Regulated crystallization and piezoelectric properties of bio-based poly(L-lactic acid)/ diatomite composite fibers by electrospinning

Biodegradable poly(L-lactic acid) (PLLA) is recognized as a flexible piezoelectric material that overcomes the limitations of brittle piezoelectric ceramics and non-degradable piezoelectric polymer materials. The piezoelectric properties of PLLA are closely associated to its crystallinity and crystal phase structure. In this study, natural diatomite (DE) is used to adjust the crystallization behaviors and piezoelectric properties of PLLA. The PLLA/DE biodegradable composite fibers with enhanced piezoelectric properties were prepared via electrospinning. Our findings show that DE act as nucleating agents, facilitating the formation of α-phase crystals and thereby enhancing the crystallinity, Young’s modulus, and piezoelectric properties of PLLA. The piezoelectric device fabricated from the PLLA/DE composite fibers containing 5 wt% DE demonstrates an output voltage nearly 2.5 times greater than that of the neat PLLA sample, while also exhibiting excellent stability even after 1000 cycles. With good flexibility, high piezoelectric performance, and degradability, the developed DE/PLLA composite fibers can be easily integrated into devices to produce high-performance piezoelectric materials suitable for environmentally friendly applications.