The surface of mercapto-functionalized mesoporous silica having a highly ordered open pore network was modified into a super-hydrophilic surface through a stepwise sulfonation process involving oxidation and ionization reactions. The initial mesoporous silica was prepared using an acid-catalyzed sol-gel reaction between tetraethoxysilane (TEOS) and 3-mercaptopropyltrimethoxysilane (MPTMS) in th...

A simple and effective means for obtaining hollow silica particles of controlled diameter from about 60 to 120 nm is presented. The synthesis utilizes equilibrium vesicles as templates for the directed growth of silica. Two different surfactant systems are used to form the vesicular templates: (a) mixtures of cetyltrimethylammonium bromide (CTAB) and sodium perfluorooctanoate (FC7) and (b) mixt...

Silica refractory bricks are used especially in the metallurgical industries, due to desirable properties such as particularly their high melting point and their rigidity and strength at high temperatures. In this research, different amount of SiC were added to Silica refractory containing different binders such as Borax, Boric acid, Calcium nitride, Sodium tri poly phosphate, Sodium hexametaph...

a type of zeolite from the analcime family was prepared by using triethanolamine, silica gel and sodium aluminate. the average particle size was around 24 µm. ftir, xrd and sem results approved the type of zeolite which was formed

A direct approach for producing methanol from methane in a three-step, liquid phase process is reported. In the first step, methane is reacted with SO3 to form methanesulfonic acid (MSA) at 75 8C using a free-radical initiator and MSA as the solvent. Urea-H2O2 in combination with RhCl3 is found to be the most effective initiator (57% conversion of SO3; 7.2% conversion of CH4). MSA is then oxidi...

In this study, the synthesis, characterization and controlled release behavior of new Hollow Silica Nano particles (HSNPs) and Magnetic Silica Nano Particles (MSNPs) were studied. Magnetic Silica Nano particles (MSNPs), as drug delivery vehicles, were synthesized through the coating of Fe3O4 nano-crystals with silica layers. The HSNPs were obtained by removal of Fe3O4 templates with hydrochlori...

The effect of dehydration on the coordination and speciation of sulfate at the Fe-(hydr)oxide-H2O interface was investigated using molecular orbital/density functional theory (MO/DFT) and Fourier transform infrared (FTIR) spectroscopy. IR frequency calculations were performed at the UB3LYP/6-31+G(d) level of theory for potential sulfate (bidentate bridging, monodentate, and H-bonded) and bisulf...

9 Mesostructured silica phases with lamellar structure were prepared by the liquid crystal templating (LCT) technique, from double chain alkylammonium surfactant and sodium silicate or tetraethylorthosilicate (TEOS) silica precursors. The structural characterization of these phases is presented and compared. Surface modification of the silica layers, together with elimination of the organic tem...

Two processes for extracting alumina from low-grade ores are described, one applicable to both clays and high-silica bauxites, and the other only to bauxites. In the former process, a line-containing sinter is prepared and annealed by cooling it slowly through the range of 1,3000 to 1,2000 C. The annealed sinter dusts to a powder which requires no grinding. This material is extracted with a sol...

Background Colloidal silica is an inorganic substance widely used as excipient in pharmaceutical preparation. It acts as a vehicule to increase the absorption of many oral drug formulations. Many excipients have been reported to induce drug hypersensitivity such as tartrazine, aspartame, benzalkonium chloride, sodium metabisulphite, propyl gallate. However, colloidal silica has never been repor...