Thermovaporous synthesis of fine crystalline gahnite (ZnAl2O4)

Solvothermal synthesis and characterization of nanosized zinc aluminate spinel used in iso-butane combustion

“…Single-phase ZnAl 2 O 4 was also confirmed with no impurities from any residual ZnO or Al 2 O 3 as observed through other methods, e.g. sol-gel [55] and thermovaporous [56] synthesis. The results of average crystallite size calculation through the Scherrer equation from the line-shape analysis of the (3 1 1) reflection at 2Â = 36.8 • , shows an exponentiallike growth relationship to the calcination temperature.…”

Atomic Scale Design of Spinel ZnAl2O4 Nanocrystal Synthesis

“…Several different hydrothermal synthesis approaches have been used to prepare ZnAl 2 O 4 including autoclave synthesis (ACS), ,, supercritical flow synthesis (SCFS), and microwave assisted synthesis (MWS). ,, A general disadvantage reported in the literature for all three methods is that impurities of AlOOH and ZnO are readily formed. ,, ACS requires relatively simple equipment but is limited by the temperature restrictions imposed by the safe operating parameters of the autoclave, slow heating rates, and low overall control. SCFS provides strong control of synthesis parameters such as temperature, pressure, and flow rate but is limited by short residence times in the reactor.…”

“…Several different hydrothermal synthesis approaches have been used to prepare ZnAl 2 O 4 including autoclave synthesis (ACS), 11,15,16 supercritical flow synthesis (SCFS), 2 and microwave assisted synthesis (MWS). 4,17,18 A general disadvantage reported in the literature for all three methods is that impurities of AlOOH and ZnO are readily formed.…”

Barium Titanate Synthesis in Water Vapor: From Mechanism to Ceramics Properties

“…Besides the properties of the final product, there are different factors to consider when choosing strategies for BaTiO 3 powder production, such as energy consumption, the availability and cost of the initial substances, the complexity of the equipment and its servicing, and the environmental impact of the process. In this regard, a method of complex oxide synthesis in a medium of water vapor, as previously reported for several compositions [35,36] including BaTiO 3 [37][38][39][40], appears attractive as it is performed with widely available simple oxides as starting compounds and requires fairly mild conditions for the reaction (a temperature below 350 • C and autogenous vapor pressure). Compared to a technically relative hydrothermal method, this one does not involve the use of aggressive media with hard-to-remove auxiliary substances (NaOH and KOH).…”