Self-Cleaning of Surfaces and Water Droplet Mobility

Chapter 1 INTRODUCTIOn

Chapter 2 Wetting Characteristics of Surfaces

2.1 INTRODUCTION

2.2 WETTING STATES AND PROPERTIES

2.2.1 Wetting on Smooth Surfaces

2.2.2 Wetting on Rough Surfaces

2.2.3 Contact Angle Hysteresis

2.2.4 Lubricant Impregnated Surfaces

2.2.5 Particle Adhesion on Surfaces

2.2.5.1 JKR (Johnson-Kandall-Roberts) Model

2.2.5.2 DMT (Derjagin, Muller, Toropov) Model

2.2.5.3 Hamaker’s model

2.2.5.4 Rumpf-Rabinovich model

2.3 DUST PARTICLES REMOVAL AND SURFACE CLEANING

2.3.1 Gravitational Force

2.3.2 Lift Force (inertial force and shear stress)

2.3.3 Drag Force due to Pressure and Shear on the particle Surface

2.3.4 Centrifugal Force

2.3.5 Friction Force

2.3 MEASUREMENTS AND ASSESSMENTS OF WETTING STATES

2.3.1. Smooth Surfaces

2.3.1.1 Drop Dimensions

2.3.1.2 Droplet free surface Profile

2.3.1.3 Axisymmetric Droplet Shape Analysis-Profile (ADSA-P)

2.3.1.4 Wilhelmy Method

2.3.1.5 Capillary Rise at a Vertical Plate

2.3.2 Rough Surfaces

2.3.2.1. Axisymmetric Droplet Shape Analysis Method -Diameter (ADSA-D)

2.3.2.2 Capillary Penetration Methods for particles

2.4 FREE ENERGIES OF SURFACES AND INTERFACES

2.5 SPREADING COEFFICIENT OF LIQUIDS

　

Chapter 3 Surfaces for Self-Cleaning

3.1 INTRODUCTION

3.2 SURFACE CHARACTERISTICS

3.3 DEVELOPMENT, SYNTHESIZING AND FABRICATION PROCESSES

3.3.1 Lithography

3.3.1.1 Conventional Lithography

3.3.1.1.1 Photolithography

3.3.1.1.2 Particle Beam Lithography

3.3.1.2 Unconventional Lithography

3.3.2 Templating

3.3.3 Etching

3.3.4 Coating

3.3.4.1 Spin Coating

3.3.4.2 Spray Coating

3.3.4.3 Dip Coating

3.3.5 Sol-Gel Method

3.3.6 Layer-by-Layer Fabrication

3.4 Analysis and Assessment

3.4.1 Oil Impregnated Hydrophobic Glass Surfaces in Relation to Self-Cleaning

3.4.2 Solvent Induced-Crystallization

3.4.3 Solvent-Induced Crystallization and Texture Copying by Polydimethylsiloxane

3.4.4 PDMS Replication of Laser Textured Surfaces

3.4.5 Laser Treatment of Zirconia Surfaces and Surface Hydrophobicity

Chapter 4 Environmental Dust on Surfaces

4.1 INTRODUCTION

4.2 CLASSIFICATION OF DUST PARTICLES

4.2.1 Dust Particle Size Distribution, Shapes and Analysis

4.2.2 Dust Particles Adhesion on Surfaces

4.2.3 Surface Energy and Cloaking of Dust Particles

4.3 CHEMO-MECHANICS OF MUD FORMED FROM DUST PARTICLES

4.3.1 Characteristics of Mud formed from Dust Particles

4.3.2 Mechanical Properties of Dry Mud

4.3.3 UV Visible Transmittance of Dusty and Dust Removed Surfaces

4.4 DUST ON OIL IMPREGNATED SURFACES

Chapter 5 Water Droplet Dynamics and Heat Transfer

5.1 INTRODUCTION

5.2 DROPLET ADHESION ON HYDROPHOBIC SURFACE AND THERMAL EFFECTS

5.2.1 Mechanics of Droplet Attachment on Hydrophobic Surface

5.2.2 Water Droplet Attachment on Hydrophobic Surface: Force Balance and Heating

5.3 DROPLET SLIDING AND ROLLING ON SURFACES

5.3.1 Experimental

5.3.2 Numerical Modelling of Droplet on Hydrophobic Surface

5.3.2.1 Initial Condition

5.3.2.2 Boundary Conditions

5.3.3 Findings of Experiments and Simulations

5.4 DROPLET DYNAMICS ON SURFACES WITH REVERSIBLY EXCHANGING WETTING STATES

5.4.1 Experimental

5.4.2 Surface Morphology and Reversible Wetting State on Surface

5.4.3 Water Droplet Dynamics on Solid Phase N-Octadecane Coated Hydrophobic Surface

5.5 DROPLET HEAT TRANSFER

5.5.1 Heat Transfer and Internal Fluidity of Droplet on Hydrophilic and Hydrophobic Surfaces

5.5.1.1 Initial Conditions

5.5.1.2 Boundary Conditions

5.5.1.3 Findings

5.5.2 Local Heating of Droplet by A Radiation Source

5.5.2.1 Heating and Flow Analysis

5.5.2.1.1 Initial Conditions

5.5.2.1.2 Boundary Conditions

5.5.2.2 Experimental and Validation of Flow Field Predictions

5.5.2.3 Findings

5.5.3 Droplet Heat Transfer on Hydrophobic Micro-Post Arrays

5.5.3.1 Flow and Heat Transfer Analysis

5.5.3.1.1 Initial Conditions

5.5.3.1.2 Boundary conditions

5.5.3.2 Experimental

5.5.3.3 Findings

5.5.4 Heating of a Ferro-Liquid Droplet Heat on Water Surface

5.5.4.1 Heating and Flow Analysis

5.5.4.1.1 Initial Condition

5.5.4.1.2 Boundary condition

5.5.4.2 Validation Study for velocity Field

5.5.4.3 Findings

　

CHAPTER 6 - DUST EFFECTS ON SURFACES IN HUMID ENVIRONMENT AND APPLICATIONS

6.1 INTRODUCTION

6.2 DUST AND MUD EFFECTS ON GLASS SURFACES

6.2.1 Experimental

6.2.2 Characteristics of Dry Mud and Its Influence on Glass Surfaces

6.3 MUD CHARACTERISTICS ON BISPHENOL-A POLYCARBONATE

6.3.1 Mud Formed from Dust Particles

6.3.2 Analysis of Mud Residues

6.3.3 Analysis of Mud Removal

6.3.4 Effect of Dried Solution

6.4 MUD EFFECT ON INCONEL 718 SURFACE

6.4.1 Experimental Analysis

6.4.2 Characteristics of Laser Treated Surface

6.4.3 Surface Hydrophobicity and Surface Free Energy

6.4.4 Dried Liquid Solution on Laser Textured Surface

6.5 DRY MUD EFFECT OF TIN COATED SURFACE

6.5.1 Laser Treated Surface and Mud Characteristics

6.5.2 Assessment of Surface Free Energy and Mud Adhesion

6.6 MUD EFFECTS ON ALUMINUM SURFACES

6.6.1 Experimental Analysis

6.6.2 Dry Mud Characterization on Aluminum Surface

6.6.3 Mechanical Properties of Dry Mud Solution on Aluminum

6.7 MUD EFFECT ON LASER TREATED ALUMINA SURFACE

6.7.1 Experimental Study

6.7.2 Morphological and Metallurgical Aspects of Surface Prior and After Mud Forming

6.7.3 Properties and Adhesion Work for Dry Mud Removal

6.7.4 Wetting State of Surface after Mud Removal

6.8 LASER TREATED AND SOL-GEL COATED ALUMINA SURFACE WITH MUD EFFECT

6.8.1 Experimental Analysis

6.8.2 Surface Characteristics of Laser Treated and Sol-Gel Coated Alumina Tiles

6.8.3 Laser Treated/Sol-Gel Coated Surfaces and Dry Mud Removal

CHAPTER 7 – Application of Water Droplet for Self-Cleaning of Surfaces

7.1 INTRODUCTION

7.2 DUST PARTICLES REMOVAL THROUGH ROTATING DISC

7.2.1 Dynamics of Dust Particles on Rotating Disk

7.2.2 Experimental Analysis

7.2.3 Dynamic Analysis of Dust Particles on A Rotating Disk

7.3 DROPLET DYNAMICS AND DUST REMOVAL

7.3.1 Experimental and Texture Characteristics

7.3.2 Droplet Dynamics on Dusty Hydrophobic Surface

7.4 THERMOCAPILLARY EFFECT ON DUST REMOVAL FROM HYDROPHOBIC SURFACE

7.4.1 Formulation Numerical Analysis of Thermal and Flow Fields

7.4.2 Experimental and Validation of Predictions

7.4.3. Internal Fluidity of Sessile Droplet and Dust Particles

Chapter 8: Concluding Remarks