Download or read book Theoretical examinations of interface mediated interactions between colloidal particles written by Martin Michael Müller and published by . This book was released on 2004 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Particles at Fluid Interfaces and Membranes written by P. Kralchevsky and published by Elsevier. This book was released on 2001-01-22 with total page 669 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the small world of micrometer to nanometer scale many natural and industrial processes include attachment of colloid particles (solid spheres, liquid droplets, gas bubbles or protein macromolecules) to fluid interfaces and their confinement in liquid films. This may lead to the appearance of lateral interactions between particles at interfaces, or between inclusions in phospholipid membranes, followed eventually by the formation of two-dimensional ordered arrays. The book is devoted to the description of such processes, their consecutive stages, and to the investigation of the underlying physico-chemical mechanisms. The first six chapters give a concise but informative introduction to the basic knowledge in surface and colloid science, which includes both traditional concepts and some recent results. Chapters 1 and 2 are devoted to the basic theory of capillarity, kinetics of surfactant adsorption, shapes of axisymmetric fluid interfaces, contact angles and line tension. Chapters 3 and 4 present a generalization of the theory of capillarity to the case, in which the variation of the interfacial (membrane) curvature contributes to the total energy of the system. The generalized Laplace equation is applied to determine the configurations of free and adherent biological cells. Chapters 5 and 6 are focused on the role of thin liquid films and hydrodynamic factors in the attachment of solid and fluid particles to an interface. Surface forces of various physical nature are presented and their relative importance is discussed. Hydrodynamic interactions of a colloidal particle with an interface (or another particle) are also considered.Chapters 7 to 10 are devoted to the theoretical foundation of various kinds of capillary forces. When two particles are attached to the same interface (membrane), capillary interactions, mediated by the interface or membrane, appear between them. Two major kinds of capillary interactions are described: (i) capillary immersion force related to the surface wettability (Chapter 7), (ii) capillary flotation force originating from interfacial deformations due to particle weight (Chapter 8). Special attention is paid to the theory of capillary immersion forces between particles entrapped in spherical liquid films (Chapter 9). A generalization of the theory of immersion forces allows one to describe membrane-mediated interactions between protein inclusions into a lipid bilayer (Chapter 10).Chapter 11 is devoted to the theory of the capillary bridges and the capillary-bridge forces, whose importance has been recognized in phenomena like consolidation of granules and soils, wetting of powders, capillary condensation, long-range hydrophobic attraction, etc. The nucleation of capillary bridges is also examined.Chapter 12 considers solid particles, which have an irregular wetting perimeter upon attachment to a fluid interface. The undulated contact line induces interfacial deformations, which engender a special lateral capillary force between the particles. The latter contributes to the dilatational and shear elastic moduli of particulate adsorption monolayers.Chapter 13 describes how lateral capillary forces, facilitated by convective flows and some specific and non-specific interactions, can lead to the aggregation and ordering of various particles at fluid interfaces or in thin liquid films. Recent results on fabricating two-dimensional (2D) arrays from micrometer and sub-micrometer latex particles, as well as 2D crystals from proteins and protein complexes, are reviewed. Chapter 14 presents applied aspects of the particle-surface interaction in antifoaming and defoaming. The mechanisms of antifoaming action involve as a necessary step the entering of an antifoam particle at the air-water interface. The considered mechanisms indicate the factors for control of foaminess.

Download or read book Fluid Structure Interactions in Low Reynolds Number Flows written by Camille Duprat and published by Royal Society of Chemistry. This book was released on 2016 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: An approachable introduction to low Reynolds number flows and elasticity for those new to the area across engineering, physics, chemistry and biology.

Download or read book The Giant Vesicle Book written by Rumiana Dimova and published by CRC Press. This book was released on 2019-11-19 with total page 1144 pages. Available in PDF, EPUB and Kindle. Book excerpt: Giant vesicles are widely used as a model membrane system, both for basic biological systems and for their promising applications in the development of smart materials and cell mimetics, as well as in driving new technologies in synthetic biology and for the cosmetics and pharmaceutical industry. The reader is guided to use giant vesicles, from the formation of simple membrane platforms to advanced membrane and cell system models. It also includes fundamentals for understanding lipid or polymer membrane structure, properties and behavior. Every chapter includes ideas for further applications and discussions on the implications of the observed phenomena towards understanding membrane-related processes. The Giant Vesicle Book is meant to be a road companion, a trusted guide for those making their first steps in this field as well as a source of information required by experts. Key Features • A complete summary of the field, covering fundamental concepts, practical methods, core theory, and the most promising applications • A start-up package of theoretical and experimental information for newcomers in the field • Extensive protocols for establishing the required preparations and assays • Tips and instructions for carefully performing and interpreting measurements with giant vesicles or for observing them, including pitfalls • Approaches developed for investigating giant vesicles as well as brief overviews of previous studies implementing the described techniques • Handy tables with data and structures for ready reference

Download or read book Interactions Between Colloidal Particles at Oil water Interfaces written by Bum Jun Park and published by ProQuest. This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The behavior of colloidal particles at two-dimensional interfaces is of considerable interests in terms of industrial applications and model systems for research. To systematically study colloidal particle behaviors at 2D interfaces, we directly measure interaction forces between particle pairs, dynamics of a confined particle in a fixed geometry, and micromechanical properties of aggregates or percolated networks. For doing this, we use multiple time-shared optical traps which enable us to measure forces in the piconewton range (0.1-100 pN). First, the trapping forces for a single ray at the interface were calculated while varying the particle position at the 2D interfaces. The trapping force is described by the contributions of reflected and refracted rays with their corresponding powers, which are determined by Fresnel reflection and transmission coefficients. Based on the Ashkin's calculation in the 3D aqueous phase, we found that the trapping and scattering forces are mainly determined by the first reflection of the incident ray and the next three refractions to the medium. At 2D interfaces, the trapping force is considered for two geometries; (a) when the incident ray is incident on a particle in the aqueous phase, (b) when a transmitted ray at the liquid interface enters into a particle in the oil phase. In the first geometry, the trapping forces do not change, regardless of the refraction orders if the second refracted ray is to the oil phase. The dimensionless factors Q g and Q s of the gradient force and the scattering force decrease compared to those in the 3D aqueous space, and Q s decreases more than Q g . This suggests that the presence of the interface provides good trapping conditions. In the second geometry, the magnitude of dimensionless factors is consistent with those calculated in the first geometry when the incident angle is in the range of 0

Download or read book Capillary Interactions Between Colloidal Particles at Curved Fluid Interfaces written by Jan Jerzy Guzowski and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Surface Patterning with Colloidal Monolayers written by Nicolas Vogel and published by Springer Science & Business Media. This book was released on 2012-12-28 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: How can the two dimensional crystallization of colloids be used to form highly ordered colloidal monolayers on solid substrates? What application does this have in generating arrays of nanostructures? These questions are addressed in Nicolas Vogel's thesis. Vogel describes a simple preparation method for the formation of uniform colloidal crystals over large areas, which he refines to yield more complex binary and non-close-packed arrangements. These monolayers can be applied to a process termed colloidal lithography which is used to prepare high quality metallic nanostructures with tailored properties defined to suit a variety of applications. Moreover, the author describes a method used to create metallic nanodot arrays with a resolution unprecedented for colloidal lithography methods. The author also outlines methodology to embed nanoparticle arrays into the substrate, which is developed and used to design robust, re-usable biosensor platforms and nanoscale patterns of biomimetic lipid bilayer membranes. The research in this thesis has led to a large number of publications in internationally renowned journals.

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 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 Liquid Crystal Colloids written by Igor Muševič and published by Springer. This book was released on 2017-05-14 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together the many concepts and discoveries in liquid crystal colloids contributed over the last twenty years and scattered across numerous articles and book chapters. It provides both a historical overview of the development of the field and a clear perspective on the future applications in photonics. The book covers all phenomena observed in liquid crystal colloids with an emphasis on experimental tools and applications of topology in condensed matter, as well as practical micro-photonics applications. It includes a number of spectacular manifestations of new topological phenomena not found or difficult to observe in other systems. Starting from the early works on nematic colloids, it explains the basics of topological defects in ordered media, charge and winding, and the elastic forces between colloidal particles in nematics. Following a detailed description of experimental methods, such as optical tweezing and particle tracking, the book eases the reader into the theoretical part, which deals with elastic deformation of nematic liquid crystals due to inclusions and surface alignment. This is discussed in the context of basic mean field Landau-de Gennes Q-tensor theory, with a brief explanation of the free-energy minimization numerical methods. There then follows an excursion into the topology of complex nematic colloidal structures, colloidal entanglement, knotting and linking. Nematic droplets, shells, handlebodies and chiral topological structures are addressed in separate chapters. The book concludes with an extensive chapter on the photonic properties of nematic dispersions, presenting the concept of integrated soft matter photonics and discussing the concepts of nematic and chiral nematic microlasers, surface-sensitive photonic devices and smectic microfibers. The text is complemented by a large bibliography, explanatory sketches and beautiful micrographs.

Download or read book Colloidal Particles at a Liquid liquid Interface written by Iain Alexander Aylett Muntz and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Interactions and Micromechanics of Colloidal Aggregates written by John Peter Pantina and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Colloidal gels exhibit rheological properties, such as yield stress and viscoelasticity, which arise from the manner in which stress is transmitted through the microstructure. Insight into the mechanisms of stress transmission is critical in developing a full understanding of the rheological properties of these materials. Paramount to this is a thorough knowledge of the interparticle interactions. To systematically study the influence of nanoscale particle interactions on gel elasticity and yield stress, we use multiple time-shared optical traps to direct the assembly of colloidal aggregates consisting of dozens of particles. This novel technique provides a direct method of measuring the micromechanical properties and near contact interactions of aggregates that mimic the gel backbone as a function of physicochemical conditions, such as the ionic strength, ionic species, and the presence of surfactant additives. We begin by measuring the response of chain aggregates composed of colloidal PMMA in adhesive contact, due to the presence of inorganic salts in solution, to an applied bending moment. The aggregates were found to exhibit an elastic response below a critical bending moment. The simplified geometry of the aggregate allows us determine the single-bond rigidity from the measured chain elasticity, which is then related to the work of adhesion, W SL, through the Johnson-Kendall-Roberts (JKR) theory of adhesion. Next, we study the effect surfactant additives have on the micromechanics of aggregates. It is observed that both the single-bond elasticity, and the critical bending moment decreases as the surfactant concentration increases. However, ionic surfactants do so more efficiently than non-ionic surfactants. This is a consequence of the greater particle surface charge that arises from the adsorption of ionic surfactants, which in turn results in a larger Columbic repulsion between the particles. Finally, we measure the interactions and micromechanics of colloidal particles confined to an oil-water interface. A very long ranged repulsion is initially observed between particles, in agreement with theoretical descriptions of an electrostatic dipole arising from a small number of dissociated charge groups on the particle surface in the oil phase. As the sample ages, however, the repulsion is found to decrease until the particles are capable of aggregating. The results from this work are expected to aid in the development of improved microrheological models of colloidal gels by providing better descriptions of the near-contact interactions between particles, as well as greater insight into the manner in which stress is transmitted through the gel backbone. These models will permit a greater degree of rational engineering to be incorporated into the development of colloidal gels for industrial applications. (Abstract shortened by UMI.).

Download or read book Condensed Matter Field Theory written by Alexander Altland and published by Cambridge University Press. This book was released on 2010-03-11 with total page 785 pages. Available in PDF, EPUB and Kindle. Book excerpt: This primer is aimed at elevating graduate students of condensed matter theory to a level where they can engage in independent research. Topics covered include second quantisation, path and functional field integration, mean-field theory and collective phenomena.

Download or read book The Equilibrium Theory of Inhomogeneous Polymers written by Glenn Fredrickson and published by Oxford University Press on Demand. This book was released on 2006 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a pedagogical introduction to the theoretical and computer simulation techniques that are useful in the design of polymer formulations including personal care products, multiphase plastic materials, processed foods, and colloidal and nanoparticle dispersions. The book serves to unify previous work in a common language and provides a balanced treatment of analytical theory and numerical techniques, including an introduction to the exciting new field offield-theoretic polymer simulations - the direct numerical simulation of field theory models of meso-structured polymer melts, solutions, and dispersions.

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 Polymeric Stabilization of Colloidal Dispersions written by Donald H. Napper and published by . This book was released on 1983 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Solid Liquid Two Phase Flow written by Sümer M. Peker and published by Elsevier. This book was released on 2011-04-18 with total page 535 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an undertaking of a pioneering work of uniting three vast fields of interfacial phenomena, rheology and fluid mechanics within the framework of solid-liquid two phase flow. No wonder, much finer books will be written in the future as the visionary aims of many nations in combining molecular chemistry, biology, transport and interfacial phenomena for the fundamental understanding of processes and capabilities of new materials will be achieved. Solid-liquid systems where solid particles with a wide range of physical properties, sizes ranging from nano- to macro- scale and concentrations varying from very dilute to highly concentrated, are suspended in liquids of different rheological behavior flowing in various regimes are taken up in this book. Interactions among solid particles in molecular scale are extended to aggregations in the macro scale and related to settling, flow and rheological behavior of the suspensions in a coherent, sequential manner. The classical concept of solid particles is extended to include nanoparticles, colloids, microorganisms and cellular materials. The flow of these systems is investigated under pressure, electrical, magnetic and chemical driving forces in channels ranging from macro-scale pipes to micro channels. Complementary separation and mixing processes are also taken under consideration with micro- and macro-scale counterparts.- Up-to-date including emerging technologies- Coherent, sequential approach- Wide scope: microorganisms, nanoparticles, polymer solutions, minerals, wastewater sludge, etc- All flow conditions, settling and non-settling particles, non-Newtonian flow, etc- Processes accompanying conveying in channels, such as sedimentation, separation, mixing