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

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 degrees 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 pi-stacking between the anilinium and carbazole groups. The cyclic voltammetry confirmed the persistence of electroactivity at a pH near 7.

Automated summary

In this research, a brush-like polyaniline (BL PAni) was developed to overcome the limitations of conventional polyaniline (PAni) in processability and dedoping at high pH. The synthesis of BL PAni involved grafting PAni chains using different polymerization methods, and the structure was confirmed by spectroscopic techniques. The thermal properties were analyzed, and the BL PAni showed absorption properties in the visible and near-infrared regions, as well as resistance to dedoping at high temperature and neutral pH. The absorption range and electroactivity were studied, highlighting the potential applications of BL PAni in various fields.