Mechanisms governing the enhanced thermal stability of acid and base treated polypyrrole

Evaluation of the Conductivity of the Polypyrrole Film via Its CC Bonds Stretching on Surface‐Enhanced Raman Spectrum

“…That is why the doping levels are always higher than the N /N ratios shown in some published XPS results [16 ± 20]. In addition, unusual higher N /N ratios are measured in the presence of higher electrolyte concentration used in polymerization [20] and in the presence of N À O species [12,13,21,22], which don×t benefit the conductivity of PPy. Therefore, the conductivity of PPy cannot be satisfactorily evaluated via XPS measurements alone.…”

“…Some XPS experiments [12,13] showed that the doping level changed with the treated PPy according to the level of acidity; and as a result, the corresponding conductivity also changed. However, a number of discrepancies can be found in the published XPS results, due partly to the different methods used in spectra deconvolution and peak assignments.…”

Chemical Reactivity of Polypyrrole and Its Relevance to Polypyrrole Based Electrochemical Sensors

“…A prolonged exposition to oxygen can lead also to N À O and peroxide species formation [37,38]. The stability enhancement for polypyrrole in the presence of oxygen can be obtained by introduction of copper (which was retained in the film after Cu deposition and following oxidation) or polyethylene oxide [39,40].…”

Characteristics of vibration modes of polypyrrole on surface-enhanced Raman scattering spectra

“…Generally, the conductivity of doped-PPy is primarily dependent on the doping level and the kinds of dopant [26,27]. From the X-ray photoelectron spectroscopy (XPS) experiments [28,29], it was found that the doping level changed with the treated PPy according to the level of acidity; and as a result, the corresponding conductivity was also changed.…”

“…Many researchers [30,31,35,41,42] have focused on the former peak because of poor spectral results or the latter peak becoming insignificant, perhaps disappearing, when the conductivity of PPy is low. Some efforts have also been made to correlate the conductivities of PPy films in various states with their corresponding Raman peaks of backbone stretching of C@C bonds [33,44] and doping levels obtained from XPS analysis [28,29]. Nevertheless, the correlation has not yet been made between the conductivity of PPy and the relative intensities of Raman peaks of C-H in-plane deformation of PPy.…”