Interfacial behavior of Pluronic F68 aqueous solutions in the presence of sodium dodecyl sulfate

This study investigates interfacial rheology, interfacial tension, and foam formation in the context of porous hydrogel development. We utilize diacrylated Pluronic F68 (PF68-DA), which is a bifunctional tri-block copolymer of poly(ethylene oxide) and poly(propylene oxide), as both macromer and surfactant. In addition, sodium dodecyl sulfate (SDS) is included as a co-surfactant. The focus is on the interactions and properties of PF68-DA and SDS at water-air interface for the formation of foam precursors that are used for synthesis of porous hydrogels. The foam formation and stability are influenced by Ostwald ripening and coalescence. In this work, therefore, the interfacial tension and dilatational interfacial rheology of PF68-DA and SDS aqueous mixtures are studied. We found that SDS weakens the interfacial loss modulus, but not necessarily the foam stability. Since SDS modifies interfacial properties, foam stability and consequently the porous structure of hydrogel can be tuned by SDS concentration.