Download or read book Modelling the Behaviour of Dense Colloidal Suspensions of Cuboids written by Luca Tonti and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Suspensions of Colloidal Particles and Aggregates written by Frank Babick and published by Springer. This book was released on 2016-04-04 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses the properties of particles in colloidal suspensions. It has a focus on particle aggregates and the dependency of their physical behaviour on morphological parameters. For this purpose, relevant theories and methodological tools are reviewed and applied to selected examples. The book is divided into four main chapters. The first of them introduces important measurement techniques for the determination of particle size and interfacial properties in colloidal suspensions. A further chapter is devoted to the physico-chemical properties of colloidal particles—highlighting the interfacial phenomena and the corresponding interactions between particles. The book’s central chapter examines the structure-property relations of colloidal aggregates. This comprises concepts to quantify size and structure of aggregates, models and numerical tools for calculating the (light) scattering and hydrodynamic properties of aggregates, and a discussion on van-der-Waals and double layer interactions between aggregates. It is illustrated how such knowledge may significantly enhance the characterisation of colloidal suspensions. The final part of the book refers to the information, ideas and concepts already presented in order to address technical aspects of the preparation of colloidal suspensions—in particular the performance of relevant dispersion techniques and the stability of colloidal suspensions.
Download or read book Density Dependent Interactions and Structure of Charged Colloidal Dispersions in the Weak Screening Regime written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We determine the structure of charge-stabilized colloidal suspensions at low ionic strength over an extended range of particle volume fractions using a combination of light and small angle neutron scattering experiments. The variation of the structure factor with concentration is analyzed within a one-component model of a colloidal suspension. We show that the observed structural behavior corresponds to a nonmonotonic density dependence of the colloid effective charge and the mean interparticle interaction energy. Our findings are corroborated by similar observations from primitive model computer simulations of salt-free colloidal suspensions.
Download or read book Phase Behavior and Effective Interactions in Colloidal Suspensions written by and published by Cuvillier Verlag. This book was released on 2007-04-25 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Colloidal suspensions describe particles with size from typically a few nanometers to a few microns which are dispersed in a medium. In physics, in chemistry, and in biology colloids play an important role and the study of colloidal systems underwent a recent renaissance. This is based on the development of experimental techniques, the availability of extensive computer simulations and well-developed theoretical approaches. From a technological point of view, the relevance of micro- and nanostructured materials and the presence of colloids in nature and everyday life motivates study of this rich field. In this thesis the phase behavior and the effective interactions of colloidal suspensions in bulk, in contact with surfaces, and in confined geometry are studied. For mixtures of particles with hard-core interactions the model introduced by Asakura, Oosawa and Vrij provides an appropriate starting-point. Based on that model the free-volume theory and the density functional theory are employed. In experimental systems one faces particles with properties such as the size or the shape which are described by a distribution. To capture that issue a generalized approach based on free-volume theory for treating mixtures of colloids and a polydisperse depletion agent is presented. Within that approach it is possible to treat size and morphology polydispersity. A depletion agent with a bimodal distribution possessing two length scales can be studied. Though the Asakura-Oosawa-Vrij model describes a simple fluid - a mixture of hard spheres and ideal polymer - the phenomenology is rather rich: in contact with a wall one finds layering and wetting effects and in confined geometry of a narrow pore one finds capillary condensation. The competition between both effects manifests itself in thermodynamic properties like the excess colloid adsorption and the solvation force between the two confining walls. Solvent phase separation complicates the evaluation of interparticle interactions between the solute particles. We address this question for the wall-colloid and the colloid-colloid geometry. For a non-spherical particle the effect of curvature on thermodynamic quantities is studied.
Download or read book Contact and Macroscopic Aging in Dense Suspensions at the Colloidal Edge written by Francesco Bonacci and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dense colloidal suspensions (or pastes) constitute a broad class of materials found in areas ranging from environmental systems (e.g. silts, clays), to industry (ceramics, drilling muds, slurries), construction (plaster, cements), foodstuff, cosmetics, pharmaceuticals (toothpaste, medical ceramics). Their most remarkable feature is thixotropy: a slow evolution of their mechanical properties when switching from rest to flow (at fixed density, in the absence of drainage). Thus, their viscosity under flow, or their shear modulus and yield stress at rest, depend both on time and strain history. Thixotropy enables these systems to switch reversibly between solid- and liquid-like states with sharply contrasted properties. At rest, it is usually accompanied with aging--slow, non-exponential dynamics at long times. In recent decades, tremendous progress has been made towards understanding the dynamics of so-called "stabilized" suspensions, in which the formation of interparticle adhesive contacts is fully avoided by tuning inter-particle interactions (via double-layer polarization, or polymer depletion effects). Confocal microscopy was instrumental to such progresses, yet may only be applied to transparent, i.e. nearly index matched, systems, hence is limited to systems in which van der Waals forces are absent. Meanwhile, studies of "non-stabilized" suspensions have tended to focus on very dilute systems (i.e. packing fractions at most a few percent) where a structural evolution (the formation of flocs) could be imaged and thus analyzed, e.g., using light scattering techniques. The tremendous success of these studies has created an observational bias as, today, classical works on suspensions only mention structural dynamics as the root cause of thixotopy. But the pastes of civil and environmental engineering, are dense and generally contain significant concentrations of ions; these screen Coulombic repulsion and allow attractive van der Waals forces to bring particles into solid-solid contacts, which are likely to impact macroscopic properties and their evolution by a number of mechanisms. Indeed, it is well-known that, the macroscopic response of non-colloidal granular materials, is affected by contact friction, which is time- dependent. In cements, the formation of hydrate gels between grains, which determines the late-time strength and mechanical properties of solid concrete, was proposed to play a role in thixotropy. In fact, it remains unclear how solid-solid contacts may affect just the elastic modulus of colloidal systems. By designing an optical trap three-point bending test, Pantina and Furst showed that beams of PMMA and polystyrene particles present a finite flexural modulus, which entails that the contacts formed between particles resist rotation. The flexural modulus of polystyrene particle rods was later shown to evolve in time. These two elements lead us to ask whether the evolution of the contact bending stiffness could be responsible for mechanical aging in pastes, without invoking changes in the network structure. This work aims to investigate the potential existence of a link between contact and macroscopic aging, by combining measurements performed at the particle level, through optical-trap three-point bending tests and confocal microscopy, and at the macroscopic scale, through rheometry. To achieve it, we study the aging behavior of model dense colloidal suspensions composed of silica (SiO2) and PMMA particles suspended in divalent electrolyte aqueous solutions, at moderate concentrations. The use of model ionic systems enables us to carefully control a number of parameters expected to affect the rheology of real suspensions in the dense regime, such as the volume fraction, the size and the shape of the particles and the magnitude of the interactions.
Download or read book Accelerated Lattice Boltzmann Model for Colloidal Suspensions written by Hassan Farhat and published by Springer Science & Business Media. This book was released on 2014-04-12 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: Colloids are ubiquitous in the food, medical, cosmetics, polymers, water purification, and pharmaceutical industries. The thermal, mechanical, and storage properties of colloids are highly dependent on their interface morphology and their rheological behavior. Numerical methods provide a convenient and reliable tool for the study of colloids. Accelerated Lattice Boltzmann Model for Colloidal Suspensions introduce the main building-blocks for an improved lattice Boltzmann–based numerical tool designed for the study of colloidal rheology and interface morphology. This book also covers the migrating multi-block used to simulate single component, multi-component, multiphase, and single component multiphase flows and their validation by experimental, numerical, and analytical solutions. Among other topics discussed are the hybrid lattice Boltzmann method (LBM) for surfactant-covered droplets; biological suspensions such as blood; used in conjunction with the suppression of coalescence for investigating the rheology of colloids and microvasculature blood flow. The presented LBM model provides a flexible numerical platform consisting of various modules that could be used separately or in combination for the study of a variety of colloids and biological flow deformation problems.
Download or read book Behavior of Concentrated Colloidal Suspensions by Stokesian Dynamics Simulation written by Thank Ngoc Phung and published by . This book was released on 1993 with total page 485 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Active and Nonlinear Microrheology of Dense Colloidal Suspensions written by Christian Josef Harrer and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dense Colloidal Suspensions in Microchannel Flow written by Philipp Kanehl and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Oscillatory Perturbation of Dense Colloidal Suspensions written by Rachel E. Courtland and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nonlinear Microrheology of Dense Colloidal Suspensions written by Igor Gazuz and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure and Diffusion in Dense Confined Colloidal Suspensions written by Bianxiao Cui and published by . This book was released on 2002 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modern Aspects of Colloidal Dispersions written by Ronald H. Ottewill and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the papers presented at a meeting sponsored by the Colloid and Interface Science Group of the Faraday Division, Royal Society of Chemistry, which was held at Wills Hall, University of Bristol from the 14th - 16th April 1997. The pur pose of the meeting, which was entitled Colloidal Dispersions, was to discuss the subject of concentrated colloidal systems including, dispersions, emulsions and powders, in order to emphasize recent advances in experimental and theoretical understanding of these systems and how these advances could be applied to practical utitisation in the wide range of industries which are involved with colloidal systems. The papers presented at the meeting were given by the principal participants in a 5 year project on Colloid Technology, which started on the 1st August 1992, and was funded by the Department of Trade and Industry (DTI) of the U.K. and a consortium of industries which was composed of ICI, Schlumberger, Unilever and Zeneca. The academic centres involved were, the Universities of Bristol, Cambridge, Edinburgh and Imperial College, London. Each of the papers published in this volume formed the focus for a discussion on that topic so that each subject was discussed in so me depth by the participants. J ean Proctor and Meg Staff have been tremendously helpful as secretaries at Bristol and Cambridge respectively throughout the project. Also, their help with the various meetings and with the production of this volume was invaluable. We thank them most warmly for their very able assistance.
Download or read book Nonlinear Response of Dense Colloidal Suspensions Under Oscillatory Shear written by Joseph M. Brader and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theory and Applications of Colloidal Suspension Rheology written by Norman J. Wagner and published by Cambridge University Press. This book was released on 2021-04-15 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: Essential text on the practical application and theory of colloidal suspension rheology, written by an international coalition of experts.
Download or read book Rheology for Chemists written by J W Goodwin and published by Royal Society of Chemistry. This book was released on 2019-04-05 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rheology is primarily concerned with materials: scientific, engineering and everyday products whose mechanical behaviour cannot be described using classical theories. From biological to geological systems, the key to understanding the viscous and elastic behaviour firmly rests in the relationship between the interactions between atoms and molecules and how this controls the structure, and ultimately the physical and mechanical properties. Rheology for Chemists An Introduction takes the reader through the range of rheological ideas without the use of the complex mathematics. The book gives particular emphasis on the temporal behaviour and microstructural aspects of materials, and is detailed in scope of reference. An excellent introduction to the newer scientific areas of soft matter and complex fluid research, the second edition also refers to system dimension and the maturing of the instrumentation market. This book is a valuable resource for practitioners working in the field, and offers a comprehensive introduction for graduate and post graduates. "... well-suited for self-study by research workers and technologists, who, confronted with technical problems in this area, would like a straightforward introduction to the subject of rheology." Chemical Educator, "... full of valuable insights and up-to-date information." Chemistry World
Download or read book Process and Chemical Engineering written by and published by . This book was released on 2002 with total page 774 pages. Available in PDF, EPUB and Kindle. Book excerpt:
