Download or read book Nanoscale Modeling for Ultra thin Liquid Films written by David Michael Phillips and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nanoscale structure forming processes written by Viktor Elofsson and published by Linköping University Electronic Press. This book was released on 2016-11-30 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin film growth from the vapor phase has for a long time intrigued researchers endeavouring to unravel and understand atomistic surface processes that govern film formation. Their motivation has not been purely scientific, but also driven by numerous applications where this understanding is paramount to knowledge-based design of novel film materials with tailored properties. Within the above framework, this thesis investigates growth of metal films on weakly bonding substrates, a combination of great relevance for applications concerning e.g., catalysis, graphene metallization and architectural glazing. When metal vapor condenses on weakly bonding substrates three dimensional islands nucleate, grow and coalesce prior to forming a continuous film. The combined effect of these initial growth stages on film formation and morphology evolution is studied using pulsed vapor fluxes for the model system Ag/SiO2. It is shown that the competition between island growth and coalescence completion determines structure evolution. The effect of the initial growth stages on film formation is also examined for the tilted columnar microstructure obtained when vapor arrives at an angle that deviates from the substrate surface normal. This is done using two metals with distinctly different nucleation behaviour, and the findings suggest that the column tilt angle is set by nucleation conditions in conjunction with shadowing of the vapor flux by adjacent islands. Vapor arriving at an angle can in addition result in films that exhibit preferred crystallographic orientations, both out-of-plane and in-plane. Their emergence is commonly described by an evolutionary growth model, which for some materials predict a double in-plane alignment that has not been observed experimentally. Here, an experiment is designed to replicate the model’s growth conditions, confirming the existence of double in-plane alignment. New and added film functionalities can further be unlocked by alloying. Properties are then largely set by chemistry and atomic arrangement, where the latter can be affected by thermodynamics, kinetics and vapor flux modulation. Their combined effect on atomic arrangement is here unravelled by presenting a research methodology that encompasses high resolution vapor flux modulation, nanoscale structure v vi probes and growth simulations. The methodology is deployed to study the immiscible Ag-Cu and miscible Ag-Au model systems, for which it is shown that capping of Cu by Ag atoms via near surface diffusion processes and rough morphology of the Ag-Au growth front are the decisive structure forming processes in each respective system. The results generated in this thesis are of relevance for tuning structure of metal films grown on weakly bonding substrates. They also indicate that improved growth models are required to accurately describe structure evolution and emergence of a preferred in-plane orientation in films where vapor arrives at an angle that deviates from the substrate surface normal. In addition, this thesis presents a methodology that can be used to identify and understand structure forming processes in multicomponent films, which may enable tailoring of atomic arrangement and related properties in technologically relevant material systems.

Download or read book Nano and mesoscale morphology evolution of metal films on weakly interacting surfaces written by Bo Lü and published by Linköping University Electronic Press. This book was released on 2018-01-11 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin films are structures consisting of one or several nanoscale atomic layers of material that are used to either functionalize a surface or constitute components in more complex devices. Many properties of a film are closely related to its microstructure, which allows films to be tailored to meet specific technological requirements. Atom-by-atom film growth from the vapor phase involves a multitude of atomic processes that may not be easily studied experimentally in real-time because they occur in small length- (? Å) and timescales (? ns). Therefore, different types of computer simulation methods have been developed in order to test theoretical models of thin film growth and unravel what experiments cannot show. In order to compare simulated and experimental results, the simulations must be able to model events on experimental time-scales, i.e. on the order of microseconds to seconds. This is achievable with the kinetic Monte Carlo (kMC) method. In this work, the initial growth stages of metal deposition on weakly-interacting substrates is studied using both kMC simulations as well as experiments whereby growth was monitored using in situ probes. Such film/substrate material combinations are widely encountered in technological applications including low-emissivity window coatings to parts of microelectronics components. In the first part of this work, a kMC algorithm was developed to model the growth processes of island nucleation, growth and coalescence when these are functions of deposition parameters such as the vapor deposition rate and substrate temperature. The dynamic interplay between these growth processes was studied in terms of the scaling behavior of the film thickness at the elongation transition, for both continuous and pulsed deposition fluxes, and revealed in both cases two distinct growth regimes in which coalescence is either active or frozen out during deposition. These growth regimes were subsequently confirmed in growth experiments of Ag on SiO2, again for both pulsed and continuous deposition, by measuring the percolation thickness as well as the continuous film formation thickness. However, quantitative agreement with regards to scaling exponents in the two growth regimes was not found between simulations and experiments, and this prompted the development of a method to determine the elongation transition thickness experimentally. Using this method, the elongation transition of Ag on SiO2 was measured, with scaling exponents found in much better agreement with the simulation results. Further, these measurement data also allowed the calculation of surface properties such as the terrace diffusion barrier of Ag on SiO2 and the average island coalescence rate. In the second part of this thesis, pioneering work is done to develop a fully atomistic, on-lattice model which describes the growth of Ag on weakly-interacting substrates. Simulations performed using this model revealed several key atomic-scale processes occurring at the film/substrate interface and on islands which govern island shape evolution, thereby contributing to a better understanding of how 3D island growth occurs at the atomic scale for a wide class of materials. The latter provides insights into the directed growth of metal nanostructures with controlled shapes on weakly-interacting substrates, including twodimensional crystals for use in catalytic and nano-electronic applications.

Download or read book Thin Liquid Films with Nanoparticles and Rod like Ions as Models for Nanofluidics written by Silke Stöckle and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the rise of nanotechnology in the last decade, nanofluidics has been established as a research field and gained increased interest in science and industry. Natural aqueous nanofluidic systems are very complex, there is often a predominance of liquid interfaces or the fluid contains charged or differently shaped colloids. The effects, promoted by these additives, are far from being completely understood and interesting questions arise with regards to the confinement of such complex fluidic systems. A systematic study of nanofluidic processes requires designing suitable experimental model nano - channels with required characteristics. The present work employed thin liquid films (TLFs) as experimental models. They have proven to be useful experimental tools because of their simple geometry, reproducible preparation, and controllable liquid interfaces. The thickness of the channels can be adjusted easily by the concentration of electrolyte in the film forming solution. This way, channel dimensions from 5 - 100 nm are possible, a high flexibility for an experimental system. TLFs have liquid IFs of different charge and properties and they offer the possibility to confine differently shaped ions and molecules to very small spaces, or to subject them to controlled forces. This makes the foam films a unique "device" available to obtain information about fluidic systems in nanometer dimensions. The main goal of this thesis was to study nanofluidic processes using TLFs as models, or tools, and to subtract information about natural systems plus deepen the understanding on physical chemical conditions. The presented work showed that foam films can be used as experimental models to understand the behavior of liquids in nano - sized confinement. In the first part of the thesis, we studied the process of thinning of thin liquid films stabilized with the non - ionic surfactant n - dodecyl - ß - maltoside (ß - C12G2) with primary interest in interfacial diffusion processes during the thinning process dependent on surfactant concentration 64. The surfactant concentration in the film forming solutions was varied at constant electrolyte (NaCl) concentration. The velocity of thinning was analyzed combining previously developed theoretical approaches. Qualitative information about the mobility of the surfactant molecules at the film surfaces was obtained. We found that above a certain limiting surfactant concentration the film surfaces were completely immobile and they behaved as non - deformable, which decelerated the thinning process. This follows the predictions for Reynolds flow of liquid between two non - deformable disks. In the second part of the thesis, we designed a TLF nanofluidic system containing rod - like multivalent ions and compared this system to films containing monovalent ions. We presented first results which recognized for the first time the existence of an additional attractive force in the foam films based on the electrostatic interaction between rod - like ions and oppositely charged surfaces. We may speculate that this is an ion bridging component of the disjoining pressure. The results show that for films prepared in presence of spermidine the transformation of the thicker CF to the thinnest NBF is more probable as films prepared with NaCl at similar conditions of electrostatic interaction. This effect is not a result of specific adsorption of any of the ions at the fluid surfaces and it does not lead to any changes in the equilibrium properties of the CF and NBF. Our hypothesis was proven using the trivalent ion Y3+ which does not show ion bridging. The experimental results are compared to theoretical predictions and a quantitative agreement on the system's energy gain for the change from CF to NBF could be obtained. In the third part of the work, the behavior of nanoparticles in confinement was investigated with respect to their impact on the fluid flow velocity. The particles altered the flow velocity by an unexpected high amount, so that the resulting changes in the dynamic viscosity could not be explained by a realistic change of the fluid viscosity. Only aggregation, flocculation and plug formation can explain the experimental results. The particle systems in the presented thesis had a great impact on the film interfaces due to the stabilizer molecules present in the bulk solution. Finally, the location of the particles with respect to their lateral and vertical arrangement in the film was studied with advanced reflectivity and scattering methods. Neutron Reflectometry studies were performed to investigate the location of nanoparticles in the TLF perpendicular to the IF. For the first time, we study TLFs using grazing incidence small angle X - ray scattering (GISAXS), which is a technique sensitive to the lateral arrangement of particles in confined volumes. This work provides preliminary data on a lateral ordering of particles in the film.

Download or read book Advances in Chemical Physics Volume 129 written by Stuart A. Rice and published by John Wiley & Sons. This book was released on 2004-08-02 with total page 655 pages. Available in PDF, EPUB and Kindle. Book excerpt: This series provides the chemical physics field with a forum for critical, authoritative evaluations of advances in every area of the discipline. Volume 129 in the series continues to report recent advances with significant, up-to-date chapters by internationally recognized researchers.

Download or read book Nanoscale Liquid Interfaces written by Thierry Ondarcuhu and published by CRC Press. This book was released on 2013-04-17 with total page 769 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses the recent developments in the investigation and manipulation of liquids at the nanoscale. This new field has shown important breakthroughs on the basic understanding of physical mechanisms involving liquid interfaces, which led to applications in nanopatterning. It has also consequences in force microscopy imaging in liquid env

Download or read book Thin Liquid Films written by Ralf Blossey and published by Springer Science & Business Media. This book was released on 2012-05-22 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a treatise on the thermodynamic and dynamic properties of thin liquid films at solid surfaces and, in particular, their rupture instabilities. For the quantitative study of these phenomena, polymer thin films (sometimes referred to as “ultrathin”) have proven to be an invaluable experimental model system. What is it that makes thin film instabilities special and interesting? First, thin polymeric films have an important range of applications. An understanding of their instabilities is therefore of practical relevance for the design of such films. The first chapter of the book intends to give a snapshot of current applications, and an outlook on promising future ones. Second, thin liquid films are an interdisciplinary research topic, which leads to a fairly heterogeneous community working on the topic. It justifies attempting to write a text which gives a coherent presentation of the field which researchers across their specialized communities might be interested in. Finally, thin liquid films are an interesting laboratory for a theorist to confront a well-established theory, hydrodynamics, with its limits. Thin films are therefore a field in which a highly fruitful exchange and collaboration exists between experimentalists and theorists. The book stretches from the more concrete to more abstract levels of study: we roughly progress from applications via theory and experiment to rigorous mathematical theory. For an experimental scientist, the book should serve as a reference and guide to what is the current consensus of the theoretical underpinnings of the field of thin film dynamics. Controversial problems on which such a consensus has not yet been reached are clearly indicated in the text, as well as discussed in a final chapter. From a theoretical point of view, the field of dewetting has mainly been treated in a mathematically ‘light’ yet elegant fashion, often making use of scaling arguments. For the untrained researcher, this approach is not always easy to follow. The present book attempts to bridge between the ‘light’ and the ‘rigorous’, always with the ambition to enhance insight and understanding - and to not let go the elegance of the theory.

Download or read book Nanoscale Flow written by Sarhan M. Musa and published by CRC Press. This book was released on 2018-09-03 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the physical properties and dynamical behavior of nanochannel flows has been of great interest in recent years and is important for the theoretical study of fluid dynamics and engineering applications in physics, chemistry, medicine, and electronics. The flows inside nanoscale pores are also important due to their highly beneficial drag and heat transfer properties. Nanoscale Flow: Advances, Modeling, and Applications presents the latest research in the multidisciplinary area of nanoscale flow. Featuring contributions from top inventors in industry, academia, and government, this comprehensive book: Highlights the current status of research on nucleate pool boiling heat transfer, flow boiling heat transfer, and critical heat flux (CHF) phenomena of nanofluids Describes two novel fractal models for pool boiling heat transfer of nanofluids, including subcooled pool boiling and nucleate pool boiling Explores thermal conductivity enhancement in nanofluids measured with a hot-wire calorimeter Discusses two-phase laminar mixed convection AL2O3–water nanofluid in an elliptic duct Explains the principles of molecular and omics imaging and spectroscopy techniques for cancer detection Analyzes fluid dynamics modeling of the tumor vasculature and drug transport Studies the properties of nanoscale particles and their impact on diagnosis, therapeutics, and theranostics Provides a brief background and review of medical nanoscale flow applications Contains useful appendices of physical constants, equations, common symbols, mathematical formulas, the periodic table, and more A valuable reference for engineers, scientists, and biologists, Nanoscale Flow: Advances, Modeling, and Applications is also designed for researchers, universities, industrial institutions, and government, giving it broad appeal.

Download or read book Multiscale Materials Modeling for Nanomechanics written by Christopher R. Weinberger and published by Springer. This book was released on 2016-08-30 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a unique combination of chapters that together provide a practical introduction to multiscale modeling applied to nanoscale materials mechanics. The goal of this book is to present a balanced treatment of both the theory of the methodology, as well as some practical aspects of conducting the simulations and models. The first half of the book covers some fundamental modeling and simulation techniques ranging from ab-inito methods to the continuum scale. Included in this set of methods are several different concurrent multiscale methods for bridging time and length scales applicable to mechanics at the nanoscale regime. The second half of the book presents a range of case studies from a varied selection of research groups focusing either on a the application of multiscale modeling to a specific nanomaterial, or novel analysis techniques aimed at exploring nanomechanics. Readers are also directed to helpful sites and other resources throughout the book where the simulation codes and methodologies discussed herein can be accessed. Emphasis on the practicality of the detailed techniques is especially felt in the latter half of the book, which is dedicated to specific examples to study nanomechanics and multiscale materials behavior. An instructive avenue for learning how to effectively apply these simulation tools to solve nanomechanics problems is to study previous endeavors. Therefore, each chapter is written by a unique team of experts who have used multiscale materials modeling to solve a practical nanomechanics problem. These chapters provide an extensive picture of the multiscale materials landscape from problem statement through the final results and outlook, providing readers with a roadmap for incorporating these techniques into their own research.

Download or read book Glancing Angle Deposition of Thin Films written by Matthew M. Hawkeye and published by John Wiley & Sons. This book was released on 2014-07-03 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a highly practical treatment of Glancing Angle Deposition (GLAD), a thin film fabrication technology optimized to produce precise nanostructures from a wide range of materials. GLAD provides an elegant method for fabricating arrays of nanoscale helices, chevrons, columns, and other porous thin film architectures using physical vapour deposition processes such as sputtering or evaporation. The book gathers existing procedures, methodologies, and experimental designs into a single, cohesive volume which will be useful both as a ready reference for those in the field and as a definitive guide for those entering it. It covers: Development and description of GLAD techniques for nanostructuring thin films Properties and characterization of nanohelices, nanoposts, and other porous films Design and engineering of optical GLAD films including fabrication and testing, and chiral films Post-deposition processing and integration to optimize film behaviour and structure Deposition systems and requirements for GLAD fabrication A patent survey, extensive relevant literature, and a survey of GLAD's wide range of material properties and diverse applications.

Download or read book Metal film growth on weakly interacting substrates written by Víctor Gervilla Palomar and published by Linköping University Electronic Press. This book was released on 2019-02-11 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin films are nanoscale layers of material, with exotic properties useful in diverse areas, ranging from biomedicine to nanoelectronics and surface protection. Film properties are not only determined by their chemical composition, but also by their microstructure and roughness, features that depend crucially on the growth process due to the inherent out-of equilibrium nature of the film deposition techniques. This fact suggest that it is possible to control film growth, and in turn film properties, in a knowledge-based manner by tuning the deposition conditions. This requires a good understanding of the elementary film-forming processes, and the way by which they are affected by atomic-scale kinetics. The kinetic Monte Carlo (kMC) method is a simulation tool that can model film evolution over extended time scales, of the order of microseconds, and beyond, and thus constitutes a powerful complement to experimental research aiming to obtain an universal understanding of thin film formation and morphological evolution. In this work, kMC simulations, coupled with analytical modelling, are used to investigate the early stages of formation of metal films and nanostructures supported on weakly-interacting substrates. This starts with the formation and growth of faceted 3D islands, that relies first on facile adatom ascent at single-layer island steps and subsequently on facile adatom upward diffusion from the base to the top of the island across its facets. Interlayer mass transport is limited by the rate at which adatoms cross from the sidewall facets to the island top, a process that determines the final height of the islands and leads non-trivial growth dynamics, as increasing temperatures favour 3D growth as a result of the upward transport. These findings explain the high roughness observed experimentally in metallic films grown on weakly-interacting substrates at high temperatures. The second part of the study focus on the next logical step of film formation, when 3D islands come into contact and fuse into a single one, or coalesce. The research reveals that the faceted island structure governs the macroscopic process of coalescence as well as its dynamics, and that morphological changes depend on 2D nucleation on the II facets. In addition, deposition during coalescence is found to accelerate the process and modify its dynamics, by contributing to the nucleation of new facets. This study provides useful knowledge concerning metal growth on weakly-interacting substrates, and, in particular, identifies the key atomistic processes controlling the early stages of formation of thin films, which can be used to tailor deposition conditions in order to achieve films with unique properties and applications.

Download or read book Fundamentals of Nanoscale Film Analysis written by Terry L. Alford and published by Springer Science & Business Media. This book was released on 2007-04-03 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: From materials science to integrated circuit development, much of modern technology is moving from the microscale toward the nanoscale. This book focuses on the fundamental physics underlying innovative techniques for analyzing surfaces and near-surfaces. New analytical techniques have emerged to meet these technological requirements, all based on a few processes that govern the interactions of particles and radiation with matter. This book addresses the fundamentals and application of these processes, from thin films to field effect transistors.

Download or read book Advances in Heat Transfer written by and published by Elsevier. This book was released on 2024-10-05 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Heat Transfer, Volume 58 presents the latest in a serial that highlights new advances in the field, with this updated volume presenting interesting chapters written by an international board of authors. Sample chapters in this new release include Nanoscale Thin Film Evaporation and Ice thermal energy storage modeling: A review. - Provides the authority and expertise of leading contributors from an international board of authors - Presents the latest release in Advances in Heat Transfer serials

Download or read book Advances in Thin Films Nanostructured Materials and Coatings written by Alexander D. Pogrebnjak and published by Springer. This book was released on 2019-02-08 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights the latest advances in chemical and physical methods for thin-film deposition and surface engineering, including ion- and plasma-assisted processes, focusing on explaining the synthesis/processing–structure–properties relationship for a variety of thin-film systems. It covers topics such as advances in thin-film synthesis; new thin-film materials: diamond-like films, granular alloys, high-entropy alloys, oxynitrides, and intermetallic compounds; ultra-hard, wear- and oxidation-resistant and multifunctional coatings; superconducting, magnetic, semiconducting, and dielectric films; electrochemical and electroless depositions; thin-film characterization and instrumentation; and industrial applications.

Download or read book Soft Matter And Biomaterials On The Nanoscale The Wspc Reference On Functional Nanomaterials Part I In 4 Volumes written by and published by World Scientific. This book was released on 2020-06-24 with total page 1885 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is indexed in Chemical Abstracts ServiceSoft and bio-nanomaterials offer a tremendously rich behavior due to the diversity and tailorability of their structures. Built from polymers, nanoparticles, small and large molecules, peptoids and other nanoscale building blocks, such materials exhibit exciting functions, either intrinsically or through the engineering of their organization and combination of blocks. Thus, it is not surprising that a variety of challenges, for example, in energy storage, environment protection, advanced manufacturing, purification and healthcare, can be addressed using these materials. The recent advances in understanding the behavior of soft matter and biomaterials are being actively translated into functional materials systems and devices, which take advantages of newly discovered and specifically created morphologies with desired properties. This major reference work presents a detailed overview of recent research developments on fundamental and application-inspired aspects of soft and bio-nanomaterials and their emerging functions, and will be divided into four volumes: Vol 1: Soft Matter under Geometrical Confinement: From Fundamentals at Planar Surfaces and Interfaces to Functionalities of Nanoporous Materials; Vol 2: Polymers on the Nanoscale: Nano-structured Polymers and Their Applications; Vol 3: Bio-Inspired Nanomaterials: Nanomaterials Built from Biomolecules and Using Bio-derived Principles; Vol 4: Nanomedicine: Nanoscale Materials in Nano/Bio Medicine.

Download or read book Encyclopedia of Chemical Processing written by Sunggyu Lee and published by Taylor & Francis US. This book was released on 2006 with total page 682 pages. Available in PDF, EPUB and Kindle. Book excerpt: Collecting information of vital interest to chemical, polymer, mechanical, electrical, and civil engineers, as well as chemists and chemical researchers, this "Encyclopedia "supplies nearly 350 articles on current design, engineering, science, and manufacturing practices-offering expertly written articles on technologies at the forefront of the field to maximize and enhance the research and production phases of current and emerging chemical manufacturing practices and techniques.

Download or read book Methods for the Direct Simulation of Nanoscale Film Breakup and Contact Angles written by Kyle Mahady and published by . This book was released on 2015 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis investigates direct simulation of fluids with free surfaces and contact lines, with a focus on capturing nanoscale physics in a continuum based computational framework. Free surfaces and contact lines have long presented some of the most challenging problems in computational fluid dynamics. Extensive progress has been made in recent years, and a wide variety of different methods are currently employed for direct simulation in these contexts. The complexity of the full governing equations for such flows poses significant challenges in terms of analytical techniques, and leads to lengthy computational times for direct simulations. For these reasons, reduced models are preferable in many contexts, even when it is not clear that such reduced models strictly apply. Recent advances in nanotechnology motivate the comparison between direct simulations and reduced models by presenting situations in which each possesses advantages; these experiments involve the deposition of nanoscale flat metallic structures onto a surface with unprecedented precision, the almost instantaneous liquefaction of which leads to new initial liquid configurations which have been previously impossible to achieve in an experimental setup. The mechanisms that lead to the instability of these structures are a combination of classical liquid instability (such as Rayleigh-Plateau), novel capillary instabilities driven by the initial geometry, and nanoscale physics. This study begins by examining the differences in qualitative behavior between direct numerical simulation of the full equations and a particular reduced model in the context of wetting and dewetting of drops. Afterwards, a specific initial liquid geometry is presented, the breakup of which requires direct numerical simulation in order to explain the experimental behavior. A parameter study of this geometry demonstrates that it offers a rich variety of dynamics; the breakup of the geometry is found to result in nanoparticle arrangements previously unobtainable using similar techniques, and through careful tuning of the parameters the end state of the breakup can be various combinations of metallic filaments and nanoparticles. While such instabilities are driven by surface tension, an important class of thin film instability is driven by intermolecular fluid/solid interactions. A numerical method is developed which, for the first time, permits the explicit inclusion of this fluid/solid interaction in the context of direct numerical simulations. This method not only allows for modeling and simulating film breakup, but additionally yields a numerical method for the simulation of contact angles as well.