(22b) Fabrication of Polyaniline/Poly(ethylene oxide)/Graphene Nanofibers Via Electrospinning

Electrospinning is a convenient method to produce polymer nanofibers with controlled diameters on the order of tens of nanometers to micrometers. The resulting non-woven fiber mats have high specific surface areas of around 1â??100 m2/g. Combining these properties with the high electrical conductivity of intrinsically conductive polymers, conductive electrospun fiber mats are promising for a variety of applications such as
electronic, magnetic, biomedical, sensor and optical fields.
Polyaniline (PANi) is one of the most studied intrinsically conductive polymers (ICPs) and it is unique due to its ease of synthesis, environmental stability, and simple doping/dedoping chemistry, yet it is relatively hard to process compared to most other polymers. As is common among ICPs, it has a fairly rigid backbone due to its high aromaticity. Thus, the elasticity of its solutions is generally insufficient for it to be electrospun directly into fibers. Moreover, PANi has poor solubility in common solvents, which further complicates it electrospinnability. To circumvent these problems, it is possible to electrospun PANi nanofibers by adding an easily electrospinable polymer to the organic solutions such as poly(ethylene oxide) (PEO). However, the presence of an insulator copolymer (PEO) decreases the fibers conductivity due to dilution of the conducting component. A good strategy for improving the electrical properties of this electrospun fibers blend is to incorporate graphene, which has unique electrical conductivity, into the nanofibers.
Since the discovery of graphene in 2004, it has attracted tremendous research interest. Graphene is a single-atom-thick, two-dimensional sheet of sp2-hybrized carbon atoms arranged in a honeycomb crystal structure with exceptionally high strength, surface area, thermal conductivity, and electronic conductivity. Therefore, considering the excellent properties of graphene and PANi, a highly conductive PANi/PEO composite with graphene as nanofillers may be obtained.
In this work, we report the fabrication of electrospun PANi/PEO nanofibers filled with non-covalently functionalized graphene sheets. The fabricated graphene/polymer nanofibers have the potential to serve in a variety of applications, including conductive wires and sensors.