Hybrid materials possessing piezo- and ferroelectric properties emerge as excellent alternatives to conventional piezoceramics due to their merits of facile synthesis, lightweight nature, ease of fabrication and mechanical flexibility. Inspired by the structural stability of aminophosphonium compounds, here we report the first A3BX6 type cyanometallate [Ph2(iPrNH)2P]3[Fe(CN)6] ( 1 ), which shows a ferroelectric saturation polarization (Ps) of 3.71 μC cm−2. Compound 1 exhibits a high electrostrictive coefficient (Q33) of 0.73 m4 C−2, far exceeding those of piezoceramics (0.034–0.096 m4 C−2). Piezoresponse force microscopy (PFM) analysis demonstrates the polarization switching and domain structure of 1 further confirming its ferroelectric nature. Furthermore, thermoplastic polyurethane (TPU) polymer composite films of 1 were prepared and employed as piezoelectric nanogenerators. Notably, the 15 wt % 1 -TPU device gave a maximum output voltage of 13.57 V and a power density of 6.03 μW cm−2. 相似文献
We report the preparation of highly compressible and elastic piezoelectric aerogels of carboxylated cellulose nanocrystals (CNCs). Aqueous CNC dispersions containing polyethyleneimine and crosslinker were frozen isotropically to yield isotropic aerogels, while oriented aerogels were prepared by directional freezing. These aerogels were highly flexible and porous (~?85% void fraction), exhibiting greater than 90% recovery at 50% compressive strain even after 100 compression–decompression cycles. Since such aerogels with low bulk modulus and high anisotropy would be an ideal platform for leveraging the piezoelectric properties of CNCs, we used them to prepare piezoelectric nanogenerator devices and determined their energy transduction behavior. Anisotropic aerogels led to an enhanced open-circuit voltage of 840 mV (at ~?8 N applied force), which is over 2.6 times higher than isotropic aerogels (320 mV). The energy density of anisotropic aerogels was around 52 nW/cm2, representing outstanding piezoelectric performance for cellulose-based aerogels. Such aerogels with high compressibility, elastic recovery and exceptional piezoelectric performance could have potential applications in sensors, wearable electronics, etc.
Organic–inorganic hybrid ferroelectrics are an exciting class of molecular materials with promising applications in the area of energy and electronics. The synthesis, ferroelectric and piezoelectric energy harvesting behavior of a 3d metal ion‐containing A4BX6 type organic–inorganic hybrid salt [Ph3MeP]4[Ni(NCS)6] ( 1 ) is now presented. P‐E hysteresis loop studies on 1 show a remnant ferroelectric polarization value of 18.71 μC cm?2, at room temperature. Composite thermoplastic polyurethane (TPU) devices with 5, 10, 15 and 20 wt % compositions of 1 were prepared and employed for piezoelectric energy harvesting studies. A maximum output voltage of 19.29 V and a calculated power density value of 2.51 mW cm?3 were observed for the 15 wt % 1 ‐TPU device. The capacitor charging experiments on the 15 wt % 1 ‐TPU composite device shows an excellent energy storage performance with the highest stored energies and measured charges of 198.8 μJ and 600 μC, respectively. 相似文献
A new binary organic salt diphenyl diisopropylamino phosphonium hexaflurophosphate (DPDP?PF6) was shown to exhibit a good ferroelectric response and employed for mechanical energy harvesting application. The phosphonium salt crystallizes in the monoclinic noncentrosymmetric space group Cc and exhibits an H‐bonded 1D chain structure due to N?H???F interactions. Ferroelectric measurements on the single crystals of DPDP?PF6 gave a well‐saturated rectangular hysteresis loop with a remnant (Pr) polarization value of 6 μC cm?2. Further, composite devices based on polydimethylsiloxane (PDMS) films for various weight percentages (3, 5, 7, 10 and 20 wt %) of DPDP?PF6 were prepared and examined for power generation by using an impact test setup. A maximum output peak‐to‐peak voltage (VPP) of 8.5 V and an output peak‐to‐peak current (IPP) of 0.5 μA was obtained for the non‐poled composite film with 10 wt % of DPDP?PF6. These results show the efficacy of organic ferroelectric substances as potential micropower generators. 相似文献
Organic ferroelectrics due to their low cost, easy preparation, light weight, high flexibility and phase stability are gaining tremendous attention in the field of portable electronics. In this work, we report the synthesis, structure and ferroelectric behavior of a two-component ammonium salt 2 , containing a bulky [Bn(4-BrBn)NMe2]+ (Bn=benzyl and 4-BrBn=4-bromobenzyl) cation and tetrahedral (BF4)− anion. The structural analysis revealed the presence of rich non-classical C−H⋅⋅⋅F and C−H⋅⋅⋅Br interactions in this molecule that were quantified by Hirshfeld surface analysis. The polarization (P) vs. electric field (E) hysteresis loop measurements on 2 gave a remnant polarization (Pr) of 14.4 μC cm−2 at room temperature. Flexible polymer composites with various (5, 10, 15 and 20) weight percentages (wt%) of 2 in thermoplastic polyurethane (TPU) were prepared and tested for mechanical energy harvesting applications. A notable peak-to-peak output voltage of 20 V, maximum current density of 1.1 μA cm−2 and power density of 21.1 μW cm−2 were recorded for the 15 wt% 2 -TPU composite device. Furthermore, the voltage output generated from this device was utilized to rapidly charge a 100 μF capacitor, with stored energies and measured charges of 156 μJ and 121.6 μC, respectively. 相似文献