摘要
以氯化镧水溶液为原料,通过水解和热处理制备出纳米氧化镧粉体。研究了反应温度、反应物浓度、分散剂和煅烧温度对纳米氧化镧原始粒径、比表面积和团聚现象的影响。利用BET、TEM和XRD等技术对纳米氧化镧粉体进行表征。XRD、 DSC 和 TG表明,氢氧化镧在750℃下煅烧2小时,完全转化为纳米氧化镧;BET结果说明,当热处理温度超过800℃时,纳米氧化镧粒子快速增大,比表面积急剧下降。TEM显示,反应温度和反应浓度是影响纳米氧化镧的原始粒径的重要因素, 反应温度升高,平均原始粒径逐渐增大;反应浓度增加,平均原始粒径下降,团聚现象加剧。通过加入聚乙二醇可有效减轻纳米氧化镧的团聚现象。
The precursor of nanosized lanthanum oxide was prepared by the neutrality of lanthanum chloride solution. The effects of reaction temperature, reactant concentration, dispersant and calcining temperature on the primary particle size, specific surface area and agglomeration of nanosized lanthanum oxide were investigated. The powder of nanosized lanthanum oxide was characterized by XRD, TEM and BET. XRD, DSC and TG results indicate that phase transformation occurs at 608℃,and all lanthanum hydroxide transforms into lanthanum oxide when it is calcined at 750℃ for 2h. The BET results show that when the temperature of heat treatment is higher than 800℃, particle size grows and specific surface area drops quickly. TEM reveals that the reaction temperature and reactant concentration are important factors affecting the primary particle size. When the reaction temperature rises, the average primary particle size of nanosized lanthanum oxide enlarges gradually. It reduces and severe agglomeration of partides occurs while the reactant concentration increases. The addition of PEG can restrain the agglomeration of nanosized lanthanum oxide effectively.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2003年第6期685-688,共4页
Journal of Chemical Engineering of Chinese Universities
基金
江苏省"九五"科技攻关资助项目(BG 98010-1)。
关键词
纳米氧化镧
原始粒径
比表面积
团聚
nanosized lanthanum oxide
primary particle size
specific surface area
agglomeration
