Chemical modification of nano-structured polyaniline by N-grafting of hexadecylbromide

Abstract

This study aims to explore an effective route for the preparation of conductive N-substituted polyaniline by incorporation of hexadecyl side chains into the fully reduced form of nano-structured polyaniline leucoemeraldine base. For this purpose, at first nano-structured emeraldine salt polyaniline was synthesized by interfacial chemical oxidative polymerization. The dark green product salt was neutralized by an ammonia solution in order to give us an emeraldine base (EB). Thereafter, the reduced form of nano-structured polyaniline was prepared by treating the obtained EB with phenylhydrazine in methanol. The excess amount of butyllithium was applied to abstract protons from the amine nitrogens of nanostructured LEB polyaniline chains. Thereafter, deprotonated polyaniline was reacted with hexadecylbromide to prepare poly(N-hexadecylaniline) through N-grafting reaction. The obtained poly(N-hexadecylaniline) was characterized using Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry, and thermal gravimetry analysis (TGA). The average diameters of unsubstituted and substituted polyaniline particles were determined by particle size analyzer. The optical properties of the poly(N-hexadecylaniline) in the undoped and doped state were obtained using UV-vis spectroscopy and the electrical conductivity of the sample was measured using sample in which the conductive materials were sandwiched between two Ni electrodes at room temperature. Also, electroactivity of the synthesized polymer was investigated under cyclic voltammetric conditions on the surface of the working glassy carbon electrode. The solubility of the obtained polymer was examined in common organic solvents.

Poly(N‐octadecylaniline) Synthesized at the Air‐Water Interface: Aligned Nanofibers and Gold Nanocomposite Assembly via the Langmuir‐Blodgett Technique

“…Earlier reports on poly(N‐alkylanilines) show that even though they possess polaronic absorption, the conductivities are generally low;, in fact, the conductivity has been shown to decrease with increasing length of the alkyl chain . We have carried out conductivity measurements on thin films of PNOA and PNOA_Au fabricated by drop‐casting chloroform solutions of the polymer and the polymer nanocomposite on a patterned ITO‐coated glass substrate; details of the experimental procedure are added in the Supporting Information (see also Table S2) .…”

“…We have explored earlier, the polymerization of N‐octadecylaniline (NOA) in Langmuir films to form poly(N‐octadecylaniline) (PNOA), focusing on the impact of polyelectrolyte templating . PNOA has been synthesized by alkylation of PANI, and LB films of pre‐formed PNOA have been reported . Concomitant synthesis of PANI (or PNOA) and Au nanoparticles in a Langmuir film to form their nanostructures and composites, as well as their organized/aligned assembly using the LB technique are not known.…”

Chemical and electrochemical grafting of polyaniline onto poly(vinyl chloride): synthesis, characterization, and materials properties

“…Recently, more and more research projects are conducted for the modification of PANI, and some considerable advances and promising results have been obtained, in the academic and industrial communities. The most commonly used approaches toward modified PANI can be listed as (1) doping of PANI with functional organic acids; (2) monomer modification (e.g., rings and N ‐substituted anilines); (3) preparation of PANI composites with thermoplastic polymers; and (4) incorporation of polar functional groups, polymeric chains, or long and flexible alkyl chains into the PANI backbone . In this respect, synthesis of PANI copolymers with processable and commercial polymers (e.g., poly(vinyl chloride) and polystyrene) can be considered as an efficient and versatile approach for exploiting the conducting PANI and overcoming its aforementioned deficiencies …”

Synthesis of water‐soluble conductive copolymer based on polyaniline

“…These side chains can be either ring substituted or N ‐substituted . The N ‐substituted PANIs have obtained better processability; however, their conductivity has been greatly reduced . Another research that has altered the electrochemical properties of PANI is to couple the polymer with aryl diazonium ions .…”