Download or read book Understanding and Controlling Wetting Phenomena at the Micro nanoscale written by Zuankai Wang and published by ProQuest. This book was released on 2008 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nanostructured Thin Films and Surfaces written by and published by John Wiley & Sons. This book was released on 2010-03-08 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book series Nanomaterials for the Life Sciences, provides an in-depth overview of all nanomaterial types and their uses in the life sciences. Each volume is dedicated to a specific material class and covers fundamentals, synthesis and characterization strategies, structure-property relationships and biomedical applications. The series brings nanomaterials to the Life Scientists and life science to the Materials Scientists so that synergies are seen and developed to the fullest. Written by international experts of various facets of this exciting field of research, the series is aimed at scientists of the following disciplines: biology, chemistry, materials science, physics, bioengineering, and medicine, together with cell biology, biomedical engineering, pharmaceutical chemistry, and toxicology, both in academia and fundamental research as well as in pharmaceutical companies. VOLUME 5 - Nanostructured Thin Films and Surfaces

Download or read book Nanoscale and Microscale Phenomena written by Yogesh M. Joshi and published by Springer. This book was released on 2015-06-04 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is an outcome of research work in the areas of nanotechnology, interfacial science, nano- and micro-fluidics and manufacturing, soft matter, and transport phenomena at nano- and micro-scales. The contributing authors represent prominent research groups from Indian Institute of Technology Bombay, Indian Institute of Technology Kanpur and Indian Institute of Science, Bangalore. The book has 13 chapters and the entire work presented in the chapters is based on research carried out over past three years. The chapters are designed with number of coloured illustrations, figures and tables. The book will be highly beneficial to academicians as well as industrial professionals working in the mentioned areas.

Download or read book Micro and Nanoscale Phenomena in Tribology written by Yip-Wah Chung and published by CRC Press. This book was released on 2011-10-19 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Drawn from presentations at a recent National Science Foundation Summer Institute on Nanomechanics, Nanomaterials, and Micro/Nanomanufacturing, Micro- and Nanoscale Phenomena in Tribology explores the convergence of the multiple science and engineering disciplines involved in tribology and the connection from the macro to nano world. Written by specialists from computation, materials science, mechanical engineering, surface physics, and chemistry, each chapter provides up-to-date coverage of both basic and advanced topics and includes extensive references for further study. After discussing the evolution of tribology in the micro and nano world, the book describes contact conditions spanning between macroscale and nanoscale contacts. It presents an overview of fundamental continuum treatments of interfacial contact and lubrication under a wide range of conditions, including novel advances in contact simulation. It also gives a thorough account of the nature of surface energies and forces in nanostructures as well as adhesion in dry and wet environments. The book then explains how to perform friction measurements at the nanoscale and interpret friction data before demonstrating how micro- and nanotextured surfaces affect adhesion, friction, and wetting. The final chapters emphasize the importance of surface chemistry and molecular dynamics simulation in tribology. With numerous examples and figures throughout, this volume presents a thorough account of important advancements in tribology that offer insight into micro- and nanoscale phenomena. By enabling a better understanding of fundamental micro- and nanoscale interactions, the book helps readers effectively design and fabricate durable tribological components for various engineering and biological systems.

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 Dynamic Wetting by Nanofluids written by Gui Lu and published by Springer. This book was released on 2015-11-24 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: This PhD thesis presents the latest research findings on nanofluid wetting kinetics, which has wide applications in nano/microscale processes and devices. It analyzes complex dynamic wetting by nanofluids using both experiments and multi-scale simulation methods, and presents multiscale (from nano to macroscale) mechanisms and tunable methods to elucidate and control nanofluid dynamic wetting. The book is of interest to university researchers, R&D engineers and graduate students in surface science, materials science and thermal engineering.

Download or read book Challenges in Nanoscale Physics of Wetting Phenomena written by Shahriar Afkhami and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nanoscale Wetting and Its Implications to Macroscopic Surface Phenomena written by Tak Sing Wong and published by . This book was released on 2009 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wetting and Wettability written by Mahmood Aliofkhazraei and published by BoD – Books on Demand. This book was released on 2015-12-16 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: On the liquid 's surface, the molecules have fewer neighbors in comparison with the bulk volume. As a result, the energy interaction shows itself in the surface tension. Traditionally, the surface tension can be assumed as a force in the unit of the length which can be counted by the unit of Newton on squared meter, or energy on the units of the surface. The surface tension, implies the interface between liquid and vapor, which is an example of the surface tensions. The equilibrium between these surface tensions, decides that a droplet on a solid surface, would have a droplet form or will change to layer form. This book collects new developments in wetting and wettability science.

Download or read book Wetting and Phase change Phenomena on Micro nanostructures for Enhanced Heat Transfer written by Rong Xiao (Ph. D.) and published by . This book was released on 2013 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Micro/nanostructures have been extensively studied to amplify the intrinsic wettability of materials to create superhydrophilic or superhydrophobic surfaces. Such extreme wetting properties can influence the heat transfer performance during phase-change which is of great importance in a wide range of applications including thermal management, building environment, water harvesting and power production. In particular, superhydrophilic surfaces have been of interest to achieve thin film evaporation with high heat fluxes. Meanwhile, superhydrophobic surfaces with dropwise condensation promises higher heat transfer coefficients than typical filmwise condensation. My thesis work aims at improving fundamental understanding as well as demonstrating practical enhancements in these two areas. A key challenge to realizing thin film evaporation is the ability to achieve efficient fluid transport using superhydrophilic surfaces. Accordingly, we developed a semi-analytical model based on the balance between capillary pressure and viscous resistance to predict the propagation rates in micropillar arrays with high aspect ratios. Our experimental results showed good agreement with the model, and design guidelines for optimal propagation rates were proposed. For micropillar arrays with low aspect ratio and large spacing between pillars, however, we identified that the microscopic sweeping of the liquid front becomes important. We studied this phenomenon, explained the effect of such microscale dynamics on the overall propagation behavior, and proposed a strategy to account for these dynamics. While these propagation studies provide a means to deliver liquid to high heat flux regions, we investigated a different configuration using nanoporous membrane that decouples capillarity from the viscous resistance to demonstrate the potential heat dissipation capability. With nanoporous membranes with average pore diameters of 150 nm and thicknesses of 50 [mu]m, we achieved interfacial heat fluxes as high as 96 W/cm2 via evaporation with isopropyl alcohol. The effect of membrane thickness was studied to offer designs that promise dissipation of 1000 W/cm 2 . Meanwhile, we developed new metrology to measure transient heat transfer coefficients with a temporal resolution of 0.2 seconds during the evaporation process. Such a technique offers insight into the relationship between liquid morphology and heat transfer behavior. Finally, for enhanced condensation, we demonstrated immersion condensation using a composite surface fabricated by infusing hydrophobic oil into micro/nanostructures with a heterogeneous coating. With this approach, three key attributes to maximize heat transfer coefficient, low departure radii, low contact angle, and high nucleation density, were achieved simultaneously. We specifically elucidated the mechanism for the increase in nucleation density and attribute it to the combined effect of reduced water-oil interfacial energy and local high surface energy sites. As a result, we demonstrated approximately 100% enhancement in heat transfer coefficient over state-of-the-art superhydrophobic surfaces with the presence of non-condensable gases. This thesis presents improved fundamental understanding of wetting, evaporation, and condensation processes on micro/nanostructures as well as practical implementation of these structures for enhanced heat transfer. The insights gained demonstrate the potential of new nanostructure engineering approaches to improve the performance of various thermal management and energy production applications.

Download or read book Wettability and Interfacial Phenomena written by Rita Khanna and published by BoD – Books on Demand. This book was released on 2019-05-22 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wettability at the solid/liquid interface, its dynamics, tunability, the influence of operating parameters, surface and interfacial phenomena play an increasingly significant role in a wide variety of applications, for example, material processing, nanotechnology, oil recovery, oil spills, chemical leaching, water management, and disease transmission. Although a mature field, it is experiencing dramatic developments on several fronts with emerging applications in new fields. This book presents a collection of eight chapters on nanoscale wetting phenomena, oil extraction from reservoir rocks, the role of coatings, particle morphology, surface roughness and viscosity in metal processing, and practical applications of superhydrophobic behaviour in cell culturing, isolation, anti-icing, anti-reflective and anti-corrosion coatings in the transportation and optical devices fields.

Download or read book Manipulation of Nanoscale Materials written by Katsuhiko Ariga and published by Royal Society of Chemistry. This book was released on 2012-09-05 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: Techniques and strategies for the production of nanomaterials and nanostructures have developed to an advanced level. However, the concepts and methods needed to correctly architect these materials into viable applications remains seriously lacking. This book introduces the concept of "Nanoarchitechtonics", a term introduced by Dr Masakazu Aono to describe the correct manipulation of nanoscale materials in the creation of nano-devices and applications. With contributions from across the globe, Manipulation of Nanoscale Materials presents a broad spectrum of nanomaterials and their applications. Following an introductory chapter prepared by the editors, the book is divided into three further sections of chapters, detailing Nanoarchitectonics for Materials Development, Materials Nanoarchitechtonics for Bio-Conjugates and Bio-Applications, Materials Nanoarchitechtonics for Advanced Devices. The first book in its field, this is essential reading for anyone creating or deploying nanomaterials. Fully referenced to the primary literature, this title presents an excellent source of information, and inspiration, to the reader and should appeal to experienced materials scientists, nanotechnologists and postgraduate students. Dr. Katsuhiko Ariga is the Director of Supermolecules Group and Principal Investigator of World Premier International (WPI) Research Center for Materials Nanoarchitectonics (MANA), the National Institute for Materials Science (NIMS). Dr Masakazu Aono is Director General of MANA and group leader of the nano-system organiszation group MANA, NIMS.

Download or read book Wetting of Two Dimensional Physically Patterned Surfaces written by Michael Bell and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An understanding of wetting phenomena is important, in part, due to the many practical applications of controlled wetting. Some of the most exciting applications involve superhydrophobic surfaces, on which water droplets exhibit contact angles larger than 150 degrees and contact angle hysteresis less than 10 degrees. These surfaces are notable for their low-drag, antifouling, and self-cleaning properties, among others. Wetting is known to be affected by both the chemistry and the physical patterning of a surface, with the chemistry affecting what is called the intrinsic contact angle, which is the contact angle displayed by a droplet on a smooth flat surface made of the given material. To date, the largest intrinsic contact angle observed for any material is only about 120 degrees, which does not confer superhydrophobicity. Thus, physical patterning is a crucial component of any superhydrophobic surface. Interestingly, many natural examples of superhydrophobic surfaces exist, with one of the most notable being the lotus leaf. In designing such surfaces, scientists have turned to the natural examples for inspiration, and have found that most natural examples have multiple (usually two) scales of roughness, commonly referred to as hierarchical roughness. Though hierarchical roughness is ubiquitous in the superhydrophobic surfaces of the natural world, its precise role in conferring superhydrophobicity has so far remained elusive.In this work, we develop a thermodynamic model to study the wetting of two-dimensional physically patterned surfaces. Past models that have been developed for this purpose often make several assumptions: the drop must be much larger than the surface features while simultaneously being small enough that the effects of gravity are negligible. Many of these models ultimately rely on the older Cassie and Wenzel models, which themselves make assumptions about the drop size relative to the surface features--namely that the drop is again much larger than the surface features. In this work, we relax these assumptions. We begin by investigating the role of hierarchical roughness (specifically dual-scale roughness) in affecting static contact angles by making no assumptions other than that the effect of gravity is negligible, though the surface features are allowed to be similar in size to the droplet. By investigating phase diagrams of contact angles as a function of surface feature parameters, we find that the nanoscale roughness in hierarchical roughness serves mainly to amplify the intrinsic contact angle of the macroscale roughness, thereby allowing for large contact angles on relatively low aspect ratio macroscale structures. Next, we lift the assumption of the negligible effect of gravity, and consider arbitrarily-sized droplets relative to the surface features, for which the effect of gravity is non-negligible. From this, we find that the effect of gravity is primarily to shift the boundary between the Cassie and Wenzel modes in the phase diagram. Other effects of gravity on contact angles occur mainly when the drops are similar in size to the surface features. Further, by comparing predictions of a circular cap model with a deformable cap model, we find that the gravitationally-induced deformations mainly affect the contact angle, with the equilibrium wetting configurations predicted by both models being otherwise quite similar.Both of these studies reinforce the idea that pinning effects become less important when the surface features become much smaller than the drop size. We next explore this regime, in which the Cassie and Wenzel models become valid, in more detail. Specifically, we use perturbation theory to derive a correction to the Wenzel equation to properly account for the volume of liquid stored in the grooves which was not considered in the original derivation. By considering both the two- and three-dimensional cases, we find an intuitive explanation for the two-dimensional correction which unfortunately breaks down in the three-dimensional case, due to an unexpected factor of two which arises in the first-order correction term. Finally, we investigate the roles of physical patterning on contact angle hysteresis, and we conclude by discussing potential future directions for this research.

Download or read book Capillarity and Wetting Phenomena written by Pierre-Gilles de Gennes and published by Springer Science & Business Media. This book was released on 2013-03-20 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of capillarity is in the midst of a veritable explosion. What is offered here is not a comprehensive review of the latest research but rather a compendium of principles designed for the undergraduate student and for readers interested in the physics underlying these phenomena.

Download or read book Control Technologies for Emerging Micro and Nanoscale Systems written by Evangelos Eleftheriou and published by Springer. This book was released on 2011-07-15 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprises a selection of the presentations made at the “Workshop on Dynamics and Control of Micro and Nanoscale Systems” held at IBM Research – Zurich, Switzerland, on the 10th and 11th of December 2009. The aim of the workshop was to bring together some of the leading researchers in the field of dynamics and control of micro- and nanoscale systems. It proved an excellent forum for discussing new ideas and approaches.

Download or read book Examining Wetting and Dewetting Processes in Thin films on Crystalline Substrates at the Nanoscale written by Sahar Hihath and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Controlling the wetting and dewetting of ultra-thin films on solid substrates is important for a variety of technological and fundamental research applications. These applications include film deposition for semiconductor manufacturing, the growth of nanowires through nanoparticle-based catalysis sites, to making ordered arrays of nanoscale particles for electronic and optical devices. However, despite the importance of these processes, the underlying mechanisms by which a film wets a surface or dewets from it is still often unclear and widely debated. In this dissertation we examine wetting and dewetting processes in three materials systems that are relevant for device applications with the ultimate goal of understanding what mechanisms drive the wetting (or dewetting) process in each case. First, we examine the formation of wetting layers between nanoparticle films and highly conductive GaAs substrates for spintronic applications. In this case, the formation of a wetting layer is important for nanoparticle adhesion on the substrate surface. Wetting layers can be made by annealing these systems, which causes elemental diffusion from nanoparticles into the substrate, thereby adhesion between the nanoparticles and the substrate. Here we investigate the feasibility of forming a wetting layer underneath nanoparticles post-annealing in a system of Fe3O4 nanoparticles on a (100) GaAs substrate by studying the interface structure and composition via Transmission Electron Microscopy (TEM), Scanning Transmission Electron Microscopy (STEM), Electron Energy Loss Spectroscopy (EELS) and Energy Dispersive X-ray Spectroscopy (EDXS). Electron Energy-Loss fine structures of the Fe-L3,2 and O-K absorption edges were quantitatively analyzed to gain insight about the compositional gradient of the interface between the nanoparticles and the GaAs substrate. Additionally, real-space density functional theory calculations of the dynamical form factor was performed to confirm the experimental observations. Second, the fundamental mechanisms that govern the onset of dewetting of thin metal films in both liquid and solid state are investigated. Dewetting processes are used in numerous technological applications. For instance, the dewetting of thin films on substrates is used for making spatially ordered nanoparticle arrays for use in plasmonics, nanophotonics, and magnetics. [1] In addition to dewetting applications in industry and research, dewetting processes have adverse impact on the reliability of semiconductor devices as it can limit the functionality of metal contacts utilized in transistors at elevated temperatures. The morphological changes during dewetting have been studied previously in plan-view by Scanning Electron Microscopy (SEM) after the annealing is completed, and in some cases in cross-section via real-time Transmission Electron Microscopy (TEM). However, due to temporal limitations of image acquisition in TEM, which is in the range of milliseconds, it has not been possible thus far to investigate the dynamics of the dewetting process with high-speed time resolution from nano- to micro-seconds. To gain insights into the fundamental mechanisms involved in dewetting, the early stages of the dewetting process were investigated via Dynamic Transmission Electron Microscopy (DTEM) with nanosecond time and nanometer spatial resolution. The experiments were performed on plan-view TEM samples consisting of nickel thin-films on (100) silicon substrates with a 2-3 nm thick native oxide. The laser ablation dynamics were captured, which involved liquid phase dewetting of the nickel film followed by substrate fracture and nanoscale particle expulsion. Finally, to capture the full dynamics of the dewetting process the experiments were performed on a system of nickel thin-films on (100) Strontium Titanate (STO) substrates. Samples of nickel thin-films on STO substrates have lower thermal expansion coefficient mismatch compared to the system discussed above. Thus, the STO substrates did not fracture after laser irradiation and enabled us to capture the progress of hole growth with time. Valence Electron Energy Loss spectroscopy was used to find the thickness of the TEM sample in order to calculate the geometry and simulate the temperature fields via finite element analysis with COMSOL Multiphysics package. Spatio-temporal temperature plots acquired from finite element modeling suggests that both liquid and solid-state dewetting processes were observed depending upon the magnitude of the laser energy used.

Download or read book Mesoscale Chemistry written by National Research Council and published by National Academies Press. This book was released on 2015-08-06 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last few decades great strides have been made in chemistry at the nanoscale, where the atomic granularity of matter and the exact positions of individual atoms are key determinants of structure and dynamics. Less attention, however, has been paid to the mesoscale-it is at this scale, in the range extending from large molecules (10 nm) through viruses to eukaryotic cells (10 microns), where interesting ensemble effects and the functionality that is critical to macroscopic phenomenon begins to manifest itself and cannot be described by laws on the scale of atoms and molecules alone. To further explore how knowledge about mesoscale phenomena can impact chemical research and development activities and vice versa, the Chemical Sciences Roundtable of the National Research Council convened a workshop on mesoscale chemistry in November 2014. With a focus on the research on chemical phenomena at the mesoscale, participants examined the opportunities that utilizing those behaviors can have for developing new catalysts, adding new functionality to materials, and increasing our understanding of biological and interfacial systems. The workshop also highlighted some of the challenges for analysis and description of mesoscale structures. This report summarizes the presentations and discussion of the workshop.