Considerations when determining low interfacial tensions

Abstract

Surfactants are often used to create low or “ultralow” oil–water interfacial tensions (IFTs). These molecules, in some cases, may also lead to the inadvertent formation of microemulsion phases which can obscure IFT measurements. Here, we present a case study of such an issue. We also introduce a little-known micropipette technique which has many advantages over the more common spinning drop method for determining low/ultralow IFTs.