B. Kavitha

Synthesis and Characterization of Nano Size Conducting Polyaniline

Conducting polymers have attracted considerable attention in the recent years due to their unique thermal, electrical, optical and magnetic properties. These polymers have been conducive for fabrication of micro-electronic devices. Among these polymers, Polyaniline (PANI) possesses an exceptional properties including structural, thermal and electrical. We have synthesized PANI in Emeraldine salt form by chemical oxidation method with controlled pH3 by using Ammonium perdisulphate as oxidizing agent. The morphology of PANI has been determined by using X-Ray Diffraction (XRD), Scanning Electron Micrograms (SEM) and Dynamic Light Scattering (DLS). The studies revealed that Polyaniline possess rod like shape with radius around 75 nm and length around 617.6 nm. The DSC thermogram shows two exothermal peaks at around 97.07 o C and 152 o C, these peaks are attributed to the glass transition temperature (Tg) and PANI degradation temperature respectively. The final valley point (endothermic) around 175 o C is attributed to the melting point (Tm) of PANI. The voltage-current (V-I) characteristics of Polyaniline have studied at temperature 300 K. Due to semi crystalline solid nature of PANI, the transport of charge carriers may takes place in between and along PANI chains.

Triple modifier effect on physical, optical and structural properties of boro tellurite zinc lithium glasses

To investigate physical, optical and structural properties of glass samples of the Quaternary system (60-x)B2O3−xTeO2-10ZnO-30Li2O with x=0,5,10,15, and 20 mol% were prepared by conventional melt quenching technique. XRD confirmed the amorphous nature of all samples. Physical parameters like density, molar volume, Oxygen packing density and etc. calculated. Density of glass samples increased with the increase of TeO2 concentration due to the replacement of lighter B2O3 with heavier TeO2. Optical properties has studied with the help of UV-Visible spectra. Cut off wavelength is increases whereas Eopt and Urbache energies is decreased except intermediate mole fraction of TeO2 at which the triple modifier effect can be observed. Fourier Transform Infrared spectroscopy reveals that the network consists of TeO3 and TeO6 structural units along with BO3 and BO4 units.To investigate physical, optical and structural properties of glass samples of the Quaternary system (60-x)B2O3−xTeO2-10ZnO-30Li2O with x=0,5,10,15, and 20 mol% were prepared by conventional melt quenching technique. XRD confirmed the amorphous nature of all samples. Physical parameters like density, molar volume, Oxygen packing density and etc. calculated. Density of glass samples increased with the increase of TeO2 concentration due to the replacement of lighter B2O3 with heavier TeO2. Optical properties has studied with the help of UV-Visible spectra. Cut off wavelength is increases whereas Eopt and Urbache energies is decreased except intermediate mole fraction of TeO2 at which the triple modifier effect can be observed. Fourier Transform Infrared spectroscopy reveals that the network consists of TeO3 and TeO6 structural units along with BO3 and BO4 units.

Physical and optical studies on Li2O-Na2O-WO3-B2O3 glasses

Glasses with composition xLi2O-(30-x)Na2O-10WO3-60B2O3 (where x=0, 5, 10, 15, 20, 25 and 30 mol%) have been prepared using the melt quenching technique. In the present work, the mixed alkali effect (MAE) has been investigated in the above glass system through density and optical studies. The density of the present gasses varies non-linearly, the exhibiting the mixed alkali effect. From the optical absorption studies, the values of direct optical band gap, indirect optical band gap energy (Eo) and Urbach energy(ΔE) have been evaluated. The values of E0 and ΔE vary non-linearly with composition parameter, showing the mixed alkali effect.

Synthesis and characterization of metal oxide-polyaniline emeraldine salt based nanocomposite

This paper describes the synthesis of TiO2 (core)/Polyaniline (shell) core-shell structured nanocomposites and characterization of the synthesized material. The morphological characterization is performed with XRD, SEM, DLS and SANS. Spectroscopic characterization is performed with FTIR, UV/Visible and ESR techniques.

Synthesis and characterization of nanosize conducting polyaniline, titania and their composite

Core-Shell nanostructures, a family of Nanomaterials have attracted increasing research interest due to their unique structural features that consist of an inner core and an external shell of different chemical compositions. Core-Shell nanostructures have exhibited improved physical and electrical, spectroscopic properties relative to their single-component counterparts. This paper describes the synthesis of TiO2 (core) / Polyaniline (shell) core-shell structured nanocomposites and characterization of the synthesized material. The morphological characterization is performed with XRD, SEM, DLS and Spectroscopic characterization is performed with FTIR, UV/Visible and ESR techniques.

Magnetic Resosnance Studies of Nano Phase Conducting Polyaniline

Polyaniline (PANI) was synthesized in Emaraldine form by in situ chemical oxidation method by using Ammonium perdisulphate as oxidizing agent. The XRD pattern indicates that PANI is a semi crystalline solid with d-spacing 4.801 and 4.358 Ǻ. The SEM results show that the particle size lies as an average of 80 nm and length 550 nm. Similarly the UV-Visible spectra of this polymer indicate two absorption bands at around 320 nm and 640 nm. These absorption bands are attributed to the transitions of π → π* and Benzenoid to Quinoid respectively. The FT-IR spectrum of PANI shows strong bands at 3,442, 2,925, 1,598, 1,494, 1,453, 1,176, 1,112 and 744 cm−1 respectively. 1H NMR spectrum shows 6 peaks with chemical shifts δ = 7.452, 7.468, 7.505, 7.525, 7.604, 7.638 ppm. The lower three peaks at (δ = 7.452, 7.468, 7.505 ppm) are attributed to the protons related to the 14N nucleus. These spectral lines intensity ratio lies as 1:1:1. Another three peaks at (δ = 7.525, 7.604, 7.638 ppm) are attributed to the three protons, which are present at CH Benzenoid, NH, CH at Quinoid. The intensity ratio of these spectral lines is 1:2:1. The room temperature ESR spectrum of PANI Emeraldine salt shows an unresolved peak with lande’s g factor 2.010 due to polarons.