Technical development of characterization methods provides insights into clay mineral-water interactions: A comprehensive review

摘要

Clay mineral-water interactions are ubiquitous, and crucial to a variety of natural processes including all aspects of geology, sedimentology, edaphology, geomorphology, seismology, geophysics, astrobiology, geotechnical engineering, petroleum engineering, materials science, environmental science, water science, and atmospheric science. For example, the geological ultrafiltration of clay minerals results in the enrichment or depletion of solutes and isotope fractionation in mudstones, shales, and marine sediments. The hydration/dehydration of clay minerals influences partitions of water between clay and the environment. In Earth science, this partition is significant for the water cycle in the Earth?s interior. In recent decades, clay mineral-water interactions have been extensively investigated. This article provides a comprehensive overview of clay mineral-water interactions from the perspective of the technical evolution of characterization methods. A comprehensive survey of numerous literature demonstrates that our insights into the clay mineral-water interactions accumulate and deepen with the development of characterization methods, from ex situ to in situ methods (e.g., X-ray diffraction (XRD)), theory (e.g., small-angle X-ray scattering (SAXS), infrared spectroscopy (IR), nuclear magnetic resonance (NMR), and neutron scattering (NS)) to visualization (e.g., cryogenic-scanning/transmission electron microscopy (cryo-SEM/TEM,) atomic force microscopy (AFM), and transmission X-ray tomography (TXM)), and macroscopic scale (e.g., swelling/collapse) to mesoscopic scale (e.g., assembly of platelets and particles) and then to microscopic/atomic scale (e.g., atomic and platelet interactions). The information of various techniques (XRD, SAXS, AFM, TXM, spectroscopies, NS, computation, and simulation) that can obtain on clay mineral-water interactions are summarized. The advantages and disadvantages of various techniques are compared. This review may help readers gain insight into clay mineral-water interactions, and select suitable characterization methods to obtain target information.