Surfactants PANI synthesis

Besides polyanions such as SPS, anionic surfactants were able to provide the negative charges needed to template the formation of electrically conductive PANI. Indeed, micelles of sodium dodecylbenzensulfonate (SDBS) were used successfully as templates to induce the formation of linear and electrically conductive PANI [38]. On the other hand, cationic and non-ionic surfactants did not provide the negative charges and low pH environment needed for the synthesis of conducting PANI, as expected. Using a similar approach, dodecyl dipheny-loxide disulfonate (DODD) was used as a bifunctional template for the enzymatic synthesis of PANI [39]. UV-Vis and electrical conductivity studies showed that the electrically-conducting form of PANI was only obtained above the critical micellar concentration (CMC) of DODD. The bifunctional nature of the DODD provided... 

Farias and co-workers [30] reported the synthesis of thin hybrid films made of PANI and a ceramic used in the technological industry, titanium dioxide, which were prepared via the layer-by-layer self-assembly technique. Aiming to improve the dispersion of the ceramic in the polymer matrix, the commercial surfactant, cetyltrimethylammonium bromide (CTAB), was used during the formation of the... 

Surfactant- and Amphiphilic Acid-Assisted Synthesis PANI-NTs have been prepared by the oxidative polymerization of aniline with APS in an aqueous solution in the presence of SDS [82,328], SDBS [329], a mixture of ionic surfactants (CTAB and SDBS) [204], polymeric acids [330] e.g. poly(methyl vinyl ether-alt-maleic acid) [331-334] (Figure 2.16), poly(3-thiopheneacetic acid) [70], PSSA and PAA (Figure 2.16) [333],... 

The synthesis of spiral PANl nanostructures (2-D ordered spirals comprised of singlestrand PANI-NFs) by chemical oxidative polymerization using a hydrated surfactant sodium dodecylsulfonate crystallite template was recently described [406]. It was found that a spiral dislocation structure on the surface of a hydrated sodium dodecylsulfonate crystallite was responsible for the growth of the spiral PANl nanoarchitecture. It was revealed that APS has a strong tendency to induce the formation of a spiral dislocation stmcture in hydrated sodium dodecylsulfonate crystallites. A mechanism of adsorption of oligoanilines on the steps of dislocation has been proposed for the growth of PANl spirals. 

Conducting polymers constitute another category of promising pseudo-capacitive materials. The most common ones include polypyrrole (PPy), polyaniline (PANI), and poly-(3,4)-ethylenedioxythiophene (PEDOT). This group is of particular interest due to low cost and ease of synthesis. These compounds can be polymerized directly onto a collector material via EPD. Alternatively, the polymerization can be done within surfactant emulsions... 

The poly aniline nanospheres (PANI-NS) 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, Polyvinylpyrrolidone, cetyl ammonium bromide, and camphorsulfonic acid are used as received from Sigma-Aldrich. Camphorsulfonic acid surfactant as the dopant and ammonium persulfate as the oxidant were used in the present synthesis of polyaniline nanospheres (see flow chart in Fig. 8.11). Calculated quantities of aniline monomer (0.005 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 (0.005 mol) were dissolved separately in distilled water and stirred for 10 min in an ice bath. The surfactant solution was first added to the aniline monomer aqueous solution, and then the previously cooled oxidant solution was added drop wise after which the mixture was allowed to react for 10 h in an ice bath. The precipitate was filtered and washed several times with distilled water and... 

It is clearly discernible from the scanning electron micrograph, shown in Fig. 8.19, that the density of nanoflber formation remains rather constant, irrespective of the surfactant used during the synthesis of PANI-NF. Furthermore, it can be seen from Fig. 8.19that the average nanoflber diameter is approximately 250 nm. It is important to note that the surface of the nanofibers is rather rough, which is typical... 

As with the chemically grown nanofibers, the polyaniline nanofibers (PANI-NF-ES) were grown by oxidative polymerization of aniline monomer at 0 °C in an ice bath using ammonium persulfate as the oxidant in the presence of surfactant, though with slightly different conditions. 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. 

As mentioned earlier in situ approach has also been used for the synthesis of conducting polymer-metal hybrid nanocomposites. Xu et al. [35] have reported the decoration of PPy nanotubes with gold nanoparticles by an in situ reduction process. They prepared PPy nanotubes by MO-FeCl3 self-degrade template method and then reduced HAuCLi within PPy nanotubes in the presence of different surfactants such as sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB) and Tween-80. Nanowires of silver PAni nanocomposites have been reported via in situ polymerization method [36]. In this method aniline is oxidized by ammonium persulfate (APS) in the presence of dodecylbenzene sulfonic acid (DBSA) and silver nitrate (AgN03). In another approach gold-PAni core-shell... 

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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