Dielectric and nano-scale free volume properties of polyaniline/polyvinyl alcohol nanocomposites

Abstract

Polyaniline (PANI)/polyvinyl alcohol (PVA) nanocomposites has been prepared. Scanning electron microscopy, SEM of pure PVA and PANI/PVA nanocomposite films to monitor the morphology and dispersion of PANI on the surface of the PVA films. Positron annihilation lifetime measurements were carried out, in the air, at room temperature with a conventional fast-fast coincidence spectrometer. Dielectric permittivity e 0 , dielectric loss e 00 and AC conductivity r ac of PANI/PVA nanocomposites has been achieved in the range of frequencies 40 Hz-5 MHz and temperature range of 293-353 K. It was found that; O-ps lifetime, s 3 , its intensity, I 3 and relative fractional free volume, F r increase as the PANI content increases. The dielectric permitivity e 0 and loss e 00 increase with increasing the PANI content and decreases as the frequency increases. The values of the frequency exponent for the correlated barrier hopping s and the binding energy of the charge carriers W m for the investigated nanocomposites decrease with increasing PANI content. Finally, the dielectric permittivity e 0 was found to be directly proportional to the relative fractional free volume, F r .

Influence of oxygen ion implantation on the free volume parameters and electrical conductivity of a polymer‐based bakelite RPC detector material

“…The calculated values of “ S ” are plotted as a function of O + ion implantation fluences and shown in Figure . It is clear from the figure that “ S ” values at both the energies show opposite behavior with o ‐Ps lifetime (τ 3 ) and free volume size ( V f ), and exhibit good agreement with the reported results in the literature …”

Investigating mechanical, dielectric, and electromagnetic interference shielding properties of polymer blends and three component hybrid composites based on polyvinyl alcohol, polyaniline, and few layer graphene

“…Saboor et al reported the increase in dielectric constant and dielectric loss around five and eight orders of magnitude at 1 kHz by the addition of 40 wt% of PANI in styrene acrylonitrile matrix. Similarly, El‐Gamal et al recently reported PVA/PANI blends in which dielectric properties are increased around two orders of magnitude with increasing concentration of PANI in the low frequency region. Whereas, graphene as a nanofiller not only offers outstanding electrical characteristics but also have exceptional mechanical properties like tensile strength ∼130 GPa and modulus ∼1 TPa .…”

Investigation of dielectric properties of free standing electrospun nonwoven mat

“…Organic insulating polymers blends consisting PANI has been fabricated with noticeable advancement in mechanical and electrical properties, getting enormous observance from academics and industries. The electrical properties of films and pellets of PVA/PANI and PVA/PVP, respectively, have shown upgraded electrical properties of the composites like conductivity, dielectric, etc. A high throughput transaction is extended to fabricate nonwoven, breathable, and lightweight materials consisting of fine/uniform fibers making porous texture and extremely large ratio of surface area to volume .…”