Fabrication of 1st generation aromatic hyperbranched polyester/ polyvinylidene fluoride blended electrospun composites to enrich the piezoelectric performance

In this study, piezoelectric performance of polyvinylidene fluoride (PVDF) is enhanced by facile blending with aromatic hyperbranched polyester of 1 st generation (Ar.HBP-G1). Prior to blending with PVDF, Ar.HBP-G1 was synthesized by one-shot polycondensation technique using pentaerythritol (as core) and diphenolic acid (as AB 2 type monomer), and analyzed by different spectroscopic (FTIR-ATR, NMR) techniques. PVDF with varying Ar.HBP-G1 content (0, 10, 20, 30 and 40 wt.-%) were blended to obtain electrospun fibers, and their morphology examined by FE-SEM and crystallization behavior analyzed using FTIR and XRD. As-prepared electrospun PVDF/Ar.HBP-G1 composite nanofibers (NFs) were used to fabricate piezoelectric nanogenerator (PENG) using Ni-Cu coated conductive fabric as electrodes. Piezoelectric performance was evaluated by employing a periodic load of 1.0 kgf at a constant frequency of 1.0 Hz. Among the five different PENG samples used in our study, the peak-to-peak output voltage ( V p-p ) for PVDF-Ar.HBP-G1 (10 wt.-%) NF showed almost three times (4.28 V) better piezoelectric response compared to neat PVDF (1.89 V). The optimized sample (Ar.HBP-G1 (10 wt.-%)) subjected to varying load (1 to 3 kgf) and frequency (0.1 to 1.0 Hz) showed maximum V p-p of 4.28 V under 1 kgf and 1.0 Hz. Further, the PENG was employed for portable and human health monitoring energy harvesting applications.