Dielectric spectroscopy of epoxy-based barium titanate nanocomposites: effect of temperature and humidity

• Published in: IET Nanodielectrics Vol. 3; no. 1; pp. 20 - 27
• Main Authors: Zafar, Romana, Gupta, Nandini
• Format: Journal Article
• Language: English
• Published: Beijing The Institution of Engineering and Technology 01.03.2020; John Wiley & Sons, Inc; Wiley
• Subjects: barium compounds; Barium titanates; batio; BaTiO3; Broadband; Charge materials; Charge transport; charge transport behaviour; Complex permittivity; Conduction heating; dielectric materials; Dielectric properties; dielectric response; dielectric spectroscopy; Dielectrics; electrical conductivity; epoxy resin; Epoxy resins; epoxy-based barium titanate nanocomposites; filled polymers; filler loading; Fillers; frequency 0.001 hz to 1000000.0 hz; frequency 0.001 Hz to 1000000.0 Hz; Frequency ranges; High temperature; high temperature effect; Humidity; imaginary relative permittivity; low-frequency dispersion; Moisture content; molecular level; Nanocomposites; nanofabrication; Nanoparticles; Particulate composites; Permittivity; quasiDC conduction; Relative humidity; Research Article; resins; Spectroscopic analysis; surface functionalisation; surface-functionalised barium titanate nanofillers; Temperature; temperature 25.0 degC to 90.0 degC; Temperature effects; Water; water content; resins; dielectric response; dielectric spectroscopy; nanofabrication; temperature 25.0 degC to 90.0 degC; dielectric materials; nanocomposites; charge transport behaviour; imaginary relative permittivity; surface-functionalised barium titanate nanofillers; frequency 0.001 Hz to 1000000.0 Hz; water content; quasiDC conduction; barium compounds; high temperature effect; permittivity; epoxy-based barium titanate nanocomposites; BaTiO3; charge transport; epoxy resin; surface functionalisation; low-frequency dispersion; filled polymers; complex permittivity; electrical conductivity; molecular level; filler loading
• ISSN: 2514-3255; 2514-3255
• DOI: 10.1049/iet-nde.2019.0036

The information contained in the dielectric response of materials is useful to study the charge transport behaviour of dielectric materials at the molecular level. Therefore, in this work, broadband dielectric spectroscopy is used to measure complex permittivity of epoxy resin and its nanocomposites over a wide frequency range of 10−3–10+6 Hz. Measurements are carried out at different temperatures (25–90°C) and relative humidities of 50% RH and 90% RH. Nanocomposites are prepared with as-received and surface-functionalised barium titanate (BaTiO3) nanofillers incorporated into epoxy. Filler loading of 1–10% by volume are achieved and investigated. A detailed study of the effect of filler loading and surface functionalisation of particles before incorporation into the nanocomposite is included. It is seen that the addition of nanofillers increases both real and imaginary relative permittivity of the composite. Experiments are carried out to understand the effect of water content on epoxy and its nanocomposites. It reveals that low-frequency dispersion or quasi-DC conduction is exhibited at high humidity (90% RH) and high temperature (90°C).