Marangoni flow around a camphor disk regenerated by the interaction between camphor and sodium dodecyl sulfate molecules

The interaction between camphor and sodium dodecyl sulfate (SDS) was experimentally investigated to understand restoration of Marangoni flow around a camphor disk on water under the addition of SDS. With an increase in the concentration of SDS, the flow velocity decreased to almost zero up to the critical micelle concentration (cmc), but increased above the cmc. Speed of Marangoni flow around the camphor disk increased with an increase in the scale of the aqueous channel. 13C NMR, NOE experiments, and mass spectrometry were used to evaluate the interaction between camphor and SDS molecules, which increased the dissolution rate of camphor into the SDS aqueous solution. The experimental results suggest that an increase in the dissolution of camphor into SDS micelles induces the restoration of Marangoni flow.