Multi-functional enhancement of P(VDF-HFP) nanocomposites through MWCNTs loading for piezoelectric sensing

ABSTRACT This study presents the development of flexible piezoelectric nanocomposite films by incorporating multiwalled carbon nanotubes (MWCNTs) into poly(vinylidene fluoride-hexafluoropropylene) P(VDF-HFP) via solution casting. The addition of MWCNTs significantly enhanced the electroactive β-phase content, increasing crystallinity from 50.04% to 54.83% and tensile strength from 14.56 MPa to 45.13 MPa. Morphological analyses confirmed improved surface roughness and hydrophobicity, with water contact angles rising to 117.07°. Dielectric constant increased nearly fivefold (from 5.5 to 26.2 at 10 Hz), while thermal stability improved with decomposition onset shifting to 468.03 °C. Notably, the composite with 0.75 wt% MWCNTs exhibited the highest piezoelectric sensitivity, achieving a peak voltage output of 16.58 V under mechanical stress. These results demonstrate the strong potential of MWCNTs/P(VDF-HFP) composites for high-performance piezoelectric sensing applications.