DSC-NMR多尺度实验方法在水合物研究中的应用

Application of DSC-NMR multi-scale experimental method in the study of hydrate

差式扫描量热仪(DSC)、核磁共振波谱仪(NMR)及其衍生的核磁共振成像技术(MRI)作为水合物不同尺度研究的重要手段,可用于水合物成核、生长、分解过程热流曲线的获取,结构信息识别及多相态表征,日益受到国内外学者的广泛关注。阐述了3种方法在水合物研究中的应用现状,介绍了DSC恒压变温和恒压恒温宏观实验方法在水合物热力学和动力学方面的研究进展,总结了MRI在水合物相变过程中微观可视化的研究成果,综述了NMR在水合物结构识别、混合气体水合物中客体分子组成、孔穴占有率及水合数等分子尺度信息获取的应用情况。针对3种方法的优劣和特点,提出了将DSC与NMR结合,进行水合物生成和分解过程多尺度系统研究的建议。

As the important technologies for studying hydrates in different scales, differential scanning calorimeter(DSC) and nuclear magnetic resonance(NMR) spectrometer and its derivative magnetic resonance imaging(MRI) technology can be used to plot the heat flow curve in the process of hydrate nucleation, growth and decomposition, identify the structural information and provide the multiphase state characterization. And they are widely concerned by domestic and foreign scholars. In this paper, the application status of these three methods in hydrate researches was described, and the research progress of DSC macroscopic experimental method under constant pressure & variable temperature and constant pressure & constant temperature in the aspects of hydrate thermodynamics and dynamics was introduced. Then, the study results on the microscopic visualization of MRI during the phase transition of hydrate were summarized, and the application situations of NMR to the structural identification of hydrate and the information acquisition of mixed gas hydrate in the molecular scale(e.g. guest molecular composition, cave occupancy and hydrate number) were overviewed. Finally, in view of the advantages, disadvantages and characteristics of three methods, it was proposed to combine DSC and NMR together to systematically research the generation and decomposition process of hydrate in multi-scale.