Download or read book Colloidal Interactions Under Applied Fields in Confined Geometries written by Laura A. Schafer and published by . This book was released on 2002 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Field induced Phase Behavior of Colloidal Systems in Confined Geometries written by Tieying Gong and published by . This book was released on 2002 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Colloidal Dispersions Under Slit Pore Confinement written by Yan Zeng and published by Springer Science & Business Media. This book was released on 2012-12-28 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation contributes to the understanding of fundamental issues in the highly interdisciplinary field of colloidal science. Beyond colloid science, the system also serves as a model for studying interactions in biological matter. This work quantitatively investigated the scaling laws of the characteristic lengths of the structuring of colloidal dispersions and tested the generality of these laws, thereby explaining and resolving some long-standing contradictions in literature. It revealed the effect of confinement on the structuring, independently of specific properties of the confining interfaces. In addition, it resolved the influence of roughness and charge of the confining interfaces on the structuring and as well providing a method to measure the effect of surface deformability on colloidal structuring.

Download or read book Interactions of Colloidal Particles in the Presence of a Parallel Applied Field written by Frankie Kay Wood and published by . This book was released on 1989 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Colloids in Confined Geometries Hydrodynamics Simulation and Rheology written by James W. Swan and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The hydrodynamics of colloids in confined geometries is studied hierarchically beginning with the exact solutions for a spherical particle translating, rotating and deforming in the presence of a plane wall at low Reynolds number. The many-bodied hydrodynamic interactions among a collection of spherical particles near a plane wall are computed and used to study the Brownian motion of confined suspensions. The method of reflections is used to describe the motion of a single spherical particle embedded in the fluid constrained by two, parallel plane walls. From this, tables which are independent of the channel width are generated describing the particle's response to various force moments. This same approach is expanded to describe the hydrodynamic interactions among the particles comprising a colloidal dispersion confined in a channel. The simulations arising from this theory depict the short-time self-diffusivity, sedimentation rate and high frequency viscosity of suspensions of varying volume fractions in channels of varying widths. A theory for the scattering of evanescent waves by colloidal dispersions is developed and cast in the form of the diffusivity measured by classical light scattering. A series of simulations is conducted to predict the short- time self-diffusivity and the collective diffusivity measured by evanescent wave dynamic light scattering. The thesis concludes with a discussion of how the developed simulations and theories can be extended to make dynamic measurements as well as a brief consideration of some remaining, open questions.

Download or read book Advanced Theranostic Materials written by Ashutosh Tiwari and published by John Wiley & Sons. This book was released on 2015-06-30 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present book is covers the recent advances in the development on the regulation of such theragnosis system and their biomedical perspectives to act as a future nanomedicine. Advanced Theranostics Materialsis written by a distinguished group of contributors and provides comprehensive coverage of the current literature, up-to-date overview of all aspects of advanced theranostics materials ranging from system biology, diagnostics, imaging, image-guided therapy, therapeutics, biosensors, and translational medicine and personalized medicine, as well as the much broader task of covering most topics of biomedical research. The books focusses on the following topics: Part 1: System biology and translational medicine Aberrant Signaling Pathways: Hallmark of Cancer Cells and Target for Nanotherapeutics Application of Nanoparticles in Cancer Treatment Biomacromolecule-Gated Mesoporous Silica Drug Delivery Systems Construction of Functional DNA Nanostructures for Theranostic Applications Smart Polypeptide Nanocarriers for Malignancy Therapeutics Part 2: Imaging and therapeutics Dimercaptosuccinic acid-coated magnetic nanoparticles as a localized delivery system in cancer immunotherapy Cardiovascular nanomedicine Chitosan-based systems for sustained drug release Nanocapsules in biomedicine: promises and challenges Chitosan-based polyelectrolyte complexes: characteristics and application in formulation of particulate drug carriers Part 3: Diagnostics and featured prognostics Non-invasive Glucose Biosensors based on Nanomaterials Self/directed Assembly of Nanoparticles: A review on various approaches Ion exchangers – an open window for the development of advanced materials with pharmaceutical and medical applications New Titanium Alloys for Biomedical Applications

Download or read book 21st Century Nanoscience A Handbook written by Klaus D. Sattler and published by CRC Press. This book was released on 2020-11-26 with total page 465 pages. Available in PDF, EPUB and Kindle. Book excerpt: 21st Century Nanoscience - A Handbook: Nanophotonics, Nanoelectronics, and Nanoplasmonics (Volume 6) will be the most comprehensive, up-to-date large reference work for the field of nanoscience. Handbook of Nanophysics by the same editor published in the fall of 2010 and was embraced as the first comprehensive reference to consider both fundamental and applied aspects of nanophysics. This follow-up project has been conceived as a necessary expansion and full update that considers the significant advances made in the field since 2010. It goes well beyond the physics as warranted by recent developments in the field. This sixth volume in a ten-volume set covers nanophotonics, nanoelectronics, and nanoplasmonics. Key Features: Provides the most comprehensive, up-to-date large reference work for the field. Chapters written by international experts in the field. Emphasises presentation and real results and applications. This handbook distinguishes itself from other works by its breadth of coverage, readability and timely topics. The intended readership is very broad, from students and instructors to engineers, physicists, chemists, biologists, biomedical researchers, industry professionals, governmental scientists, and others whose work is impacted by nanotechnology. It will be an indispensable resource in academic, government, and industry libraries worldwide. The fields impacted by nanophysics extend from materials science and engineering to biotechnology, biomedical engineering, medicine, electrical engineering, pharmaceutical science, computer technology, aerospace engineering, mechanical engineering, food science, and beyond.

Download or read book Colloidal Interactions in Field directed Self assembly written by Pushkar P. Lele and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis discusses: (1) the fabrication of an experimental tool, namely holographic optical tweezers for simultaneously manipulating spatial locations of multiple particles, (2) development of a framework for interpreting hydrodynamic interactions between multiple particles close to a no-slip surface and comparisons of experimental data with predictive modeling results (Stokesian dynamics simulations) (3) investigations of colloidal particle interactions under external AC fields and the intriguing spontaneous pattern formations in the suspension and, (4) the use of an unconventional assemble-stretch technique for creating novel 2D and 3D crystalline arrays of anisotropically shaped particles, from spherical particle templates. By blinking holographic optical traps, we investigate the hydrodynamic interactions in multi-particle ensembles, influenced by a no-slip surface. The measurements are carried out by screening out electrostatic interactions in the suspension. We observe that with increasing proximity with the surface, the effect of particle-particle hydrodynamic interactions on the short-time self-diffusivities is screened. We use the Stokeslet representation of particles and combine it with the method of images to understand the correlated motion of particles within the ensembles. Analysis of the resultant ensemble eigen-modes reveals that even in dilute suspensions, the effective diffusivities decay as the inverse of the separations, over the range of particle-particle separations we experimented with. The relative modes exhibit dominant contributions from close neighboring particles and the collective modes incorporate long-range contributions from all particles in the ensemble. Our analysis also confirms that for larger number of particles in the ensemble, the contributions from particle-particle interactions increase and in concentrated suspensions they over-ride the strong hydrodynamic screening by the wall. We investigate the microstructure of polarizable particles in AC electric fields as a function of field strength and frequency and observe three key features: (1) The order-disorder transition as a function of field strength and frequency exhibits an ordered regime consisting of dipolar chains and crystals between two disordered regimes at low and high field strengths. While the transition to order at low field strengths is consistent with the polarization-induced interactions becoming larger than the thermal energy of the particles, the reentrant disordered regime at high field strengths is marked by large- scale rotating structures; (2) As mentioned, using blinking laser tweezers to characterize the interaction of particle pairs, we demonstrate that particle pair rotation opposite of alignment in the field direction is the microscopic phenomenon driving the observed suspension behavior. The pair particle rotation is observed to decrease with increasing frequency, thus requiring higher field strengths, in agreement with the frequency and field strength dependence of the second order-to-disorder transition; (3) The particle rotation is consistent with a mechanism based on the mutual polarization of particles, and is an effect of the phase lag between the polarization and the applied and mutually induced field. The connection we made between particle interactions and suspension microstructure answers a long-standing debate regarding the mechanism underlying the band structures in experiments employing parallel electrode geometries. Creating ordered crystalline structures from anisotropic particles is a fundamental challenge. To create such structures, either one can direct the assembly of particles from a random dispersion using external fields or, as we will show, they can be created from the controlled deformation of isotropic particle templates. Using an assemble-stretch technique we create 2D and 3D anisotropic particle assemblies from an initial template of close-packed spheres. This method enables the fabrication of anisotropic crystals from particles of any deformable material with a reasonable glass transition temperature, and thus, is a key advantage of the technique. Be- cause the aspect ratios of the particles in the deformed crystal depends solely on the applied mechanical strain, the method offers good control over particle aspect ratios, and can be used to create assemblies from different particle sizes. As long as the original template can be fabricated with long range order, the stretched anisotropic structures will also be ordered over large length scales. We demonstrate that it is also possible to simply align and stack 2D structures to create crystals in three dimensions. The assemble-and-stretch approach shows great promise for ultimately creating structures with complete photonic bandgaps. (Abstract shortened by UMI.).

Download or read book Computational Methods in Surface and Colloid Science written by Malgorzata Borowko and published by CRC Press. This book was released on 2019-04-23 with total page 625 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents computer simulation methods and mathematical modelling of physical processes used in surface science research. It offers in-depth analysis of advanced theoretical approaches to behaviours of fluids in contact with porous, semiporous and nonporous solid surfaces. The book also explores interfacial systems for a wide variety of p

Download or read book Fluids Colloids and Soft Materials written by Alberto Fernandez-Nieves and published by John Wiley & Sons. This book was released on 2016-04-27 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a compilation of self-contained chapters covering a wide range of topics within the broad field of soft condensed matter. Each chapter starts with basic definitions to bring the reader up-to-date on the topic at hand, describing how to use fluid flows to generate soft materials of high value either for applications or for basic research. Coverage includes topics related to colloidal suspensions and soft materials and how they differ in behavior, along with a roadmap for researchers on how to use soft materials to study relevant physics questions related to geometrical frustration.

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 Journal of the Physical Society of Japan written by and published by . This book was released on 2015 with total page 758 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Progress in Electrorheology written by F.E. Filisko and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: This treatise is a compendium of refereed papers based on invited talks presented at the American Chemical Society Symposium on Electrorheological (ER) Materials and Fluids. ER fluids were first investigated 50+ years ago. These fluids, which change rheology when placed in an electric field, were recognized, from the beginning, for allowing an extremely efficient interface between electrical control and mechanical devices. Critical problems, however, existed with the initial fluids, which prevented them from serious consideration for large-scale applications. While over time some of the critical problems have been solved and activity in ER technology has increased, commercial success has remained elusive. A recent Department of Energy report concluded that a primary reason for the failure to commercialize this promising technology is due to a lack in understanding the physics and chemistry of how the materials work. The goal of the symposium was to address the issue of understanding how ER materials work and how they can be used. One of the outcomes of the symposium, which we hope is conveyed in this book, is a feeling that if the mechanism of ER is to be fully understood and improved, expertise from diverse fields must be applied to the problem.

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 Dekker Encyclopedia of Nanoscience and Nanotechnology written by James A. Schwarz and published by CRC Press. This book was released on 2004 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Approaches to Problems in Liquid State Theory written by Carlo Caccamo and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 527 pages. Available in PDF, EPUB and Kindle. Book excerpt: The theory of simple and complex fluids has made considerable recent progress, due to the emergence of new concepts and theoretical tools, and also to the availability of a large body of new experimental data on increas ingly complex systems, as well as far-reaching methodological developments in numerical simulations. This AS! aimed at providing a comprehensive overview of the most significant theoretical developments, supplemented by a few presentations of cutting-edge simulation and experimental work. The impact of the Institute in the overall landscape of Statistical Mechanics received an important recognition with its inclusion in the list of satellite events of STATPHYS20, the triennal international conference on Statistical Physics held in Paris in July 1998. These Proceedings contain the texts of the 13 Lecture Courses and 9 Invited Seminars delivered at Patti. Two clear trends emerge from these Proceedings: first, the diversity of new and unexpected theoretical results relating to classic models of liq uids, which have recently been subjected to fresh scrutiny; and secondly the parallel emergence of new concepts, models and methods, aimed at investigating complex fluids and phenomena, like the phase behaviour of fluids in pores, macromolecular assemblies, and the glass transition. Many of the new tools have their roots in traditional liquid state theory, and, in conjunction with fresh input from related fields, allow it wider applicability.