Microstructure and positron behavior in FeCl₃ doped PVA/PVP blend

Abstract

We are reporting the positron behaviour in transition metal chloride FeCl3 doped PVA/PVP (50:50) blend. Pure and FeCl3 doped blend films were prepared using solution casting method and studied using X‐ray Diffraction (XRD) and Positron Annihilation Lifetime Spectroscopy (PALS). XRD studies show that the doping increases the amorphous nature of the blend and the PALS studies reveal that the o‐Ps lifetime (τ3) and intensity (I3) decreases with increase in FeCl3 doping level. This is due to chemical quenching and inhibition process of Ps due to doping concentration, which are discussed in the text. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Novel cobalt lead ferrite (CPFO)/Ps nanocomposites with enhanced structure, optical and dielectric properties

“…The patterns show that absorption increases as CPFO in the examined nanocomposite increases and experiences a red shift to higher wavelengths λ cutoff as shown in the inset in figure 7 and table 1. Pristine PS had lower absorbance in the UV and visible spectrums, but after doping the absorbance values increased due to the formation of defect states that allowed the electrons transferred from the valence (VB) to the conduction band (CB) as previously seen in other literatures [18,19].…”

“…The conductive grains, however, become more apparent at higher frequencies, enabling charge carriers to hope between nearby ions (ac conductivity frequency dependent) [66]. Figure 16 illustrates as CPFO nanoparticles increased in higher frequency region, ac conductivity increased from 6.04 * 10 −10 to 1.47 * 10 −9 δ/cm at 10 6 Hz due formation of continuous conductive paths within the polystyrene matrix, also, ac s increased with raising frequency due to the hopping process within the polymer chain [19].…”

“…The incorporating of fillers in the polymer matrix enhances the physical properties of such materials [3,4]. Polymers, such as polyvinyl alcohol (PVA) [5][6][7][8][9], polymethyl methacrylate (PMMA) [10][11][12][13][14], Polyvinylchloride (PVC) [15][16][17], polyvinyl pyrrolidone (PVP) [18], blend of polyvinyl alcohol (PVA) /polyvinyl pyrrolidone (PVP) [19,20], polyvinylidene fluoride (PVDF)/ polyvinyl chloride (PVC) [21,22] and others, are currently favoured by many researchers as appropriate matrices for enhancing polymer nanocomposite materials due to their extended lifespan, increased suppleness, reduced weightiness, simplicity of preparation, ecological persistence, good mechanical properties, and so on. Among the polymers we focused on polystyrene (C 8 H 8 ) n is a thermo-plastic polymer material that can be manufactured, processed, has outstanding chemical-physical properties, and can be completely recycled and reused.…”

Augmentation in proton conductivity of crosslinked poly(vinyl alcohol) through the introduction of polyvinyl pyrrolidone

“…11 Numerous researchers have studied the characteristics of PVP/PVA mixtures doped with different salts. 12 The PVP/PVA blend containing NaNO 3 exhibits the maximum conductivity at room temperature (1.25 Â 10 À5 S cm À1 ). 13 The PVP/PVA blend containing AlCl 3 as the dopant presented the maximum conductivity at room temperature (8.05 Â 10 À5 S cm À1 ).…”

“…Poor charge storage capacity and dopant‐dependent electrical properties are characteristics of the PVP/PVA blends synthesized following the casting process 11 . Numerous researchers have studied the characteristics of PVP/PVA mixtures doped with different salts 12 . The PVP/PVA blend containing NaNO 3 exhibits the maximum conductivity at room temperature (1.25 × 10 −5 S cm −1 ) 13 …”