In-situ formation of polyvinylidene fluoride microspheres within polycaprolactone electrospun mats

This study discusses the manufacture of hierarchical composite membranes via the combination of electrospinning and vapour-induced phase separation (VIPS). The fabrication approach here proposed makes possible the in situ generation of polyvinylidene fluoride (PVDF) spherical microparticles within electrospun nonwoven mats of polycaprolactone (PCL) fibres. Morphological investigations of the PCL-PVDF membranes show that the PVDF microspheres are distributed within the whole volume of the electrospun mats and, depending on the PVDF concentration used for the VIPS process, they can form permanent joints between fibres. Consequently, the fibre-particle systems exhibit increased Young's modulus and tensile strength (up to 1.7-fold increase) if compared to PCL electrospun mats, while maintaining a porous structure. The results of this study provide a new platform for the development of fibres-based systems that find application as scaffolds for tissue engineering, drug delivery devices, filtration elements for water, wastewater and air treatment.