Temperature‐Responsive Pickering Double Emulsions Stabilized by Binary Microgels

Abstract

Microgels are excellent emulsifiers that can self‐assemble to reduce interfacial tension and form a steric barrier at an oil‐water interface. Herein, we report a two‐step emulsification approach to prepare oil‐in‐water‐in‐oil (O/W/O) Pickering double emulsions through the dispersion of microgels in two immiscible phases. The stabilization mechanism depends on the uneven distribution and adsorption of hydrophilic water‐swollen microgels and hydrophobic octanol‐swollen microgels on either outer water droplets or inner oil droplets. Our results reveal that binary microgels outperformed single microgels in terms of interfacial tension reduction and emulsion stabilization. Notably, the binary microgel‐stabilized Pickering double emulsions show excellent temperature responsiveness owing to the intrinsic thermal sensitivity of microgels. Consequently, the selective and rapid release of encapsulated substances in different phases can be achieved through the adjustment of the ambient temperature.

Facilitating Seed Iron Uptake through Amine-Epoxide Microgels: A Novel Approach to Enhance Cucumber (Cucumis sativus) Germination

“…An interesting class of polymers is termed micro- and nanogels, characterized by an internal gel-like structure that swells when exposed to a dispersing solvent. − The size of these microgel networks typically spans from several micrometers down to nanometers, often referred to as nanogels. , These gels possess softness and responsiveness related to macromolecules, and they can crystallize based on volume fraction similar to colloids and exhibit the ability to adsorb to interfaces, thereby reducing interfacial tension, resembling surfactants. , The properties of these materials can be finely adjusted by incorporating functional groups along their molecular backbone. This design aspect allows for the creation of polymeric nano- or microgels capable of producing smart materials with remarkable swelling capacity (water uptake) and sensitivity to factors such as pH, oxidation, and temperature.…”

“… 10 − 12 The size of these microgel networks typically spans from several micrometers down to nanometers, often referred to as nanogels. 13 , 14 These gels possess softness and responsiveness related to macromolecules, and they can crystallize based on volume fraction similar to colloids and exhibit the ability to adsorb to interfaces, thereby reducing interfacial tension, resembling surfactants. 15 , 16 The properties of these materials can be finely adjusted by incorporating functional groups along their molecular backbone.…”

Multi-responsive Pickering emulsifiers: a comprehensive study on the emulsification–demulsification behavior of modified chitosan-coated Fe3O4 nanocomposites

“…Fortunately, modifying stimulus-responsive groups on NPs enables emulsification and demulsification processes upon stimulation, which effectively addresses the aforementioned issues. 6,7 Currently, several types of stimulus-responsive emulsifiers have been reported, including pH-responsive, 8–10 temperature-responsive, 11–13 CO 2 -responsive, 14–16 light-responsive, 17,18 mechanical-responsive, 19 magnetic-responsive, 20–22 REDOX-responsive 23,24 and multi-responsive. Among them, magnetic responsive emulsions have garnered widespread attention due to their advantages of low toxicity, simple operation, fast response speed, high reusability, and excellent controllability.…”