Download or read book Multiscale Experimental and Numerical Study of the Structure and the Dynamics of Water Confined in Clay Minerals written by Emmanuel Guillaud and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clay are complex minerals with a multiscale porosity and a remarkable ability to swell under humid atmosphere. These materials have many applications in catalysis, waste management, construction industry... However, the properties of confined water are still not fully understood, due in particular to the complexity of water itself. The aim of this work is, using mainly molecular simulations and vibrational spectroscopy, to understand the structure and the dynamics of water confined in clay minerals. To evaluate the accuracy of numerical models to describe water confined in clay minerals, and to understand the origin of its structural and dynamical properties, a large part of the work was devoted to the building blocks of clays: pure bulk water, water at the surface of a solid, and salt water. To this extent, the viscoelastic properties of water from the deeply supercooled regime to the boiling temperature were investigated using classical molecular dynamics. The evolution of the friction properties of water on a prototypical solid surface was also analyzed, and the accuracy of ab initio approaches and empirical salt models was studied.In a second part, those results were confronted to the properties of water confined in clay minerals at low and room temperature, studied both experimentally and numerically. Experimental work consisted mostly in extensive far- and -mid infrared absorption spectrometry measurements, whereas numerical work mainly consisted in empirical molecular dynamics simulations. Especially, the existence of confinement- or temperature-induced phase transitions of confined water was investigated.

Download or read book Relations Between the Behavior of Clay Minerals with Respect to Water and the Physical Properties of Cohesive Soils written by Waterways Experiment Station (U.S.) and published by . This book was released on 1942 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Molecular Modeling of Clays and Mineral Surfaces written by James David Kubicki and published by . This book was released on 2003 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Low temperature Phases of Interfacial Water in Clay water Systems written by Duwayne Marlo Anderson and published by . This book was released on 1970 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low temperature differential thermal analyses of selected clay-water systems were made to locate important phase change temperatures and to define fruitful temperature-pressure fields for precise calorimetric investigation. In addition to an exotherm corresponding to initial freezing, one, two or three exotherms were observed between -35C and -60C. The low temperature exotherms do not depend critically upon water content, but clearly they are related to clay mineral and exchangeable cation type. The evolution of heat in this temperature range probably corresponds to a phase change in the interfacial water. (Author).

Download or read book Clay water Interface and Its Rheological Implications written by Necip Güven and published by . This book was released on 1992 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multiscale Modeling of Clay water Systems written by Davoud Ebrahimi and published by . This book was released on 2014 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: The engineering properties of soils are highly affected by clay content and clay-water interactions. However, existing macro-scale continuum models have no length scale to describe the evolution of the clay microstructure and its role in affecting macroscopic properties. This research proposes a bottom-up multiscale modeling approach to understand the physics underlying macroscopic clay behavior. Atomistic models are developed to understand clay-water interactions using the ClayFF force field. We simulate water adsorption between clay layers for a reference mineral, Wyoming montmorillonite (Na-smectite) using molecular dynamics simulations. The elastic properties of the system are found to vary with the hydration state (amount of interlayer water) and can be well-approximated using cross-anisotropic symmetries. The simulated adsorption isotherm and stiffness are compared with available experimental measurements. We develop a perturbation approach to investigate the free energy associated with relative positions of two clay platelets in water. The free energy functions for edge-edge and faceface particle associations are used to calibrate the Gay-Berne (GB) potential that represents each platelet as a single-site ellipsoidal body. A coarse-graining upscaling approach then uses the GB potentials and molecular dynamics to represent the meso-scale aggregation of clay platelets (at submicron length scale). Results from meso-scale simulations obtain the equilibrium/ jamming configurations for mono-disperse clay platelets. The results show aggregation for a range of clay platelets dimensions and pressures with mean stack size ranging from 3-8 platelets. The particle assemblies become more ordered and exhibit more pronounced elastic anisotropy at higher confining pressures. The results are in good agreement with previously measured nanoindentation moduli over a wide range of clay packing densities. The current research represents an important step forward towards multiscale modeling of soils and can be used to study any system composed of platy constituents.

Download or read book Dynamics of Water in the Interlayer Spaces of Expanding Lattice Clay Minerals written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Surface and Interface Chemistry of Clay Minerals written by Robert Schoonheydt and published by Elsevier. This book was released on 2018-11-08 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface and Interface Chemistry of Clay Minerals, Volume 9, delivers a fundamental understanding of the surface and interface chemistry of clay minerals, thus serving as a valuable resource for researchers active in the fields of materials chemistry and sustainable chemistry. Clay minerals, with surfaces ranging from hydrophilic, to hydrophobic, are widely studied and used as adsorbents. Adsorption can occur at the edges and surfaces of clay mineral layers and particles, and in the interlayer region. This diversity in properties and the possibility to tune the surface properties of clay minerals to match the properties of adsorbed molecules is the basis for study. This book requires a fundamental understanding of the surface and interface chemistry of clay minerals, and of the interaction between adsorbate and adsorbent. It is an essential resource for clay scientists, geologists, chemists, physicists, material scientists, researchers, and students.

Download or read book The Clay water System written by Erik Forslind and published by . This book was released on 1948 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Chemistry of Clay Minerals written by Charles Edward Weaver and published by . This book was released on 1975 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Molecular Dynamics Simulation of Crystalline Swelling and Failure Properties of Montmorillonite Clay written by Babak Abbasi and published by . This book was released on 2017 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clay minerals play considerable importance in geotechnical, agricultural, and pharmaceutical applications. They are made of plate-like particles with micrometer dimensions and play a critical role in problems involving swelling, deformation, and failure in geomaterials. Understanding of these phenomena and the parameters that influence them requires studies at the nanoscale.

Download or read book Molecular Dynamics of Interfacial Water and Cations Associated with Clay Minerals written by and published by . This book was released on 2012 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microscopic and Spectroscopic Methods for Probing the Clay Water Interface written by Christopher Adam Heist and published by . This book was released on 2010 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new method of studying the swelling dynamics of clay minerals was developed using in situ atomic force microscopy (AFM). The preliminary results presented here demonstrate that this technique allows one to study individual clay mineral unit layers, explore the natural heterogeneities of samples, and monitor swelling dynamics of clay minerals in real time. Cation exchange experiments were conducted monitoring the swelling change of individual nontronite quasi-crystals as the chemical composition of the surrounding environment was manipulated several times. A proof of concept study has shown that the changes in swelling are from the exchange of interlayer cations and not from the mechanical force of replacing the solution in the fluid cell. A series of attenuated total internal reflection Fourier transform infrared spectroscopy (ATR-FTIR) experiments were performed to gain a better understanding of the organization of water within the interlayer region of two Fe-bearing clay minerals.

Download or read book A Study of Diffusion in Clay water Systems by Chemical and Electrical Methods written by John T. Turk and published by . This book was released on 1976 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Clay Water Interactions an Experimental Study of Interface Phenomena written by Erik Forslind and published by . This book was released on 1970 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: The structural properties of water adsorbed on hydrophilic intercrystalline clay mineral surfaces have been investigated by way of NMR and dielectric measuring techniques. It is shown that structural ordering of the adsorbed water layers occurs, that the adsorption takes place independent at the exchangeable cations present in the intercrystalline spaces and that these ions only modify the structural and relaxation properties of the water. The conventional hypotheses regarding the origin of the hydrophilic clay properties are shown to be untenable. (Author).

Download or read book Molecular Dynamics Simulation of Interactions Between Clay Minerals and a Controlled Organic Phase written by Qian Zhao and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Engineered organoclays are 2:1 phyllosilicate soils that have been synthesized with a controlled interlayer organic phase to exhibit enhanced strength, lower compressibility, and stronger retention of organic compounds. Engineered organoclays are highly sorptive, and have a variety of potential engineering applications as sorbents or amendments in engineered earthen barrier systems. Previous studies examined the impact of the organic coating on a soil's physical properties; however, the geochemical behaviors of organoclays, especially their interaction with organic compounds at the micro-scale, remained relatively unquantified. This study investigated the engineering behavior of montmorillonite modified with a variety of quaternary ammonium cations (QAC clays) with controlled structure and density of loading. Molecular dynamics simulations were used to model the surfactant arrangement, geochemical processes in the QAC-clay interlayer, including organic compound sorption and mass transport, as well as the surface electrokinetics of suspended QAC-clay particles. All simulations were carried out based on the combined force field of ClayFF and the Consistent-Valence Force Field to ensure the accuracy of the simulation results, and results yielded insight into the prediction of synthesized QAC-clay behaviors as sorptive material for non-polar organic compounds.

Download or read book Experimental and Numerical Modelling of a Multiple Oscillating Water Column Structure written by Thomas Kelly and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: