Enhancement of PVDF’s piezoelectricity by VGCF and MWNT

Effects of initial crystallization process on piezoelectricity of PVDF-HFP films

“…(9) and Wu et al [23], it can be found that the increase of C 0 can lead to the further increase of harvested power density. The higher open circuit voltage and harvested power density are usually caused by the higher β-phase content or higher rate of crystallization as confirmed in our previous studies [22,23,25,26]. To investigate the crystalline structure and morphology in various samples, the cross sections parallel to the stretching direction were observed using the polarized optical microscopy (POM) (ECLIPSE E400 POL, Nikon Co., Ltd., Japan).…”

“…To evaluate the piezoelectricity of the PVDF-HFP films, the open circuit voltage and the harvested power of AC circuit were measured [22,23,25,26]. The measurement setups are illustrated in Figure 2A.…”

“…Among them, the most common and important one is the mechanical stretching in solution casting method. Besides the methods named herein, addition of various fillers, such as carbon nanotube (CNT) [20][21][22][23][24], graphene [25], Ag nanowires [26], etc., to prepare PVDF homopolymer or copolymer composites represents another practical way to enhance piezoelectricity of PVDF films. Experimental results [20][21][22][23][24][25][26] have shown that the piezoelectricity of PVDF and its copolymers can be remarkably enhanced, e.g., a two-fold increase when adding 0.05 wt% reduced graphene oxide [25].…”

Fillers in advanced nanocomposites for energy harvesting

“…With a small addition of 0.05 wt% to PVDF matrices, the energy-harvesting output can be increased by 3 times (Wu et al, 2014). These materials are usually applied because of their relatively easy fabrication and low cost as well as their ideal electrical properties necessary for energyharvesting applications.…”

“…Another type of nanofiller from the class of carbon-based 1D materials is carbon nanotubes, mostly multiwalled carbon nanotubes (MWCNTs; Figure 16.10), which are frequently used in nanocomposites for energy harvesting (Wu et al, 2014;Lee et al, 2008;Sepulveda et al, 2013). In this case, the presence of carbon nanotubes as a nanofiller results in the enhancement of mechanical energy harvesting (Wu et al, 2014) because of the developed b-crystalline structure in the PVDF matrices.…”