title: Capillary rise of superspreaders.
abstract: Trisiloxane surfactants, known as 'superspreaders', are commonly employed in numerous applications where enhanced wetting is of the utmost importance. The underlying mechanisms of superspreader wetting have been a focus of scientific interest for ca. 2 decades, and a number of mechanisms have been proposed to explain the unique trisiloxane dynamics. We have studied trisiloxane behaviour in thin capillaries to get further insight into their interfacial activity. Additionally, our knowledge of the capillary rise of superspreaders is surprisingly limited, and the effect of this extraordinary group of surfactants on capillary phenomena has been largely overlooked. Diffusion was confirmed to be the limiting factor of trisiloxane behaviour. A tentative theoretical explanation for the phenomenon studied and an appropriate mathematical model are presented. It is concluded that the enhancement of wetting due to surfactant addition is also a function of geometry: the effect is clear for a sessile drop, but more complex and less beneficial in a capillary.
authors: Institute for Materials and Processes, The University of Edinburgh, Kings Buildings, Edinburgh EH9 3JL, United Kingdom.
authors: Jovana
authors: J
authors: Radulovic
authors: Khellil
authors: K
authors: Sefiane
authors: Martin E R
authors: ME
authors: Shanahan
mesh_terms: D001698:Biomedical Engineering / Q000379:methods*; D002197:Capillary Action; D004058:Diffusion; D008962:Models, Theoretical; D012833:Siloxanes / Q000737:chemistry* / Q000378:metabolism; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry* / Q000378:metabolism; D017155:Wettability
chemical_list: D012833:Siloxanes; D013501:Surface-Active Agents