Study On Preparation And Properties Of High-mobility, High-Solidity Zirconium Sol

Zirconium sol is a colloidal solution containing charged zirconium-containing fine particles uniformly dispersed in water.It can be used to prepare ZrO₂ films,ZrO₂ fibers,ZrO₂aerogels and ZrO₂ ceramic matrix composites.These ceramic materials have a wide range of applications in high temperature heat insulation,structural reinforcement,and chemical resistance.This article used three methods to prepare zirconium sol.The impregnation experiment was carried out by concentrating zirconium sol which preferably had a high solid content and low flowability.The mullite fiber mat was impregnated with the preferred zirconium sol in order to verify the impregnation performance of the zirconium sol and the effect of sintering densification.In this paper,zirconium sol was prepared by three methods.The effects of different process parameters and preparation conditions on the preparation of zirconium sol were studied.Zirconium oxychloride was used as a raw material,ammonia as a precipitant,ammonium chloride as a base liquid,and nitric acid as a peptizer to prepare zirconium sol.The results showed that zirconium sol was prepared with 0.3 mol/L NH₃·H₂O as precipitant and 0.05 mol/L NH₄Cl as the bottom liquid.When the peptizing temperature was 80°C and the peptizing time was 8 h,the sol was clear and stable.Adding 0.1wt%CTAB surfactant can reduce the viscosity and increase the stability of the sol.Zirconium sol was prepared from zirconium oxychloride as raw material,acetylacetone as complexing agent and ethylenediamine as precipitant.The results showed that when the ratio of zirconic ketone was1:1.3,the ratio of zirconium acid was 1:1,the reaction temperature was 60°C,and the reaction time was 6 hours,it was beneficial to prepare clear and stable sol.Adding 0.1wt%CTAB surfactant can reduce the viscosity and increase the stability of the sol.Zirconium sol was prepared from basic zirconium carbonate as a raw material and acetic acid as a complexing agent.The results showed that when the ratio of zirconium acid was 1:1.6,the reaction temperature was 60°C,and the reaction time was 6 h,it was beneficial to prepare clear and stable sol.Adding surfactants CTAB and PVA can increase the viscosity and stability of the sol.Through the comparison of the performances of the concentrated zirconium sol,the sol with higher solid content and higher yield were selected,and the properties of the concentrated sol were studied.The impregnation experiments with the preferred zirconium sol were performed to study the densification of the composites.The process and microstructure were analyzed.The results showed that the zirconium sol synthesized by sol-gel method with zirconium acetylacetonate as precursor had better solid content and yield than the others.When the concentration time was 10min,the sol viscosity was 10mPa·s,the solid content reached 40%,and the ceramic yield reached 20.4%.When the concentration time was 12 min,the sol was cross-linked,the stability was decreased,and the gel was easy to gel.The addition of 0.1wt%CTAB had a certain refining effect on the sol particles,which makes the sol particles more evenly distributed.The use of a preferred sol dip for the preparation of the composite material facilitates the homogenization of the interior of the composite material.