Research scientists; Julia Boos, Wiebke Drenckhan, and Cosima Stubenrauch’s have carried out a number of complex investigations to find out how the aqueous solution from a particular surfactant – the main cleaning agents in detergents – can have different properties.
Foams are dispersions of air in an aqueous surfactant solution which surrounds the closely packed air bubbles. The properties of foams strongly depend on the type and amount of surfactant, which serves to stabilise the bubbles against coalescence.
However, as the researchers discovered, if one wants to compare quantitatively the foaming properties of different surfactants (or surfactant mixtures), one needs to make sure that they have appropriate starting conditions –namely foams of the same liquid fraction, overall bubble size and overall bubble size distribution. A process which has always been overlooked.
The work of Drs. Boos, Drenckhan and Stubenrauch shows how foams need to be generated if one wants to compare quantitatively the foaming properties of different surfactant solutions.
Prof. Dr. Stubenrauch, explained:
“The protocol for studying foams presented in this work will help scientists from academia and the non-academic sector to identify the important parameters for characterising foams. It is only with this knowledge that quantitative comparisons are possible, which, in turn, allows for a proper classification of surfactants with regard to their foaming properties.”
Dr. Boos currently works as a research scientist at oelheld GmbH Stuttgart, Germany (this research was performed while she was in the group of Prof. Stubenrauch at the University of Stuttgart, Germany). Dr. Drenckhan is CNRS researcher at the Laboratoire de Physique des Solides at the University of Paris, France. Prof. Dr. Stubenrauch is Chair of “Physical Chemistry of Condensed Matter” at the University of Stuttgart, Germany.
The paper, titled “Protocol for Studying Aqueous Foams Stabilised by Surfactant Mixtures,” was published in the Journal of Surfactants and Detergents, Volume 16, (October 2013) and has been recognised as the best paper published within the journal for 2013, earning them ‘The Distinguished Paper Award’, an annual honour presented by the American Cleaning Institute (ACI) at the Annual Meeting of the American Oil Chemists’ Society (AOCS).