锆质溶胶的制备与性能表征

Preparation and properties characterization of zirconium sol

采用工业ZrOCl2·8H2O，结合非均匀沉淀法及水热法制备了锆溶胶。系统分析了不同浓度的前躯体溶液、pH值以及缓冲溶液等因素对制备的锆溶胶粒径、稳定性的影响。通过非均匀沉淀法，在室温条件下，缓慢将氨水与氧氯化锆溶液滴加至缓冲溶液中，制得前驱体沉淀，经抽滤洗涤后用硝酸重新分散滤饼，于75℃水浴加热5～12h，制得澄清透明状纳米级锆质溶胶。结果表明，溶胶中粒子呈伞状、柱状，且分散均匀。溶胶粒子大小为12—15nm。在pH值为0．8—1．4条件下，溶胶能长期稳定存在。干燥后的锆质凝胶以非晶态形式存在，且非晶态凝胶在450℃左右转变为四方相ZrO2。经1100℃热处理，保温1h转变为单斜相ZrO2。

Zirconium sol were prepared by using precipitation and hydrothermal method with industrial ZrOCl2. 8H2O. The influence of different concentration of precursor solution, value of pH and buffer solution and other factors on stability and size of zirconium sol were investigated and analyzed. By the various kinds of measurement techniques, determined a whole rational program of preparing zirconium sol, using the non-homogeneous precipitation method,while the ammonia was slowly driped to the buffer solution as precipitator. After suction filtration and rinse, defined quantity of electrolyte was added to redistribute the filter mass,heat the miscible liquids at 75 ℃ with 5 - 12 h,the uniform and stable nano-scale zirconium sol was generated. Via the TEM, nanoparticle size analyzer, TG-DSC graph and XRD of the study on the products, the results showed that the particle of the sol was appeared at columnar and umbellar. The size is about 12 to 15 nm. The zirconium sol was separated and existed stability at the range of pH value from 0.8 to 1.4. Heating the sample, the indefinite form gel powder could be transformed to t-ZrO2 at 450℃. At the process of 1 100 ℃ and continue 1 h,the gel powder could be transformed to m-ZrO2.