P3HT loaded piezoelectric electrospun fibers for tunable molecular adsorption

Electrospinning is strongly attractive for the fabrication of fibrous platforms for a wide range of applications like electronic devices, electroactive wearables and wound healing scaffolds. Recently, this versatile, reliable and low-cost technique has been investigated with a wide selection of active materials to fabricate nonwoven meshes to be used as smart filters to control the adsorption/delivery of small molecules. In this work, electrospinning is proposed for the fabrication of polyvinylidene fluoride (PVDF)-based fibers able to control the adsorption of negatively charged molecules such as Methylene Blue (MB). It is demonstrated that PVDF fibers with pronounced surface roughness - from 126 nm to 1983 nm - are able to adsorb a higher amount of MB than smooth fibers made of PCL, used as a control. Moreover, the integration of a p-type conjugated polymer such as Poly (3-hexylthiophene) (P3HT), concurs influencing the adsorption mechanism of MB, mediated by the microscopic interactions among dipolar beta phases in PVDF. In addition, an increase of MB absorption was measured in the presence of an externally applied voltage (10 kV), ascribable to the P3HT oxidation change that influences microscopic dipole interactions. Hence, we suggest the use of P3HT/Polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) fibers to design new filtering systems able to tune the absorption of negatively charged molecules for environmental and biomedical applications. (C) 2020 Elsevier B.V. All rights reserved.