Low‐temperature synthesis of uranium monocarbide by a Pechini‐type in situ polymerizable complex method |
| |
| Authors: | Hangxu Guo Jieru Wang Jing Bai Shiwei Cao Denglei Chen Yalou Sun Xiaojie Yin Wei Tian Cunmin Tan Qing Huang Zhi Qin Qihuang Deng |
| |
| Affiliation: | 1. Laboratory of Transmutation Chemistry, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China;2. School of Physical Science and Technology, University of Chinese Academy of Sciences, Beijing, China;3. School of Nuclear Science and Technology, Lanzhou University, Lanzhou, China;4. Engineering Laboratory of Specialty Fibers and Nuclear Energy Materials, Ningbo Institute of Materials Engineering and Technology, Chinese Academy of Sciences, Ningbo, China;5. College of Mechanical and Electrical Engineering, Yangtze Normal University, Chongqing, China |
| |
| Abstract: | Uranium monocarbide (UC) was successfully synthesized by the Pechini‐type in situ polymerizable complex technique (IPC) with the organic matter as the only carbon source. In the aqueous process, a mixture of citric acid (CA) and mannitol with  was polymerized to form a spongy‐like organic polymeric precursor without any precipitations. The structural evolution and formation mechanism of the precursor were investigated using XRD, DSC‐TG, SEM (EDX), TEM, and FT‐IR. XRD results demonstrated that UC was obtained with the  /mannitol/CA molar ratios of 1.0/0.3/1.0 at a low temperature of 1400°C. SEM and TEM analyses revealed that the UO2 nanoparticles were uniformly distributed in the carbon matrix to form UO2/C nanocomposites, and submicrometer‐sized ellipsoidal UC particles cemented together. FT‐IR showed that a  ‐CA chelated structure was firstly obtained, achieving the molecular scale mixing of uranium and C. Then the in situ charring guaranteed the intimate contact of UO2 and C, leading to a low reaction temperature in carbothermal reduction owing to a short diffusion distance. |
| |
| Keywords: | chelation in situ charring Pechini‐type in situ polymerizable complex method polyesterification uranium monocarbide |
|
|
was polymerized to form a spongy‐like organic polymeric precursor without any precipitations. The structural evolution and formation mechanism of the precursor were investigated using XRD, DSC‐TG, SEM (EDX), TEM, and FT‐IR. XRD results demonstrated that UC was obtained with the 
/mannitol/CA molar ratios of 1.0/0.3/1.0 at a low temperature of 1400°C. SEM and TEM analyses revealed that the UO2 nanoparticles were uniformly distributed in the carbon matrix to form UO2/C nanocomposites, and submicrometer‐sized ellipsoidal UC particles cemented together. FT‐IR showed that a 
‐CA chelated structure was firstly obtained, achieving the molecular scale mixing of uranium and C. Then the in situ charring guaranteed the intimate contact of UO2 and C, leading to a low reaction temperature in carbothermal reduction owing to a short diffusion distance.