Influence of glass polymerisation and oxidation on micro-Raman water analysis in alumino-silicate glasses
Influence of glass polymerisation and oxidation on micro-Raman water analysis in alumino-silicate glasses
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玻璃聚合和氧化对铝硅酸盐玻璃中显微拉曼水分析的影响
DOI：
10.1016/j.gca.2008.09.030
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发表时间：
2009
影响因子：
5
通讯作者：
Gilles Montagnace
中科院分区：
文献类型：
--
作者：
Maxime Merciera;Andrea Di Muroab;Daniele Giordanoc;Nicole Métricha;Priscille Lesned;Michel Pichavantd;Bruno Scailletd;Roberto Clocchiattia;Gilles Montagnace
通过显微拉曼分析确定复杂铝硅酸盐玻璃中溶解水的准确分析方法的开发需要评估光谱拓扑结构对玻璃组合物的依赖性。本文详细研究了体相组成、铁氧化态和总水含量对天然玻璃中与玻璃网络振动（LF：490 cm − 1; HF：960 cm − 1）和总水伸缩（H2OT：3550 cm − 1）相关的主要拉曼谱带的绝对和相对强度的影响。在（i）33种由天然岩石样品再熔融产生的无水玻璃中检查了光谱拓扑结构的演变，这些玻璃跨越非常大的聚合度范围（NBO/T从0.00至1.16），（ii）2套具有可变铁氧化态的合成无水玄武玻璃（Fe 3 +/Fe T从0.05至0.87），和（iii）6组天然含水玻璃（[式：见正文]从0.4至7.0重量%），其中NBO/T从0.01至0.76变化。在水浓度的探索域中，基于H2OT带高度的外部校准程序是与基质无关的，但其准确性依赖于对样品上的聚焦深度和光束能量的精确控制。基质依赖性强烈地影响基于H_2O理论的LF或HF波段的内标度，但其影响从酸性（低NBO/T，SM）到碱性（高NBO/T，SM）玻璃减小。结构参数如NBO/T（每个四面体的非桥氧）和SM（结构修饰剂的总和）比简单的组成参数（例如SiO2，Na2O + K2O）更好地描述了基质依赖性。铁的氧化态对玄武岩中的能带拓扑结构只有很小的影响，因此预计不会显著影响镁铁质（例如低SiO2、富铁）玻璃中水的拉曼测定。对相对谱带高度随聚合度的演变进行建模，使我们能够提出一个通用方程来预测天然玻璃中的溶解水含量：其中[公式：见正文]是溶解在玻璃中的总水含量（以重量%计）; TOTN表示作为计算的NBO/T和SM参数的函数的计算的ILF/IHF变化;[公式：见正文]为H2O带高，比例为参比带的比例; k为H2OT带上的线性光谱仪响应，为含水量的函数。使用该公式以0.06wt%的标准偏差再现参比玻璃的水浓度。所采用的参数化提供了一个有用的工具，对表征的组成依赖的显微拉曼程序的硅酸盐玻璃。我们表明，基于迄今为止研究的最广泛的玻璃组合物，通过显微拉曼光谱实现了溶解水含量的准确评估。
The development of an accurate analytical procedure for determination of dissolved water in complex alumino-silicate glasses via micro-Raman analysis requires the assessment of the spectra topology dependence on glass composition. We report here a detailed study of the respective influence of bulk composition, iron oxidation state and total water content on the absolute and relative intensities of the main Raman bands related to glass network vibrations (LF: ∼490cm−1; HF: ∼960cm−1) and total water stretching (H2OT: ∼3550cm−1) in natural glasses. The evolution of spectra topology was examined in (i) 33 anhydrous glasses produced by the re-melting of natural rock samples, which span a very large range of polymerisation degree (NBO/T from 0.00 to 1.16), (ii) 2 sets of synthetic anhydrous basaltic glasses with variable iron oxidation state (Fe3+/FeTfrom 0.05 to 0.87), and (iii) 6 sets of natural hydrous glasses ( [Formula: see text] from 0.4 to 7.0wt%) with NBO/T varying from 0.01 to 0.76. In the explored domain of water concentration, external calibration procedure based on the H2OTband height is matrix-independent but its accuracy relies on precise control of the focusing depth and beam energy on the sample. Matrix-dependence strongly affects the internal calibrations based on H2OTheight scaled to that of LF or HF bands but its effect decreases from acid (low NBO/T, SM) to basic (high NBO/T, SM) glasses. Structural parameters such as NBO/T (non-bridging oxygen per tetrahedron) and SM (sum of structural modifiers) describe the matrix-dependence better than simple compositional parameters (e.g. SiO2, Na2O+K2O). Iron oxidation state has only a minor influence on band topology in basalts and is thus not expected to significantly affect the Raman determinations of water in mafic (e.g. low SiO2, iron-rich) glasses. Modelling the evolution of the relative band height with polymerisation degree allows us to propose a general equation to predict the dissolved water content in natural glasses:where [Formula: see text] is the total water content (in wt%) dissolved in glass; TOTNrepresents the computed ILF/IHFvariation as a function of the calculated NBO/T and SM parameters; [Formula: see text] is the H2O band height scaled to ratio of the reference bands; k is the linearity spectrometer response on the H2OTband in function of water content. The water concentrations of the reference glasses are reproduced using this equation with a standard deviation of 0.06wt%. The adopted parameterisation provides a useful tool towards the characterisation of composition dependence of micro-Raman procedures for silicate glasses. We show, based on the widest range of glass compositions so far investigated, that accurate evaluation of dissolved water content is achieved by micro-Raman spectroscopy.