Synthesis,characterization and weight percent effect on humidity sensing properties of Polypyrrole/AlCeO3 (PPy/ACO) nanocomposites

Polypyrrole (PPy)/aluminum cerium oxide (ACO) nanocomposites with different weight percentages of the ACO nanoparticles in the matrix of PPy have been synthesized successfully. The addition of fillers in the conducting polymer makes significant changes in their electrical, chemical, mechanical and gas sensing properties. The exact amount of filler is one of the essential parameters to get the desired properties in the host polymer. So, the optimization of the percent weight of filler in the host conducting polymer is very much crucial. The structural and morphological studies were done by XRD, FTIR, SEM, and TEM. These experimental studies reveal that nanoparticles of Aluminum cerium oxide are dispersed uniformly in the PPy chains. The humidity sensing properties for different weight percent of nanocomposites were studied by using impedance analyzer in the frequency range from 100?Hz to 5?MHz and at relative humidity (% RH) variation from 30% RH to 90% RH. The graphs of impedance versus frequency for all nanocomposites showed a slightly linear dependence at all the frequencies over the entire humidity range. The complex impedance (cole-cole) graphs and the corresponding equivalent circuits were studied to understand the conduction phenomenon in nanocomposites. The conduction in pure PPy shows the contribution from grain and grain boundaries while all the nanocomposites show contribution only from grains. The lower weight percent nanocomposites exhibit better response compared to higher weight percent.     

Synthesis, characterization and conductivity studies of polypyrrole-fly ash composites

In situ polymerization of pyrrole was carried out in the presence of fly ash (FA) to synthesize polypyrrole-fly ash composites (PPy/FA) by chemical oxidation method. The PPy/FA composites have been synthesized with various compositions (10, 20, 30, 40 and 50 wt%) of fly ash in pyrrole. The surface morphology of these composites was studied with scanning electron micrograph (SEM). The polypyrrole-fly ash composites were also characterized by employing X-ray diffractometry (XRD) and infrared spectroscopy (IR). The a.c. conductivity behaviour has been investigated in the frequency range 10²–10⁶ Hz. The d.c. conductivity was studied in the temperature range from 40–200°C. The dimensions of fly ash in the matrix have a greater influence on the observed conductivity values. The results obtained for these composites are of greater scientific and technological interest.     

Correction: Thermo-electric power and humidity sensing studies of the polypyrrole-tantalum pentoxide composites

Journal of Materials Science: Materials in Electronics -     

Chemical synthesis,characterization, and direct‐current conductivity studies of polypyrrole/γ‐Fe2O3 composites

The in situ polymerization of pyrrole was carried out in the presence of γ‐Fe₂O₃ to synthesize polypyrrole/γ‐Fe₂O₃ composites by a chemical oxidation method. The polypyrrole/γ‐Fe₂O₃ composites were synthesized with various compositions, including 10, 20, 30, 40, and 50 wt % γ‐Fe₂O₃ in pyrrole. The polypyrrole/γ‐Fe₂O₃ composites were characterized with X‐ray diffractometry and infrared spectroscopy. The surface morphology of these composites was studied with scanning electron microscopy. The direct‐current conductivity was studied from 40 to 200°C. The dimensions of the γ‐Fe₂O₃ particles in the matrix had a greater influence on the conductivity values. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2797–2801, 2007