PANI fibers

In electrospun cellulose acetate/polyaniline fibers, PANI acts as a nucleating agent for the formation of crystallites. PANI increases the overall degree of crystallization, leading to increased dipoles in the nanofibrous nonwoven membranes. ... 

PPS doped with AsFs dissolves readily in AsFs, but cast films are no longer soluble. Frommer has suggested that the solubilization mechanism involves solvation of both reactive radical intermediates and dopant counterions.f In addition, dialkyl esters of phosphoric acid dope PANi and render it soluble in certain solvents such as decalin. The resulting solutions can be mixed with conventional polymers and used to prepare films and fibers. 

One of the major drawbacks of PANI is its processability, which is not as good as that of thermoplastics. Unfortunately, many of the PANI applications require its use either as thin film, free-standing film, fiber or nanowires. Several methods to prepare films, which were first studied with chemically synthesized PANI, such as in situ chemical deposition, casting using solvents, and layer by layer assemblies, have been adapted in order to process PANI using the enzymatically synthesized polymer. 

PANI Fibers Made with Enzymatically-Synthesized PANI... 

The ability of a polymer to be spun into a fiber has been considered a proof of the concept of polymer processability for many years. Wanga et al. [72] have prepared enzymatically synthesized PANI fibers. First, the water-soluble and conductive form of PANI was synthesized using SPS as template and HRP as catalyst. Later, the resulting aqueous dispersion was used to prepare fibers by using a dry-spinning method. The microstructure, mechanical properties, and electrical conductivity of these fibers were improved by traditional fiber techniques such as hot drawing. 

PVC with doped PANI and an additive intrinsically electrically conductive films or fibers KuUsami Wessling, 1992-1994... 

Polyaniline tosylate (PANI), and PETG for films, inks, fibers, and coatings, in shielding, antistatic and adhesives Shacklette et al., 1993... 

By contrast, the ECP must have conjugated rigid-rod macromolecules. Several such polymers show high electrical conductivity (usually after doping), viz. polyacetylene (PAc), polyaniline (PANI), polypyrrole (PPy), polyparaphenylenes (PPP), or poly-3-octyl thiophene (POT). The resins are expensive, difficult to process, brittle and affected by ambient moisture, thus blending is desirable. For uniaxially stretched fibers the percolation threshold is 1.8 vol%, hence low concentration of ECP (usually 5-6 vol%) provides sufficient phase co-continuity to ascertain conductivity similar to that of copper wires (see Table 1.79). 

Dexmer J., Leroy C. M., Binet L., et al.. Vanadium oxide-PANI nanocomposite-based macroscopic fibers ID alcohol sensors bearing enhanced toughness, Chem. Mater., 20(17), 5541-5549, 2008. 

Figure 2.4 SEM image of the PANI-NFs doped with p-TSA [APS]/[aniline]= 1 1, reaction time 12h [aniline] = 0.2M, [acid]/[aniline] = 0.5 1. (Reprinted with permission from Macromol. Rapid Common., Nanoscaled Polyaniline Fibers prepared by ferric chloride as an oxidant by L. Zhang, M. Wan and Y. Wei, 27, 366-371. Copyright (2006) Wiley-VCH)...

Figure 2.7 Schematic illustration of the formation and aggregation of PAN particles. The green fibers and purple dots represent PANI particles that result from homogeneous and heterogeneous nucleation, respectively. (Reprinted with permission from the Journal of the American Chemical Society, Shape and Aggregation Control of nanoparticles Not shaken, not stirred by D. Li and R. B. Kaner, 128, 968-975. Copyright (2006) American Chemical Society)...

Au/PANI-CSA coaxial nanocables have been successfully synthesized by the oxidation of aniline with chloroauric acid in the presence of CSA [397]. PANI-CSA nanotubes were obtained by dissolving the Au nanowire core of the Au/PANI-CSA nanocables. Purified flagella fibers displaying an anionic aspartate-glutamate loop peptide with 18 carboxylate groups were used to initiate formation of PANI-NTs [398]. 

Other studies in 2000 by Drew et al. reported that it is very difficult to spin fibers of PANI complexed to sulfonated polystyrene (PANFSPS), even when solutions containing sodium chloride and dodecyl benzene sulfonic acid sodium salt were used to lower the surface tension and thereby enhance electrospinning [16,17]. However, PANFSPS nanofibers can be produced by adding a carrier polymer such as PEO, polyacrylonitrile, or polyurethane. Also reported was the use of electrostatically layered sulfonated polystyrene as a template for the surface polymerization of conjugated polymers in their conducting form. Enzymatic synthesis of PANI and a copolymer of pyrrole and PEDOT was done on electrospun nanofiber... 

Another study by Hong et al. also reports the preparation of conducting PANI/nylon-6 composites with high electrical conductivity and superior mechanical properties, such as flexibility and lightness [24]. PANI was chemically polymerized on the surface of the nylon-6 electrospun nanofiber webs. The electrical conductivity measurements showed that the conductivity of the PANI/nylon-6 composite electrospun fiber webs was superior to that of PANI/nylon-6 plain-weave fabrics because of the high surface area/volume ratios. The volume conductivities of the PANI/nylon-6 composite electrospun fiber webs increased from 0.5 to 1.5 S cm as the di sion time increased from 10 min to 4h because of the even distribution of PANI in the electrospun fiber webs. However, the surface conductivities of the PANI/nylon-6 composite electrospun fiber webs somewhat decreased from 0.22 to 0.14 S cm as the di sion time increased, probably because PANI was contaminated with aniline monomers, aniline oligomers, and some alkyl chains, which served as electrical resistants. 

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