水基溶胶-凝胶法制备稀土/碱土金属硅酸盐纳米粉  

Preparation of Rare Earth/Alkaline Earth Composite Silicates Nanopowder by Water-Based Sol-Gel Method

作　　者：李波[1] 张树人[1] 周晓华[1] 王升[1] 尧彬[1] 

机构地区：[1]电子科技大学微电子与固体电子学院,四川成都610054

出　　处：《中国稀土学报》2005年第2期166-170,共5页Journal of the Chinese Society of Rare Earths

摘　　要：采用水基溶胶凝胶法,以廉价的无机盐Y2O3,MgO为前驱物,Si(OC2H5)4为络合剂,PEG4000为复合表面活性剂,氨水调节pH值,并利用无水乙醇超声分散技术,成功制备了分散性良好的稀土碱土金属复合硅酸盐纳米粉xY2O3·yMgO·zSiO2(YMS),考察了初始溶液的pH值、温度及浓度对溶液—溶胶—凝胶转变的影响,并利用TG DTA,XRD,TEM分析手段对复合硅酸盐纳米粉YMS的性质进行了研究。实验表明,在60℃<T<90℃,pH≤3,V1∶V2=4∶1的条件下,能够在较短时间得到均匀透明的溶胶、凝胶,干凝胶经过650,750,850,950℃焙烧2h后得到的纳米粉平均粒度分别为25.9,40.2,51.8,67.9nm,且纳米粉在850℃附近从无定形态向结晶态转变,850℃以下为非晶态,粉体颗粒均匀呈球形且分散性好,高于850℃为Y4MgSi3O13六方晶相,颗粒间致密度提高,同时晶粒不断长大,并出现轻微软团聚。A novel water-based sol-gel method for preparation of rare earth/alkaline earth composite silicates nanopowder was introduced. The nanometer xY_2O_3·yMgO·zSiO_2 (YMS) powder was synthesized with low-cost MgCO_3 and Y_2O_3 as precursors, TEOS as complexing agent and PEG4000 as compound surfactant. In the processes, pH adjusting with NH_3·H_2O and ultrasonic dispersing with absolute ethyl alcohol were also employed. Effect of pH, concentration and temperature of the solution on the formation of sol-gel was investigated, and the characteristics of so acquired xerogel and powder were analyzed by TG-DTA, XRD and TEM. The results show that the uniform transparent sol-gel is achieved easily when 60 ℃<T<90 ℃, pH≤3, V_1∶V_2=4∶1. The composite silicates nanopowder obtained by calcining at 650, 750, 850, 950 ℃ for 2 h is well dispersive, and the average particle size is about 25.9, 40.2, 51.8, 67.9 nm respectively. The nanopowder remained amorphous below 850 ℃, and begins to crystallize around 850 ℃ with an hexagonal structure. Nanoparticles are agglomerated slightly with elevation of calcining temperature.

关 键 词：水基溶胶-凝胶法 碱土金属氧化物 复合硅酸盐纳米粉 稀土 

分 类 号：O614.33[理学—无机化学]