Ultrasonic and dielectric relaxations in PDMS/ZnO nanocomposite

Abstract

In this article, we present the impact of ZnO nanoparticles on ultrasonic and dielectric properties of Polydimethylsiloxane (PDMS)-based nanocomposites in a wide temperature range. The complex dielectric permittivity was measured as a function of the frequency at various temperatures and it was shown that the magnitude and the position of the dielectric loss peak in the temperature scale depend on the concentration of fillers in PDMS/ ZnO composite. The temperature dependences of ultrasonic wave attenuation showed attenuation peaks similar to those obtained by means of the dielectric spectroscopy. These peaks are attributed to the dynamic glass transition and obey the Vogel-FulcherTammann (VFT) equation. Values of the static glass transition temperature obtained analyzing the dielectric and ultrasonic data are consistent and increase with the concentration of ZnO. The ultrasonic wave attenuation and velocity in these composites depend on the filler concentration.

Dielectric, Ferroelectric, and Piezoelectric Investigation of Polymer‐Based P(VDF‐TrFE) Composites

“…Sputtered Al electrodes on the sample surface were used for electrical contacts. In the frequency range of 1 MHz–1 GHz dielectric properties were studied by measuring the complex reflection coefficients using a vector network analyzer Agilent 8714ET and a coaxial line . Elmika 2400 scalar network analyzer in combination with waveguides of various dimensions was used for dielectric spectroscopy investigation in GHz frequencies (40 GHz).…”

Carbon-Coated Nickel Nanoparticles: Effect on the Magnetic and Electric Properties of Composite Materials

“…We can assume that, being introduced into the PDMS matrix, Ni@C interact with polymer .The glass transition occurs at higher temperatures. In this case, Ni@C 108 can play the role of crystallization nuclei, similarly to other nanoparticles [46].…”

Thermosetting polymers in cold sintering: The fabrication of ZnO‐polydimethylsiloxane composites

“…Previous studies have explored the ZnO-PDMS composite system from an electrical property perspective, where the ZnO was introduced as a nanofiller (eg, nanorods, nanoparticles) to augment a PDMS matrix. 32,33 In such a nanocomposite system where the characteristic electrical responses of the constituent materials occur at different length/time scales, impedance spectroscopy has proven a powerful method to elucidating the interfacial and bulk electrical responses. 34,35 This study also investigates the influence of the volume fraction of polymer on the densification behavior, final density, microstructure, and electrical properties of the cold sintered (1 − x) ZnO − x PDMS composites (with x = 0.00, 0.01, 0.03, and 0.05).…”