Preparation of UO_2 fine particles from uranium alkoxide

UCl_4可作为制备铀醇盐的起始原料。以UO_2和CCl_4为原料制备UCl_4。采用了UO_2和CCl_4的三种反应方法。第一种方法是将UO_2粉末和CCl_4溶液装入PYREX胶囊中，在300 ℃左右加热。第二种方法是化学气相沉积法。将UO_2和CCl_4分别置于PYREX密闭管中。UO_2在550 ℃加热，在300-350 ℃范围内沉积出UCl_4单晶。第三种方法也是CDV方法。将UO_2置于开口的PYREX管中心，加热至620 ℃，使氩气从CCl_4溶液中鼓出，通过加热的UO_2粉末。用CVD法制备的UCl_4与Li或Na醇盐反应可制得U（IV）醇盐。以UCl_4和醇钠为原料，制备乙醇U（IV）的乙醇溶液，采用醇盐法制备了UO_2微粒。取90%乙醇-10%H_2O约100 μ l加入乙醇铀溶液中。乙醇铀（IV）水解成聚合氧化铀，最后得到氧化铀微粒，离心分离，红外线灯干燥。用扫描电子显微镜（SEM）测量了氧化铀颗粒的电子显微照片。结果表明，制备出了亚微米级单分散的氧化铀颗粒。

UCl_4 can be used as the starting materials for U (IV) alkoxide preparation. UCl_4 was prepared from UO_2 and CCl_4. The three reaction methods of UO_2 and CCl_4 were applied. The first one was as followed : UO_2 powder and CCl_4 solution were enclosed in a PYREX capsule, which was heated about at 300ﾟC.The second way was one of the Chemical Vapor Deposition(CVD) method. UO_2 and CCl_4 were placed in a PYREX closed tube separately. UO_2 was heated at 550ﾟC,and produced UCl_4 deposited at 300-350ﾟC region as a single crystal. The third way was also CDV method. UO_2 was placed at the center of open PYREX tube, and heated 620ﾟC.Argon gas which hed been bubbling through CCl_4 solution was passed through the heated UO_2 powder. The produced UCl_4 vapor deposited about 300ﾟC region as a single crystal.U (IV) alkoxide can be prepared by reaction with UCl_4 produced by CVD method and Li or Na alkoxide. U (IV) ethoxide in ethanol solution which was prepared from UCl_4 and Na alkoxide was used to make UO_2 fine particles by alkoxide method. About 100mul of 90% ethanol-10% H_2O was taken into the U (IV) ethoxide solution. U (IV) ethoxide was hydrolyzed to polymerized uranium oxide, and finally to fine particles of uranium oxide, that were separated from ethanol solution by centrifuge, and were dried by infra-red lamp. The electron micrographs of the uranium oxide particles were measured by scanning electron microscope (SEM). It is concluded by the micrographs that sub-micrometer mono dispersed uranium oxide particles had been prepared.