Tunable size and shape of conductive poly(N‐methylaniline) based on surfactant template and doping

Poly(N‐methylaniline) (PNMA) is one of the polyaniline derivatives with N‐substituted position. Polyaniline derivatives have attracted attention due to their higher solubility in common solvents than pristine polyaniline, but they still possess lower electrical conductivity. In this work, PNMA was synthesized via chemical oxidative polymerization in an ethanol–water system. The effect of surfactant type, namely anionic sodium dodecylbenzenesulfonate (SDBS), cationic cetyltrimethylammonium bromide and non‐ionic Tween20, on the electrical conductivity, doping level and morphology was investigated. PNMA prepared with the SDBS system possessed the highest electrical conductivity among the obtained PNMAs with and without surfactants. The effect of $N_{{\mathrm{\text{HClO}}}_4}$/N_NMA dopant mole ratios on the re‐doping, crystallinity, morphology and particle size was also examined. Using an $N_{{\mathrm{\text{HClO}}}_4}$/N_NMA mole ratio of 10:1 in the re‐doping process provided the highest electrical conductivity of 15.53 ± 2.5 S cm^?1, a doping level of 55.59%, along with hollow spherical particles with the thinnest membrane. Electron microscopy images revealed that the morphology of PNMA particles depended mainly on the surfactant type but not the $N_{{\mathrm{\text{HClO}}}_4}$/N_NMA mole ratio. © 2019 Society of Chemical Industry