Freezing and melting transitions in mesoporous solids: From fundamental understanding to advanced characterization using thermoporometry

本提案的主要目标是开发一个分析框架，该框架将允许对介孔固体中的固液平衡和相变进行可靠的解释，并将基于一个强大的介孔固体结构分析工具箱。为了实现这一目标，我们计划开展补充性的实验和理论工作。理论部分将主要基于最近开发的串联孔隙模型（SCPM），其中包括对密闭空间相变的最新理解。这个框架将被用来捕捉融化和冻结转变的具体特征。特别是，我们将进行特别的努力(i)利用Kossel-Stranski晶体生长模型来探索SPCM的适用条件，（ii）寻找求解反问题的策略，从实验转变曲线中推导出孔径分布（psd）。计划在各自的实验中验证理论结果。该项目实验部分的另一个重点将是实验确定用于热测量的几种选定液体的微观过渡核。这些核心将为评估psd提供基础。计划中的实验将使用模型孔隙系统进行，例如(i) MCM-41和SBA-15，用于编译过渡核，以及（ii）具有不同结构特性的随机孔隙玻璃，用于验证SCPM并开发新的结构分析策略

The main objective of this proposal is to develop an analytical framework which will allow a reliable interpretation of the solid-liquid equilibiria and phase transitions in mesoporous solids and will base a robust structural analysis toolbox for mesoporous solids using thermoporometry. To meet this objective, complementary experimental and theoretical works are planned. Theoretical part will majorly be based on the recently developed serially-connected pore model (SCPM), which includes recent advancements done in understanding of phase transition in confined spaces. This framework will be adopted to capture specific features of the melting and freezing transitions. In particular, special efforts will be undertaken (i) to explore the conditions of applicability of the SPCM by using the Kossel-Stranski crystal-growth model and (ii) to find the strategies for solving the inverse problem to derive the pore size distributions (PSDs) from the experimental transition curves. Theoretical findings are planned to be validated in the respective experiments. Another focus of the experimental part of the project will be the experimental determination of the microscopic transition kernels for several selected liquids used in thermoporometry. These kernels will provide a basis for the assessment of the PSDs. The experiments planned will be performed using model pore systems, such as (i) MCM-41 and SBA-15 for compiling the transition kernels, and (ii) random pore glasses with different structural properties for the validation of the SCPM and for developing of new strategies for structural analysis