Industrial precipitation of zirconyl chloride: The effect of pH and solution concentration on calcination of zirconia

Abstract

In situ and ex situ x-ray diffraction, and transmission electron microscopy were used to investigate the calcination of four samples of zirconia manufactured using two different zirconia reactant solution concentrations (0.81 and 1.62 M) with precipitation carried out at pH 3 and 12. The calcinations were investigated over the temperature range from room temperature to 1000 ºC. It was found that varying the precipitation conditions resulted in differing calcination routes; it is believed that variations in particle size and initial degree of hydration are responsible for these differences. It was also found that the initial phase produced after calcination was tetragonal zirconia, which underwent a process of crystallite growth to a size of ~30 nm before transformation from tetragonal to monoclinic.

Combined SANS and SAXS study of the action of ultrasound on the structure of amorphous zirconia gels

“…The effect of pH on hydrous zirconia properties is also extensively discussed elsewhere [66][67][68].…”

Steroid/mucokinetic hybrid nanoporous microparticles for pulmonary drug delivery

“…Microparticles made only from budesonide and ambroxol-HCl had 36 smooth surfaces. In the presence of ammonium carbonate ((NH 4 ) 2 CO 3 ), NPMPs were formulated, with 37 significantly (P < 0.05) superior aerodynamic properties (MMAD = 1.87 ± 0.22 lm and FPF = 84.0 ± 38 2.6%). The formation of nanopores and the increase in the specific surface area in the presence of (NH 4 ) 2-39 CO 3 were mainly attributed to the neutralisation of ambroxol-HCl to form ambroxol base.…”

Application of Zirconia in Dentistry: Biological, Mechanical and Optical Considerations

“…Carter et al, 2009), sol-gel (Diaz-Parralejo et al, 2001Heshmatpour & Aghakhanpour, 2011), hydrothermal synthesis also supported by microwave radiation Kanade et al, 2008). The hydrothermal method (hydrolysis) to produce ZrO 2 -based nanocrystalline powders was first used in 1990.…”