Download or read book Investigating Flow Behaviors of Colloidal Materials at the Single particle Scale written by Yen-Chih Lin and published by . This book was released on 2017 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: My thesis work focuses on the nonlinear mechanical behaviors of colloidal suspensions at the particle-level. This work covers both quiescent and strongly sheared suspensions. For quiescent suspensions, we image their 3D structures with confocal microscopy, and implement Stress Assessment from Local Structural Anisotropy (SALSA) to visualize the stress fields in them. Unlike traditional numerical methods, SALSA takes a statistical approach converting the probability of hard-sphere Brownian collisions to stresses. This direct stress measurement allows us to quantify the particle-level stresses surrounding vacancies, dislocations, and grain boundaries in crystalline materials. To drive the suspensions away from equilibrium, we develop a confocal-rheoscope, which is able to shear and image colloidal materials simultaneously. Using this device, we investigate the nonlinear flow behavior governed by Brownian motion, shear induced diffusion, and advection, and more importantly, disentangle them. We also study particle assembly and its corresponding rheological properties under confinement. Finally, we study even more strongly sheared suspensions, in which particle dynamics are too fast to be imaged by a confocal microscope. Here, we use flow reversal rheometry to reveal the underlying mechanism of suspension shear thickening where the viscosity increases with shear rate. We show that the thickening behavior of a suspension arises from the particle contact forces rather than hydrodynamic interactions. Such findings then lead us to design a biaxial shear protocol that can tune the suspension viscosity on demand. This viscosity tuning capability is a foundational step toward using dense suspensions in 3D printing, energy storage, and robotics. ...

Download or read book Suspensions of Colloidal Particles and Aggregates written by Frank Babick and published by Springer. This book was released on 2018-04-25 with total page 341 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 Colloids and the Depletion Interaction written by Henk N.W. Lekkerkerker and published by Springer Science & Business Media. This book was released on 2011-05-12 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: Colloids are submicron particles that are ubiquitous in nature (milk, clay, blood) and industrial products (paints, drilling fluids, food). In recent decades it has become clear that adding depletants such as polymers or small colloids to colloidal dispersions allows one to tune the interactions between the colloids and in this way control the stability, structure and rheological properties of colloidal dispersions. This book offers a concise introduction to the fundamentals of depletion effects and their influence on the phase behavior of colloidal dispersions. Throughout the book, conceptual explanations are accompanied by experimental and computer simulation results. From the review by Kurt Binder: "They have succeeded in writing a monograph that is a very well balanced compromise between a very pedagogic introduction, suitable for students and other newcomers, and reviews of the advanced research trends in the field. Thus each chapter contains many and up to date references, but in the initial sections of the chapters, there are suggested exercises which will help the interested reader to recapitulate the main points of the treatment and to deepen his understanding of the subject. Only elementary knowledge of statistical thermodynamics is needed as a background for understanding the derivations presented in this book; thus this text is suitable also for advanced teaching purposes, useful of courses which deal with the physics for soft condensed matter. There does not yet exist any other book with a similar scope..... The readability of this book is furthermore enhanced by a list of symbols, and index of keywords, and last not least by a large number of figures, including many pedagogic sketches which were specifically prepared for this book. Thus, this book promises to be very useful for students and related applied sciences alike." Eur. Phys. J. E (2015) 38: 73

Download or read book Confined Flow of Attractive Colloidal Suspensions written by Rahul Pandey and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Attractive particulate fluids flowing through complex confined geometries are frequently used in technological applications. While the flow properties of hard-sphere suspensions in micro-scale geometries have been studied extensively, the effects of interparticle attractions and particle size dispersity on the confined flow properties of particulate suspensions are not well understood. We used confocal microscopy, particle tracking, and bulk rheology to study the confined structure, dynamics, and flow properties of colloid-polymer mixtures, which serve as simple models of attractive particulate suspensions. We employed poly(methyl-methacrylate) spheres that were suspended in a refractive-index and density- matched solvent, and induced a controlled short-range depletion attraction between particles by adding non-absorbing linear polystyrene. First, we investigated the effects of particle size dispersity on confinement-induced solidification of colloid-polymer mixtures. We formulated mixtures of polymer and bidispersed colloids with particle size ratio aS/aL ≈ 0.49 at a constant total volume fraction fT and measured the dynamics of the large particles as a function of the volume fraction of large particles. The dynamics of large particles became slower as the volume fraction of large particles r=fL/fT was decreased or the confinement thickness was decreased, indicating increasingly solid-like behavior. Second, we investigated the effects of variation in particle size dispersity r on the rheology and microstructure of mixtures of polymer and bidispersed colloids. Significant changes in rheology and microstructure were observed only at high volume fractions of large particles. By contrast, dense suspensions fT = 0.40 were strong gels at all concentration of large particles and exhibited only modest rheological and microstructural changes. Finally, we investigated the effects of variation in interparticle attractions on the microchannel flow of colloid-polymer mixtures. In suspensions with weak interparticle attractions, the number density of particles increased downstream in the channel due to shear-induced migration and consolidation by compression. In suspensions with stronger interparticle attractions, an interconnected network of particles suppressed these mechanisms and prevented the increase in density downstream. Together, our results indicate that the confined structure, dynamics, and flow properties of attractive colloidal suspensions can be controllably tuned from fluid-like to solid-like by varying the interparticle attractions and the particle size dispersity.

Download or read book Colloidal Suspension Rheology written by Jan Mewis and published by Cambridge University Press. This book was released on 2012 with total page 417 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented in an accessible and introductory manner, this is the first book devoted to the comprehensive study of colloidal suspensions.

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 Modelling of Pollutants in Complex Environmental Systems written by Grady Hanrahan and published by ILM Publications. This book was released on 2010 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: Environmental modelling has enjoyed a long tradition, but there is a defined need to continually address both the power and the limitations of such models, as well as their quantitative assessment. This book showcases modern environmental modelling methods, the basic theory behind them and their incorporation into complex environmental investigations. It highlights advanced computing technologies and how they have led to unprecedented and adaptive modelling, simulation and decision-support tools to study complex environmental systems, and how they can be applied to current environmental concerns. This volume is essential reading for researchers in academia, industry and government-related bodies who have a vested interest in all aspects of environmental modelling. Features include: A range of modern environmental modelling techniques are described by experts from around the world, including the USA, Canada, Australia, Europe and Thailand; many examples from air, water, soil/sediment and biological matrices are covered in detail throughout the book; key chapters are included on modelling uncertainty and sensitivity analysis; and, a selection of figures are provided in full colour to enable greater comprehension of the topics discussed.

Download or read book Physics of Complex Colloids written by C. Bechinger and published by IOS Press. This book was released on 2013-06-24 with total page 639 pages. Available in PDF, EPUB and Kindle. Book excerpt: Colloids are systems comprised of particles of mesoscopic size suspended in a liquid. They have recently been attracting increased attention from scientists and engineers due to the fact that they are nowadays present in many industrial products such as paints, oil additives, electronic ink displays and drugs. Colloids also serve as versatile model systems for phenomena and structures from solid-state physics, surface science and statistical mechanics, and can easily be studied using tabletop experiments to provide insight into processes not readily accessible in atomic systems. This book presents the lectures delivered at the 2012 Enrico Fermi School ‘Physics of Complex Colloids’, held in Varenna, Italy, in July 2012. The school addressed experimental, theoretical and numerical results and methods, and the lectures covered a broad spectrum of topics from the starting point of the synthesis of colloids and their use in commercial products. The lectures review the state-of-the-art of colloidal science in a pedagogical way, discussing both the basics and the latest results, and this book will serve as a reference for both students and experts in this rapidly growing field.

Download or read book Intermolecular and Surface Forces written by Jacob N. Israelachvili and published by Academic Press. This book was released on 2011-07-22 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt: Intermolecular and Surface Forces describes the role of various intermolecular and interparticle forces in determining the properties of simple systems such as gases, liquids and solids, with a special focus on more complex colloidal, polymeric and biological systems. The book provides a thorough foundation in theories and concepts of intermolecular forces, allowing researchers and students to recognize which forces are important in any particular system, as well as how to control these forces. This third edition is expanded into three sections and contains five new chapters over the previous edition. - Starts from the basics and builds up to more complex systems - Covers all aspects of intermolecular and interparticle forces both at the fundamental and applied levels - Multidisciplinary approach: bringing together and unifying phenomena from different fields - This new edition has an expanded Part III and new chapters on non-equilibrium (dynamic) interactions, and tribology (friction forces)

Download or read book Anisotropic Particle Assemblies written by Ning Wu and published by Elsevier. This book was released on 2018-07-12 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anisotropic Particle Assemblies: Synthesis, Assembly, Modeling, and Applications covers the synthesis, assembly, modeling, and applications of various types of anisotropic particles. Topics such as chemical synthesis and scalable fabrication of colloidal molecules, molecular mimetic self-assembly, directed assembly under external fields, theoretical and numerical multi-scale modeling, anisotropic materials with novel interfacial properties, and the applications of these topics in renewable energy, intelligent micro-machines, and biomedical fields are discussed in depth. Contributors to this book are internationally known experts who have been actively studying each of these subfields for many years.This book is an invaluable reference for researchers and chemical engineers who are working at the intersection of physics, chemistry, chemical engineering, and materials science and engineering. It educates students, trains the next generation of researchers, and stimulates continuous development in this rapidly emerging area for new materials and innovative technologies. - Provides comprehensive coverage on new developments in anisotropic particles - Features chapters written by emerging and leading experts in each of the subfields - Contains information that will appeal to a broad spectrum of professionals, including but not limited to chemical engineers, chemists, physicists, and materials scientists and engineers - Serves as both a reference book for researchers and a textbook for graduate students

Download or read book Collective Behavior of Colloidal Particles on Fluid Interface written by Shenghan Yan and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: It is well known that charged colloidal particles may form an effective two dimensional suspension at a fluidic interface. Research toward the understanding of the dynamics and collective behavior of these suspended particles is at the core of engineering Pickering emulsions, which have a broad range of practical applications. In the first half of this dissertation, we will explore the single phase particle monolayer. Although microscopic images and rheological measurements have been obtained in abundance, the underlying physics behind the collective behavior of such systems is yet to be fully understood. We started by examining the attractive and repulsive potentials in this system. In the case of charged colloidal particles at a fluidic interface, capillary attraction rises from the meniscus deformation, which is predominantly due to the mismatch of dielectric constants between the aqueous phase and the non-polar phase. On the other hand, aggregation is prevented by the long range Coulombic repulsion through the non-polar phase as proposed by Aveyard and coworkers. With the basic knowledge of interaction potentials present, Monte Carlo simulation and Brownian dynamics simulation were performed, assuming pair-wise interactions with all physical constants of a system consisting of latex particles trapped at a water-decane interface. Microscopic images of such a system were recorded concurrently, serving as an internal verification of the numerical simulation. Furthermore, the pair distribution function in the radial direction and the angular order parameter, were extracted from the equilibrium configuration of the Monte Carlo simulation as well as real-time microscopic images to investigate the phase transition behaviour. The primitive simulation results agreed with the experimental observation qualitatively, showing a two-dimensional phase transition from a disordered phase to an ordered solid phase as the surface coverage of the particles increases. In the second half of the dissertation, we focus on the coalescence experiments involving a Pickering droplet. Many experiments have been performed where two particle laden interfaces have been brought into close contact in a controlled manner and various observations, including particle "bridging", have been made in an attempt to understand the stabilization mechanism of interfacial particles in a Pickering emulsion. One of the most interesting observations is the tendency for the particles on one interface to "evacuate" and those on the other interface to "aggregate" during the close approach of the surfaces. In this work, we propose to understand the mechanism of particle evacuation- aggregation via a combined experimental and theoretical approach. First, we performed real-time experiments where two particle-laden water-decane interfaces were brought into contact. Many phenomena including particle evacuation-aggregationand bridging were observed. We then developed a Brownian dynamics simulation of the evacuation-aggregation including the important relevant interparticle interactions that we presumed were important in describing the phenomena. In order to do so, we had to answer three questions. First, what are the relevant aspects of the charged particle interaction within the same interface? Second, what is the charge interaction across the two approaching interfaces? Third, what are the flow effects, including the flow between the two interfaces during approach, on the particle motion and how can we model such a flow? Toward this goal, we have incorporated both reasonable electric inter-particle interactions from available literature studies and flow interactions via a porous media model that relates the particle velocity to the local surface coverage through the effective permeability of a porous media. Thus the flow effects are captured in a mean field sense. The BD simulations were able to capture the evacuation-aggregation qualitatively and, in most instances, quantitatively. In particular the diameter of the evacuated area decreases with increasing surface coverage in both simulations and experiments, and we will describe the physical mechanisms leading to this behavior by analyzing the particle force balance in the BD simulations.

Download or read book Colloidal Particles at Liquid Interfaces written by Bernard P. Binks and published by Cambridge University Press. This book was released on 2006-08-17 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: The understanding of how small solid particles operate at liquid interfaces is minimal. This book brings together the topics actively being investigated, with contributions from experts in the field. It will be of interest to researchers in chemistry, physics, chemical engineering, pharmacy, food science and materials science.

Download or read book Acting Principles of Nano Scaled Matrix Additives for Composite Structures written by Michael Sinapius and published by Springer Nature. This book was released on 2021-05-22 with total page 479 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book explores the effect of nanoscale matrix additives along the four levels of material formation, particle-resin interaction, the influence of nanoparticles on the processability of the polymer, the influence of nanoparticles on polymer curing and the influence of nanoparticles on the fiber plastic composite. Fiber-reinforced plastics have a significantly higher lightweight construction potential in components with a primary single- or biaxial stress state compared to isotropic metals. At the same time, their insensitivity to corrosion and their advantageous fatigue properties can help to reduce maintenance costs. Due to their outstanding specific mechanical properties, they are among today's high-performance lightweight construction materials. These properties make them particularly attractive in the field of mobility. However, as soon as the matrix properties dominate the mechanical properties, e.g. in the case of fibre-parallel compressive strength, significant weaknesses become apparent in the mechanical properties. Here, one approach is to significantly increase the matrix properties through nanoscale ceramic additives and at the same time to guarantee the processability of the resin.

Download or read book Actinide Nanoparticle Research written by Stepan N. Kalmykov and published by Springer Science & Business Media. This book was released on 2011-06-17 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first book to cover actinide nano research. It is of interest both for fundamental research into the chemistry and physics of f-block elements as well as for applied researchers such as those studying the long-term safety of nuclear waste disposal and developing remediation strategies. The authors cover important issues of the formation of actinide nano-particles, their properties and structure, environmental behavior of colloids and nanoparticles related to the safe disposal of nuclear wastes, modeling and advanced methods of characterization at the nano-scale.

Download or read book Recent Awards in Engineering written by and published by . This book was released on 1983 with total page 986 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Environmental Colloids and Particles written by Kevin J. Wilkinson and published by John Wiley & Sons. This book was released on 2007-01-30 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text presents the current knowledge of environmental colloids and includes reviews of the current understanding of structure, role and behaviour of environmental colloids and particles, whilst focussing directly on aquatic systems and soils. In addition, there is substantial critical assessment of the techniques employed for the sampling, size fractionation and characterisation of colloids and particles. Chemical, physical and biological processes and interactions involving colloids are described, and particular attention is paid to quantitative approaches that take account of particle heterogeneity and polydispersity. Presents critical reviews of the state-of-the-art knowledge of environmental colloids Critical assessment of techniques employed for the sampling, size fractionation and characterisation of colloids and particles are given Theoretical and experimental aspects of the methods as well as the required developments and possible recommendations are discussed Each chapter gives a brief introduction general enough for the non-specialist Written by a internationally recognized group of contributors

Download or read book Colloidal Particles in Critical Fluids written by and published by Cuvillier Verlag. This book was released on 2004-01-22 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: