Increasing uses of engineered nanoparticles (ENPs) in commercial products and industrial applications has eventually resulted to their releases into atmospheric, terrestrial, and aquatic environments. However, knowledge gaps in ENPs toxicity, fate, and behaviour currently limit our ability to quantify risk assessment of materials with nanoscale dimensions, and therefore, the extent of the resul...

The methanol-to-olefin (MTO) process allows the conversion of methanol/dimethyl ether into olefins on acidic zeolites via the so-called hydrocarbon pool mechanism. However, the site and mechanism of formation of the first carbon-carbon bond are still a matter of debate. Here, we show that the Lewis acidic Al sites on the 110 facet of γ-Al2O3 can readily activate dimethyl ether to yield CH4, alk...

in this work, boehmite sol was prepared by a previously applied and validated method; hydrolysis of aluminum chloride hexa-hydrate. in order to obtain precise results, the effect of ph after adding precipitating agent, aging time, peptizing temperature and ultrasonic vibration time on the crystallite size of final precipitate were investigated in a narrow range. the preparation conditions appli...

heavy metals, as gamma alumina nanoparticles pollutants, in water resources. Therefore, the purpose of this paper was to evaluate the removal of copper (II) ions from aqueous solutions using gamma alumina nanoparticles as a adsorbent. Batch adsorption studies carried out to study various parameters included contact time, initial concentration of copper (II) ions, pH, and gamma alumina nanoparti...

Nanofiltration with inorganic meso-porous membranes is being considered more and more for water purification applications. For specific applications inorganic membranes may have advantages over organic polymer-based membranes due to their rigid pore structure, and thermochemical stability. However, the permeability and, partly through that, the permselectivity of inorganic membranes need to be ...

In this work, mesoporous spherical γ-AlOOH and γ-Al2O3 particles were rapidly prepared by spray pyrolysis (SP) at different temperatures (400°C–700°C) without the use of template materials. A sol-gel-derived colloidal solution boehmite was ultrasonicated to generate fine droplets, which continuously transferred into a quartz reactor heated specific temperature constant flow N2 gas. Under ultras...

This work presents a fast and direct controlled routine for the fabrication of fully dense alumina based on reactive spark plasma sintering (reactive-SPS) boehmite (γ-AlOOH) nano-powders obtained by sol–gel technique. The evolution transition aluminas during has been studied. Some powders were seeded with α-Al2O3 particles prior to gelation. Boehmite exhibited at 1070 °C, enhancing transformati...

The oxidation kinetics of 5 vol% nano-Ni dispersed Al2O3 with Si-doping (nano-Ni/Al2O3-Si) was studied in the present paper. The starting powder mixture was prepared by drying aqueous slurry consisting of alumina with nickel nitrate and Si (OCH3)4. The powder mixture was reduced at 600 C for 12 h in a stream of Ar-1%H2 gas mixture. Nano-Ni/Al2O3-Si was densified by pulsed electric current sinte...

Alumina nanofibers were prepared by a technique that combined the sol-gel and electrospinning methods. The solution to be electrospun was prepared by mixing aluminum isopropoxide (AIP) in ethanol, which was then refluxed in the presence of an acid catalyst and polyvinylpyrolidone (PVP) in ethanol. The characterization results showed that alumina nanofibers with diameters in the range of 102 to ...