Droplet Wetting and Evaporation

Droplet Wetting and Evaporation PDF Author: David Brutin
Publisher: Academic Press
ISBN: 0128008083
Category : Science
Languages : en
Pages : 464

Book Description
Droplet Wetting and Evaporation provides engineers, students, and researchers with the first comprehensive guide to the theory and applications of droplet wetting and evaporation. Beginning with a relevant theoretical background, the book moves on to consider specific aspects, including heat transfer, flow instabilities, and the drying of complex fluid droplets. Each chapter covers the principles of the subject, addressing corresponding practical issues and problems. The text is ideal for a broad range of domains, from aerospace and materials, to biomedical applications, comprehensively relaying the challenges and approaches from the different communities leading the way in droplet research and development. Provides a broad, cross-subject coverage of theory and application that is ideal for engineers, students and researchers who need to follow all major developments in this interdisciplinary field Includes comprehensive discussions of heat transfer, flow instabilities, and the drying of complex fluid droplets Begins with an accessible summary of fundamental theory before moving on to specific areas such as heat transfer, flow instabilities, and the drying of complex fluid droplets

Wetting and Evaporation: Droplets of Pure and Complex Fluids

Wetting and Evaporation: Droplets of Pure and Complex Fluids PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 156

Book Description


Microscale Surface Tension and Its Applications

Microscale Surface Tension and Its Applications PDF Author: Pierre Lambert
Publisher: MDPI
ISBN: 3039215647
Category : Technology & Engineering
Languages : en
Pages : 240

Book Description
Building on advances in miniaturization and soft matter, surface tension effects are a major key to the development of soft/fluidic microrobotics. Benefiting from scaling laws, surface tension and capillary effects can enable sensing, actuation, adhesion, confinement, compliance, and other structural and functional properties necessary in micro- and nanosystems. Various applications are under development: microfluidic and lab-on-chip devices, soft gripping and manipulation of particles, colloidal and interfacial assemblies, fluidic/droplet mechatronics. The capillary action is ubiquitous in drops, bubbles and menisci, opening a broad spectrum of technological solutions and scientific investigations. Identified grand challenges to the establishment of fluidic microrobotics include mastering the dynamics of capillary effects, controlling the hysteresis arising from wetting and evaporation, improving the dispensing and handling of tiny droplets, and developing a mechatronic approach for the control and programming of surface tension effects. In this Special Issue of Micromachines, we invite contributions covering all aspects of microscale engineering relying on surface tension. Particularly, we welcome contributions on fundamentals or applications related to: Drop-botics: fluidic or surface tension-based micro/nanorobotics: capillary manipulation, gripping, and actuation, sensing, folding, propulsion and bio-inspired solutions; Control of surface tension effects: surface tension gradients, active surfactants, thermocapillarity, electrowetting, elastocapillarity; Handling of droplets, bubbles and liquid bridges: dispensing, confinement, displacement, stretching, rupture, evaporation; Capillary forces: modelling, measurement, simulation; Interfacial engineering: smart liquids, surface treatments; Interfacial fluidic and capillary assembly of colloids and devices; Biological applications of surface tension, including lab-on-chip and organ-on-chip systems.

Evaporation-induced Non-wetting Droplets on Superhydrophilic Surfaces

Evaporation-induced Non-wetting Droplets on Superhydrophilic Surfaces PDF Author: Solomon E. Adera
Publisher:
ISBN:
Category :
Languages : en
Pages : 68

Book Description
A droplet deposited on a rough, lyophilic surface satisfying the imbibition condition, results in spontaneous spreading and hence complete wetting. However, in this thesis, we demonstrate that this wetting behavior can be altered by superheating the substrate such that droplets can reside in a non-wetting state due to evaporation. Photolithography and deep reactive ion etching were used to fabricate well-defined silicon micropillar arrays with a square pattern with varying pillar diameter, height, and center-to-center spacing. Water droplets placed on these microstructured surfaces at room temperature demonstrated superhydrophilic behavior with liquid filling the voids between pillars resulting in very low contact angle, and hence complete wetting. However, when the microstructured surface was superheated above a critical superheat, the superhydrophilicity was lost and non-wetting droplets were formed on the top surface of the micropillar array structure. The superheat required to deposit a non-wetting droplet (> 75°C) was found to be significantly higher than that required to sustain an already deposited non-wetting droplet (

Surface Wetting

Surface Wetting PDF Author: Kock-Yee Law
Publisher: Springer
ISBN: 3319252143
Category : Technology & Engineering
Languages : en
Pages : 169

Book Description
This book describes wetting fundamentals and reviews the standard protocol for contact angle measurements. The authors include a brief overview of applications of contact angle measurements in surface science and engineering. They also discuss recent advances and research trends in wetting fundamentals and include measurement techniques and data interpretation of contract angles.

Wetting and Evaporation Studies on Molecularly Modified Surfaces

Wetting and Evaporation Studies on Molecularly Modified Surfaces PDF Author: Dinah Michele Soolaman
Publisher:
ISBN:
Category : Chemistry, Technical
Languages : en
Pages : 0

Book Description
Wetting and evaporation of liquid microdroplets on solid surfaces are ubiquitous in nature. Two of the many important factors that influence how a droplet wets and "escapes", are the Chemical composition and Roughness of the solid surface. In order to gain a better understanding of these processes as a whole, a systematic study on the factors that influence wetting/evaporation behaviour, including the liquid ́s composition, the liquid-solid interface, and the substrate morphology has been carried out in this thesis. In particular, the evaporation profile and its correlation with the wetting hysteresis have been studied using both water and binary mixtures on self-assembled monolayer (SAM) surfaces. Based on surface modification with mixed SAMs in conjunction with microcontact printing and electrochemical deposition techniques, this work aims at a comprehensive and controlled study of how molecular/structural modification dictate the wetting and evaporation behaviour of microdroplets on the surface.

Electrowetting

Electrowetting PDF Author: Frieder Mugele
Publisher: John Wiley & Sons
ISBN: 3527412298
Category : Science
Languages : en
Pages : 323

Book Description
Starting from the basic principles of wetting, electrowetting and fluid dynamics all the way up to those engineering aspects relevant for the development of specific devices, this is a comprehensive introduction and overview of the theoretical and practical aspects. Written by two of the most knowledgeable experts in the field, the text covers both current as well as possible future applications, providing basic working principles of lab-on-a-chip devices and such optofluidic devices as adaptive lenses and optical switches. Furthermore, novel e-paper display technology, energy harvesting and supercapacitors as well as electrowetting in the nano-world are discussed. Finally, the book contains a series of exercises and questions for use in courses on microfluidics or electrowetting. With its all-encompassing scope, this book will equally serve the growing community of students and academic and industrial researchers as both an introduction and a standard reference.

Dynamic Wetting by Nanofluids

Dynamic Wetting by Nanofluids PDF Author: Gui Lu
Publisher: Springer
ISBN: 3662487659
Category : Technology & Engineering
Languages : en
Pages : 122

Book Description
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.

Evaporation and Droplet Growth in Gaseous Media

Evaporation and Droplet Growth in Gaseous Media PDF Author: N.A. Fuchs
Publisher: Elsevier
ISBN: 1483225631
Category : Science
Languages : en
Pages : 81

Book Description
Evaporation and Droplet Growth in Gaseous Media deals with the evaporation of droplets of liquid in gaseous media and the reverse process of droplet growth in a medium supersaturated with the vapor of the liquid. Thediscussion is restricted to the kinetics of evaporation and growth of droplets of pure liquids (and heat transfer to the same). Comprised of three chapters, this book first examines the quasi-stationary evaporation and growth of droplets that are motionless relative to the medium and the hydrodynamic factor is absent. The Maxwell equation, the basis of the theory of evaporation of droplets in a gaseous medium, is taken into account. The influence of the Stefan flow and the concentration change at the surface on the rate of evaporation are considered, along with the evaporation of droplets in a vessel with absorbing walls and the fall in temperature of both free evaporating droplets and supported evaporating droplets. The second chapter is devoted to the quasi-stationary evaporation of droplets in a stream of gas, that is, droplets moving relative to the medium. The last chapter focuses on non-stationary evaporation and growth of droplets that either motionless or moving relative to the medium. This monograph will be of interest to students, practitioners, and researchers in inorganic and structural chemistry.

Sessile Drops of Biological Fluids : Evaporation and Wetting

Sessile Drops of Biological Fluids : Evaporation and Wetting PDF Author: Wassim Bou-Zeid
Publisher:
ISBN:
Category :
Languages : en
Pages : 198

Book Description
Spreading/evaporation process of droplets over solid surfaces is a fundamental process and a wide research field because of number of applications in printing, micro-electronics, DNA analysis and even in biomedical. This experimental work aims to investigate the effect of relative humidity on the contact line dynamics, on the evaporation dynamics and on the final pattern of a drop of whole human blood. The spreading of a pure fluid model that has the same physical properties as human blood was studied and compared to the blood. We showed that bio-colloids play significant effect on the dynamics of contact line and the pinning effect of the drop. For low contact angles, we showed that the spreading/evaporation process could be divided into two regimes. A fast first regime determined by a balance between viscous forces and capillary forces and a second slower regime dominated by the evaporation rate. Physical mechanisms that are responsible for the spreading enhancement are proposed and discussed. The average velocity of the contact line was found to follow the same behaviour as Tanner's model, where the spreading dynamics and geometrical parameters of the droplet are function of relative humidity. The experimental measurements are in a good agreement with the purely diffusive model where the equilibrium wetting radius and contact angle are function of relative humidity. For the morphological analysis of crack patterns, a manual segmentation method was used as a reference for the validation of the automatic developed segmentation method. We showed that the evaporation rate influences structural distribution of plaques in the corona region and hence, the mean crack spacing.