determines the packing density of SiO2 colloids (i.e., amounts of packing defects) in the resultant materials. The present method could produce mesoporous silica spheres with remarkable pore-structural tunability (291 < BET surface area <807 m(2) g(-1), 0.42 < pore volume <0.92 cm(3) g(-1), 3.1 < pore size <26 nm). Hierarchically porous materials can also be synthesized by the evaporation-induced phase separation of solvent medium during the aerosol-assisted assembly of SiO2 colloids. By adding aluminum and Pt precursors into the SiO2 colloid suspensions before the aerosol-assisted assembly, mesoporous aluminosilicates supporting uniform Pt nanoclusters (∼2 nm) can also be synthesized. This indicates that the synthesis strategy can be used for the direct synthesis of functional silicate materials.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology , Daejeon 305-701, Republic of Korea.
authors.forename: Kyungmin
authors.initials: K
authors.lastname: Min
authors.forename: Chang Hyuck
authors.initials: CH
authors.lastname: Choi
authors.forename: Myoung Yeob
authors.initials: MY
authors.lastname: Kim
authors.forename: Minkee
authors.initials: M
authors.lastname: Choi
mesh_terms: D000336:Aerosols; D003102:Colloids; D008670:Metals / Q000737:chemistry; D036103:Nanotechnology / Q000191:economics / Q000379:methods*; D016062:Porosity; D017640:Silicates / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D014835:Volatilization
chemical_list: D000336:Aerosols; D003102:Colloids; D008670:Metals; D017640:Silicates; D012822:Silicon Dioxide