Recycled EPS Fibers Hybridized With PVDF and CNTs for Flexible Energy Harvesting Applications

With the growing demand for flexible, portable and wearable energy sources, polymer/carbon nanotube composites have attracted growing interest for energy harvesting applications. In this study, we present the morphology, structure, and initial piezoelectric behavior of electrospun hybrid fibers comprising recycled expanded polystyrene (rEPS), neat polyvinylidene fluoride (PVDF), and functionalized carbon nanotubes (f-CNTs). Various hybrid fibers, including rEPS/PVDF, rEPS/CNT, and rEPS/PVDF/CNT, were fabricated by optimizing the polymer solutions and operational conditions during electrospinning. Among the fibers, rEPS/CNT exhibited the highest output voltage of 0.39 V under a compressive force of 3.5 N, outperforming both rEPS/PVDF and rEPS/PVDF/CNT composite fibers. While the energy harvesting performance remains moderate, rEPS/CNT composite fibers demonstrated the potential for further development as flexible nanogenerators (NGs). These preliminary results suggest that rEPS-based fibers, particularly those incorporating f-CNTs, may offer a pathway toward the fabrication of lightweight, flexible, and self-powered devices, although additional work is required to enhance their electrical output and device stability.