Tunable morphology of monodisperse polymer particles with microfluidics

Abstract

In this work, we propose a novel method to fabricate polymer particles with controlled morphology in microchannel by solidification of polymer solutions and study the transition in the shape of these particles from spheres, to cups, and to donuts. The non-spherical geometries are achieved through nonuniform diffusion of the solvent, leading to non-uniform solidification. By adjusting the flow rates of both continuous and dispersed phases, the spatial heterogeneity in the solvent diffusion rate and thus the morphology of the final polymer particles can be tuned. This approach offers a one-step continuous process for the fabrication of non-spherical polymer particles. The technique is applicable to different polymers under appropriate polymer-solvent combinations. The ability to tune the shapes of polymer particles easily will create new opportunities for applications that require anisotropic functional particles, such as in biomedical engineering.