Surfactants polyaniline nanofiber synthesis

X. Zhang and S. K. Manohar, Polyaniline nanofibers chemical synthesis using surfactants, Chem. Commun., 2360-2361 (2004). 

The polyaniline nanofibers (PANI-NF) were synthesized by oxidative polymerization of aniline monomer at 0 °C in an ice bath using ammonium persulfate as the oxidant in the presence of surfactant. Aniline, ammonium persulfate, dodecyl benzene sulfonic acid, acrylmethylpropyl sulfonic acid, and camphorsulfonic acid are used as received from Sigma-Aldrich. Sulfonic acid-based surfactants as the dopant and ammonium persulfate as the oxidant were used in the present synthesis of polyaniline nanofibers (see flow charf in Fig. 8.17). Calculated quantities of aniline monomer (0.05 mol) were mixed with 50 mL of distilled water and stirred using magnetic stirrer for 10 min. Meanwhile, calculated quantities of surfactant (0.75 mol) and oxidant (0.05 mol) were dissolved separately in distilled water and stirred for 10 min in an ice bath. The surfactant solution was first added into the aniline monomer aqueous solution and then previously cooled oxidant solution dropwise, and the mixture was allowed to react for 15 h in an ice bath. 

Fig. 8.17 Flow chart for the synthesis of polyaniline nanofibers prepared in an aqueous medium with different surfactants and using ammonium persulfate as oxidizing agent...

By integrating CNTs with PANi nanofibers, high density and high-suiface areas are possible that can lead to improvements in the conductivity and the development of electronic devices with superior properties [78]. The composites of PANi-CNT can be synthesized by various methods such as electrochemical processing, surfactant free aqueous polymerization, micelle-CNT hybrid template directed synthesis, inverse emulsion pathways, interfacial polymerization, plasma polymerization, in-situ and ex-situ polymerization. The details of these methods have been discussed by Oueiny et al. [8]. In-situ polymerization is one of the most important methods developed so far to integrate CNTs and polyaniline. Polymerization methods include stirring, static placement, sonication and emulsion polymerization [78]. 

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