Polymer Microparticles with Controllable Surface Textures Generated through Interfacial Instabilities of Emulsion Droplets

A general and versatile route to prepare hierarchical polymer microparticles via interfacial instabilities of emulsion droplets is demonstrated. Uniform emulsion droplets containing hydrophobic polymers and n-hexadecanol (HD) are generated through microfluidic devices. When organic solvent diffuses through the aqueous phase and evaporates, shrinking emulsion droplets containing HD and polystyrene (PS) will trigger interfacial instabilities to form microparticles with wrinkled surfaces. Interestingly, surface-textures of the particles can be accurately tailored from smooth to high textures by varying the HD concentration and/or the rate of solvent evaporation. Moreover, composite particles can be generated by suspending different hydrophobic species to the initial polymer solutions. This versatile approach for preparing particles with highly textured surfaces can be extended to other type of hydrophobic polymers which will find potential applications in the fields of drug delivery, tissue engineering, catalysis, coating, and device fabrication.