Brush-like Polyaniline with Optical and Electroactive Properties at Neutral pH and High Temperature

Abstract

In this research, a brush-like polyaniline (poly(2-acrylamide-2-methyl-1-propanesulfonate)-g-polyaniline)-b-poly(N-vinylcarbazole) (BL PAni) was developed as a strategy to overcome the limited processability and dedoping above pH 4 of conventional polyaniline (PAni). For the BL PAni synthesis, RAFT polymerization (homopolymer), RAFT-mediated surfactant-free emulsion polymerization (block copolymer), and interfacial oxidative polymerization were applied to graft the PAni chains. NMR and FT-IR spectroscopies were performed to confirm the structural elucidation of the reaction pathways, while the thermal properties were analyzed by TGA and DSC. Notably, the BL PAni presents absorption throughout the visible region and up to the near-infrared, showing dedoping resistance at up to 80 °C and at a neutral pH. The absorption range of the BL PAni, block copolymer, and homopolymer were studied by UV–Vis spectroscopy in solid-state and dispersion/solution, highlighting BL PAni and poly(anilinium 2-acrylamide-2-methyl-1-propanesulfonate)-b-poly(N-vinylcarbazole) (PAAMP-b-PVK) due to the π-stacking between the anilinium and carbazole groups. The cyclic voltammetry confirmed the persistence of electroactivity at a pH near 7.

Silk Fibroin-g-Polyaniline Platform for the Design of Biocompatible-Electroactive Substrate

“…It is worth noting that in the graft PAni copolymers, the conjugation present in the conductive chain is not interrupted, which does not modify the electrochemical properties of PAni, which is different to other copolymer systems [ 8 ]. Furthermore, the electrochemical activity of PAni will depend on the polymerization process, dopant agent, and interaction with other polymers [ 38 , 39 , 40 ].…”