Study On Preparation And Mechanism Of ZrO₂ Nono-Powders

The classical mechanics and statistic thermodynamic equations in the process of nana-ZrO2 preparation were systemically derived in this study. The relations between interfacial tension and the content of mixture were established. The relations between the radius of deposited particles and chemical reaction conditions were mainly deduced, which laid the theoretic foundation for practical processes.Commercial pure ZrOCl2 8H2O with different contents used as raw material reacts with analytic pure NH3 H2O to produce prodromal body by means of titration method. The prepared prodromal body was calcined at different temperatures to obtain ZrO₂ powder. The optimized ZrOCl2 8H2O was used as raw material to fabricate ZrO2 powder in the same way by two processes of adding surface active agent PEG and n-butyl alcohol, respectively. Compared with the process without surface active agent PEG, the results were obtained as follow:The moving route for nano-paritcles in balance system is successfully deducedas using classic mechanics three dimensional model: R = Its validity remains to be proofed. The relationship between the interfacial tensionand the content of mixture is obtained as . This equation lays thetheoretic foundation to determine the content of surface-active agent. The relationship between radius of particle and reacting conditions is determined as. For the first time, the temperature limit is analyzed as. The method for adding surface-active agent by three stages is put forward.X-ray analyses show that ZrO2 powder is consisted of monoclinic phase and tetragonal phase. Most of them are monoclinic phase. Particle size of obtained ZrO2 powder is determined to be in the range of nanometer by means of calculating specific area and X-ray as well as SEM, which is in agreement with theoretical prediction. Under the experimental conditions used, particle sizes of Zr(OH)4 andZrO2 powders are decreased with increasing initial concentration of ZrOCl2-8H2O. Agglomeration for ZrC>2 becomes severe when initial concentration of ZrOCl2-8H2O is more than 1.5M due to no addition of surface-active agent PEG.. By adding surface-active agent PEG and drying with butanol, both agglomeration of ZrO2 particle and particles size are significantly decreased. Particle size of ZrC>2 powder is the smallest and the dispersibility of ZrC>2 powder is fine when 2.0% PEG is added under the experimental conditions used.