Microdroplet-based Synthesis of Polymethylsilsesquioxane Microspheres with Controllable Size, Surface Morphology, and Internal Structure

•Large-sized polymethylsilsesquioxane spheres were prepared by microdroplet method.•A step T-junction microchannel was used to generate monodispersed microdroplets.•The microdroplets were solidified via rapid in-situ interfacial polycondensation.•Corrugated/smooth surface and loose/dense internal structure could be obtained.•Particle size could be tuned from tens of microns (∼20 μm) to hundreds of microns.