Microfluidics 2 Surface tension, contact angle, capillary flow
|
|
- Mitchell Simon
- 5 years ago
- Views:
Transcription
1 MT Microfluidics and BioMEMS Microfluidics 2 Surface tension, contact angle, capillary flow Ville Jokinen
2 Surface tension & Surface energy Work required to create new surface = surface energy x area created δw = γ δa = γ Lδx Fundamental definition of surface energy: γ = δw / δa [ J / m 2 ] Hunter: Introduction to Modern Colloid Science, p.134 Surface energy is also known as surface tension: γ = δf / δx [ N / m] Concept applicable to all surfaces and interfaces: solid-solid, solid-liquid, liquid-liquid, solid-gas, liquid-gas Interfaces Surfaces
3 Molecular basis of surface energy The surface layer lacks some of the bonds in bulk phase This increased potential energy compared to the bulk is called surface energy!
4 Surface tension measurement: Drop weight method: Gravity = perimeter x surface tension mg = 2πr x γ Empirical correction factor needed force tensiometry Wilhelmy plate method: Force tensiometry: The force a liquid exerts on a plate is measured F = 2 L γ No correction factor needed Good method also in practice
5 Temperature dependence: water: 68 mj/m 2 at 50 o C, 59 mj/m 2 at 100 o C Water has a very high surface energy because of strong intermolecular bonds.
6 Scaling: surface forces vs body forces Surface area to volume ratio scales as d -1 Microsystems often dominated by surface effects An example: h Reservoir droplet Flow channel Case 1: The flow channel is a microchannel: 100 μm x 100 μm x 100 mm, Volume 1 μl Volume: Hydrostatic pressure from reservoir 10 Pa Area: Capillary pressure from channel 3000 Pa Surface dominated! Case 2: The flow channel is a garden hose: 1 cm x 1 cm x 10 m, Volume 1 liter Volume: Hydrostatic pressure from reservoir 1000 Pa Area: Capillary pressure from channel 30 Pa Volume dominated!
7 Bond number: Does gravity matter? Dimensionless number that characterizes the ratio of surface forces to body forces Capillary pressure= γ /L, Hydrostatic pressure= ρal a = acceleration (for gravity, 9.81m/s 2 ) L = characteristic length scale γ = surface tension ρ = density Bo = ρal 2 γ If Bo < 1 the system is dominated by surface forces (opposed to body forces) For water, Bo = 1 at around 1 mm range. Microfluidic channels are usually smaller than this so gravity typically does not matter in microfluidics. Example from previous page, water in a channel with 100 µm and 1 cm dimensions: Bo 1.4 * 10-3 (for 100 µm) Bo 14 (for 1 cm)
8 Surface tension measurement: optical tensiometry Drop shape analysis: Optical tensiometry: Surface tension measured from the shape of a hanging droplet Shape determined by the balance of gravity (hydrostatic pressure) and surface tension (laplace pressure). Image from biolin scientific.
9 Capillary number Dimensionless number that characterizes the ratio of viscous forces to surface forces Viscous shear pressure = µv/l, Capillary pressure= γ /L µ = dynamic viscosity (in multiphase systems, opt for the higher viscosity) γ = surface tension v = velocity Ca = µv γ Viscous forces and surface forces are both significant at microscale. Capillary numbers can be high or low. Illustration: a droplet of liquid is immobilized in a channel where an immiscible liquid flows. Will it stay as a sphere held together by surface tension or be elongated due to shear forces? Lower Ca (more influence of surface tension) Higher Ca (less influence of surface tension)
10 Surface energy, cohesion, adhesion Surface energy is linked to adhesion between materials and intra material cohesion. Work of cohesion, W 11 : Before separation: γ 11 =0 After separation: 2γ 1 Material 1 Material 1 γ 11 Material 1 Material 1 γ 1 γ 1 W 11 = 2γ 1-0 = 2γ 1 Work of adhesion, W 12 : Before separation: γ 12 After separation: γ 1 + γ 2 W 12 = γ 1 + γ 2 - γ 12 Material 2 Material 1 γ 12 Material 2 Material 1 γ 2 γ 1
11 Contact angle, experimental A liquid droplet makes a certain angle of contact with a solid surface The angle is called the apparent contact angle θ Property of a solid-liquid-fluid three phase system For a fixed liquid and fluid, contact angle is characteristic parameter of a surface/material
12 Contact angle, theoretical Young s equation: γ LG cos(θ) = γ SG - γ SL θ Thermodynamical, or Young s, contact angle γ LG Liquid-vapor surface energy ( liquid surface tension ) (often also γ l, γ lv ) γ SG Solid-vapor surface energy ( solid surface energy ) (often also γ s, γ sv ) γ SL Solid-liquid surface energy ( solid-liquid interface energy ) The thermodynamical contact angle does not necessarily equal the experimental contact angle on real surfaces because of hysteresis.
13 Contact angle hysteresis On real surfaces: θ rec < θ eq < θ adv Hysteresis θ adv θ rec θ rec = Receding contact angle θ eq = Equilibrium/static contact angle θ adv = Advancing contact angle Reasons for contact angle hysteresis: Adsorption of molecules from the solution Desorption of molecules from the surface Chemical inhomogenities Physical surface topography Which experimental contact angle is the one appearing in Young s equation? Unresolved, but some suggestions that have been made in the literature: 1. θ adv 2. (θ adv + θ rec ) /2 3. acos ((cos θ adv + cosθ rec )/2) 4. the most stable θ (e.g. after vibrations or other source of energy)
14 Contact angle measurement Same tools and methods as for surface tension: Force tensiometry, often Wilhelmy plate Optical goniometry of a sessile droplet Optical goniometry Wilhelmy plate method
15 Measuring solid-vapor surface energies With some assumptions, γ sv can be estimated by contact angle measurements Zisman method: Surface energy of a solid is the surface energy of the highest surface tension liquid exhibiting complete wetting. (= critical surface tension) Other (better) methods: Owens-Wendt Good-vanOss Important point: Solid liquid and solid-vapour surface tensions are difficult to measure. Liquid-vapour surface tensions and the contact angle are easy to measure.
16 Hydrophilic/ Hydrophobic terminology For water: hydrophilic/hydrophobic For oils: oleophilic/oleophobic For liquids in general: hygrophilic/hygrophobic, omniphilic/omniphobic θ = 0 Completely wetting θ 5 Superhydrophilic 0 < θ < 90 Hydrophilic Wetting 90 < θ < 150 Hydrophobic Nonwetting 150 < θ < 180 Superhydrophobic Ultrahydrophobic SiO 2 Clean metals roughness+chemistry SU-8, Si PDMS, Teflon roughness+chemistry
17 Contact angle on structured surfaces On the lowest surface energy planar surfaces, contact angles only go up to 120 for water and 75 for oils. Beyond that, topography can be used to enhance contact angle Cassie state: Possible on intrinsically hydrophobic surfaces Results in increased hydrophobicity cos(θ c ) = f cos(θ) -1 +f f = air fraction Wenzel state: Possible on any surface Results in enhanced intrinsic contact angle cos(θ w ) = r cos(θ) r = roughness factor Note! The contact angle is enhanced but the chemical nature of the surface remains the same The enhanced contact angles are relevant for fluidics, but not directly in e.g. adsorption
18 Superhydrophobicity Micro/nanostructures combined to hydrophobic surface properties can result in superhydrophobic surfaces. Properties: θ > 150, water repellent, water deposited on top stays as intact droplets and moves easily low sliding angles, self cleaning Silicon nanopillars (black silicon) Left: oxidized silicon surface θ 0 Right: fluoropolymer coating θ 170 Jokinen, Sainiemi, Franssila: Advanced Materials 2008
19 Young s equation and adhesion, number of independent parameters: Adhesion = γ γ cosθ = γ lv sv lv + γ γ sl sv γ sl On first sight, these two equations contain 4 parameters each. However, since the solid surface is unable to deform, γ sv + γ sl = constant. In wetting phenomena, we are only interested in changes, which is why the 2 solid surface energy terms only ever appear in the term (γ sv - γ sl ) and not independently. So in reality, both wetting related equations have only 3 independent terms. This is good news since both γ lv and cos(θ) are easily measurable, and measuring 2/3 of independent parameters is enough to know everything about the system. Inserting Young s equation into the work of adhesion equation we get: AAAAAAAAAAAAAAA = γ llll + γ llll cos θ = γ llll (1 + cos θ ) This is called the Young-Dupré equation, and it relates the work of adhesion to the surface tension and contact angle. You can test what happens to adhesion when θ=0, 90 or 180 degrees. Compare the results to the equation for the work of cohesion.
20 Laplace pressure There is a pressure difference across a curved liquid surface. Young-Laplace equation Calculating radius of curvature For a spherical droplet or bubble: 1 μl spherical water droplet in air, P 140 Pa Pressure is higher inside a spherical 1 μl spherical air bubble in water, P -140 Pa bubble or a droplet!
21 Capillary pressure and contact angle Liquid makes a contact angle of θ with a capillary with radius r. 1. What is the curvature of the meniscus? 2. What is the Capillary pressure? 1. From the triangle in the figure we get: r/r= cos(θ) so R=r/cos(θ) Curvature of the sphere was defined as -2/R (bubble) so Curvature = -2 cos(θ) / r 2. Capillary pressure is the corresponding Laplace pressure: P cap = γ * Curvature = -2 γ cos(θ) / r θ R θ r
22 Capillary rise and depression Hydrostatic pressure ρgδh = -4γcos(θ)/d Capillary pressure Note that θ is the only material parameter of the capillary that is needed, not eg. γ SG or γ SL
23 Capillary filling of microfluidic channels Main differences to classical capillary rise: Horizontal vs vertical Capillary filling continues until the channel network is full Geometry usually non circular and nonuniform materials Hydrophilic walls contribute to filling, hydrophobic oppose it θ t h θ l θ r θ b w P cosθt + cosθb = γ ( h + cosθl + cosθr ) w (is still just a form of Laplace pressure): The capillary pressure is calculated at the filling front (and possibly the de-wetting front), already filled areas still contribute to flow resistance.
24 Droplet microfluidics Microfluidics does not always mean continuous flow in a channel. Droplet microfluidics and digital microfluidics increasingly common Discrete droplets, either 2 immiscible liquid phases or liquid droplets and air. Each droplet can be viewed as a single experiment.
25 Droplet generation Two immiscible phases, typically water and oil/fluorinated oil. The walls of the system are wetting toward the continuous phase and anti-wetting toward the dispersed phase Droplet production is dependent on: capillary number, geometry, and ratio of the flows of the dispersed and the continuous phases. Shear forces attempt to divide the dispersed phase while surface tension tries to keep the dispersed phase together. Ca typically Droplet generation rate can be in the range of 10kHz T junction Flow focusing Lab Chip, 2010, 10,
26 Digital microfluidics, electrowetting Droplets on hydrophobic surfaces, surface tension holds the droplets together (no spreading) Electrowetting used to move the droplets. Either one open surface or more commonly between 2 hydrophobic plates. V = applied voltage C = capacitance γ s =solid surface energy γ w = water surface energy γ 0 ws = water solid interfacial energy with no electric field.
27 CD microfluidics Actuating force by centrifugation. Capillary valves and hydrophobic valves to control flow.
28 Review The importance of surfaces in microfluidics/bio-mems Surface energy, Laplace pressure Contact angle, theoretical and experimental aspects Capillary rise and capillary filling of microfluidic channels Shear and surface tension effects for microfluidics Reading material For lecture 2, the reading material is: Chapter 5, surface tension, from a book Physics of Continuous matter by B. Lautrup. Pages Available from link: /Lautrup/surface.pdf
DLVO interaction between the spheres
DLVO interaction between the spheres DL-interaction energy for two spheres: D w ( x) 64c π ktrϕ e λ DL 2 x λ 2 0 0 D DLVO interaction w ( x) 64πkTRϕ e λ DLVO AR /12x 2 x λd 2 0 D Lecture 11 Contact angle
More informationMicrofluidics 1 Basics, Laminar flow, shear and flow profiles
MT-0.6081 Microfluidics and BioMEMS Microfluidics 1 Basics, Laminar flow, shear and flow profiles 11.1.2017 Ville Jokinen Outline of the next 3 weeks: Today: Microfluidics 1: Laminar flow, flow profiles,
More informationLecture 7 Contact angle phenomena and wetting
Lecture 7 Contact angle phenomena and Contact angle phenomena and wetting Young s equation Drop on the surface complete spreading Establishing finite contact angle γ cosθ = γ γ L S SL γ S γ > 0 partial
More informationemulsions, and foams March 21 22, 2009
Wetting and adhesion Dispersions in liquids: suspensions, emulsions, and foams ACS National Meeting March 21 22, 2009 Salt Lake City Ian Morrison 2009 Ian Morrison 2009 Lecure 2 - Wetting and adhesion
More informationSurface and Interfacial Tensions. Lecture 1
Surface and Interfacial Tensions Lecture 1 Surface tension is a pull Surfaces and Interfaces 1 Thermodynamics for Interfacial Systems Work must be done to increase surface area just as work must be done
More informationReaction at the Interfaces
Reaction at the Interfaces Lecture 1 On the course Physics and Chemistry of Interfaces by HansJürgen Butt, Karlheinz Graf, and Michael Kappl Wiley VCH; 2nd edition (2006) http://homes.nano.aau.dk/lg/surface2009.htm
More informationPraktikum zur. Materialanalytik
Praktikum zur Materialanalytik Functionalized Surfaces B510 Stand: 20.10.2017 Table of contents Introduction 2 Basics 2 Surface tension 2 From wettability to the contact angle 4 The Young equation 5 Wetting
More informationIntroduction to Micro/Nanofluidics. Date: 2015/03/13. Dr. Yi-Chung Tung. Outline
Introduction to Micro/Nanofluidics Date: 2015/03/13 Dr. Yi-Chung Tung Outline Introduction to Microfluidics Basic Fluid Mechanics Concepts Equivalent Fluidic Circuit Model Conclusion What is Microfluidics
More informationSurface Tension and its measurements
Surface Tension and its measurements Surface Tension Surface tension is a fundamental property by which the gas liquid interfaces are characterized. The zone between a gaseous phase and a liquid phase
More informationSurface chemistry. Liquid-gas, solid-gas and solid-liquid surfaces.
Surface chemistry. Liquid-gas, solid-gas and solid-liquid surfaces. Levente Novák & István Bányai, University of Debrecen Dept of Colloid and Environmental Chemistry http://kolloid.unideb.hu/~kolloid/
More informationFrieder Mugele. Physics of Complex Fluids. University of Twente. Jacco Snoeier Physics of Fluids / UT
coorganizers: Frieder Mugele Physics of Comple Fluids Jacco Snoeier Physics of Fluids / UT University of Twente Anton Darhuber Mesoscopic Transport Phenomena / Tu/e speakers: José Bico (ESPCI Paris) Daniel
More informationMultiphase Flow and Heat Transfer
Multiphase Flow and Heat Transfer ME546 -Sudheer Siddapureddy sudheer@iitp.ac.in Surface Tension The free surface between air and water at a molecular scale Molecules sitting at a free liquid surface against
More informationResonant Oscillations of Liquid Marbles
Resonant Oscillations of Liquid Marbles Glen McHale*, Stephen J. Elliott*, Michael I. Newton*, Dale L. Herbertson* and Kadir Esmer $ *School of Science & Technology, Nottingham Trent University, UK $ Department
More informationColloidal Particles at Liquid Interfaces: An Introduction
1 Colloidal Particles at Liquid Interfaces: An Introduction Bernard P. Binks and Tommy S. Horozov Surfactant and Colloid Group, Department of Chemistry, University of Hull, Hull, HU6 7RX, UK 1.1 Some Basic
More informationESS 5855 Surface Engineering for. MicroElectroMechanicalechanical Systems. Fall 2010
ESS 5855 Surface Engineering for Microelectromechanical Systems Fall 2010 MicroElectroMechanicalechanical Systems Miniaturized systems with integrated electrical and mechanical components for actuation
More informationExperimental Studies of Liquid Marbles and Superhydrophobic Surfaces
Experimental Studies of Liquid Marbles and Superhydrophobic Surfaces Stephen James Elliott A thesis submitted in partial fulfilment of the requirements of Nottingham Trent University for the degree of
More informationThe Origins of Surface and Interfacial Tension
The Origins of Surface and Interfacial Tension Imbalance of intermolecular forces exists at the liquid-air interface γ la= the surface tension that exists at the liquid-air interface Suppose we have a
More informationP = 1 3 (σ xx + σ yy + σ zz ) = F A. It is created by the bombardment of the surface by molecules of fluid.
CEE 3310 Thermodynamic Properties, Aug. 27, 2010 11 1.4 Review A fluid is a substance that can not support a shear stress. Liquids differ from gasses in that liquids that do not completely fill a container
More informationChanges of polymer material wettability by surface discharge
Changes of polymer material wettability by surface discharge Surface discharge and material treatment Surface treatment of materials in low temperature plasma belongs to the modern and very perspective
More informationLotus leaf -Traditional, but smart pack from nature- Weon-Sun SHIN DEPT of FOOD & NUTRITION HANYANG UNIVERSITY
Lotus leaf -Traditional, but smart pack from nature- Weon-Sun SHIN DEPT of FOOD & NUTRITION HANYANG UNIVERSITY Learning from nature & tradition Rice culture Buhdism Traditional lunch-box The way of cooking
More informationFluid Mechanics Introduction
Fluid Mechanics Introduction Fluid mechanics study the fluid under all conditions of rest and motion. Its approach is analytical, mathematical, and empirical (experimental and observation). Fluid can be
More informationThe Wilhelmy balance. How can we measure surface tension? Surface tension, contact angles and wettability. Measuring surface tension.
ow can we measure surface tension? Surface tension, contact angles and wettability www.wikihow.com/measure-surface-tension Measuring surface tension The Wilhelmy balance F Some methods: Wilhelmy plate
More informationdrops in motion Frieder Mugele the physics of electrowetting and its applications Physics of Complex Fluids University of Twente
drops in motion the physics of electrowetting and its applications Frieder Mugele Physics of Complex Fluids niversity of Twente 1 electrowetting: the switch on the wettability voltage outline q q q q q
More informationFormation of Droplets and Bubbles in a Microfluidic T-junction. Scaling and Mechanism of Break-Up. Supplementary Information
Formation of Droplets and Bubbles in a Microfluidic T-junction Scaling and Mechanism of Break-Up Supplementary Information Piotr Garstecki 1,2 *, Michael J. Fuerstman 1, Howard A. Stone 3 and George M.
More informationFE Fluids Review March 23, 2012 Steve Burian (Civil & Environmental Engineering)
Topic: Fluid Properties 1. If 6 m 3 of oil weighs 47 kn, calculate its specific weight, density, and specific gravity. 2. 10.0 L of an incompressible liquid exert a force of 20 N at the earth s surface.
More informationTopography driven spreading. School of Biomedical & Natural Sciences, Nottingham Trent University. Clifton Lane, Nottingham NG11 8NS, UK.
Postprint Version G. McHale, N. J. Shirtcliffe, S. Aqil, C. C. Perry and M. I. Newton, Topography driven spreading, Phys. Rev. Lett. 93, Art. No. 036102 (2004); DOI: 10.1103/PhysRevLett.93.036102. The
More informationthose research efforts, the number of scientific publications, patents and review articles in the field has also shown dramatic growth.
Preface Surface properties have critical roles in determination of the overall performance and applications of materials in many diverse fields. Some of these properties include friction, scratch resistance,
More informationPart II Fundamentals of Fluid Mechanics By Munson, Young, and Okiishi
Part II Fundamentals of Fluid Mechanics By Munson, Young, and Okiishi WHAT we will learn I. Characterization of Fluids - What is the fluid? (Physical properties of Fluid) II. Behavior of fluids - Fluid
More informationPHYSICS OF FLUID SPREADING ON ROUGH SURFACES
INTERNATIONAL JOURNAL OF NUMERICAL ANALYSIS AND MODELING Volume 5, Supp, Pages 85 92 c 2008 Institute for Scientific Computing and Information PHYSICS OF FLUID SPREADING ON ROUGH SURFACES K. M. HAY AND
More informationExperimental and Theoretical Study of Motion of Drops on Horizontal Solid Surfaces with a Wettability Gradient Nadjoua Moumen
Experimental and Theoretical Study of Motion of Drops on Horizontal Solid Surfaces with a Wettability Gradient Nadjoua Moumen Department of Chemical and Biomolecular Engineering Clarkson University Outline
More informationCHAPTER 1 Fluids and their Properties
FLUID MECHANICS Gaza CHAPTER 1 Fluids and their Properties Dr. Khalil Mahmoud ALASTAL Objectives of this Chapter: Define the nature of a fluid. Show where fluid mechanics concepts are common with those
More informationThe evaporation of sessile droplets onto solid surfaces : experiments and simulations of the contact line pinning-depinning
The evaporation of sessile droplets onto solid surfaces : experiments and simulations of the contact line pinning-depinning L.Kabeya-Mukeba, N.Vandewalle and S.Dorbolo GRASP, Institut de Physique B5a,
More informationGravitational effects on the deformation of a droplet adhering to a horizontal solid surface in shear flow
PHYSICS OF FLUIDS 19, 122105 2007 Gravitational effects on the deformation of a droplet adhering to a horizontal solid surface in shear flow P. Dimitrakopoulos Department of Chemical and Biomolecular Engineering,
More informationCourse + Lectures notes + additional info
Course + Lectures notes + additional info www.phys.tue.nl/nfcmr/college/college.html Examination : oral 3 days (to be determined) Week 1: Intro tu 24-4-2018 13:45 15:30 dr.ir. L. Pel Introduction + porosity
More informationInterfaces and interfacial energy
Interfaces and interfacial energy 1/14 kinds: l/g }{{ l/l } mobile s/g s/l s/s Example. Estimate the percetage of water molecules on the surface of a fog droplet of diameter (i) 0.1 mm (naked eye visibility
More informationElectrowetting-Induced Dewetting Transitions on Superhydrophobic Surfaces
Purdue University Purdue e-pubs Birck and NCN Publications Birck Nanotechnology Center 9-6-2011 Electrowetting-Induced Dewetting Transitions on Superhydrophobic Surfaces Niru Kumari Birck Nanotechnology
More informationFluid flow Pressure Bernoulli Principle Surface Tension
Lecture 9. Fluid flow Pressure Bernoulli Principle Surface Tension A v L A is the area Fluid flow Speed of a fluid in a pipe is not the same as the flow rate Relating: Fluid flow rate to Average speed
More informationBFC FLUID MECHANICS BFC NOOR ALIZA AHMAD
BFC 10403 FLUID MECHANICS CHAPTER 1.0: Principles of Fluid 1.1 Introduction to Fluid Mechanics 1.2 Thermodynamic Properties of a Fluid: Density, specific weight, specific gravity, viscocity (kelikatan)berat
More informationFluid Mechanics-61341
An-Najah National University College of Engineering Fluid Mechanics-61341 Chapter [1] Fundamentals 1 The Book (Elementary Fluid Mechanics by Street, Watters and Vennard) Each chapter includes: Concepts
More informationResearch Article Theoretical Model of Droplet Wettability on a Low-Surface-Energy Solid under the Influence of Gravity
e Scientific World Journal, Article ID 647694, 5 pages http://dx.doi.org/1.1155/214/647694 esearch Article Theoretical Model of Droplet Wettability on a Low-Surface-Energy Solid under the Influence of
More informationChapter -6(Section-1) Surface Tension
Chapter -6(Section-1) Surface Tension Free surface of the liquid tends to minimize the surface area. e.g.(1)if the small quantity of mercury is allowed to fall on the floor, it converted in to small spherical
More informationChapter 10. Solids and Fluids
Chapter 10 Solids and Fluids Surface Tension Net force on molecule A is zero Pulled equally in all directions Net force on B is not zero No molecules above to act on it Pulled toward the center of the
More informationSurface forces action in a vicinity of three phase contact line and other current problems in kinetics of wetting and spreading
Loughborough University Institutional Repository Surface forces action in a vicinity of three phase contact line and other current problems in kinetics of wetting and spreading This item was submitted
More informationEffects and applications of surface tension for fluidic MEMS components
Effects and applications of surface tension for fluidic MEMS components Ryan T. Marinis and Ryszard J. Pryputniewicz NEST NanoEngineering, Science and Technology CHSLT Center for Holographic Studies and
More informationSta$s$cal mechanics of hystere$c capillary phenomena: predic$ons of contact angle on rough surfaces and liquid reten$on in unsaturated porous media
Sta$s$cal mechanics of hystere$c capillary phenomena: predic$ons of contact angle on rough surfaces and liquid reten$on in unsaturated porous media Michel Louge h@p://grainflowresearch.mae.cornell.edu/
More informationCalculate the total volumes of the following typical microfluidic channel dimensions.
Microfluidics and BioMEMS, 2018, Exercise 1. Unit conversions and laminar flow. (Note: this version, both the assignment and the model solutions, is now fixed (18.1.2018) so that the flow rate is 0.25µl/min
More informationCHAPTER 2. SOIL-WATER POTENTIAL: CONCEPTS AND MEASUREMENT
SSC107 Fall 2000 Chapter 2, Page - 1 - CHAPTER 2. SOIL-WATER POTENTIAL: CONCEPTS AND MEASUREMENT Contents: Transport mechanisms Water properties Definition of soil-water potential Measurement of soil-water
More informationElectrowetting on dielectrics on lubricating fluid based slippery surfaces with negligible hysteresis
Electrowetting on dielectrics on lubricating fluid based slippery surfaces with negligible hysteresis J. Barman a, A. K. Nagarajan b and K. Khare a* a Department of Physics, Indian Institute of Technology
More informationNUMERICAL INVESTIGATION OF THERMOCAPILLARY INDUCED MOTION OF A LIQUID SLUG IN A CAPILLARY TUBE
Proceedings of the Asian Conference on Thermal Sciences 2017, 1st ACTS March 26-30, 2017, Jeju Island, Korea ACTS-P00786 NUMERICAL INVESTIGATION OF THERMOCAPILLARY INDUCED MOTION OF A LIQUID SLUG IN A
More informationWe may have a general idea that a solid is hard and a fluid is soft. This is not satisfactory from
Chapter 1. Introduction 1.1 Some Characteristics of Fluids We may have a general idea that a solid is hard and a fluid is soft. This is not satisfactory from scientific or engineering point of view. In
More informationWetting and Adhesion: Manipulating Topography and Surface Free Energy
Wetting and Adhesion: Manipulating Topography and Surface Free Energy Professor Glen McHale School of Science & Technology Abhesion Meeting, Society for Adhesion and Adhesives, London, UK 23 rd April 2009
More informationEffect of F-AOT surfactant on the interface between supercritical CO 2 and nickel plating solution
Effect of F-AOT surfactant on the interface between supercritical CO 2 and nickel plating solution Ji-Young Park, Jong Sung Lim* Supercritical Research Laboratory, KIST * Department of Chemical Engineering,
More informationSupplementary Materials for
advances.sciencemag.org/cgi/content/full/2/10/e1600964/dc1 Supplementary Materials for Constructing 3D heterogeneous hydrogels from electrically manipulated prepolymer droplets and crosslinked microgels
More informationResearch Article Validation of Methods for the Optical Characterisation of the Wettability of Polymeric Films for Food Packaging
Industrial Engineering, Article ID 6235, 6 pages http://dx.doi.org/.1155/14/6235 Research Article Validation of Methods for the Optical Characterisation of the Wettability of Polymeric Films for Food Packaging
More informationDeformation of a droplet adhering to a solid surface in shear flow: onset of interfacial sliding
J. Fluid Mech. (27), vol. 58, pp. 451 466. c 27 Cambridge University Press doi:1.117/s2211275721 Printed in the United Kingdom 451 Deformation of a droplet adhering to a solid surface in shear flow: onset
More informationFluid flow Pressure Bernoulli Principle Surface Tension
Lecture 9. Fluid flow Pressure Bernoulli Principle Surface Tension Fluid flow Speed of a fluid in a pipe is not the same as the flow rate Depends on the radius of the pipe. example: Low speed Large flow
More information2. Determine the surface tension of water with the capillary-rise method.
Fakultät für Physik und Geowissenschaften Physikalisches Grundpraktikum M19e Surface Tension Tasks 1. Determine the surface tension σ of an organic liquid using the anchor-ring method. Use three different
More informationSupporting Information
Supporting Information On the Minimal Size of Coffee Ring Structure Xiaoying Shen, Chih-Ming Ho and Tak-Sing Wong * Mechanical and Aerospace Engineering Department, University of California, Los Angeles,
More informationCompound pendant drop tensiometry for. surface tension measurement at zero Bond number
Compound pendant drop tensiometry for surface tension measurement at zero Bond number Michael J. Neeson, Derek Y. C. Chan,,, and Rico F. Tabor, Department of Mathematics and Statistics, University of Melbourne,
More informationMacroscopic conservation equation based model for surface tension driven flow
Advances in Fluid Mechanics VII 133 Macroscopic conservation equation based model for surface tension driven flow T. M. Adams & A. R. White Department of Mechanical Engineering, Rose-Hulman Institute of
More informationElectrowetting. space and ε l the liquid dielectric constant, Eq. (1) can be written as. γ = ε 0ε l 2d V2. (2)
600 Electrowetting and hence a reduced flow rate in the pressure-drop direction. This reduced flow rate seems to suggest that the liquid have an apparent higher viscosity. The apparent viscosity is called
More informationCapillarity and Wetting Phenomena
? Pierre-Gilles de Gennes Frangoise Brochard-Wyart David Quere Capillarity and Wetting Phenomena Drops, Bubbles, Pearls, Waves Translated by Axel Reisinger With 177 Figures Springer Springer New York Berlin
More informationInterfacial Flows of Contact Line Dynamics and Liquid Displacement in a Circular Microchannel
Proceedings of the 3 rd World Congress on Mechanical, Chemical, and Material Engineering (MCM'17) Rome, Italy June 8 10, 2017 Paper No. HTFF 159 ISSN: 2369-8136 DOI: 10.11159/htff17.159 Interfacial Flows
More informationInterface Location of Capillary Driven Flow in Circular Micro Channel Using by COMSOL
Interface Location of Capillary Driven Flow in Circular Micro Channel Using by COMSOL ARSHYA BAMSHAD 1, MOHAMMAD H. SABOUR 2, ALIREZA NIKFARJAM 3 Faculty of New Sciences & Technologies University of Tehran
More informationUniversity of Hail Faculty of Engineering DEPARTMENT OF MECHANICAL ENGINEERING. ME Fluid Mechanics Lecture notes. Chapter 1
University of Hail Faculty of Engineering DEPARTMENT OF MECHANICAL ENGINEERING ME 311 - Fluid Mechanics Lecture notes Chapter 1 Introduction and fluid properties Prepared by : Dr. N. Ait Messaoudene Based
More information5.2 Surface Tension Capillary Pressure: The Young-Laplace Equation. Figure 5.1 Origin of surface tension at liquid-vapor interface.
5.2.1 Capillary Pressure: The Young-Laplace Equation Vapor Fo Fs Fs Fi Figure 5.1 Origin of surface tension at liquid-vapor interface. Liquid 1 5.2.1 Capillary Pressure: The Young-Laplace Equation Figure
More informationGeneralized Wenzel equation for contact angle of droplets on spherical rough solid substrates
Science Front Publishers Journal for Foundations and Applications of Physics, 3 (2), (2016) (sciencefront.org) ISSN 2394-3688 Generalized Wenzel equation for contact angle of droplets on spherical rough
More informationChapter 11. Freedom of Motion. Comparisons of the States of Matter. Liquids, Solids, and Intermolecular Forces
Liquids, Solids, and Intermolecular Forces Chapter 11 Comparisons of the States of Matter The solid and liquid states have a much higher density than the gas state The solid and liquid states have similar
More informationAN OPTIMAL CURVE FOR FASTEST TRANSPROTATION OF LIQUID DROPS ON A SUPERHYDROPHOBIC SURFACE
AN OPTIMAL CURVE FOR FASTEST TRANSPROTATION OF LIQUID DROPS ON A SUPERHYDROPHOBIC SURFACE ABSTRACT Kwangseok Seo, Minyoung Kim, Do Hyun Kim Department of Chemical and Biomolecular Engineering, Korea Advanced
More informationLiquids and solids are essentially incompressible substances and the variation of their density with pressure is usually negligible.
Properties of Fluids Intensive properties are those that are independent of the mass of a system i.e. temperature, pressure and density. Extensive properties are those whose values depend on the size of
More informationSupplementary Information Surface energy and wettability of van der Waals structures
Electronic Supplementary Material (ESI) for Nanoscale. This journal is The Royal Society of Chemistry 2016 Supplementary Material (ESI) for Nanoscale Supplementary Information Surface energy and wettability
More informationChapter 9: Solids and Fluids
Chapter 9: Solids and Fluids State of matters: Solid, Liquid, Gas and Plasma. Solids Has definite volume and shape Can be crystalline or amorphous Molecules are held in specific locations by electrical
More informationElectrokinetic Phenomena
Introduction to BioMEMS & Medical Microdevices Microfluidic Principles Part 2 Companion lecture to the textbook: Fundamentals of BioMEMS and Medical Microdevices, by Prof., http://saliterman.umn.edu/ Electrokinetic
More informationLIQUID FILM THICKNESS OF OSCILLATING FLOW IN A MICRO TUBE
Proceedings of the ASME/JSME 2011 8th Thermal Engineering Joint Conference AJTEC2011 March 13-17, 2011, Honolulu, Hawaii, USA AJTEC2011-44190 LIQUID FILM THICKNESS OF OSCILLATING FLOW IN A MICRO TUBE Youngbae
More informationCapillarity of Rectangular Micro Grooves and Their Application to Heat Pipes
Tamkang Journal of Science and Engineering, Vol. 8, No 3, pp. 249 255 (2005) 249 Capillarity of Rectangular Micro Grooves and Their Application to Heat Pipes Horng-Jou Wang, Hsin-Chang Tsai, Hwang-Kuen
More informationFigure 3: Problem 7. (a) 0.9 m (b) 1.8 m (c) 2.7 m (d) 3.6 m
1. For the manometer shown in figure 1, if the absolute pressure at point A is 1.013 10 5 Pa, the absolute pressure at point B is (ρ water =10 3 kg/m 3, ρ Hg =13.56 10 3 kg/m 3, ρ oil = 800kg/m 3 ): (a)
More informationUsing Microfluidic Device to Study Rheological Properties of Heavy Oil
Using Microfluidic Device to Study Rheological Properties of Heavy Oil Kiarash Keshmiri a, Saeed Mozaffari a, b, Plamen Tchoukov a, Haibo Huang c, Neda Nazemifard a, * a Department of Chemical and Materials
More informationII. FLUID INTERFACES AND CAPILLARITY
CONTENTS Preface vii I. INTRODUCTION 1 A. Interfaces 1 B. Colloids 4 C. The bridge to nanoscience 10 1. What is nanoscience? 10 2. Nanostructures and assemblies 12 3. Generic nanoscience 17 4. New tools
More informationCHAPTER 2. Theory: Wetting Phenomena
CHAPTER 2 2.1 Introduction Wetting phenomena are ubiquitous in nature and technology. Wetting phenomena are an area where chemistry, physics, and engineering intersect. Macroscopically the word Surface
More informationChapter 13 States of Matter Forces of Attraction 13.3 Liquids and Solids 13.4 Phase Changes
Chapter 13 States of Matter 13.2 Forces of Attraction 13.3 Liquids and Solids 13.4 Phase Changes I. Forces of Attraction (13.2) Intramolecular forces? (forces within) Covalent Bonds, Ionic Bonds, and metallic
More informationLecture 18: Microfluidic MEMS, Applications
MECH 466 Microelectromechanical Systems University of Victoria Dept. of Mechanical Engineering Lecture 18: Microfluidic MEMS, Applications 1 Overview Microfluidic Electrokinetic Flow Basic Microfluidic
More informationSurface chemistry. Liquid-gas, solid-gas and solid-liquid surfaces. Levente Novák István Bányai
Surface chemistry. Liquid-gas, solid-gas and solid-liquid surfaces. Levente Novák István Bányai Surfaces and Interfaces Defining of interfacial region Types of interfaces: surface vs interface Surface
More informationABSTRACT. WANG, YONGXIN. Robustness of Hydrophobic and Oleophobic Fabrics. (Under the direction of Drs. Stephen Michielsen and Hoon Joo Lee).
ABSTRACT WANG, YONGXIN. Robustness of Hydrophobic and Oleophobic Fabrics. (Under the direction of Drs. Stephen Michielsen and Hoon Joo Lee). A hydrophobic and oleophobic surface can be defined as a surface
More informationFormulae that you may or may not find useful. E v = V. dy dx = v u. y cp y = I xc/a y. Volume of an entire sphere = 4πr3 = πd3
CE30 Test 1 Solution Key Date: 26 Sept. 2017 COVER PAGE Write your name on each sheet of paper that you hand in. Read all questions very carefully. If the problem statement is not clear, you should ask
More informationFoundations of. Colloid Science SECOND EDITION. Robert J. Hunter. School of Chemistry University of Sydney OXPORD UNIVERSITY PRESS
Foundations of Colloid Science SECOND EDITION Robert J. Hunter School of Chemistry University of Sydney OXPORD UNIVERSITY PRESS CONTENTS 1 NATURE OF COLLOIDAL DISPERSIONS 1.1 Introduction 1 1.2 Technological
More informationSelf-cleaning of hydrophobic rough surfaces by coalescence-induced wetting transition
arxiv:1810.13073v1 [physics.comp-ph] 31 Oct 2018 Self-cleaning of hydrophobic rough surfaces by coalescence-induced wetting transition Kaixuan Zhang 1,2, Zhen Li 2,,, Martin Maxey 2, Shuo Chen 1, and George
More informationSupplementary Information. Continuous Transfer of Liquid Metal Droplets Across a Fluid-Fluid Interface Within an Integrated Microfluidic Chip
Electronic Supplementary Material (ESI) for Lab on a Chip. This journal is The Royal Society of Chemistry 2015 Supplementary Information Continuous Transfer of Liquid Metal Droplets Across a Fluid-Fluid
More informationSuperhydrophobic surfaces. José Bico PMMH-ESPCI, Paris
Superhydrophobic surfaces José Bico PMMH-ESPCI, Paris Superhydrophobic surfaces José Bico PMMH-ESPCI, Paris? Rain droplet on a window film pinning tear 180? mercury calefaction Leidenfrost point, T = 150
More information3.10. Capillary Condensation and Adsorption Hysteresis
3.10. Capillary Condensation and Adsorption Hysteresis We shall restrict our attention to the adsorption behavior of porous solids. Hysteresis: two quantities of adsorbed material for each equilibrium
More informationISCST shall not be responsible for statements or opinions contained in papers or printed in its publications.
Modeling of Drop Motion on Solid Surfaces with Wettability Gradients J. B. McLaughlin, Sp. S. Saravanan, N. Moumen, and R. S. Subramanian Department of Chemical Engineering Clarkson University Potsdam,
More informationFluid Mechanics Theory I
Fluid Mechanics Theory I Last Class: 1. Introduction 2. MicroTAS or Lab on a Chip 3. Microfluidics Length Scale 4. Fundamentals 5. Different Aspects of Microfluidcs Today s Contents: 1. Introduction to
More informationChapter 10 - Mechanical Properties of Fluids. The blood pressure in humans is greater at the feet than at the brain
Question 10.1: Explain why The blood pressure in humans is greater at the feet than at the brain Atmospheric pressure at a height of about 6 km decreases to nearly half of its value at the sea level, though
More informationSimulation of T-junction using LBM and VOF ENERGY 224 Final Project Yifan Wang,
Simulation of T-junction using LBM and VOF ENERGY 224 Final Project Yifan Wang, yfwang09@stanford.edu 1. Problem setting In this project, we present a benchmark simulation for segmented flows, which contain
More informationOn the displacement of three-dimensional fluid droplets adhering to a plane wall in viscous pressure-driven flows
J. Fluid Mech. (2001), vol. 435, pp. 327 350. Printed in the United Kingdom c 2001 Cambridge University Press 327 On the displacement of three-dimensional fluid droplets adhering to a plane wall in viscous
More informationWettability of CaCO 3 surfaces
Colloids and Surfaces A: Physicochemical and Engineering Aspects 157 (1999) 333 340 www.elsevier.nl/locate/colsurfa Wettability of CaCO 3 surfaces Malvina G. Orkoula a,b, Petros G. Koutsoukos a,b, *, Michel
More informationWettability of carbonate reservoir minerals under carbon storage conditions
TCCS-9 Wettability of carbonate reservoir minerals under carbon storage conditions Dr Mihaela Stevar and Prof Martin Trusler 13 June 2017 1 Outline Background Objectives http://www.hydrobead.com/ Experimental
More informationElectrowetting based microliter drop tensiometer. Arun G. Banpurkar* Kevin Nichols and Frieder Mugele
Electrowetting based microliter drop tensiometer Arun G. Banpurkar* Kevin Nichols and Frieder Mugele Physics of Complex Fluids, Faculty of Science and Technology, IMPACT and MESA+ Institute, University
More informationSupplementary Figures
Supplementary Figures 1 Supplementary Figure 1 Micro and nano-textured boiling surfaces. (a) A schematic of the textured boiling surfaces. (b) An isometric view of the square array of square micropillars.
More informationSessile drops in microgravity
ArXiv, April 24, 2013 Sessile drops in microgravity Amelia Carolina Sparavigna Dipartimento di Scienza Applicata e Tecnologia Politecnico di Torino, Torino, Italy Interfaces with a liquid are governing
More informationNUMERICAL SIMULATION OF MICRO-FILTRATION OF OIL-IN-WATER EMULSIONS. Tohid Darvishzadeh
NUMERICAL SIMULATION OF MICRO-FILTRATION OF OIL-IN-WATER EMULSIONS By Tohid Darvishzadeh A DISSERTATION Submitted to Michigan State University in partial fulfillment of the requirements for the degree
More information