Preparation of Conductive Nanofibers

There are various methods to synthesize polymer nanostructures, i.e., template synthesis, chiral reactions, self-assembly, interfacial polymerization and electrospinning. Recent developments in conducting polymer nanotubes and nanofibers were summarized by Long et al. Different preparation methods, physical properties, and potential applications of one-dimensional nanostructures of conjugated polyaniline (PANI), pol5 3nrole (PPy) and poly (3, 4-ethylenediox3d hiophene) (PEDOT) were discussed. 

Blending with other pol5miers and coating insulating potymer with conducting pol5miers are the most familiar techniques. 

Blending with a spinnable polymer is a common way to compensate poor spinnability. However, the presence of an insulating carrier polymer introduces a conductivity percolation threshold by limiting their usage in the applications where high conductivities are required. The polymerization of a conductive monomer on the surface of a fiber, made with a common polymer and a catalyser/ doping agent is also another approach. ° °  

---

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. 

Pt superfine clusters on conductive supports are effective catalysts of redox reactions proceeding in fuel cells. High specific surface, support conductivity, high dispersity (nanosizes of Pt clusters) and their strong fixation on a surface are necessary criterions of preparation of the effective catalyst. From these points of view CNM for example single- (SWNT) and multi-walled (MWNT) nanotubes, nanofibers (CNF) and x-ray amorphous carbon (AC) can be a successful supports of Pt clusters. 

Graphene-polymer nanocomposites share with other nanocomposites the characteristic of remarkable improvements in properties and percolation thresholds at very low filler contents. Although the majority of research has focused on polymer nanocomposites based on layered materials of natural origin, such as an MMT type of layered silicate compounds or synthetic clay (layered double hydroxide), the electrical and thermal conductivity of clay minerals are quite poor [177]. To overcome these shortcomings, carbon-based nanofillers, such as CB, carbon nanotubes, carbon nanofibers, and graphite have been introduced to the preparation of polymer nanocomposites. Among these, carbon nanotubes have proven to be very effective as conductive fillers. An important drawback of them as nanofillers is their high production costs, which... 

G. L. Teoh, K. Y. Liew, and W. A. K. Mahmood, Preparation of polyaniline-Al203 composites nanofibers with controllable conductivity. Mater. Lett., 61,4947-4949 (2007). 

M. Wei, J. Lee, B. Kang, and J. Mead, Preparation of core-sheath nanofibers from conducting polymer blends, Macromolec. Rapid Commun., 26, 1127-1132 (2005). 

---