Dilational Rheology of Extended Surfactants at the Air/Water and Oil/Water Interfaces: Effect of Propylene Oxide Group Numbers.

In this paper, the interfacial properties of extended surfactants with different oxypropylene (PO) groups were comprehensively investigated by using interfacial dilational rheology. The differences in molecular orientation, spatial configuration, and relaxation process were compared at the gas-water interface and oil-water interface. The influences of the PO groups on the interface viscoelasticity were analyzed, providing important theoretical support for the wide application of extended surfactants.