Sol–gel synthesis of powders consisting of regularly shaped submicron silica spheres (∅400–600 nm) is described. IR and absorption spectra of such powders have been obtained. The IR spectra demonstrate that the silica spheres heated at 800 °C are hydroxyl-free. The TEM measurements show that the dimensions of silica nanoparticles do not change during heating. Films of self-organized silica nano...

The solvent free route for the synthesis of diaryl sulfoxides from arenes and thionyl chloride in the presence of Lewis acids such as aluminum chloride and ferric chloride on silica gel are described.

A facile and efficient synthesis of bis(indolyl)methanes derivatives (3a-u) was reported via a condensation reaction of aldehydes and indole in the presence of by silica-supported-3-(triethoxysilyl) propane-1-ammonium chloride catalysis under solvent free conditions. We studied the reaction in different conditions and optimized. The use of just 0.02 g of (silica gel-ammonium salt) is sufficient...

silica sulfuric acid is found to catalyze efficiently the condensation of o-phenylenediamines with various linear and cyclic ketones to afford the corresponding 1,5-benzodiazepines in quantitative yields under solvent-free conditions at room temperature

The effects of whole body irradiation (WBR) on particle clearance and the development of pulmonary fibrosis have been investigated. Using carbon, clearance is accomplished by polymorphonuclear leukocytes (PMN) and alveolar macrophages (AM), and only a few particles reach the interstitum. However, in preirradiated mice, the usual eflux of inflammatory cells is much delayed so that more free carb...

An epidemiological investigation was undertaken to determine the relationship between silicosis in hardrock miners in Ontario and cumulative exposure to silica (free crystalline silica--alpha quartz) dust. This report describes the analytic method and presents the risk estimates.

Silica sulfuric acid is found to catalyze efficiently the condensation of o-phenylenediamines with various linear and cyclic ketones to afford the corresponding 1,5-benzodiazepines in quantitative yields under solvent-free conditions at room temperature

sol–gel chemistry is an efficient tool to control the morphology and reactivity of solids. drying is the crucial step due to the capillary forces exerted during the classic ambient drying process, which induces the collapse of the wet gel porosity. the use of n, n-dimethylformamide (dmf), a newly found dcca were found to be effective in the sol–gel synthesis of crack-free silica gel monolith fr...