Experimental Studies on Current, Susceptance, Impedance and Electrical Modulus of Polypyrrole/Molybdenum Trioxide Composites

Polypyrrole/molybdenum trioxide composites (PPy/MoO3) were synthesized by chemical oxidation method, which involved the polymerization of pyrrole (PPy) with molybdenum trioxide (MoO3). This process involved ammonium persulphate which acted as an oxidizing agent.Diverse compositions of MoO3 such as 10, 20, 30, 40 and 50 wt. % in pyrrole were used to synthesize PPy/MoO3 composites.Scanning Electron Microscopy (SEM) image of the above composites has revealed the presence of multiple phases comprising of MoO3 particles embedded in PPy chain. The observed increase in current could be due to hopping of a large number of charge carriers between favorable localized sites and is attributed to change in the distribution pattern of MoO3 particles.The present study also involved the measurement of susceptance, impedance and electrical modulus, and has disclosed the major influence of dimensions of MoO3 particles present in the matrix on all the properties. The composites discussed in the present study may throw some light on their applications in various areas namely humidity sensor, micro power generator, dielectrics and as semiconductors

Structural, DC Conductivity and Electric Modulus Studies of Polypyrrole Praseodymium Manganite Nanocomposites

Praseodymium Calcium Manganite (PCM) nanoparticles were synthesized by sol-gel method. Polypyrrole (PPy) and polypyrrole–praseodymium manganite nanocomposites (PPy/PCM) were synthesized by in-situ chemical polymerization method. Transmission electron microscope (TEM) confirmed good crystallinity with 42-63 nm average particle size. Scanning electron microscope (SEM) exhibited well-defined core structure of PPy and the PPy/PCM nanocomposites. X-ray diffraction (XRD) patterns of PPy showed amorphous nature and those of composites showed semicrystalline nature. UV-Vis spectroscopy was used to study the energy band gap for all the nanocomposites and hence they may find a place in wide band gap applications. The UV (231nm) and visible (363 nm and 377 nm) emissions were observed from the spectrum. DC conductivity was studied from 473 to 303 K for all the nanocomposites and found that conduction is of semiconductor type. Analysis of electric modulus confirmed the contribution from grain and grain boundary, non-Debye type relaxation and dc conductivity obeyed Correlated Barrier Hopping (CBH) model

Characterization of Multiphase Polypyrrole/Vanadium Oxide Nano Composites for a.c. Conductivity and Dielectric Properties

Vanadium oxide: Phase-1 and Phase-2 nano powers were synthesized from vanadium pentoxide in the presence of glucose using hydrothermal technique. The polypyrrole/vanadium oxide (PV P-1 and PV P-2) nano composites were synthesized with 15, 30, 45 and 60 weight percents of vanadium oxide: Phase-1 and Phase-2 in pyrrole, by the chemical polymerization (oxidation) method. The SEM micrographs of vanadium oxide: Phase-1 and Phase-2 nano powders have shown  mixture of nano belts & rods and PV P-1 & PV P-2 nano composites indicate that the composites have cluster formation with almost spherical nature particles and form elongated chains at some places. Conductivity versus frequency  plots shown that exponential increase for conductivity. The value of s increases to 1.13x10-3 S/cm for 15 wt. % of VO2 P-1 in polypyrrole & to 2.43x10-3 S/cm for 30 wt. % of VO2 P-2 in polypyrrole at 1 MHz

Structural and Electrical Characterization of Polypyrrole and Cobalt Aluminum Oxide Nanocomposites

To investigate electrical properties of conducting polypyrrole (PPy) and cobalt aluminum oxide (CAO) nanocomposites, impedance analyzer in frequency range of 100 Hz to 5 MHz is used. In this work, PPy/CAO nanocomposites were synthesized by chemical oxidation polymerization method in different weight percent of CAO in PPy. The dielectric properties and AC conductivity studies were carried out for different nanocomposites in temperature range of room temperature to 180 °C. With the increase in frequency, the dielectric constant for all the nanocomposites was observed to decrease. AC conductivity of PPy was improved by addition of CAO nanopowder

Structural and Electrical Characterization of Polypyrrole and Cobalt Aluminum Oxide Nanocomposites

To investigate electrical properties of conducting polypyrrole (PPy) and cobalt aluminum oxide (CAO) nanocomposites, impedance analyzer in frequency range of 100 Hz to 5 MHz is used. In this work, PPy/CAO nanocomposites were synthesized by chemical oxidation polymerization method in different weight percent of CAO in PPy. The dielectric properties and AC conductivity studies were carried out for different nanocomposites in temperature range of room temperature to 180 °C. With the increase in frequency, the dielectric constant for all the nanocomposites was observed to decrease. AC conductivity of PPy was improved by addition of CAO nanopowder

Conductivity and DSC studies of poly(ethylene glycol) and its salt complexes

456-458<span style="font-size: 15.0pt;mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">The temperature response of conductivity of poly(ethylene glycol) (PEG) and its salt complexes like KCI, KBr and KI has been studied in the temperature range 299 to 331 K. Doping of PEG with KCI and KBr increased the conductivity by about 2.5 times for KCI and about 6.25 times for KBr, while doping with KI reduced the conductivity to about 0.05 times its pure component value. This may be due to the presence of dissolved salt in the solid, or alternatively may be due to the changes in the structure of PEG induced by the presence of salt. DSC studies on the samples were carried out wherein a beautiful peak was observed near the melting point. Analysis of DSC results confirms that the reaction is endothermic and the peak shifts towards higher value for different salts as compared to pure PEG. </span

Structural, DC Conductivity and Electric Modulus Studies of Polypyrrole Praseodymium Manganite Nanocomposites

165-174Praseodymium Calcium Manganite (PCM) nanoparticles were synthesized by sol-gel method. Polypyrrole (PPy) and polypyrrole–praseodymium manganite nanocomposites (PPy/PCM) were synthesized by in-situ chemical polymerization method. Transmission electron microscope (TEM) confirmed good crystallinity with 42-63 nm average particle size. Scanning electron microscope (SEM) exhibited well-defined core structure of PPy and the PPy/PCM nanocomposites. X-ray diffraction (XRD) patterns of PPy showed amorphous nature and those of composites showed semicrystalline nature. UVVis spectroscopy was used to study the energy band gap for all the nanocomposites and hence they may find a place in wide band gap applications. The UV (231nm) and visible (363 nm and 377 nm) emissions were observed from the spectrum. DC conductivity was studied from 473 to 303 K for all the nanocomposites and found that conduction is of semiconductor type. Analysis of electric modulus confirmed the contribution from grain and grain boundary, non-Debye type relaxation and dc conductivity obeyed Correlated Barrier Hopping (CBH) model

Studies of thermo-electric power and dielectric modulus of polypyrrole/zirconium oxide-molybdenum trioxide (PZM) composites

Zirconium oxide-molybdenum trioxide doped polypyrrole composites have been synthesized in the presence of ammonium persulphate (oxidizing agent), with different 15, 30, 45 and 60\ua0wt% of zirconium oxide-molybdenum trioxide (ZM) in pyrrole, by the chemical polymerization (oxidation) process. The polypyrrole/zirconium oxide-molybdenum trioxide (PZM) composites have exhibited crystalline nature, which has been confirmed by powder X-ray diffraction patterns. The Fourier transform infrared graphs show that the stretching frequencies of the composites have shifted towards the lower frequency side. The scanning electron microscopy micrographs indicate that the composites are of spherical nature and form elongated chains; an increase in the particles size when compared with polypyrrole and ZM particles is also observed. Thermo electric power and transport properties studies reveal that there is an interaction between polypyrrole and the ZM particles and the weight percents of the ZM particles have an influence on the properties of the pure polypyrrole. Studies shown that, the PZM composites are good materials in conductivity, dielectric properties, micro power generator, thermo cooling, as semiconductors as well as may be in humidity, gas and thermal sensor.\ua0\ua9 2018, Springer Science+Business Media, LLC, part of Springer Nature