Monodisperse porous emulsion-templated microparticles with varied morphology using ‘plug-and-play’ microfluidics

• A reliable and highly reproducible continuous flow setup to produce tunable polyHIPEs with controlled characteristics such as size, shape, and porosity. • The continuous flow setup is easily accessible and cheap. • Changing flow conditions unlocks synthesis of particles with different morphologies and a broad range of sizes. • A highly uniform core porosity is achieved. • Particles can homogenously functionalized. Despite the challenge of forming unstable emulsion droplets in a second continuous phase, combining high-internal phase emulsions (HIPEs) with microfluidic particle generation presents a promising tool for generating polyHIPE particles with controlled characteristics such as size, shape, and porosity. Herein, an accessible ‘plug and play’ microfluidic platform is developed for generating polyHIPE particles with controlled size and morphology. The employed HIPE contains a low surfactant concentration (3 wt%) while the monomer composition can be varied to alter the mechanical properties of the resulting polyHIPE particles. Varying only the emulsion preparation and microfluidic flow rates can be used to generate particle sizes from 220 µm to >1 mm, with spherical, various ellipsoidal, and rod-like morphologies. Uniform surface and core porosity is confirmed via scanning electron microscopy (SEM), while the possibility of surface modification is highlighted by reacting residual acrylates with a photoactive tetrazole to yield fluorescent microparticles.