Aluminium oxide (Al2O3), commonly known as alumina, is a widespread naturally occurring compound that has a broad range of industrial applications. Besides its use as a pigment or abrasive, alumina also plays a vital role as catalyst support for desulfurization or hydrogenation reactions. In the latter case, the active phase on the catalyst often consists of nickel metal nanoparticles. The inte...

We compare the adsorption properties of intact supported silicalite membranes with those of silicalite powder and of alumina supports using nitrogen and argon as adsorbates at 77 K. We disentangle contributions from the membrane and support and find that the support contributes significantly to the total quantity adsorbed due to its relative thickness. The micropore-filling regions of the adsor...

A new rapid, very simple and one-step sol-gel strategy for the large-scale preparation of highly porous γ-Al₂O₃ is presented. The resulting mesoporous alumina materials feature high surface areas (400 m² g-1), large pore volumes (0.8 mL g-1) and the γ-Al₂O₃ phase is obtained at low temperature (500 °C). The main advantages and drawbacks of different preparations of mesoporous alumina materials ...

A novel and aqueous gel-casting process has been successfully developed to fabricate porous MgAl₂O₄ ceramics by using hydratable alumina and MgO powders as raw materials and deionized water as hydration agent. The effects of different amounts of deionized water on the hydration properties, apparent porosity, bulk density, microstructure, pore size distribution and compressive strength of the sa...

This study investigated the mechanisms of stabilizing lead-laden sludge by blending it into the production process of aluminum-rich ceramics, and quantitatively evaluated the prolonged leachability of the product phases. Sintering experiments were performed using powder mixtures of lead oxide and γ-alumina with different Pb/Al molar ratios within the temperature range of 600-1000 °C. By mixing ...

background: an increase in surface roughness of ceramics may decrease strength and affect the clinical success of ceramic restorations. however, little is known about the effect of acidic agents on ceramic restorations. the aim of this study was to evaluate the surface roughness of dental ceramics after being immersed in acidic agents.     methods: eighty-three ceramic disk specimens (12.0 mm i...

Sintered blanks for spherical bodies of rolling from silicon nitride ceramics were obtained using the addition an yttrium-containing organoalumoxane ― element organic oligomer, soluble in traditional solvents and pyrolysis into oxide aluminum-sintering additive a given mass ratio Al2O3/Y2O3 = 3/1. Studies conducted thermogravimetry, X-ray phase analysis, optical electron scanning microscopy sho...

Titanium Aluminide and TiAl matrix composites reinforced with alumina fibers (PRD166) were fabricated by powder metallurgy. During isothermal oxidation at 950 and 1070 OC, composites containing PRD166 fibers exhibited larger weight gains than monolithic TiAI; the composites showed evidence of oxidation along the perimeter of the fibers. A fiber reaction, which was observed after oxidation in ai...

Foods and pharmaceuticals materials are exposed to various environmental conditions during processing and while in storage; therefore, stability and quality are key attributes of concern. The properties of foods and pharmaceutical materials that define their quality are affected by conditions such as temperature, humidity and time. Glass transition is considered a key material property to under...