The relationship between nanoscaled morphology and macroscopic electrical conductivity of polypyrrole (PPy) nanostructures was qualitatively investigated. The PPy nanostructures were prepared via microemulsion polymerization using ionic surfactants. The morphology of PPy was influenced by both the type of ionic surfactants and reaction sequences; specifically, the PPy structures were highly influenced by the reaction sequence when anionic surfactant of SDS was used. By changing reaction sequence, a gel-like PPy was formed influencing on the macroscopic electrical conductivity. The results indicate that the macroscopic conductivity of PPy is affected by its nanoscaled structures as determined by the reaction conditions. 相似文献
Conducting/electroactive polypyrrole polymers are synthesized electrochemically on glassy carbon in various electrolytes (counterions). The polymers' electroactivity is measured using cyclic voltammetry. The electrolytes are chloride, nitrate, p-toluene sulfonate, dodecyl sulfate, and dodecylbenzenesulfonate of sodium and potassium ferrocyanide. It is found that the electrolyte (dopant) markedly affects the redox behavior of the polypyrrole films. 相似文献
Conducting polymer composites of polyvinylferrocene and polypyrrole (PVF/PPy) were synthesized chemically by the in situ polymerization of pyrrole in the presence of PVF using FeCl3 as oxidant. Acetic (CH3COOH) and boric (H3BO3) acids were used as the synthesis medium. Effects of the synthesis medium on the properties of the PVF/PPy composite were investigated. The PVF/PPy composites and homopolymers were characterized by fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and magnetic susceptibility techniques. Conductivity measurements were performed using the four‐probe technique. We found that the conductivities of PVF/PPy‐H3BO3 (1.19 S cm?1) and PVF/PPy‐CH3COOH (4.5×10?1 S cm?1) increased relative to those of the homopolymers of PPy‐H3BO3 (2.1×10?2 S cm?1) and PPy‐CH3COOH (1.2×10?2 S cm?1) due to the interaction of PVF with the pyrrole moiety. The stability of all homopolymers and composites were investigated by thermogravimetric analysis and by conductivity measurements during heating‐cooling cycles. There was a small drop in conductivity caused by the annealing of PVF/PPy composites at 70°C. The conductivity of all samples increased with temperature and exhibited stable electrical behavior with increasing temperature. TGA analysis of samples showed that the composites were more stable than the homopolymers or PVF separately. The magnetic susceptibility values of samples were negative, except for PVF/PPy‐H3BO3. Morphology changes of the composites investigated by scanning electron microscopy (SEM), attributed to synthesis conditions, have a significant effect on their conductivity. 相似文献
Unique nanocomposites of polypyrrole/Au and polypyrrole/Pt hybrid nanotubes are synthesized employing polypyrrole (PPy) nanotubes as an advanced support by solution reduction. The conducting polymer PPy nanotubes are fabricated by using pre‐prepared MnO2 nanowires as the reactive templates. MnO2 nanowires induce the 1D polymerization of pyrrole monomers and the simultaneous dissolution of the templates affords the hollow tube‐like structure. The loading content of metal nanoparticles in the nanocomposites could be adjusted by simply changing the amount of metal precursors. This work provides an efficient approach to fabricate an important kind of metal/conducting polymer hybrid nanotubes that are potentially useful for electrocatalyst and sensor materials. 相似文献
A series of electrically conductive polypyrrole/clay nanocomposites were synthesized in this work by using one-pot emulsion oxidative polymerization of pyrrole in the presence of unmodified clay and using DBSNa as the surfactant. The effect of surfactant on the morphological and electrical properties of PPy also were investigated and discussed in some extent. Electrical conductivity of the samples was measured by using samples in which the conductive materials was sandwiched between two Ni electrodes at room temperature. PPy/MMT nanocomposites were characterized by using XRD, TEM, TGA and DSC means of investigation. Intercalated structures were determined for the nanocomposites as confirmed by XRD and TEM studies. Electrical conductivity of the nanocomposites was measured to be dependent to the clay content, and the methods of preparation. Measurement also showed that polymerization of pyrrole monomers pre-intercalated between the clay gallery spaces of the clay led to higher conductivity for the nanocomposite in the same level of clay content. Thermal property measurements showed a lower thermal decomposition rate for the PPy/MMT nanocomposites with respect to the PPy. 相似文献
We report the functionalization of polypyrrole (PPy) with a “sticky” biomolecule dopamine (DA), which mimics the essential component of mussel adhesive protein. PPy is one of the most promising electrically conductive polymers with good biocompatibility. The research findings reveal that the DA functionalization enhances the dispersibility and stability of PPy in water and its film adhesion to substrate surface significantly. The electrical conductivity of PPy increases to a maximum value and then decreases with the increasing DA concentration. An optimal DA to pyrrole (Py) mole ratio is found to be between 0.1 and 0.2, at which both conductivity and adhesion of DA‐functionalized PPy has been improved.