Assembly of small molecule surfactants at highly dynamic air-water interfaces.

Small-angle neutron scattering has been used to probe the interfacial structure of foams stabilised by small molecule surfactants at concentrations well below their critical micelle concentration. The data for wet foams showed a pronounced Q dependence at low Q and noticeable inflexions over the mid Q range. These features were found to be dependent on the surfactant structure (mainly the alkyl chain length) with various inflexions across the measured Q range as a function of the chain length but independent of factors such as concentration and foam age/height.