In order to understand the beneficial effect of Pt on the adherence of thermally grown alumina scales, sessile drop experiments were performed to study the wetting of poly-crystalline alumina by nickel-aluminum alloys with or without platinum addition where the amount of Pt ranged from 2.4 to 10 at.%. Subsequent interfacial structure was evaluated using atomic force microscopy. Platinum additio...

The effects of (+ )-catechin adsorption to the alumina surface were studied by -potential and surface free energy determination. The presence of catechin causes essential changes in the alumina -potential, which at the concentration slightly higher than 10 M reverses from the positive into negative one. At constant concentration of catechin (10 M), the effect on -potential of alumina as a funct...

This paper presents a part of our work on understanding the effect of nanoscale pore space confinement on ion sorption by mesoporous materials. Acid-base titration experiments were performed on both mesoporous alumina and alumina particles under various ionic strengths. The point of zero charge (PZC) for mesoporous alumina was measured to be approximately 9.1, similar to that for nonmesoporous ...

The synthesis of materials with tailored properties is one of the most active areas of material science [1, 2]. Among so many materials, γ-alumina due to the significant application in catalysis, electronic and ceramic industry has been studied extensively [3]. Various processes have been employed for the preparation of high quality alumina, including sol-gel processing from aluminum alkoxides....

Niobia/alumina model catalysts were prepared by physical vapor deposition of Nb in an oxygen atmosphere onto thin alumina films. Structural characterization, performed with scanning tunneling microscopy and infrared reflection absorption spectroscopy, revealed highly dispersed N2O5 nanoparticles exposing Nb=O groups. Thermal stability of the system was also examined. The results are compared wi...

Cracks free mullite-alumina Functionally Gradient Ceramics (FGC) have been obtained by sequential slip casting of Mullite-alumina slurries with diserent mullite/alumina ratios. These slurries were prepared with 65 % solids content and viscosities rangingpom 10 to 40 mPa.s. 7he presence of cracks perpendicular to the FGC layers have been attributed to residual stresses developed because of the m...

Co-synthesis of In2O3 and ZnO nanowires (NWs) were grown on silicon and alumina substrates using vapour transport deposition method. Their morphological structures showed that the NWs were rather aligned on silicon substrate and randomly oriented on alumina substrate. The formation of NWs on silicon substrate was found to be dominated by the growth of ZnO NWs while that on alumina substrate was...

The dispersion and coordination of aluminium species on the surface of silica-alumina based materials are essential for controlling their catalytic activity and selectivity. Al and Al are two common coordinations of Al species in the silica network and alumina phase, respectively. Al is rare in nature and was found hitherto only in the alumina phase or interfaces containing alumina, a behavior ...

BACKGROUND AND PURPOSE Excessive wear of acetabular liners in hip replacements may lead to osteolysis and cup loosening. Different head materials are currently used. We measured differences in wear between alumina and cobalt-chrome heads with the same polyethylene liner. PATIENTS AND METHODS 39 patients (43 hips) with osteoarthritis were included in a study with 10-year follow-up. Wear was me...

Selecting a proper support in the catalyst system plays an important role in hydrogen production via ethanol steam reforming. In this study, sol gel made alumina supports prepared for nickel (Ni) catalysts were calcined at different temperatures. A series of (Ni/AlS.G.) catalysts were synthesized by an impregnation procedure. The influence of varying the calcination temperature of the sol gel m...