Dielectric properties of sol–gel synthesized polysulfone–ZnO nanocomposites

Abstract

The research on development of nanodielectric material is the requirement of capacitor industry. The polymeric material could not have a high dielectric constant due to limitation of structure and physical properties. However, combination of suitable nanofiller can increase the dielectric constant several times. We have reported the dielectric properties of polysulfone ? ZnO nanodielectric system. The dielectric properties are observed to be governed by dipolar polarization fully and interfacial polarization partially. The relaxation time of dipoles is quite high: It means that nanodipoles have sufficient relaxation time to orient in the direction of field. Interface provides additional trapping level for storage of charge carriers energetically. The permittivity of new material increases many times of base material even at lower concentration of fillers.

Structural, Optical and Dielectric Properties of Some Nanocomposites Derived from Copper Oxide Nanoparticles Embedded in Poly(vinylpyrrolidone) Matrix

“…Further, the ε ′ values present a significant decline as the frequency increases till low constant values are found in the high frequency range. This enhancement in the dielectric constant with an increase in the metal oxide level in the PVP films can be attributed to the electrostatic interactions between the CuO nanoparticles and dipolar groups of the PVP chain, leading to additional polarization under an electric field [53,54]. For example, at 1 kHz, the ε ′ for the PVP is 3.8, whereas for the CuO/PVP nanocomposites, the following values were found: 4.2 (PC3), 5.5 (PC4) and 7.5 (PC5).…”

“…As temperature increases, a substantial enhancement in ε ′ was observed as a function of CuO loading. The significant increase in the dielectric constant at higher temperatures (>50 • C) suggests that charge carriers can move freely in the polymer sample due to the segmental mobility of the polymer chains enhancing the dipolar orientation, and hence, the dielectric constant increases [54,60]. Also, the density of charge carriers is higher when the CuO nanoparticle level in the host matrix increases, leading to their accumulation at the interface between the polymer and CuO nanoparticles; thus, higher values of ε ′ were obtained.…”

Insights into the optical, magnetic and dielectric properties of some novel polysulfone/NiFe2O4 composite materials

“…Polymer nanocomposites containing organic/inorganic components can be obtained by grafting synthetic polymers on inorganic particles or by adding modified nanoparticles into polymer matrices leading to improved physical, mechanical, electrical properties, etc., of the material. In addition, a marked improvement was observed in dielectric constant or relative permittivity values after incorporation of various types of nanoparticles in polymer matrices . Polymer nanocomposites embedding nanoparticles show more advantages than polymer composites with micrometric fillers due to their enhanced interfacial surface.…”

“…The physical properties of synthesized polymer nanocomposites depend essentially on some parameters such as grain size, preparation method and the degree of dispersion of the particles in the polymer matrix . In recent years, various synthetic polymers, such as poly(vinylydene fluoride), aromatic polyimide, polysulfone (PSU) and others, have been used to develop composite materials with improved dielectric and magnetic properties. These polymers present a number of advantageous properties such as high chemical resistance, good thermal stability, superior mechanical properties, biocompatibility, electroactive properties (piezoelectric, pyroelectric and ferroelectric activities) and low surface energy.…”