The influence of polymerization rate on conductivity and crystallinity of electropolymerized polypyrrole

A combined molecular dynamics and experimental study of doped polypyrrole

“…For PPy specifically, the average chain length for PPy electrochemically synthesized with low current density at lower temperatures is reported to be around 12 repeat units [24], which is short compared with other polymers. Experimental studies describing the chain packing of PPy are limited, but previous X-ray diffraction data show that PPy is mostly amorphous with small crystalline peaks detected under certain synthesis conditions [30]. …”

“…These density results fall somewhat below experimental measurements. Experimentally determined density values for doped PPy films previously reported using the flotation method range from 1.37 to 1.48 g/cm 3 [25, 26], but given the sensitivity of PPy’s properties to synthesis conditions and dopant selection [30, 33], relevant values may also fall outside this range. In the current study, we have performed our own density of flotation experiments on PPyCl and obtained a density of 1.46 g/cm 3 .…”

Polypyrrole materials for detection and discrimination of volatile organic compounds

“…The properties of electrochemically deposited PPy are also affected by other parameters such as potential, current density, solvent, substrate type and temperature. Dyreklev et al reported that the rate of polymerisation (controlled by deposition current density) strongly influenced the structure and electrical properties of galvanostatically prepared PPy with lithium perchlorate (LiClO 4 ) as counter-ion [10], finding that the conductivity of the films was negatively correlated with increased current density.…”

The actuation behavior and stability of p‐toluene sulfonate doped polypyrrole films formed at different deposition current densities

“…5(B)]. As reported in the literature, 28,37 the C¼ ¼C peak is related to the conjugation length of PPy and the doping level. This peak shifts to a higher wave number if PPy is present at a lower doping level or contains shorter PPy chain lengths, Figure 5 Raman spectra of as-grown PPy/pTS films polymerized at different current densities.…”

“…24 Therefore, at a lower deposition current density, the route for the polymerization has a higher probability for radical-neutral coupling than for radical-radical coupling. This could reduce the number of defects and lead to longer polymer chains 28 and formed films with better qualities. As discussed earlier, PPy/pTS films mainly showed actuation strain at more negative potentials, below À0.2 V. However, solvent reduction is more likely to happen at the lower potentials in an aqueous solvent, which might lead to degradation of films.…”