静电纺丝法制备锆酸镧超细纤维

Preparation of lanthanum zirconate ultrafine fibers via electrospinning method

为了获得直径更加均匀、细小的锆酸镧纤维,以无水三氯化镧和八水氧氯化锆为原料,聚乙烯吡咯烷酮(PVP)为助纺剂,采用溶胶-凝胶法制备纺丝溶液,经静电纺丝技术制备出前驱体纤维,再分别经800、1 000以及1 200℃保温8 h煅烧后获得La_2Zr_2O_7超细纤维。利用DTA-TG、FTIR、XRD和SEM研究了锆酸镧纤维的形成过程。结果表明:1)未经煅烧的前驱体纤维粗细均匀,平均直径为400 nm;2)当煅烧温度为800℃时,开始形成萤石型锆酸镧纤维,纤维直径变细,平均直径为250 nm,纤维表面光滑;3)当煅烧温度为1 000℃时,纤维中残余有机基团消失,物相为烧绿石结构的锆酸镧,纤维表面开始变得不光滑,平均直径为180 nm;4)当煅烧温度提高到1 200℃时,锆酸镧纤维开始弯曲、粘连,表面更加粗糙。

This work aimed at obtaining uniform and fine lanthanum zirconate fibers. Anhydrous lanthanum chloride and zirconium oxychloride octahydrate were used as raw materials and polyvinylpyrrolidone （PVP） as the spinning aid, respectively. Spinning solution was prepared by the sol - gel method and the fi- ber precursor was obtained by electrospinning. Then the precursor was fired at different temperatures （800,1 000 and 1 200℃） soaking for 8 h to get ultrafine LazZr207 fibers. The formation process of lantha- num zirconate fibers was studied by DTA-TG,FTIR,XRD and SEM. The results show that the precursor fibers are uniform and their average diameter is 400 nm;when the calcination temperature is 800℃,the fluo-rite type lanthanum zirconate fibers with smooth surface form and their average diameter is 250 nm;when the calcination temperature increases to 1 000℃, the remnant organic groups in the fibers disappear, meanwhile the fibers are lanthanum zirconate of pyrochlore phase structure; the fiber surface becomes rough and their average diameter is 180 nm;as the calcination temperature increases to 1 200℃,the lanthanum zirconate fibers are bent,adhensive and their surface becomes rougher.