Abstract Potash lime silicate glasses were extensively used during the Middle Ages as components of stained glass windows. Their external faces have been subjected to alteration in the atmospheric medium for centuries, leading to the development of thick alteration layers on the surfaces. This alteration is mainly caused by water in liquid (rainfall) or gaseous (vapor) form. In order to implement geochemical models simulating the long-term behavior of these glasses by coupling the different atmospheric factors, it is necessary to study mechanisms and kinetics of alteration induced by these different hygroscopic situations (rainfall and relative humidity). The aim of this study is here to evaluate the impact of liquid water on stained glass windows and especially to determine alteration rate laws of dissolution and interdiffusion as a function of pH and temperature. For that, a medieval model glass was altered in aqueous solution in batch experiments at different pH values (from 2 to 11), temperatures (from 5 to 70 °C) and saturation states of the solution. From the elemental concentrations in solution, the release rate of elements was calculated and the pH- and T-dependencies were determined. The dissolution and interdiffusion rate laws can now be used to simulate the alteration of a medieval glass submitted to a rainfall event. Moreover, this study highlights that the Si-K-Ca medieval glass presents a very low pH-dependency at alkaline pH, which can be explained by its composition.

中文翻译：

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作为 pH 值和温度函数的中世纪钾钙硅酸盐玻璃的变化率：低 pH 依赖性溶解

摘要 钾钙硅酸盐玻璃在中世纪被广泛用作彩色玻璃窗的组成部分。几个世纪以来，它们的外表面一直在大气介质中发生变化，导致表面形成厚厚的变化层。这种变化主要是由液态（降雨）或气态（蒸气）形式的水引起的。为了通过耦合不同的大气因素来实现模拟这些玻璃长期行为的地球化学模型，有必要研究这些不同吸湿情况（降雨和相对湿度）引起的变化机制和动力学。本研究的目的是评估液态水对彩色玻璃窗的影响，尤其是确定溶解和相互扩散随 pH 值和温度变化的变化速率规律。为此，中世纪模型玻璃在不同 pH 值（从 2 到 11）、温度（从 5 到 70 °C）和溶液饱和状态的批量实验中在水溶液中进行了改变。根据溶液中的元素浓度，计算元素的释放速率并确定 pH 和 T 依赖性。溶解和相互扩散速率定律现在可用于模拟中世纪玻璃在降雨事件中的变化。此外，这项研究强调了 Si-K-Ca 中世纪玻璃在碱性 pH 下呈现出非常低的 pH 依赖性，这可以通过其成分来解释。