Preparation of microparticles through co-flowing of partially miscible liquids

•Microparticles generated by co-flowing of two partially miscible liquid phases.•Liquid miscibility varied by changing the amount of co-solvent in inner phase.•The miscibility influenced the flow, the particle size, distribution & morphology.•The approach facilitated the formation of small particles with large apertures.

Monodisperse microparticles find applications in a wide range of areas. Generation of such particles of several microns in size at a large scale is a difficult task. This paper reports a proof of concept using a microfluidic device that coaxially flows partially miscible liquids for the production of microparticles. The approach makes use of both the physical forces of the process and the chemical properties of the liquid systems that allows for careful control of the mixing and droplet formation processes. Initial results show that, with this approach, particles with a reasonably narrow size distribution can be produced and liquid miscibility can be used as an additional avenue to manipulate the mean particle size and morphology.