Kapoor Saurabh, Youngman Randall E, Zakharchuk Kiryl, Yaremchenko Aleksey, Smith Nicholas J, Goel Ashutosh
Department of Materials Science and Engineering , Rutgers, The State University of New Jersey , Piscataway , New Jersey 08854 , United States.
Science and Technology Division , Corning Incorporated , Painted Post , New York 14870 , United States.
J Phys Chem B. 2018 Dec 6;122(48):10913-10927. doi: 10.1021/acs.jpcb.8b06155. Epub 2018 Nov 26.
Despite an ongoing strenuous effort to understand the compositional and structural drivers controlling the chemical durability of oxide glasses, there is still no complete consensus on the basic mechanism of glass dissolution that applies to a wide composition space. One major reason for this problem is the structural complexity contained within the multicomponent silicate glasses chosen for glass corrosion studies. The nonsilicate network polyhedra present in these glasses interact with one another, often in unpredictable ways, by forming a variety of structural associations, for example, Al-B and B-B, resulting in significant influence on both the structure of the glass network and related macroscopic properties. Likewise, the formation of a variety of next-neighbor linkages, as well as increasingly complex interactions involving Si and differently coordinated next-nearest neighbor cations, is very difficult to decipher experimentally. Consideration of these factors motivates instead a different strategy: that is, the study of a sequence of SiO-free ternary or quaternary glass compositions, whose structures can be unambiguously determined and robustly linked to their corrosion properties. With this aim, the present study is focused on understanding the structural drivers governing the kinetics and mechanism of corrosion of ternary NaO-AlO-BO glasses (in water) over a broad composition space comprising compositions with distinct structural features. It has been shown that the addition of AlO to binary sodium borate glasses decreases their corrosion rate in water and converts their dissolution behavior from congruent to incongruent leading to the formation of six-coordinated alumina, and higher concentration of four-coordinated boron (in comparison to pre-dissolution glasses) in post-dissolution glass samples. The drivers controlling the corrosion kinetics and mechanism in these glasses based on their underlying structure have been elucidated. Some open questions have been proposed which require an extensive analysis of surface chemistry of pre- and post-dissolution samples and will be investigated in our future work.
尽管人们一直在努力深入了解控制氧化物玻璃化学耐久性的成分和结构驱动因素，但对于适用于广泛成分空间的玻璃溶解基本机制仍未达成完全共识。造成这一问题的一个主要原因是用于玻璃腐蚀研究的多组分硅酸盐玻璃中包含的结构复杂性。这些玻璃中存在的非硅酸盐网络多面体相互作用，通常以不可预测的方式形成各种结构关联，例如Al-B和B-B，这对玻璃网络结构和相关宏观性能都有重大影响。同样，形成各种近邻键，以及涉及Si和不同配位的次近邻阳离子的日益复杂的相互作用，很难通过实验来解读。考虑到这些因素，促使我们采用一种不同的策略：即研究一系列不含SiO的三元或四元玻璃成分，其结构可以明确确定并与它们的腐蚀性能紧密联系起来。出于这个目的，本研究的重点是了解在一个包含具有不同结构特征成分的广泛成分空间中，控制三元NaO-AlO-BO玻璃（在水中）腐蚀动力学和机制的结构驱动因素。研究表明，向二元硼酸钠玻璃中添加AlO会降低其在水中的腐蚀速率，并将其溶解行为从一致溶解转变为不一致溶解，导致形成六配位氧化铝，并且在溶解后玻璃样品中四配位硼的浓度更高（与溶解前的玻璃相比）。基于这些玻璃的底层结构，已经阐明了控制其腐蚀动力学和机制的驱动因素。提出了一些开放性问题，这些问题需要对溶解前和溶解后样品的表面化学进行广泛分析，并将在我们未来的工作中进行研究。
