Sedimentation studies have been carried out to optimize the dispersion conditions of aqueous alumina nanopowder suspensions with or without dispersants (ammonium salt of polymethacrylic acid or rhamnolipids at 15%). Different dispersant dosages, solid loadings, pulp densities and pH values were examined. The iso-electric point (IEP) of the alumina nanopowder was found to be pHiep= 9.2. The expe...

Homogeneous distribution of mullite in the matrix of alumina can be obtained through sol-gel method. In this work, nanopowder of alumina-mullite composite was synthesized with high homogeneity and high purity. So aluminum chloride hexahydrate and tetraethyl orthosilicate were used instead of alumina or mullite nanopowder. Studying the simultaneouse thermal analysis (STA) of mullite precursor re...

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...

highly sinterable alumina nano-powders have been synthesized by a sol-gel combustion method with glycine asfuel. the preparation involved the thermal decomposition of a chelating agent (fuel)-nitrate gel and theformation of amorphous precursors. the nanopowders calcined at 1100°c were characterized by x-ray powderdiffraction (xrd) and scanning electron microscopy (sem). it was found that the ch...

Title of dissertation: HIGH ELASTIC MODULUS NANOPOWDER REINFORCED RESIN COMPOSITES FOR DENTAL APPLICATIONS Yijun Wang, Doctor of Philosophy, 2007 Dissertation directed by: Associate Professor Isabel K. Lloyd Department of Material Science and Engineering Dental restorations account for more than $3 billion dollars a year on the market. Among them, all-ceramic dental crowns draw more and more at...

Efficient nanopowder processing requires knowledge of the powder's mechanical properties. Due to the large surface area to volume ratio, nanoparticles experience relatively strong attractive interactions, leading to the formation of micron-size porous structures called agglomerates. Significant effort has been directed towards the development of models and experimental procedures to estimate th...

Si nanopowder is fabricated using the simple beads milling method. Fabricated Si nanopowder reacts with water in the neutral pH region between 7 and 9 to generate hydrogen. The hydrogen generation rate greatly increases with pH, while pH does not change after the hydrogen generation reaction. In the case of the reactions of Si nanopowder with strong alkaline solutions (eg pH13.9), 1600 mL hydro...