Download or read book Fabrication and Characterisation of Nanostructured Surfaces with Extreme Wettabilities written by Nan Gao and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Formation and Characterisation of Micro and Nanostructured Surfaces Through Combinations of Top down and Bottom up Fabrication Methodologies written by Simon J. Leigh and published by . This book was released on 2009 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fabrication and Characterization of Nanostructured Surfaces for Enhanced Heat Transfer written by Changho Choi and published by . This book was released on 2010 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: This objective of this study is to investigate the capability of nanostructured surfaces on dissipating heat flux by performing pool boiling and convective flow boiling. The generation of ultra-high heat flux from high performance electric devices has motivated a number of investigations related to advanced heat transfer especially in two-phase boiling performance. It has been reported by a number of researchers that nanostructured surfaces can result in much enhanced boiling performance, compared to the conventional methods by creating desire conditions for heat transfer. In this thesis, various nanostructured surfaces having different morphology were prepared on several engineering relevant substrates and were characterized for their pool boiling performance. Microreactor-assisted-nanomaterial-deposition, MAND [trademark symbol] was used to fabricate a variety of different ZnO nanostructured surfaces by careful adjustment of the processing parameters. ZSM-5 zeolite was synthesized using hydrothermal reaction. ZnO nanostructures in minichannel were also successfully deposited via a flow cell for the application of flow boiling experiment. Scanning electron microscopy (SEM) and Atomic Force Microscopy (AFM) were carried out to characterize the micro- and nanostructures. Contact angle measurement was conducted to evaluate wettability and X-ray Diffraction (XRD) was used to determine the crystalline structures. The most significant enhancement of critical heat flux (CHF) and heat transfer coefficient (HTC) was observed in the flower like ZnO nanostructured surface. We observed pool boiling CHF of 80-82.5 W/cm2 for nanostructured ZnO on Al surfaces versus a CHF of 23.2 W/cm2 on a bare Al surface with a wall superheat reduction of 25-38°C. This new CHF values on nanostructured surfaces corresponds to a boiling heat transfer coefficient as high as ~ 23000 W/m2K. This represents an increase of almost 4X in CHF on nano-textured surfaces, which is the highest enhancement factor reported today.
Download or read book Fabrication and a Study of the Wetting Properties of Nanostructured Surfaces written by and published by . This book was released on 2007 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluid behavior at the microscale exhibits large surface to volume ratios increasing the significance of interfacial phenomena. We have studied two microfluidic phenomena that utilize interplay between microstructure and chemical composition. The first one causes liquid droplets to roll off from surfaces with a very high contact angle. This phenomenon is called superhydrophobic behavior, can be controlled by several tuning parameters. The second one changes the wettability of liquids on a dielectric coated surface with electric potential. The experimental studies were done by first fabricating an ordered array of glass nanocones. Fiber drawing and differential glass etching processes were used to produce cone like structures with lattice constant of 40 [Mu]m down to 1.6 [Mu]m. The superhydrophobic behavior was first studied and modeled in a series of nanocone wafers of increasing aspect ratio from .3 to 15. The characterization was done by the measurement of the contact and rolling angles. The Wenzel to Cassie transition of wetting states was observed. The contact angles were calculated by using the 'axisymmetric drop shape analysis' approach. Next, the study of the electrowetting behavior of two broad categories of structured surfaces was done. One was a low aspect ratio surface exhibiting Wenzel wetting and the other was a high aspect ratio surface exhibiting Cassie wetting. The device for experimental study was prepared by coating additional layers, which included conductive gold and dielectric Parylene-C coatings. Studies were done using silicone oil and air as the ambient medium. Images of drops were taken at different voltages and the contact angles were calculated geometrically. Electrowetting on nanocone arrays was modeled using an energybased approach and the obtained theoretical curves were compared to the experimental ones. Oil helped in achieving a large contact angle change. A qualitative analysis of the electrowetting properties of the surfaces was done based on the voltage-contact angle curves.
Download or read book The Formation and Characterisation of Micro and Nanostructured Surfaces Through Combinations of Top down and Bottom up Fabrication Methodologies written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The research presented in this thesis explores work on micro and nanoscale patterning and structuring, towards 3D patterning of surfaces. The undertaking of such work is key to the advancement in areas such as microelectronics, nanotechnology and device and sensor fabrication. Chapter 1 (Nanotechnology: Introduction to Small Technology) presents an introduction to the background of the thesis research and information on the concepts and techniques used throughout the thesis. The first experimental chapter, Chapter 2 (Laying the Molecular Foundations) explores the patterning of monomolecular self-assembled-monolayers (instead of conventional polymeric resists) with electron beam lithography to form chemical patterns on gold surfaces. The chemical patterns on the surface then direct the self-assembly of gold nanoparticles with complementary chemistry. Chapter 3 (From the Foundations Upwards) utilises the self-assembling ability of the nanoparticles from the previous chapter and explores how they can be incorporated into a multilayer structure on a surface. This multilayer assembly is achieved by the layer-by-layer deposition methodology in conjunction with a charged polyelectrolyte. The layer-by-layer deposition process is followed with three different characterization techniques and the results compared. The chapter also examines other routes to directly patterning the layer-by-layer assembled structures such as photolithography and microfluidics. Chapter 4 (Printing and Scratching) explores the versatility of the nanoparticles and polyelectrolytes (from Chapter 3) towards alternative deposition techniques; in this case, a standard consumer-grade inkjet printer is used to deposit the materials to surfaces. Futhermore, an Atomic Force Microscope is then used to define patterns and structures in the printed structures. Chapter 5 (Corrugations and Collagen) introduces the recovery and transfer of micro/nanostructured gold surfaces from gold-coated CD-R disks to silicon.
Download or read book Parallel Fabrication and Optoelectronic Characterization of Nanostructured Surfaces written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Among the more notable accomplishments during the course of this contract we identify the following results: (1) We have used diblock copolymers to transfer nanoscale periodic patterns to substrates. The nanopatterns have been transferred both in the form of etched holes and in arrays of metal dots. This has been performed without the need for silicon nitride layers or multi-layered resists. (2) We have conducted experiments using a closed-loop MM to measure the coefficient of thermal expansion (CTE) of a reference material. We have found that the piezo scanner non-linearity (0.2%) is unacceptably large for metrologic MM Moire interferometry. We have ordered a new closed-loop MM that incorporates a flexure-based scanner with a nonlinearity of 0.05%. The new instrumentation will allow us to overcome the piezo non-linearity difficulties, and (3) We have demonstrated a method for utilizing nanomasks for pattern transfer to an arbitrary substrate via an intermediate transfer layer (ITL). This approach is distinct from the technique of applying the nanomasks directly to the surface to be patterned. The ITL is a layer of a resist-like material into which the bionanomask pattern is transferred before it is then transferred to the substrate.
Download or read book Concise Encyclopedia of Biomedical Polymers and Polymeric Biomaterials written by Munmaya Mishra and published by CRC Press. This book was released on 2017-08-16 with total page 2663 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Concise Encyclopedia of Biomedical Polymers and Polymeric Biomaterials presents new and selected content from the 11-volume Biomedical Polymers and Polymeric Biomaterials Encyclopedia. The carefully culled content includes groundbreaking work from the earlier published work as well as exclusive online material added since its publication in print. A diverse and global team of renowned scientists provide cutting edge information concerning polymers and polymeric biomaterials. Acknowledging the evolving nature of the field, the encyclopedia also features newly added content in areas such as tissue engineering, tissue repair and reconstruction, and biomimetic materials.
Download or read book Fabrication of Nanostructured Surfaces with Well defined Chemistry Using Particle Lithography written by Jie-Ren Li and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fabrication and Robustness Testing of Superhydrophobic Nanostructured Surfaces for Enhanced Jumping Condensation written by Jean Hope Sack and published by . This book was released on 2015 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increasing worldwide and domestic demands for power and clean water will require advanced heat transfer materials. Superhydrophobic micro- and nano-structured surfaces which promote a jumping droplet mode of condensation have been shown to enhance heat transfer over conventional film wise condensation surfaces, but limited robustness testing has been reported validating feasibility of industrial implementation. This thesis seeks to quantify the robustness of a variety of nanostructures, substrates and coatings by analyzing contact angle measurements and SEM imaging over the course of accelerated robustness testing. This testing was enabled through the design and construction of three custom-built setups intended to accelerate the onset of failure mechanisms. These setups consist of a flow setup to observe resistance to shear flows from internal condensation steam flow, a droplet impingement setup to test mechanical durability, and an elevated temperature condensation chamber to characterize thermal stability. Methods for fabricating nanostructures were also developed, and scalable zinc oxide nanowires (ZnO) and copper oxide nanoblades (CuO) were used. CuO nanoblades were etched into copper, and ZnO nanowires were grown on silicon, low carbon steel, titanium, stainless steel, and electroplated nickel. Hydrophobic coatings tested on these surfaces included stearic acid and two polymer coatings: P2i (40nm) and Semblant. Observed failure mechanisms were coating degradation and poor nanostructure adhesion. Nanostrucure adhesion issues were observed as delamination of ZnO nanowires primarily on stainless steel substrates. Adhesion was improved through the addition of an electroplated nickel layer before nanowire growth, but delamination was still observed. This is likely the result a large mismatch in coefficient of thermal expansion between the ZnO nanowires and the substrate. The etched CuO nanostructures with a fluorinated polymer coating (P2i) showed very little change in performance throughout robustness testing. Characterization methods included contact angle measurements to monitor surface uniformity and durability, and scanning electron microscope (SEM) imaging to observe nanostructure degradation and delamination. Preliminary work was also done to functionalize the inside of tubes and design a dedicated test setup to characterize heat transfer measurements for internal jumping condensation. This setup will allow for extended robustness testing over a range of temperatures, pressures, and geometries, and give baseline heat flux values for comparison with dropwise or filmwise internal condensation. While ZnO nanowires still require additional testing and development, CuO nanoblades are good candidates for internal heat transfer measurements and scaled up robustness testing. Assuming this characterization confirms the expected benefits of jumping condensation from increased droplet removal and nucleation density, this technology has the potential to significantly improve power plant efficiency and output worldwide.
Download or read book Parallel Fabrication and Electronic Characterization of Nanostructured and Nanoheterostructured Metal Surfaces written by and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Among the more notable accomplishments during the course% of this contract we identify the following results: 0 A precisely ordered and precisely located array of 5 nm diameter nanoclusters has been fabricated by first etching into the substrate an array of holes with diameters comparable to the size of nanoclusters sought and then depositing adatoms on the substrate. Our methods enable rapid fabrication of arrays for fundamental studies and provide a route to manufacturability of nanostructure arrays for technological purposes. We reported the ability to control the morphology of nanometer thick Ti oxide films which were created via a parallel nanofabrication process using a two-dimensional protein crystal as a template. Atomic force microscopy was used to examine the evolution of these structures from a periodic array of nanometer-scale dots (nanodots) to a screen containing a periodic array of nanometer-scale holes (nanoscreen) as the film thickness was increased. We reported the creation of large arrays of nanometer-scale dots (nanodot arrays) with the oxides of several additional metals near Ti in the periodic table. A computer simulation of nanoscale hole formation based on curvature dependent sputtering and surface self-diffusion was formulated. The model simulates the experimental data from our nanopatterning process quite well.
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 Superhydrophobic Surfaces written by Russell J. Crawford and published by Elsevier. This book was released on 2015-02-19 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superhydrophobic Surfaces analyzes the fundamental concepts of superhydrophobicity and gives insight into the design of superhydrophobic surfaces. The book serves as a reference for the manufacturing of materials with superior water-repellency, self-cleaning, anti-icing and corrosion resistance. It thoroughly discusses many types of hydrophobic surfaces such as natural superhydrophobic surfaces, superhydrophobic polymers, metallic superhydrophobic surfaces, biological interfaces, and advanced/hybrid superhydrophobic surfaces. - Provides an adequate blend of complex engineering concepts with in-depth explanations of biological principles guiding the advancement of these technologies - Describes complex ideas in simple scientific language, avoiding overcomplicated equations and discipline-specific jargon - Includes practical information for manufacturing superhydrophobic surfaces - Written by experts with complementary skills and diverse scientific backgrounds in engineering, microbiology and surface sciences
Download or read book Bijels written by Paul S Clegg and published by Royal Society of Chemistry. This book was released on 2020-03-27 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bicontinuous interfacially jammed emulsion gels, now commonly termed 'bijels', are a class of soft materials, in which interpenetrating, continuous domains of two immiscible fluids are maintained in a rigid arrangement by a jammed layer of colloidal particles at their interface. Such gels have unusual material properties that promise exciting applications across diverse fields from energy materials and catalysis, to food science. This is the first book on the subject and provides the reader with a fundamental introduction. Edited by a recognised authority on bijels, the reader will learn about the bijel and its formation. Bringing together current understanding, this book aims to bring the potential application of bijels to diverse materials challenges closer to fruition. This is a must-have resource for anyone working in soft matter and applied fields.
Download or read book Ice Adhesion written by K. L. Mittal and published by John Wiley & Sons. This book was released on 2020-12-15 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt: This unique book presents ways to mitigate the disastrous effects of snow/ice accumulation and discusses the mechanisms of new coatings deicing technologies. The strategies currently used to combat ice accumulation problems involve chemical, mechanical or electrical approaches. These are expensive and labor intensive, and the use of chemicals raises serious environmental concerns. The availability of truly icephobic surfaces or coatings will be a big boon in preventing the devastating effects of ice accumulation. Currently, there is tremendous interest in harnessing nanotechnology in rendering surfaces icephobic or in devising icephobic surface materials and coatings, and all signals indicate that such interest will continue unabated in the future. As the key issue regarding icephobic materials or coatings is their durability, much effort is being spent in developing surface materials or coatings which can be effective over a long period. With the tremendous activity in this arena, there is strong hope that in the not too distant future, durable surface materials or coatings will come to fruition. This book contains 20 chapters by subject matter experts and is divided into three parts— Part 1: Fundamentals of Ice Formation and Characterization; Part 2: Ice Adhesion and Its Measurement; and Part 3: Methods to Mitigate Ice Adhesion. The topics covered include: factors influencing the formation, adhesion and friction of ice; ice nucleation on solid surfaces; physics of ice nucleation and growth on a surface; condensation frosting; defrosting properties of structured surfaces; relationship between surface free energy and ice adhesion to surfaces; metrology of ice adhesion; test methods for quantifying ice adhesion strength to surfaces; interlaboratory studies of ice adhesion strength; mechanisms of surface icing and deicing technologies; icephobicities of superhydrophobic surfaces; anti-icing using microstructured surfaces; icephobic surfaces: features and challenges; bio-inspired anti-icing surface materials; durability of anti-icing coatings; durability of icephobic coatings; bio-inspired icephobic coatings; protection from ice accretion on aircraft; and numerical modeling and its application to inflight icing.
Download or read book Handbook of Nanocellulose and Cellulose Nanocomposites 2 Volume Set written by Hanieh Kargarzadeh and published by John Wiley & Sons. This book was released on 2017-06-19 with total page 914 pages. Available in PDF, EPUB and Kindle. Book excerpt: An up-to-date and comprehensive overview summarizing recent achievements, the state of the art, and trends in research into nanocellulose and cellulose nanocomposites. Following an introduction, this ready references discusses the characterization as well surface modification of cellulose nanocomposites before going into details of the manufacturing and the self-assembly of such compounds. After a description of various alternatives, including thermoplastic, thermosetting, rubber, and fully green cellulose nanocomposites, the book continues with their mechanic and thermal properties, as well as crystallization and rheology behavior. A summary of spectroscopic and water sorption properties precedes a look at environmental health and safety of these nanocomposites. With its coverage of a wide variety of materials, important characterization tools and resulting applications, this is an essential reference for beginners as well as experienced researchers.
Download or read book Stimuli Responsive Dewetting Wetting Smart Surfaces and Interfaces written by Atsushi Hozumi and published by Springer. This book was released on 2018-11-16 with total page 467 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superhydrophobic surfaces, artificially mimicking lotus leaves, have captured the attention of scientists and engineers over the past few decades. Recent trends have shifted from superhydrophobicity to superominipohobicity, or superamphiphobicity. In addition, dynamic rather than static surface wetting/dewetting properties, which can be triggered by various stimuli, including temperature, pH, magnetic/electric fields, solvents, light exposure etc, have been highly sought after for commercial applications. This book will focus on recent topics related to various stimuli-responsive wetting/dewetting surfaces, and give an overview of the knowledge and concepts of how to design and establish these smart artificial surfaces, which can be used for technical developments in a wide variety research fields.
Download or read book Functional Polymer Coatings written by Limin Wu and published by John Wiley & Sons. This book was released on 2015-06-15 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: Focusing on a variety of coatings, this book provides detailed discussion on preparation, novel techniques, recent developments, and design theories to present the advantages of each function and provide the tools for better product performance and properties. • Presents advantages and benefits of properties and applications of the novel coating types • Includes chapters on specific and novel coatings, like nanocomposite, surface wettability tunable, stimuli-responsive, anti-fouling, antibacterial, self-healing, and structural coloring • Provides detailed discussion on recent developments in the field as well as current and future perspectives • Acts as a guide for polymer and materials researchers in optimizing polymer coating properties and increasing product performance
