Jee Young Taek, Park Miran, Cho Seungryong, Yun Jong-Il
Department of Nuclear and Quantum Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
Sci Rep. 2019 Feb 4;9(1):1346. doi: 10.1038/s41598-018-38022-3.
This paper presents, for the first time, a study to analyze the surface morphology of metal extracted from a high temperature molten salt medium in the electrodeposit using x-ray radiography and computed tomography. Widely used methods such as scanning electron microscopy and inductively coupled plasma-optical emission spectrometry/mass spectrometry are destructive and the related processes are often subject to the air condition. The x-ray imaging can provide rich information of the target sample in a non-destructive way without invoking hydrolysis or oxidation of a hygroscopic sample. In this study, the x-ray imaging conditions were optimized as following: tube voltage at 100 kVp and the current exposure time product at 8.8 mAs in our in-house x-ray imaging system. LiCl-KCl and cerium metals used in this work produced substantially distinguishable contrasts in the radiography due to their distinctive attenuation characteristics, and this difference was well quantified in the histograms of brightness. Electrodeposits obtained by chronoamperometry and chronopotentiometry demonstrated a completely different behavior of electrodeposition even at the same applied charge. In particular, computed tomography and volumetric analysis clearly showed the structural and morphological dissimilarity. The structure of cerium metal in the electrodeposit was successfully separated from the chloride salt structure in the CT image by an image segmentation process.
本文首次展示了一项利用X射线成像技术和计算机断层扫描分析从高温熔盐介质中提取的金属在电沉积物中的表面形态的研究。扫描电子显微镜和电感耦合等离子体发射光谱法/质谱法等广泛使用的方法具有破坏性，且相关过程往往受空气条件影响。X射线成像可以以非破坏性的方式提供目标样品的丰富信息，而不会引发吸湿性样品的水解或氧化。在本研究中，X射线成像条件优化如下：在我们的内部X射线成像系统中，管电压为100 kVp，电流曝光时间乘积为8.8 mAs。本研究中使用的LiCl-KCl和铈金属由于其独特的衰减特性，在射线照相中产生了明显可区分的对比度，并且这种差异在亮度直方图中得到了很好的量化。计时电流法和计时电位法获得的电沉积物即使在相同的施加电荷下也表现出完全不同的电沉积行为。特别是，计算机断层扫描和体积分析清楚地显示了结构和形态上的差异。通过图像分割过程，成功地在CT图像中将电沉积物中铈金属的结构与氯化物盐结构分离。
