Stabilization of mesoporous nanocrystalline zirconia with Laponite

The mesoporous nanocrystalline zircoina was synthesized via solid state reaction-structure directing method in the presence of Laponite. The introduction of Laponite renders the higher thermal stability and lamellar track to the zirconia. Laponite acts as inhibitor for crystal growth and also hard template for the mesostructure. The role of Laponite is attributed to the interaction between the zirconia precursors and the nano-platelets of Laponite via the bridge of hydrophilic segments of surfactant. It results in the formation of Zr-O-Mg-O-Si frameworks in the direction of Laponite layer with the condensation of frameworks during the calcination process, which contributes the higher stability and lamellar structure to the nano-sized zirconia samples

New Approach for the Removal of Metal Ions from Water: Adsorption onto Aquatic Plants and Microwave Reaction for the Fabrication of Nanometals

We adsorb heavy metal ions such as Ag + , Pb 2+ , and Ru 3+ onto an aquatic plant and convert the adsorbed ions to the corresponding nanometallic particles by the polyol reaction carried out in a microwave oven

Materials synthesis and characterization of 8YSZ nano materials for the fabrication of electrolyte membranes for solid oxide fuel cells

Two different nanosized materials were synthesized by two preparation methods, namely a sonochemical technique and a spray pyrolysis process. The powder properties, the sintering behavior and the resulting crystallinity with respect to their utilisation for solid oxide fuel cell electrolytes were investigated. While the spray pyrolysis provides crystallized powder without any organic residue, the sonochemical powder is amorphous with some organic residue. Crystallization begins in the 400-500 degreesC temperature domain. The particle sizes vary between 10 and 50 nm for the sonochemical powder and between 50 nm and 1 mum for the spray pyrolysis powder, as determined by SEM analyses. Crystal growth of both powders starts between 800 and 1000 degreesC. After heating and sintering at 1300 degreesC the resulting grain sizes of the spray pyrolysis powder are 5 times larger than those of the sonochemical powder (about 250 nm and 1.2 mum, respectively). Additionally, the maximum rate of grain growth for the spray-pyrolysed material at 97 nm/h is even higher compared with 22 nm/h for the sonochemical powder. (C) 2003 Elsevier Ltd and Techna S.r.l. All rights reserved

The sonochemical preparation of a mesoporous NiO/yttria stabilized zirconia composite

A sonochemical process for the fabrication of the mesoporous composite NiO/yttria stabilized zirconia (YSZ) is described. Its surface area after the extraction of the surfactant is 193 m(2)/g for a sample containing 40 atom-% Ni. The main advantages of the sonochemical method, as compared with previous works, are the short reaction time (6 h) and that there is no requirement for the glycolation of the nickel, yttrium, and zirconium ions. The reduction of NiO/YSZ to the corresponding Ni/YSZ is also reported. (C) 2003 Elsevier Science Inc. All rights reserved