On the Spreading of an Insoluble Surfactant over a Thin Viscous Liquid Layer

✍ Scribed by Victor M. Starov; Alain de Ryck; Manuel G. Velarde

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 212 KB
• Volume: 190
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1997.4863

✦ Synopsis

Reported here are results of a theoretical and experimental cases such that nonsolubility conditions can be used during study of the spreading of an insoluble surfactant over a thin liquid a certain period in the spreading process. Let us consider layer. Initial concentrations of surfactant above and below CMC two characteristic time scales associated with surfactant have been considered. If the concentration is above CMC two transfer: (i) t d ˙accounts for the transfer from the liquiddistinct stages of spreading are found. (i) The first stage is the air surface to the bulk, and (ii) t a ˙accounts for transfer faster, and it is connected with micelle dissolution; (ii) the second from the bulk back to the surface. In both cases these characstage is the slower, when the surfactant concentration falls below teristic time scales depend on energy and entropy (of con-CMC. In the second stage, the formation of a dry spot in the center figuration due to the orientation of the tails of the surfactants) of the film is observed. A similarity solution of the corresponding equations for spreading gives good agreement with experimental differences between corresponding states, as described by observations.