Optical and electrical properties of kaolinite/polystyrene composite

• Published in: Journal of physics. D, Applied physics Applied physics, 2009-07, Vol.42 (14), p.145405-145405 (7)
• Main Authors: Sbeih, S A, Zihlif, A M
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric loss and relaxation; Dielectric properties of solids and liquids; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Optical constants: refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Permittivity (dielectric function); Physics
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/42/14/145405

The optical and electrical characteristics of kaolinite/polystyrene composites containing 20 wt% kaolinite with grain sizes of 63, 106, 212 and 300 mum and neat polystyrene were studied. The optical absorption spectra were collected in the wavelength range 300-800 nm using a spectrophotometer. The optical band gap and energy tail widths of localized states were determined for the prepared composites. It was found that the optical energy gap and the energy tail width vary with the kaolinite grain size. The electrical properties were studied using ac impedance measurements performed at different temperatures and frequency range 100 kHz-1 MHz. Impedance, dielectric constant, dielectric loss and ac conductivity showed frequency and temperature dependence. The relaxation time and thermal activation energy of the electrical conduction vary with kaolinite grain sizes and temperature. The universal power law of the ac conductivity behaviour is satisfied for different grain sizes and at different temperatures.