Covalently linked nanocomposites of polypyrrole with graphene: Strategic design toward optimized properties

Abstract

Graphene-based nanocomposites with conducting polymers have attracted increasing interest due to the enhanced synergistic properties, which can potentiate and broaden applications. In this context, covalent functionalization stands out as a strategic designing tool, which optimizes the interaction between the nanocomposites components. Herein, covalently linked polymeric nanocomposites were obtained between graphene derivatives and polypyrrole (Ppy) under mild routes (i.e., aqueous, room temperature). First, pyrrole was covalently functionalized on graphene oxide (GO) through stable amide bonds and further polymerization with FeCl 3 led to the polymeric nanocomposites. Finally, to improve conductivity, GO was reduced using NaBH 4 . Similarly, analogous noncovalent nanocomposites were obtained for comparison purposes. All samples were thoroughly characterized by thermogravimetric analysis, scanning electron microscopy, and infrared and Raman spectroscopy, confirming the targeted functionalization, polymerization, and reduction processes. Moreover, the covalent link effectively enhances the interaction of the nanocomposite's components as evidenced by its improved electrochemical stability (300 cycles), compared to the non-covalent composites which loses conductivity in the initial stages. Indeed, Ppy is known for its low stability, limiting its applications. Overall, the results herein evidence that covalently linked nanocomposites can be successfully obtained with optimized electrochemical response, promising for applications as supercapacitors and artificial muscles.

Graphene Oxide-Polypyrrole Coating for Functional Ceramics

“…The position of the D bands shifted from 1318 for the GO layer to 1324 cm −1 corresponding to the GO coating reduced by the chemical approach, which suggests an improved reduction degree by the chemical reduction approach with respect to the electrochemical one. On the other hand, the growth of PPy at the surface of the modified GO ceramics is confirmed from the appearance of new bands located at 1370 cm −1 , which is attributed to the ring stretching, and 1400 cm −1 [ 47 , 48 ], along with the evolution of the typical GO bands, where the shift in the position of the G peak to 1580 cm −1 corresponding to the PPy/rGO C composite coating indicates a marked coupling and charge transfer between the PPy and rGO [ 49 ].…”

Anchoring conductive polymeric monomers on single-walled carbon nanotubes: towards covalently linked nanocomposites

“…Upon polymerization, FTIR analysis of Poly-SWCNT-BPI and SWCNT-Ox-Ppy shows the typical bands of Ppy. [48] Focus is given to the presence of the band at 960 cm -1 attributed to the C-C out-of-plane vibrations. This is a characteristic signature of Ppy polymerization.…”

Improving Electrochemical Properties of Polypyrrole Coatings by Graphene Oxide and Carbon Nanotubes

“…A small shift appears in the position of the G peak, namely 1590 cm −1 in the Raman spectra corresponding to the PPy/rGO composite coating. The PPy presence is also indicated by the new band located at 1370 cm −1 attributed to the ring stretching and the one at 1492 cm −1 [57,58]. The peak intensity ratio ID/IG for the rGO appears larger with respect to the composite.…”