Alumina nanorods were prepared from chromium-containing alumina sludge, and the effects of doping elements, such as Cr, Fe, and Mg, were researched. The results show that the crystal transformation of alumina is restricted by the doped Cr and facilitated by the doped Fe and Mg, which is transformed from θ-Al2O3 to α-Al2O3 in the calcination process. Meanwhile, the crystal transformation of alum...

Mesoporous alumina catalysts that incorporate nickel (Ni-Alumina) with different Ni/Al molar ratios of 1:2, 1:5 and 1:10 were synthesized by a one-step sol–gel method using lauric acid as a template. The prepared Ni-Alumina catalysts showed a relatively high surface area with a narrow pore size distribution after calcination at 700 ◦C; these effects were independent of the Ni/Al molar ratio. Al...

The phase transformation of aluminum hydrates yields various forms of alumina (d, q, K) and eventually alpha-alumina. The decrease in the specific surface area of alumina upon heat treatment is due to changes in crystalline structure and hence a decrease in the porosity of the material, Although the conversion of gamma-alumina to alpha-structure takes place with a lowering in surface area and p...

mfi-type zeolite membranes (zsm-5) were prepared on α-alumina tubular supports and tested for separation of h2/co mixtures. the effect of pressure and temperature on h2 and co flows and selectivity was investigated. the best results in this work were obtained with a zsm-5 membrane prepared over a porous α-alumina tube seeded with zeolite nanocrystals synthesized with microwave technique. in thi...

Alumina nanopowders produced by electrical explosion of wires were sintered using the spark plasma sintering technique. The results of XRD analysis show that the main phase in the compacted nanopowders is α-Al2O3. According to the SEM observations, the sintered alumina nanopowder consists of micron-sized faceted grains and nano-sized necked grains. The increase in sintering temperature resulted...

The objective of this study was to clarify the effects of silane coupling agents and solutions of different polarity on polymethyl methacrylate (PMMA) bonding to alumina. Three silane coupling agents (3-methacryloxypropyltrimethoxysilane (MPS),3-aminopropyltriethoxysilane (APS) and N-2 (aminoethyl) 3-aminopropyltriethoxysilane) and 3 different polar solutions, 70% ethanol, isopropanol and tolue...

Neutron reflection and adsorption isotherm measurements have been used to study the adsorption behaviour of hexanoic acid onto α-alumina surfaces. Importantly, the pH dependence of the behaviour has been characterised with a pronounced maximum in adsorption identified at a pH of approximately 5, close to the pKa of the acid. The adsorbed layer is identified as a bilayer, which is reasonable giv...

Spray drying is widely used for producing granulated feed materials for compaction process, which is the current industrial method for manufacturing alumina-zirconia femoral heads. The optimization of the granules compaction behavior requires the control of the slurry rheology. Moreover, for a dual-phase ceramic suspension, the even phase distribution has to be kept through the atomization step...

Simple nanoporous alumina matrix modification procedure, in which the electrically highly insulating alumina barrier layer at the bottom of the pores is replaced with the conductive layer of the gold beds, was described. This modification makes possible the direct electron exchange between the underlying aluminum support and the redox species encapsulated in the alumina pores, thus, providing t...