Model and Experimental Study of Surfactant Solutions and Pure Liquids Contact Angles on Complex Surfaces - Drops and Bubbles in Contact with Solid Surfaces - page 175

Model and Experimental Study of Surfactant Solutions and
Pure Liquids Contact Angles on Complex Surfaces

A. J. B. Milne a , Karina Grundke b , Mirko Nitschke b , Ralf Frenzel b and
Alidad Amirfazli a

a

Department of Mechanical Engineering, University of Alberta Edmonton, AB, T6G 2G8, Canada.
E-mail: [e-mail]

b

Leibniz Institute of Polymer Research Dresden, D-01005, Dresden, Germany

Contents

A. Introduction ............................................... 175

1. Wetting of Pure Liquids . . .................................... 176

B. Literature on Surfactant Solution Wetting . .............................. 179

C. Contact Angle Model Derivation ................................... 181

1. Model Results and Theoretical Behavior ............................ 184

D. Experimental Procedure—Wetting of Smooth and Superhydrophobic Surfaces by Pure Liquids
andSurfactantSolutions ........................................ 189

E.ExperimentalResultsandDiscussion ................................. 192

1. Smooth Surfaces—Surfactant Solutions ............................. 192

2. Surfaces—Surfactant Solutions and Pure Liquids ....................... 193

3. aluminum surfaces]Aluminum Surfaces—Surfactant Solutions and Pure Liquids . . .... 196

4. AKD surfaces]AKD Surfaces-Surfactant Solutions and Pure Liquids . ........... 198

5.InvestigatingtheRoleofintrinsiccontactangle]IntrinsicContactAngle ........... 200

F.ClosingRemarks ............................................ 203

G.Acknowledgements........................................... 206

H.References................................................ 207

A. Introduction
In this chapter we study wetting (contact angles) on complex surfaces. We define a
complex surface as one that is heterogeneous and/or rough (in contrast to a 'simple'
surface which is smooth, chemically homogeneous, hard, non-reactive, etc.). Cer-
tain rough hydrophobic surfaces are superhydrophobic surfaces (SHS), displaying
extremely high contact angles, repellency and mobility of liquids on the surface.
The main focus of this chapter will be on SHS, but heterogeneous smooth sur-