Template-free PANI synthesis

Radiolythic Synthesis PANI-NFs can be produced by irradiating aqueous solutions of aniline, APS, and HCl with y-rays [183]. This template-free radiolytic synthesis of PANI-NFs can be carried out completely in an aqueous phase. The synthesized PANI is virtually... 

The chemical methods for the preparation of nanomaterial could be categorized as either template-directed or template-free. The template synthesis methods commonly used for the production of one-dimensional nanostructured PANI are further subdivided into hard template (physical template) synthesis and soft template (chemical template) synthesis approach according to the solubility of the templates in the reaction media. Non-template routes for the synthesis of one-dimensional nanostructured PANI such as rapid-mixing reaction method, radiolytic synthesis, interfacial polymerization, and sonochemical synthesis have also been reported [56], Other approaches like combined soft and hard template synthesis are also known. An overview of hard-template, soft-template, and template-free procedures are presented in the following paragraphs. 

Synthesis of PANI in Template-Free, Dispersed and Micellar Media... 

Solid-State Mechanochemical Synthesis Facile template-free solid-state mechano-chemical synthesis of highly branched PANI-NFs with coralloid tree-like superstrueture, via the oxidative polymerization of aniline hydrochloride with FeCl3 6H2O, has been demonstrated [194]. The synthetic yield ( 8%) was comparable to that of the solution interfacial polymerization method. Solid-phase mechanochemical synthesis of branched PANI-NFs was also achieved by using anhydrous FeCl3 as the oxidant [195]. 

Dopant-Free Template-Free Method PANI-NTs have been prepared by the oxidative polymerization of anihne with APS in water without added acid (Figure 2.18) [199,350,380,381]. This is a facile and efficient approach to synthesize PANI-NTs because it not only omits hard templates and post-treatment template removal, but also simplifies reagents. A modification of the dopant-free template-free method of PANI-NTs synthesis... 

Miscellaneous Template-Free Methods PANI-NTs, having cavities of various diameters, have been found as by-products of PANI-NF synthesis through the oxidation of aniline with silver nitrate in aqueous solutions of HNO3 [225]. Ag was obtained as nanopartieles accompanying macroscopic Ag flakes in the resulting PANI/Ag composite. 

Bertino and coworkers fabricated PANI nanofibers using radiolyfic synthesis as a new template-free pathway. PANI nanofibers were formed in aqueous solufions of aniline, ammonium peroxydisulfate, and hydrochloric acid with gamma ray irradiation. Typical PANI nanofibers had fhe diameters of 50-100 nm and the length of 1-3 im [180]. 

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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