Improvement of Piezoelectric Property of Poly(Vinylidene Fluoride) Nanocomposites Using Multi-Walled Carbon Nanotubes

We improved the piezoelectric property of poly (vinylidene fluoride) (PVDF) by employing multi-walled carbon nanotube (MWCNT) as nanofillers. The MWCNT/PVDF nanocomposite was prepared by the solution casting method with MWCNT contents ranging from 0.0 wt.% to 0.3 wt.%. To induce the piezoelectric β-phase crystal structure, the nanocomposite films were drawn lengthwise with a ratio of 4 ~ 5 and polarized by step-wise poling method. To evaluate the piezoelectric property, the output voltages of the nanocomposite films were measured through extensive experimental vibration tests. The experimental results show that the nanocomposite films with 0.05 wt.% MWCNT possess the highest output voltage, i.e., around 2 times as that of pure PVDF films. The main reason is that more β-crystalline phase can be formed at this content, as confirmed by X-ray diffraction.