Structuring liquids through solvent-assisted interfacial association of oppositely charged polyelectrolytes and amphiphiles

Sculpting liquids into different shapes through arresting liquid/liquid (L/L) interfaces represents a hot area of nanoscience. Nanoparticle Surfactant (NPS) assemblies, based on confined interactions of functionalized nanoparticles or polymers with specific ligands at the L/L interface, offer a robust platform for synthesizing these structured liquids, which reveal exciting material properties due to the combination of the mobility of liquid components with the solid-like characteristic of NPS assemblies. There is an intense interest in novel structured liquids produced from simple compounds with versatile application potentials. Complexes of oppositely charged commercial polyelectrolytes and traditional aliphatic surfactants (AlS) are good candidates for this goal since they reveal rich structural features and could adsorb at various interfaces. However, they have not been applied yet for structuring liquids. In the present paper, we report on arrested fatty alcohol/water interfaces based on the association of a water-soluble polyelectrolyte (PE) and an oil-soluble fatty amine with the specific involvement of the organic solvent molecules, which act as cosurfactant in the surface region. The formed solid films enable the synthesis of temperature-sensitive all-in-liquid constructs from affordable materials and offer alternatives to bulk PE/AlS/alkanol assemblies prepared earlier through numerous synthesis steps.