Tuning the Dielectric Constant and Surface Engineering of a BaTiO₃/Porous PDMS Composite Film for Enhanced Triboelectric Nanogenerator Output Performance

Abstract

In this work, synergistic effects derived from surface engineering and dielectric property tuning were exploited to enhance the output performance of a triboelectric nanogenerator (TENG) based on an inorganic/porous PDMS composite in a contact–separation mode. BaTiO3 (BT)/porous PDMS films with different BT weight ratios were fabricated and evaluated for triboelectric nanogenerator (TENG) application. Maximum output signals of ca. 2500 V, 150 μA, and a power density of 1.2 W m–2 are achieved from the TENG containing 7 wt % BT, which is the best compromise in terms of surface roughness, dielectric constant, and surface contact area as evidenced by SEM and AFM studies. These electrical signals are 2 times higher than those observed for the TENG without BT. The 7BT/porous PDMS-based TENG also shows high stability without a significant loss of output voltage for at least 24 000 cycles. With this optimized TENG, more than 350 LEDs are lit up and a wireless transmitter is operated within 9 s. This work not only shows the promoting effects from porous surfaces and an optimized dielectric constant but also offers a rapid and template/waste-free fabrication process for porous PDMS composite films toward large-scale production.

Increasing Permittivity and Mechanical Harvesting Response of PVDF-Based Flexible Composites by Using Ag Nanoparticles onto BaTiO3 Nanofillers

“…The characteristic peaks assigned to the nonpolar α-PVDF phase are located at 490, 532, 614, 763, 795, 855, 973, 1148, 1212, 1382, and 1423 cm −1 with the most representative intense peaks at 763 and 614 cm −1 , while the peaks specific to the ferroelectric β polymorph reported at 510, 840, 1275, and 1402 cm −1 wavenumbers, as validated in [41,47]. However, the literature reports and our FTIR data have shown that there are also peaks in the range of 870-885 cm −1 , 1171-1182 cm −1 , and 1398-1404 cm −1 which have similar characteristics to the α, β, and γ-phases or to mixed phases [19,[34][35][36][37]41,[54][55][56][57]. The most important bands are specific to the α and β phases, whose formation is dependent on the processing conditions and composition.…”

“…Both values are superior with respect to 0.122 μW/cm 2 reported for the modified BT-PVDF piezoelectric sensor in [ 11 ] or of 1 μW/cm 2 [ 21 ]. They are in the same range as reported for (Ba,Ca)(Ti, Zr)O 3 -PVDF of 16.7 μW/cm 2 [ 86 ], but lower than for hybrid PTENG reported in [ 62 ] for a complex composite formed by hybrid TiO 2 nanosheets with Ag nanoparticles embedded into a polydimethylsiloxane matrix (48 μW/cm 2 ) and with a few orders in magnitude lower than one of the highest power density of 1.21 W/m 2 reported for surface- and pore-engineered BT-polymer composites in [ 34 ]. We may conclude that the present harvesting outputs found in BT-PVDF, and in particular in (Ag-BT)-PVDF hybrid composites produced by a simple wet synthesis method, are very promising and their response can be further improved and optimized.…”

“…Finally, the addition of both types of fillers causes an enhanced permittivity, thus creating a larger capacitance of the overall device. Since both piezo/and triboelectric charges, when produced, have to first be stored for a while by the composite material itself, and then released into the external circuit and collected during the contact-separation mode, the increased capacitance is beneficial for improving the total harvesting response [ 32 , 34 ].…”

“…Some approaches were proposed to effectively increase the surface charge density to optimize the TENG device’s outputs,. Similar to PENG responses, the TENG outputs were enhanced by using conductive nanofillers (e.g., metallic or carbonaceous species) in the polymer matrix [ 32 , 33 ] or by the surface engineering of inorganic high-permittivity filler combined with the composite’s permittivity increase, as recently proposed in [ 34 ] where a power output surface density of 1.21 W/m 2 was generated. It was further shown that piezo- and triboelectric generation can be exploited synergically in the same structure instead of pairing di-similar polymer-based materials, as classically used for TENGs.…”

Superhydrophobic PDMS-pCA@CNWF Composite with UV-Resistant and Self-Cleaning Properties for Oil/Water Separation

“…As shown in Figure 4 b, in addition to peaks for C (284.8 eV) and O (102.3 eV) [ 40 , 41 ], characteristic peaks for Si can be seen for the PDMS-pCA@CNWF spectrum when compared to those of the CNWF. The peaks at 102.3 eV and 152.0 eV are attributable to Si 2p and Si 2s from PDMS [ 42 , 43 ]. Therefore, these results indicate the successful deposition of PDMS on the pCA@CNWF surface.…”