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In this study, we investigated the effect of zirconium content on lead-free barium zirconate titanate (BZT) (Ba(ZrxTi1−x)O3, with x = 0.00, 0.01, 0.03, 0.05, and 0.08), which was prepared by the sol–gel method. A single-phase perovskite BZT was obtained under calcination and sintering conditions at 1100 °C and 1300 °C. Ferroelectric measurements revealed that the Curie temperature of BaTiO3 was 399 K, and the transition temperature decreased with increasing zirconium content. At the Curie temperature, Ba(Zr0.03Ti0.97)O3 with a dielectric constant of 19,600 showed the best performance in converting supplied mechanical vibration into electrical power. The experiments focused on piezoelectric activity at a low vibrating frequency, and the output power that dissipated from the BZT system at 15 Hz was 2.47 nW (30 MΩ). The prepared lead-free sol–gel BZT is promising for energy-harvesting applications considering that the normal frequencies of ambient vibration sources are less than 100 Hz.

In this work, a superhydrophobic surface of poly (vinylidenefluoridene-hexafluoropropylene) (P(VDF-HFP)) fibers was fabricated by means of electrospinning technique. The effects of flow rate on the morphology and hydrophobicity of P(VDF-HFP) nanofibers were investigated by scanning electron microscopy (SEM) and water contact angle (WCA), respectively. The results exhibit a uniform P(VDF-HFP) fiber mat at the lowest flow rate. However, the presence of bead-on-string the fibers was exhibited at higher flow rate. The average fiber diameter of P(VDF-HFP) fibers is increased with increasing flow rates. The WCA values of the P(VDF-HFP) fibers with bead-on-string structure could reach up to 158.60°, indicating as the superhydrophobicity. These as-received porous P(VDF-HFP) fibers with superhydrophobic surface are attractive properties for self-cleaning materials used for further several industrial applications.

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In this study, different flow rates were used to produce electrospun Poly (vinylidenefluoridene-hexafluoropropylene) P(VDF-HFP) nanofibers to investigate the fiber diameter and water contact angle (WCA). The flow rate range for P(VDF-HFP) electrospinning started from 0.1 to 0.9 ml/h. The surface morphology of the nanofibers was studied by scanning electron microscopy. The intrinsic beta-phase and the degree of crystallization are confirmed from Fourier transform infrared spectroscopy and differential scanning calorimetry studies. The wettability of the nanofibers was also determined in terms of WCA. The results show continuous nanofiber mats. The P(VDF-HFP) mat at flow rate of 0.7 ml/h shows the highest values of fiber diameter of 835 nm and WCA of 152°. The electroactive beta-phase occurred during the electrospinning process is achieved with 86% of beta-phase fraction and 85% of crystalline degree. These results suggest that the as-received P(VDF-HFP) nanofibers can operate stably as the fiber strain sensor without being affected by sweat or water.