Conductive membranes show many benefits including fouling reduction for feeds containing ionic species. These membranes may be prepared either by conductive polymers or coating of the surfaces of non-conductive membranes with conductive polymer. In this research, the commercial microfiltration GVHP membrane manufactured from PVDF was coated with POLYPYRROLE using two different techniques. The conductivity of the prepared membranes was measured. In this paper, effects of various factors including concentration of the solutions, oxidizing agents, time for leaving the support in the solutions, support type and temperature on membrane conductivity were investigated.

POLYPYRROLE (PPy) nanofibers have been fabricated on glassy carbon electrode (GCE) using electrochemical technique. Electropolymerization of pyrrole (Py) for the fabrication of PPy nanofibers was occurred on GCE by applying a fixed potential of about 0.85 V for 120 sec in a mild basic solution containing sodium carbonate and sodium perchlorate. In the mild basic media, the monomer, Py, is oxidized on GCE at a potential of about 0.85 V vs. Ag/AgCl and the oxidation product of Py i.e. POLYPYRROLE nanofibers is strictly adsorbed on the electrode surface. Cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy were used for studying the electrochemical and morphological properties of electropolymerized PPy conducting polymer. These techniques confirm the electropolymerization of Py as PPy nanofibers on the electrode surface.

POLYPYRROLE/silver (PPy/Ag)nanocomposite was synthesized by a chemical oxidative method. SEM and TEM analyses were performedfor studying the morphology of the nanocomposite. It was shown that the obtained nanocomposite particles have a spherical structure with the high surface area to volume ratio that is the important factor in the biological application. The particle sizes of the PPy/Ag were 15– 25 nm obtained by TEM. The antibacterial property was assessed by the disk diffusion method against gram-negative Escherichia coli and gram-positive Staphylococcus aureus bacteria. The antibacterial mechanism of action for PPy/Ag nanocomposite was discussed. PPy/Ag showed antibacterial activity against S. aureus (5 ± 0. 5 mm) and E. coli (8 ± 0. 5 mm). Based on satisfactory antibacterial properties of PPy/Ag nanocomposite, it could be considered as a suitable material in biomedical applications.

Synthesis and processing of polymer-based materials through green friendly methods involving supercritical fluids particularly supercritical carbon dioxide (SCC) has recently received substantial technological importance because of the commercial and industrial benefits involved. In the present work, a SCC assisted green and sustainable process has been developed to synthesize POLYPYRROLE/polythiophene copolymers (PPCs). The process of synthesis has been conducted through ferric chloride-initiated chemical oxidative polymerization in the presence of various molar proportions of pyrrole to thiophene 0: 1.0, 1.0: 0, 1.0: 1.0 and 1.0: 2.0 at temperature ranging from 50 to 90oC, 1, 200 psi over 12 h in SCC. Polymerization below 90 °C afforded PPCs in semi-solid products, whereas polymerizations conducted at 90 °C under identical conditions have afforded the end products in complete solid state. The structure and properties of PPCs have been evaluated through ultraviolet–visible absorption and Fourier transform infrared spectra, elemental analysis, atomic force microscopy, simultaneous thermogravimetric–differential thermal analysis–differential thermogravimetry and four-point probe electrical conductivity methods. With molar proportion of thiophene, time and temperature, all the polymerization reactions have been conducted to completion resulting in PPCs with enhanced polymerization yield, rheoviscosity, dispersion of POLYPYRROLE into polythiophene matrix and thermal stability. This has contributed a simultaneous loss in the electrical conductivity of PPCs.

Simultaneous measurement of effective thermal conductivity (le) and effective thermal diffusivity (ce) of three samples of POLYPYRROLE doped with metals Ni and Co in different percentage: POLYPYRROLE doped with 100% Co (S1), POLYPYRROLE doped with 50-50% Ni and Co (S2), and POLYPYRROLE doped with 100% Ni (S3) have been made using transient plane source (TPS) technique. The amorphous nature of POLYPYRROLE composites was confirmed by XRD studies. Characterization through SEM and EDX gives the information of surface morphology and elemental analysis of samples. From surface morphology it is found that surface is not smooth and contains macro-granular structure. EDX results confirm the presence of metal present in the samples. Thermal transport properties i.e., effective thermal conductivity (le) and effective thermal diffusivity (ce) were measured at normal pressure from room temperature to 170oC. From these investigations, it has been found that both le and ce increase to maximum up to 110º and then a constant value is attained with further increase of temperature i.e., 170oC. The values of le and ce of sample S3 doped with 100% Ni is higher as compared to sample S1 (Co 100%) and sample S2 (Ni, Co 50-50%). This result has been explained on the basis of bonding of cobalt and nickel with POLYPYRROLE matrix during the polymerization and higher values for S3 are attributed to the more metallic nature of Ni.

The nylon and nylon/lycra yarns were coated with electrically conductive polymers such as polyaniline and POLYPYRROLE, via chemical polymerization process. Electrical conductivity of the coated yarns was measured at various strain levels using two-point probe technique and their strain sensitivities were studied. The results showed that, electrical conductivity of the coated yarns decreased with an increase in strain level. A sharp decrease in the electrical conductivity of the nylon/lycra coated yarn with the strain level was recorded whereas, a small drop in the electrical conductivity of the nylon coated yarn was observed. Linear relationships were found between the electrical conductivity and length for the nylon and nylon/lycra coated yarns. The polyaniline coated yarns showed higher strain sensitivity compared to POLYPYRROLE coated yarns. Repeatability of the strain sensitivity of the coated yarns was examined and the coated nylon/lycra yarn showed better repeatability compared to that of coated nylon yarn. The coated yarns were proposed as a flexible strain sensor in the field of intelligent materials.