Light ‐Driven Spatiotemporal Pickering Emulsion Droplet Manipulation Enabled by Plasmonic Hybrid Microgels

Plasmonic hybrid microgels are assembled by electrostatic heterocoagulation between oppositely charged microgels and Au nanoparticles, and can stabilize oil-in-water Pickering emulsions and enable precise manipulation of droplet behaviors by laser irradiation. The presented system may open new possibilities for on-demand substance transport, programmed release, and controlled catalytic reactions. AbstractThe past decades have witnessed the development of various stimuli-responsive materials with tailored functionalities,  enabling droplet manipulation through external force fields. Among different strategies, light exhibits excellent flexibility for contactless control of droplets, particularly in three-dimensional space. Here, we present a facile synthesis of plasmonic hybrid microgels based on the electrostatic heterocoagulation between cationic microgels and anionic Au nanoparticles. The hybrid microgels are effective stabilizers of oil-in-water Pickering emulsions. In addition, the laser irradiation on Au nanoparticles creats a “cascade effect” to thermally responsive microgels, which triggers a ch ange in microgel wettability, resulting in microgel desorption and emulsion destabilization. More importantly, the localized heating generated by a focused laser induces the generation of a vapor bubble inside oil droplets, leading to the formation of a novel air-in-oil-in-water (A/O/W) emulsion. Th ese A/O/W droplets are able to mimic natural microswimmers in an aqueou...
Source: Small - Category: Nanotechnology Authors: Tags: Research Article Source Type: research