Optical and electrical properties of polystyrene composites containing ultrafine iron particles

Abstract

Optical and electrical properties of conductive polymer composites made of polystyrene (PS) containing ultrafine iron particles of size 2 mm were studied under different measuring conditions: iron filler concentrations (0, 5, 10, 20, and 30 wt.%), ultraviolet radiation wavelength, temperature range (30-90 C), and applied frequency range (50 kHz-1.5 MHz). The absorption spectra from the composites were measured using a spectrophotometer. The analysis of the optical results showed that the electronic transitions are direct in the k-space. The optical energy gap and the energy tails were determined as a function of iron particles' content. It was found that optical energy gap decreased and energy tails increased with iron content. The determined refractive index (n) and the extinction coefficient (k) increased with iron concentration. The alternating current (AC) conductivity and dielectric properties were determined using impedance measurements. The collected impedance data were analyzed and showed that the dielectric constant (" 0 ) and dielectric loss (" 00 ) of the composites are increasing as iron concentration increases and decreasing as the applied frequency increases. It was found that the AC conductivity increases with increasing frequency, temperature, and iron concentration. Some theoretical and empirical models are used to describe the observed optical and electrical behavior of the prepared PS composites.

Investigation of structure, thermal and dielectric study of Dy0.05Ba0.7Sr0.25TiO3/polystyrene nanocomposites

“…Such conductivity follows the universal power law ∼Aω s (relation 5). In view of this, relation 5 is valid for the studied amorphous polystyrene and crystalline PS/Dy-BST NCPs in agreement with the data reported for amorphous and crystalline materials [47].…”

“…In addition, tanδ shows much lower values (0.02 to 0.0006, at a frequency range of 10 0 -10 6 Hz). These properties were found to be better than those reported for other polystyrene-based composites, like BST/PS [48], iron particles/PS [47], and Bi 2 O 3 /PS [49] composites. Interestingly, they would make Dy-BST/PS NCPs promising for insulation applications and energy storage devices.…”

Effects of Gamma Radiation Doses on the AC Electrical Properties of Epoxy Reinforced with Nano-Silica Composites

“…Gamma radiation is electromagnetic radiation that has a high energy level, which it able to ionize atoms by removing electrons, thus creating positively and negatively charged ions, so these increase the degree of dipole orientation, then increase the AC electrical conductivity. Additionally, when the gamma dosage is increased, it can lead to scission of branched chains, which increases the mobility of the free charge carriers and thus increases electrical conductivity [23][24][25]. The Jonscher's Universal Law Model utilizes the length distribution of conduction paths that are accessible for electric charge flow to explain the universal power-law dispersive AC conductivity seen in polymer networks and disordered matter.…”

Dielectric and mechanical properties of nickel silica core-shell reinforced PMMA nanocomposites

“…44 The increment of ac conductivity as the frequency increased due to the hoping process which allows the charge to hop from one localized state to another state inside the polymeric chains. [45][46][47][48] On the other side, the ac conductivity pushed up from 4.38*10 À15 to 2.21*10 À12 (S/cm) for PMMA film while jumped from 7.16*10 À15 insulator material to 1.26*10 À9 (S/cm) semi-conductor material at 1 Hz for 15%Ni@SiO 2 /PMMA nanocomposite film. The ac conductivity of the nanocomposite films has deeply increased with increasing temperature at a low frequency while having a noticeable increase at high frequency.…”