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 ...

there are no appreciable amounts of nickel resources in iran; therefore, secondary resources of this element are to be more considered in future. spent nickel catalysts that are used in various industrial processes are one of them. for example nickel catalyst that is used in hydrogenation of edible oil have large amounts of nickel and they are generally supported on porous materials like silica...

Monolithic ceramics have been fabricated from coated green fibers to create fibrous microstructures. The fibrous monoliths consist of high aspect ratio polycrystalline regions (cells) of a primary phase separated by thin secondphase regions (cell boundaries) designed to improve fracture resistance. The cells are the remnants of the green fiber which consists of ceramic powder and a polymer bind...

Thin alumina films have found applications in electronic circuits and cutting tools and have been recently explored as protective coatings against high temperature oxidation, but these studies have been relatively rare. In this study, amorphous alumina films 3.5 pm thick were produced by reactive sputtering on Co-30Cr-6Al-0.5Y coatings, using a pure aluminum target in Ar + 0 2 atmosphere. Isoth...

The paper reviews progress for a program of research on alumina ceramics processing, with particular reference to diffraction results achieved using tube x-rays, neutrons and synchrotron radiation. Outcomes from three related studies are examined. l Calcination of alumina hydrates to o-alumina via intermediate aluminas, including some new results indicating the co-existence of cubic and tetrago...

An efficient and green protocol for the synthesis of αaminonitriles derivatives by one-pot reaction of different aldehydes with amines and trimethylsilyl cyanides has been developed using natural alumina, alumina sulfuric acid (ASA), nano-γ-alumina, nanoalumina sulfuric acid (nano-ASA) under microwave irradiation and solvent-free conditions. The advantages of methods are short reaction times, h...

Interpenetrating Al O /Al composites were created by liquid metal infiltration of alumina structures with three-dimensional periodicity produced by a robotic deposition method. Volume-averaged lattice strains in the alumina phase were measured by synchrotron X-ray diffraction at various uniaxial compression stresses up to 200 MPa. Load transfer was observed to occur from the aluminum to the alu...

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...

BACKGROUND Numerous studies have reported that microgrooves on metal and polymer materials can affect cell adhesion, proliferation, differentiation and guidance. However, our knowledge of the cell activity associated with microgrooves on ceramics, such as alumina, zirconia, hydroxyapatite and etc, is very incomplete, owing to difficulties in the engraving of microgrooves on the hard surface of ...

Lanthanide (Ln3+) doping in alumina has shown great promise for stabilizing and promoting desirable phase formation to achieve optimized physical and chemical properties. However, doping alumina with Ln elements is generally accompanied by formation of new phases (i.e. LnAlO3, Ln2O3), and therefore inclusion of Ln-doping mechanisms for phase stabilization of the alumina lattice is indispensable...