No abstract

In this study, highly monodispersed, exceptionally stable, spherical silver nanoparticles (AgNPs) were successfully synthesized by the microwave assisted rapid and cost-effective green method. Aqueous extract of clammy cherry (Cordia obliqua Willd) fruit was used as the green reductant, and capping agent for the synthesis of AgNPs and the effect of different synthesis parameters on the optical properties of the synthesized AgNPs was also studied. The characterization of synthesized AgNPs by Fourier transform infrared spectroscopy, X-ray diffraction studies, UV-visible spectroscopy, scanning electron microscopy and transmission electron microscopy (TEM) revealed the formation of small AgNPs with narrow size distribution. TEM studies corroborated that the AgNPs are highly crystalline and spherical with an average diameter of 7.13 nm. The cyclic voltammetry profile of AgNPs modified electrode in NaOH depicted prominent redox peaks evidencing an impressive electrochemical response. The AgNPs manifested high catalytic activity towards reduction of methyl orange and rhodamine blue with apparent rate constant 0.3038 min −1 and 0.1542 min −1 respectively. Additionally, the prepared AgNPs exhibited strong antibacterial efficacy against the tested microbes.

Here, novel poly(1-naphthylamine)-tungsten disulphide (PNA-WS 2 ) nanocomposites were synthesized through an in-situ chemical oxidative polymerization of 1-naphthylamine in the presence of ultrasonically dispersed WS 2 . The effect of WS 2 addition on the optoelectrical, morphological and thermal properties of PNA was studied by using different analytical tools. SEM images revealed that PNA aggregates are well supported on the dispersed WS 2 sheets. The formation of a fibrous network of PNA over the dispersed WS 2 layers evidenced from the TEM images has suggested larger surface area and better interfacial interaction between PNA and incorporated WS 2 layers . The thermal stability was improved upon the incorporation of WS 2 . Optical bandgap values of PNA-WS 2 nanocomposites were lower than that of bulk WS 2 and pristine PNA. Electrical and dielectric studies have confirmed an improvement in conductivity and dielectric properties with increasing WS 2 content, which was credited to the better charge transport between the polar backbone of PNA and charged surface of dispersed WS 2 due to enhanced interfacial area and electrostatic interactions between the components. A maximum AC conductivity of 4.4 × 10 -3 Sm −1 was displayed by nanocomposite containing 20% WS 2 loading and a further increase in WS 2 content showed a detrimental effect in electrical and dielectric properties. The present study has demonstrated that optical and dielectric properties of composites can be readily tuned by proper control of the composition and dispersion of WS 2 within the PNA matrix.

No abstract