Micron-sized soft chemical reactors synthesized via the aerosol phase

Recent progress in materials science and complex chemical systems has highlighted the critical role of containers in directing and modulating reactivity. There is interest in innovative modes of confinement encompassing wider length scales and a diversity of container materials. Microcontainers are of special interest for having volume/surface ratios departing significantly from laboratory glassware whilst remaining amenable to automated high throughput production and observation via optical microscopy. Here, we demonstrate the generation of micron-sized calcium alginate droplets via ultrasonic atomization and their use as containers for solid particles and nanomaterials, including magnetite and carbon black. We further show that these microspheres can be used as reactors for in situ synthesis of Prussian blue and quinhydrone, possible due to their permeability towards small molecules. These versatile microreactors can also be used for payload/drug release, triggered via their rapid disassembly in response to calcium binders like EDTA.