Polypyrrole Nanofibers with Carriers

Pure PPy was used to prepare conductive nonwoven mats. PPy was synthesized using ammonium persulfate (APS) as the oxidant and dodecylbenzene sulfonic acid (DBSA) as the dopant. Chloroform and excessive amount of DBSA were used to obtain solubility. The intermolecular interaction between PPy chains were reduced by doping with high amount of D BSA but the reduction of intermolecular interaction between PPy chains decreased the interchain conduction of charge carriers and led to the decrease in bulk conductivity. 

Conductivities of nanofibers were increased up to 10 S/cm by the increase of pol5T)5n role content. Morphologies and diameters of nanofibers affect properties of nanofiber mats. Pol5T)5n-role 

The average diameter of electrospun fibers of individual fibers with and without potyp3nrole are shown in SEM images (Fig. 8.5). Mole percent of the initially added Py concentration varies from 0.035-0.070%. The average diameters of the nanofibers are reduced from 200 to 120 nm. In this stucty, elimination of surface roughness on nanofibers structure was due to the well interaction of PPy with matrix and well dispersion of latex particles in the DBSA medium resulting in an improvement in the solubility of PPy. 

The relatively low molecular weight of conductive pol miers, decrease in specific viscosity of composites resulted a small nanofiber diameters. Interaction of PPy with matrix creates a decrease in viscosity, and that causes the smaller diameter of nanofibers. Moreover, electrospinning solutions of nanofibers with small average diameters have exhibited higher conductivity. 

Polypyrrole particles can be incorporated into a carrier pol mier and this solution may be electrospun if materials are prepared with particulates smaller than the cross-section of the fiber. The coating process can be applied to the outer surface of a pre-spun fiber. The composite fibers of polystyrene/polypyrrole were suspended in DMF to dissolve the polystyrene leaving behind a hollow pol3 n role fiber.  

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Figure 4.10 SEM micrographs of electrospun nanofibers from (a) aqueous solutions of 1.5 wt% PEO as carrier with PPy content of 71.5 wt%, (b) 7.5wt% [(PPy3) (DEHS) ]x solution in DMF. The scale bar is Igm. (Reprinted with permission from Polymer, Conductive polypyrrole nanofibers via electrospinning Electrical and morphological properties by I. S. Chronakis, S. Grapenson and A. Jakob, 47, 1597-1603. Copyright (2006) Elsevier Ltd)...

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