Biocompatible and pH‐Responsive Colloidal Surfactants with Tunable Shape for Controlled Interfacial Curvature

Molecular‐surfactant‐stabilized emulsions are susceptible to coalescence and Ostwald ripening. Amphiphilic particles, which have a much stronger anchoring strength at the interface, could effectively alleviate these problems to form stable Pickering emulsions. Herein, we describe a versatile method to fabricate biocompatible amphiphilic dimer particles through controlled coprecipitation and phase separation. The dimer particles consist of a hydrophobic PLA bulb and a hydrophilic shellac–PEG bulb, thus resembling nonionic molecular surfactants. The size and diameter ratio of the dimer particles are readily tunable, providing flexible control over the water/oil interfacial curvature and thus the type of emulsion. The particle‐stabilized emulsions were stable for a long period of time and could be destabilized through a pH‐triggered response. The biocompatible amphiphilic dimer particles with tunable morphology and functionality are thus ideal colloidal surfactants for various applications. Here to stay: Biocompatible amphiphilic dimer particles with a hydrophobic polylactide (PLA) bulb and a hydrophilic shellac–PEG bulb behaved similarly to molecular surfactants (see picture). The size and diameter ratio of the dimer particles were readily tunable, providing flexible control over the water/oil interfacial curvature and thus the emulsion type. Emulsions were stable for a long period of time and could be destabilized through a pH‐triggered response.