As the α-phase ultrafine Al2O3 is a high performance material of far infrared emission, it is widely used to produce artificial ruby, sapphire, yttrium aluminum garnet and also used in the field of fiber fabric products and high pressure sodium lamp as far-infrared emission and thermal insulation materials.
Nanoparticles of zirconia (ZrO2) were in situ synthesized on the surface of carbon nanotubes by means of liquid phase reactions and a proper heat treatment process. The size of the nanoparticles could be controlled by the amount of zirconium source materials in a solution and its reaction times. In this study, the size of the nanoparticles ranged from several nanometers to twenty nanometers. It was particularly noted that the synthesized zirconia possessed a cubic structure (c-phase) which generally existed as a stable form of zirconia crystals at high temperatures (above 2370 °C) as well as a form of zirconia that could be used for enhancing the fracture toughness of alumina ceramics. Experimental results showed that the mechanical properties of alumina ceramics mixed with in situ synthesized nanoparticles on the surface of carbon nanotubes were much better than that of pristine nanotubes or zirconia nanoparticles alone. The existence of the nanoparticles on the surface of nanotubes results in improving the dispersion and bonding properties of the nanotubes in alumina matrix environment. The fracture toughness of CNT/ZrO2 alumina ceramics was also improved by the mechanism of bridging effect.
Taylor, Characterization of plasma-synthesized alumina, J.
and and and and (2008) Synthesis of zirconia nanoparticles on carbon nanotubes and their potential for enhancing the fracture toughness of alumina ceramics. Composites Part B: Engineering, 39 (7-8). pp. 1136-1141. ISSN 1359-8368
Chemical synthesis of aluminum nanoparticles - …
In addition, α-phase nano-Al2O3 with high resistivity and good insulation property, it is widely used as the main components for YGA laser crystal and integrated circuit substrates.
Alumina Nanoparticles Application:
Chemical synthesis of aluminum nanoparticles
Highly monodisperse sodium citrate-coated spherical silver nanoparticles (Ag NPs) with controlled sizes ranging from 10 to 200 nm have been synthesized by following a kinetically controlled seeded-growth approach via the reduction of silver nitrate by the combination of two chemical reducing agents: sodium citrate and tannic acid. The use of traces of tannic acid is fundamental in the synthesis of silver seeds, with an unprecedented (nanometric resolution) narrow size distribution that becomes even narrower, by size focusing, during the growth process. The homogeneous growth of Ag seeds is kinetically controlled by adjusting reaction parameters: concentrations of reducing agents, temperature, silver precursor to seed ratio, and pH. This method produces long-term stable aqueous colloidal dispersions of Ag NPs with narrow size distributions, relatively high concentrations (up to 6 × 1012 NPs/mL), and, more important, readily accessible surfaces. This was proved by studying the catalytic properties of as-synthesized Ag NPs using the reduction of Rhodamine B (RhB) by sodium borohydride as a model reaction system. As a result, we show the ability of citrate-stabilized Ag NPs to act as very efficient catalysts for the degradation of RhB while the coating with a polyvinylpyrrolidone (PVP) layer dramatically decreased the reaction rate.
pan alumina cups using TA instruments SDT Q 600
Desired polypyridine-derivatives were received by an aerobic oxidation at reaction temperatures of about 120–140 °C and residence times of about 10 min.