Polysulfone microcapsules with different wall morphology

For the production of polysulfone microcapsules, a process was proposed, which allowed the obtaining of capsules with different wall morphology. A polysulfone solution was projected to a precipitation bath. Three solvents were assessed: N , N ‐dimethylformamide, N , N ‐dimethylacetamide, and N ‐methyl‐2‐pyrrolidone. Precipitation baths were composed by water, pure or mixed with solvent. Surfaces and cross–sections of different preparations were observed by Scanning Electron Microscopy. The study was focused on capsules of 30 ± 10 µm of diameter. Microcapsules surfaces were porous and two different structures were distinguished in the cross‐section: macrovoids and sponge‐like structures. High concentration of solvent in the precipitation bath reduced the porosity of the surface and the macrovoids of the wall, thus favoring sponge‐like structures. The present work set some bases for a better control of polysulfone microcapsules morphology.