Review on Kinetics of Spreading and Wetting by Aqueous Surfactant Solutions - Drops and Bubbles in Contact with Solid Surfaces - page 37

Review on Kinetics of Spreading and Wetting by Aqueous
Surfactant Solutions

J. Radulovic a , K. Sefiane a , V. M. Starov b , N. Ivanova b , M. E. R. Shanahan c

a

Institute for Materials and Processes, The University of Edinburgh, Kings Buildings, Edinburgh,
EH9 3JL, United Kingdom. E-mail: [e-mail]

b

Department of Chemical Engineering, Loughborough University, Loughborough, LE11 3TU,
United Kingdom

c

Université de Bordeaux, Institute de Mécanique et d'Ingénierie, CNRS UMR 5295, Bâtiment A4,
351 Cours de la Libération, 33405 Talence Cedex, France

Contents

A. Introduction ............................................... 37

B. Wetting of Ideal and Real Surfaces .................................. 38

C.ofPureLiquids............................................. 40

D.SpreadingofSurfactantSolutions................................... 41

E. Spreading over Hydrophobic Substrates . . .............................. 43

F. Spreading of Surfactant Solutions over Thin Aqueous Layers: Influence of Solubility and Micelle
Disintegration.............................................. 44

G. Instabilities in the Course of Spreading . . .............................. 48

H.SpreadingofSurfactantSolutionsoverSubstrates .......................... 52

I.superspreading]Superspreading .................................... 57

J.References................................................ 64

A. Introduction

A great number of industrial processes and practical applications are based on wet-
ting and spreading. Understanding these phenomena is crucial in designing many
pharmaceutical, agricultural and bio-medical products, such as herbicides and pesti-
cides, paints and coatings, as well as ink-jet printers and lung-surfactants. Although
this interesting topic has been studied for over two centuries, there are still certain
underlying mechanisms waiting to be revealed.
Over the years, many eminent scientists have investigated this apparently lim-
itless topic, both theoretically and experimentally. Starting with Young's equation
at the beginning of the 19th century, leading to de Gennes' priceless contributions