Nanoscopic structure of borosilicate glass with additives for nuclear waste vitrification
Nanoscopic structure of borosilicate glass with additives for nuclear waste vitrification
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DOI：
10.1016/j.jnoncrysol.2021.121352
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发表时间：
2021-12-20
影响因子：
3.5
通讯作者：
Heller, William T.
中科院分区：
文献类型：
--
作者：
Motokawa, Ryuhei;Kaneko, Koji;Heller, William T.
本文研究了硼硅酸盐玻璃作为高放废液（HLLW）的主体材料在添加剂Na 2 O和CaO/ZnO存在下的纳米结构。这些添加剂已被用于降低玻璃熔点，抑制宏观相分离，并增加玻璃的化学耐久性。小角中子散射被用来阐明添加剂对纳米结构的影响，沿着与宏观和原子尺度的观察，分别使用中子成像和X射线衍射。无Na 2 O的硼硅酸盐玻璃形成了尺寸约为100 nm的SiO2和B2 O3富集域的微相分离结构，并且该材料在长达毫米的长度尺度上是均匀的。随着Na 2 O添加量的增加，畴间距减小。引入CaO/ZnO添加剂诱导的玻璃中的不均匀性，如几个纳米大小的空隙结构，虽然抑制的不均匀性由Li 2 O的共同添加。这些结果为高放废液玻璃化基质玻璃的性能提供了依据。将高放废液掺入玻璃中可能会导致主体玻璃的纳米级结构发生类似于此处所揭示的变化。
We investigated the nanoscopic structure of bomsilicate glasses as a host for high-level radioactive liquid waste (HLLW) in the presence of the additives Na2O and CaO/ZnO with and without Li2O. These additives have been used to lower the glass melting point, suppress the macroscopic phase separation, and increase the chemical durability of glasses. Small-angle neutron scattering was used to elucidate the effect of the additives on the nanoscopic structure along with macro- and atomic-scale observations obtained using neutron imaging and X-ray diffraction, respectively. The borosilicate glass made without Na2O formed a microphase-separated structure of SiO2- and B2O3-rich domains approximately 100 nm in size, and the material was homogeneous at length scales up to millimeters. With the addition of increasing amounts of Na2O, the domain spacing decreased. Introducing CaO/ZnO additives induced inhomogeneities in the glass, such as void structures several nanometers in size, although the inhomogeneity was suppressed by the coaddition of Li2O. These results provide insights into the performance of host glasses for HLLW vitrification. Incorporating HLLW into glasses is likely to cause changes in the nanoscopic structure of host glasses similar to those revealed here.