Huang Xiaojun, Li Jiayan, Su Xiaoya, Fang Ke, Wang Zishuang, Liu Lin, Wang Honglong, Yang Chenguang, Wang Xiaoguang
School of Textile Science and Engineering, Wuhan Textile University Yangguang Road No. 1, Jiangxia District Wuhan 430200 Hubei China
School of Materials Science and Engineering, Wuhan Textile University Wuhan 430200 Hubei China.
RSC Adv. 2021 Jun 21;11(35):21870-21884. doi: 10.1039/d1ra04012j. eCollection 2021 Jun 15.
To reduce the polluted areas caused by the migration of radioactive or toxic matter, a clear understanding of soil matrix stability, especially the lattice, is essential under irradiation conditions like those of β-ray irradiation. In reality, the matrix of soil or clay is silicate, with talc being one of the most simple species with a similar structure to that matter, exhibiting "2 : 1" stacking and a complete crystal. Therefore, in this work, it was irradiated by an electron beam in air with dose up to 1000 kGy. Then, variations in lattice and the intrinsic microstructural transformation process, especially in terms of defect formation and transformation, were explored. The main results show that irradiation led to talc lattice plane shrinkage and amorphization. Shrinkage and amorphization levels in the -axis were more serious than those in the -axis. For a 1000 kGy-irradiated sample, the shrinkage level of the (002) lattice plane was close to 2% near 0.2 Å and that of (020) was close to 1.3% near 0.06 Å. Variation in the (002) lattice plane was more obvious than that of (020). The main mechanisms involve the cleavage of tetrahedral Si-O and linkage of tetrahedra and octahedra. Tetrahedral Si-O cleavage was visible, leading to serious amorphization. Nevertheless, lattice plane shrinkage, especially in the -axis, was mainly caused by linkage cleavage in this direction. In addition to linkage cleavage, dehydroxylation and HO volatilization occurred, coupled with HO radiolysis. Nevertheless, those factors are secondary to lattice variation.
为减少放射性或有毒物质迁移所造成的污染区域，在诸如β射线辐照等辐照条件下，清楚了解土壤基质稳定性，尤其是晶格稳定性至关重要。实际上，土壤或黏土的基质是硅酸盐，滑石是结构与之相似的最简单物质之一，呈现“2∶1”堆积且为完整晶体。因此，在本研究中，将滑石在空气中用电子束辐照，剂量高达1000千戈瑞。然后，探究了晶格变化以及内在微观结构转变过程，尤其是缺陷形成和转变方面。主要结果表明，辐照导致滑石晶格面收缩和非晶化。c轴方向的收缩和非晶化程度比a轴更严重。对于辐照剂量为1000千戈瑞的样品，（002）晶格面在0.2埃附近的收缩程度接近2%，（020）晶格面在0.06埃附近的收缩程度接近1.3%。（002）晶格面的变化比（020）更明显。主要机制包括四面体Si - O键的断裂以及四面体与八面体的连接。四面体Si - O键的断裂很明显，导致严重的非晶化。然而，晶格面收缩，尤其是在c轴方向，主要是由该方向的连接键断裂引起的。除连接键断裂外，还发生了脱羟基作用和羟基挥发，同时伴有羟基的辐射分解。不过，这些因素相对于晶格变化来说是次要的。
