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Bimodal Pore Size Distribution (bimodal + pore_size_distribution)
Selected AbstractsMicrostructures: Facile Fabrication of Monolithic 3D Porous Silica Microstructures and a Microfluidic System Embedded with the Microstructure (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 9 2010Mater. D.-P. Kim and co-workers present the fabrication of monolithic 3D porous silica structures into a multilayer framework with bimodal pore size distribution on page 1473. The structure becomes monolithic upon pyrolyzing the stacked layers, and then easily embedded in microchannel with the aid of photolithography, leading to a microfluidic system with built-in microstructure in a site- and shape-controlled manner. [source] Facile Fabrication of Monolithic 3D Porous Silica Microstructures and a Microfluidic System Embedded with the MicrostructureADVANCED FUNCTIONAL MATERIALS, Issue 9 2010ZuoYi Xiao Abstract Monolithic 3D porous silica structures are fabricated into a multilayer framework with a bimodal pore size distribution in the micrometer and sub-micrometer range. The fabrication , which involves directed assembly of colloidal spheres, transfer printing, and removal of a sacrificial template , yields robust and mechanically stable structures over a large area. The structure becomes monolithic upon pyrolyzing the stacked layers, which induces necking of the particles. The monolithic microstructures can easily be embedded in microchannels with the aid of photolithography, leading to the formation of a microfluidic system with a built-in microstructure in a site- and shape-controlled manner. Utilization of the system results in a fourfold increase in the mixing efficiency in the microchannel. [source] High Surface Area, Mesoporous, Glassy Alumina with a Controllable Pore Size by Nanocasting from Carbon AerogelsCHEMISTRY - A EUROPEAN JOURNAL, Issue 5 2005Wen-Cui Li Dr. Abstract A strategy to synthesize amorphous, mesoporous alumina by nanocasting has been developed, involving carbon aerogel as a hard template and aluminum nitrate solution as an alumina precursor. The alumina generated exhibits small, transparent granules with a 3,6 mm diameter and has inherited the three-dimensional network structure of the carbon template. The mesopore surface area of the alumina can be as high as 365 m2,g,1, and the pore volume reaches 1.55 cm3,g,1 after calcination at 600,°C in air for 8 h. The pore parameters can be varied within a certain range by variation of the carbon aerogel template and the loading amount of the alumina precursor. At high loadings, the obtained glassy alumina clearly has a bimodal pore size distribution in the mesopore range. [source] Control of Phase and Pore Structure of Titania Powders Using HCl and NH4OH CatalystsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2001Ki Chang Song Porous titania powders were prepared by hydrolysis of titanium tetraisopropoxide (TTIP) and were characterized at various calcination temperatures by nitrogen adsorption, X-ray diffraction, and microscopy. The effect of HCl or NH4OH catalysts added during hydrolysis on the crystallinity and porosity of the titania powders was investigated. The HCl enhanced the phase transformations of the titania powders from amorphous to anatase as well as anatase to rutile, while NH4OH retarded both phase transformations. Titania powders calcined at 500°C showed bimodal pore size distributions: one was intra-aggregated pores with average pore diameters of 3,6 nm and the other was interaggregated pores with average pore diameters of 35,50 nm. The average intra-aggregated pore diameter was decreased with increasing HCl concentration, while it was increased with increasing NH4OH concentration. [source] | ||||||||||