多元纳米压敏陶瓷粉体的sol-gel合成与表征

Composite Nanometer Varistor Ceramic Powder Prepared by Sol-gel Method

为了避免单体纳米粉体的易团聚、难以分散混合均匀的缺点,为了避免化学共沉淀方法中微量添加剂易流失、成分难以精确控制的缺点,本文设计采用溶胶-凝胶方法制备多元纳米压敏陶瓷粉体材料。通过用溶胶-凝胶方法制备多元纳米压敏陶瓷粉体的研究和对多元纳米压敏陶瓷粉体的表征,得到以下主要结果:用金属醇盐和无机盐为原料,经过醇解和水解反应,形成溶胶,经过胶凝以及热分解制备多元纳米压敏陶瓷粉体的工艺技术路线是可行的。通过工艺控制可以得到粒子形状为近似球形,粒度分布范围窄,成分均匀分布、平均粒径为20 nm的多元纳米压敏陶瓷粉体。与传统方法制备的多元微米压敏陶瓷粉体相比较,多元纳米压敏陶瓷粉体的比表面积为334 m2/g,是多元微米压敏粉体比表面积的37.4倍。

Pure nanopowder is apt to conglobate and uneasy to mix evenly. In coprecipitation process, microdosage is apt to lose; therefore, the composition is uneasy to control accurately. To solve the problems, a composite nanopowder used as varistor ceramics was prepared by sol-gel method. The technology and its principle, and the physical properties of composite nanopowder are discussed. Sol is formed by alcoholysis and hydrolysis decomposition, with metal acetates and inorganic salt as raw material. Sol changes into gel in calcinations. Composite nanopowder is finally formed by heat decomposition. Of the obtained powder, the shape is close to sphere, particle size distribution narrow, ingredients distribution homogenous, and average size 20 nm. The specific surface area of nanopowder is 334 m2/g, 37.4 times of that of the conventional micrometer powder.