The transport of pure gases through a microporous membrane is described. The alumina-based membrane (pores 2.5-4 nm) is suitable for Knudsen diffusion separation . To improve the separation factor, interaction with and mobility on the pore wall of one of the gases of a mixture is necessary. To introduce surface diffusion of oxygen and hydrogen, a y-alumina membrane was impregnated with silver ....

The present work investigates the use of magnesium hydroxide, produced by magnesia hydration, as a fire retardant in polymers. The hydration was carried out in an autoclave, at temperature of 130°C for 1 hour, and the product was further submitted to cominution in a jet mill. The solids were characterized with regard to their chemical composition, particle size distribution, surface area and mo...

Oxide-supported transition-metal clusters and nanoparticles have attracted significant attention owing to their important role as components of model catalysts, sensors, solar cells and magnetic recording devices. For small clusters, functionality and structure are closely interrelated. However, knowledge of the structure of the bare cluster is insufficient as the interaction with the chemical ...

Magnesia is mainly produced from carbonate sources (magnesite (MgCO3)), and seawater brines (MgCl2). The calcination of magnesite the precipitation brine using quicklime (CaO) are processes that have significant CO2 footprints, even before considering burning hydrocarbons required to meet energy demand. There also amounts silica-based magnesia raw materials available worldwide, such as serpenti...