Self crosslinked admicelle-Fe3O4 Janus nanoparticle with high detachment energy to creat low-energy emulsified and ultra-stable Pickering emulsion

Abstract

By skillfully manipulating self-assembly and self-crosslinking activities of sodium conjugated linoleate in a wax-emulsion approach, we design a route to synthesize Janus (self-crosslinked admicelle)-decorated nano-Fe3O4 (SCA-Fe3O4 nanoparticle). The SCA-Fe3O4 nanoparticle exhibits ultra-high stability against environmental stresses of temperature (25–90 °C), salinity (0.1–1.8 M) and pH (1.8–11.7) relying on its high detachment energy at the oil/water interface to create ultra-stable Pickering emulsions. On the other hand, it is possible to demulsify the ultra-stable emulsions by simultaneously providing an external magnetic field and acidic pH under gently stirring to switch on–off the emulsions. Furthermore, the SCA-Fe3O4 nanoparticle reduces the requirement for energy density of emulsification, and achieves a new energy-saving effect in Pickering emulsion preparation comparable to low-energy emulsification methods in nanoemulsion preparation. Therefore, this strategy has good prospects to create Janus structures of various inorganic nanoparticles by a facile synthesis on the surface of frozen wax spheres, and these Janus particles have potential applications in Pickering emulsifiers, interfacial catalysts, biomedicines, and other multifunctional materials due to their asymmetric structure, unique interfacial characteristics and simplified emulsification operation.