Novel piezoelectric properties of electrospun polyamide-imide nanofiber membranes

Electrospinning is an efficient method for generating piezoelectric nanofiber membranes. However, the majority of piezoelectric nanofibers are derived from a limited pool of polymer sources, such as polyvinylidene fluoride, polyacrylonitrile, poly(l-lactic acid), and nylon-11, which restricts the exploration of piezoelectric properties from other polymer nanofibers. This study presents the first-ever investigation into the piezoelectricity of electrospun polyamide-imide (PAI) nanofibers, paving the way for the development of novel functional materials. We discovered that a PAI nanofiber membrane (with a size of 2 x 2 cm2 and a thickness of 100 mu m) subjected to compressive impacts (force of 8 N, frequency of 2 Hz) yielded an open-circuit peak-to-peak piezoelectric voltage (Vp-p) of 17.17 +/- 0.32 V and a short-circuit peak-to-peak current output (Ip-p) of 0.35 +/- 0.02 mu A. More significantly, this piezoelectric nanofiber membrane demonstrated exceptional thermal resistance, with a piezoelectric charge coefficient (d33) as high as 116 pC N-1 at room temperature, and a d33 of 97 pC N-1 at 220 degrees C. This high-temperature resistance performance surpasses that of most reported piezoelectric polymers. Additionally, molecular modeling results suggest that the presence of a net dipole moment in the vertical direction of straight PAI molecular chains enables the formation of a net large dipole in the thickness direction of the nanofiber membrane, thereby accounting for its piezoelectric properties. Electrospun PAI nanofiber membranes may constitute a novel piezoelectric material suitable for high-temperature energy harvesting and sensing applications. Electrospun polyamide-imide (PAI) nanofiber membranes exhibit excellent piezoelectric properties under both ambient temperature and high-temperature conditions.

Automated summary

Electrospun polyamide-imide (PAI) nanofiber membranes exhibit excellent piezoelectric properties under both ambient temperature and high-temperature conditions.