Revisiting water speciation in hydrous alumino-silicate glasses: A discrepancy between solid-state 1H NMR and NIR spectroscopy in the determination of X-OH and H2O
Revisiting water speciation in hydrous alumino-silicate glasses: A discrepancy between solid-state 1H NMR and NIR spectroscopy in the determination of X-OH and H2O
复制标题
重新审视水合铝硅酸盐玻璃中的水形态：固态 1H NMR 和 NIR 光谱在测定 X-OH 和 H2O 方面的差异
DOI：
10.1016/j.gca.2020.07.011
复制
发表时间：
2020
影响因子：
5
通讯作者：
Mysen, Bjorn O.
中科院分区：
文献类型：
--
作者：
Cody, George D.;Ackerson, Michael;Beaumont, Carolyn;Foustoukos, Dionysis;Le Losq, Charles;Mysen, Bjorn O.
本文重新研究了高温淬火后的水合铝硅酸盐玻璃（NaAlSi 3 O 8和“流纹岩”组成）中溶解水的形态，其主要形态为“X（Si和Al）-OH”和“H2O”。只有两种分析方法能够评估这种形态：近红外（NIR）光谱和固态1H核磁共振（NMR）光谱。据观察，表观水的形态，作为总水含量的函数，由近红外光谱测定是几乎相反的，从1H NMR数据揭示。氘（2 H）NMR和硅（29 Si）NMR报告的表观形态（解聚）趋势与1H NMR数据所示一致。与之前四次对含水NaAlSi 3 O 8玻璃的NMR研究相比，近红外数据总是报告4500（“X-OH”）和5200（“H2O”）cm− 1谱带强度随总水含量的明显系统变化，而含水NaAlSi 3 O 8的多次1H NMR研究报告OH/H2O的范围很宽。不同核磁共振研究之间的差异可能反映了不同玻璃制造方式的差异。具体而言，淬灭速率（快或慢）和合成压力（更高或更低）可能会对通过1H NMR观察到的玻璃中水的形态产生强烈影响。结论是，近红外光谱的应用，特别是使用4500（“X-OH”）和5200（“H2O”）cm− 1近红外波段的强度，不能准确评估含水铝硅酸盐玻璃中水的形态。近红外光谱仪仍然是一个非常有价值的分析工具，用于测定总水含量。
The speciation of water dissolved into and reacted with hydrous alumino-silicate glasses (of NaAlSi3O8and “rhyolitic” compositions) quenched from high temperature is re-investigated where the predominant species are expected to be “X(Si and Al)-OH” and “H2O”. Only, two analytical methods are capable of assessing such speciation: Near InfraRed (NIR) spectroscopy and solid-state1H Nuclear Magnetic Resonance (NMR) spectroscopy. It is observed that the apparent water speciation, as a function of total water content, as determined by NIR spectroscopy is nearly the opposite from what the1H NMR data reveal. Deuterium (2H) NMR and silicon (29Si) NMR report consistent trends in apparent speciation (depolymerization) with those indicated by the1H NMR data. Compared with four previous NMR studies of hydrous NaAlSi3O8glasses it is shown that whereas NIR data always report the same apparent systematic variation in the intensity of the 4500 (“X-OH”) and 5200 (“H2O”) cm−1bands with total water content, multiple1H NMR studies of hydrous NaAlSi3O8report a wide range in OH/H2O. The discrepancy between the various NMR studies likely reflects differences in how the various glasses were made. Specifically, quench rate (fast or slow) and synthesis pressure (higher or lower), might impose a strong effect on observed water speciation in glasses via1H NMR. It is concluded that the application of NIR spectroscopy, specifically the use of the intensities of the 4500 (“X-OH”) and 5200 (“H2O”) cm−1NIR bands, does not provide an accurate assessment of water speciation in hydrous alumino-silicate glasses. NIR spectroscopy does remain a very valuable analytical tool for determination of total water content.
登录
查看更多内容
上地幔压力和温度下合成的水合硅酸盐熔体的分子内 D-H 分配存在很大差异
影响因子：
3.1
作者：
Ying Wang;S. X. Cody;D. Foustoukos;B. Mysen;G. Cody
通讯作者：
G. Cody
影响因子：
3.9
作者：
Chertkova, Nadezda;Yamashita, Shigeru
通讯作者：
Yamashita, Shigeru
影响因子：
--
作者：
BOYD, FR;ENGLAND, JL
通讯作者：
ENGLAND, JL
钠长石玻璃中的水：OH 基团、孤立分子和簇
影响因子：
3.5
作者：
V. O. Zavelsky;N. Bezmen;V. Zharikov
通讯作者：
V. Zharikov
硅酸盐淬火熔体中氢同位素的分子内分馏
影响因子：
3.1
作者：
C. Losq;B. Mysen;G. Cody
通讯作者：
G. Cody