Topo-chemical characterisation of dissolution processes of phosphate glasses

磷酸盐玻璃溶解过程的拓扑化学表征

• 批准号: 286173484
• 负责人: Professorin Dr. Delia Brauer
• 金额: --
• 依托单位: Department of Materials
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/286173484?language=en
• 关键词: Topo; chemical; characterisation; dissolution; processes

Phosphate glasses can dissolve in aqueous solutions, which is a great advantage for some applications (e.g. controlled release), but a pronounced drawback for others (e.g. laser glasses or optical filters). Tailoring and controlling glass dissolution has so far, based on our current knowledge, been achieved by phenomenological approaches only. An improved understanding of the dissolution mechanism may pave the way towards the structural design of optimised glasses of tailored solubility or improved chemical stability. Here, 31P solution nuclear magnetic resonance (NMR) spectroscopy will be used to characterise phosphate fragments formed during dissolution, either using in situ or ex situ approaches. This will give insight into network dissolution and fragmentation as well as hydrolysis occurring in solution. Modified topology-based calculations, which account for field strength, packing and medium-range (sterical) effects, have been used successfully to describe the mechanical properties of phosphate glasses. These structure-based models will be extended here to allow for precise quantitative prediction and optimisation of the dissolution process. The aim of this study is the combination of experimental investigations with topological and structure-chemical models. This will give insight into the mechanisms of phosphate glass dissolution and, subsequently, allow for the development of new strategies for controlling and tailoring glass solubility, through optimised glass compositions on the one hand and control of chemical parameters during dissolution on the other hand.

磷酸盐玻璃可以溶解在水溶液中，这对于某些应用（例如控释）是一个很大的优势，但对于其他应用（例如激光玻璃或滤光片）是一个明显的缺点。根据我们目前的知识，定制和控制玻璃溶解迄今为止仅通过唯象方法实现。对溶解机制的更好理解可以为定制溶解度或改善化学稳定性的优化玻璃的结构设计铺平道路。在这里，31P溶液核磁共振（NMR）光谱将被用来表征溶解过程中形成的磷酸盐片段，无论是使用原位或非原位方法。这将深入了解网络溶解和断裂以及溶液中发生的水解。修正的拓扑计算，占场强，包装和中程（空间）效应，已成功地用于描述磷酸盐玻璃的机械性能。这些基于结构的模型将在这里进行扩展，以允许精确的定量预测和优化的溶解过程。本研究的目的是结合拓扑和结构化学模型的实验研究。这将深入了解磷酸盐玻璃溶解的机制，并随后允许开发用于控制和定制玻璃溶解度的新策略，一方面通过优化玻璃组合物，另一方面通过控制溶解期间的化学参数。