Preparation of poly(ε-caprolactone) microspheres and fibers with controllable surface morphology

Poly(epsilon-caprolactone) (PCL) microspheres with different surface architectures were prepared by electro-spraying a solution containing polymer, host solvent and guest solvent. With increasing polymer concentration, PCL gradually turned from collapsed particles to regular uniform microspheres and finally to fibers. Non-solvent induced phase separation was responsible for formation of surface pores, and the pore density on the microsphere surface could be varied by selecting different guest solvent or by changing the amount of the non-solvent. The surface morphology of electrospun fibers could be tuned from smooth to rough and porous by varying the weight ratio between non-solvent and polymer that controlled the coalescence of the non-solvent nuclei. (C) 2017 Elsevier Ltd. All rights reserved.