Effect of particles size on the optical constants of iron/polystyrene composites via UV-radiation

Abstract

The present study deals with the optical characteristics of polystyrene (PS) composites containing iron particles of different sizes: 5, 40, 110, and 250 μm. The optical absorption spectra were collected in the wavelength range 300-800 nm using a UV-spectrophotometer. The optical results obtained were analyzed in terms of the absorption formula for non-crystalline materials. The optical energy gap and other basic optical constants such as refractive index, dielectric constants, and optical conductivity were investigated and showed a clear dependence on the iron particles size. It was found that the optical energy gap for the iron-filled composites is less than that for the neat PS, and it decreases as the iron particle size decreases. The refractive index of the prepared composites was determined from the collected transmittance and reflectance spectra. It was found that the calculated dielectric constant and refractive index of the composites increase when the iron particles size decreases. The optical dispersion behavior of the composites was described by the single-oscillator model. Enhancement in the optical conductivity was observed with decreasing the iron particles size.

Optical and electrical properties of polystyrene composites containing ultrafine iron particles

“…The appearance of the exponential band around the 380 nm wavelength is due to the lack of long-range order in these samples. 11 The optical energy gap (E opt ) generally represents the energy difference between the localized states in valence band and the extended states in conduction band. On this basis, the energy E opt can be taken to represent the mobility gap.…”

“…7,10 Many reports appeared in literature dealing with optical and electrical properties of iron-filled polymer composite. For example, AL-Aqrabawi et al 11 studied the absorption coefficient, optical energy gap, energy tails, refractive index, dielectric constants, and optical conductivity for polystyrene (PS) composites containing iron of different particle sizes. They found that the electron transition is direct in k-space and the optical energy gap values increase with increase in the size of iron particles.…”

Effect of aluminum oxide nanoparticles additives and gamma irradiation on the structural and optical properties of syndiotactic polystyrene

“…It is reported that the incorporation of nanoparticles in PS for the synthesis of nanocomposite has potential merit in optoelectronic, catalyst, and chemical sensors applications . Although various studies investigated the properties of sPS nanocomposites as a function of the content of nanosized fillers , none of these have focused on systems with Al 2 O 3 embedded in sPS. However, studying the structure of polymers that are embedded with nanoparticles is important to describe the change in crystallinity and lattice parameters after introducing the nanofiller in the polymer matrix.…”