Fabrication and characterization of conductive electrospun nanofiber mats of carbon nanofiber/poly(vinyl alcohol)/poly(lactic acid) ternary nanocomposites for flexible electronics applications

Structural flexibility, high electrical conductivity, and biodegradability are some of the desired electrode properties required in electrode materials for various biomedical, biofuel cell, and flexible electronics applications. In this study, biodegradable polyvinyl alcohol (PVA) was covalently grafted onto surface-modified carbon nanofibers (mCFs) to form a highly conductive nanocomposite (PVA/mCF). This PVA/mCF nanocomposite was electrospun (PVA/mCF@PLA-es) or dip-coated (PVA/mCF@PLA) on neat polylactic acid (PLA) electrospun nanofiber mats to fabricate non-woven, flexible, and conductive nanofiber mats. The surface impedance of the PVA/mCF nanocomposite was reduced by 106 times compared to that of the neat polymer with no noticeable capacitance. Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, X-Ray diffraction (XRD), and electron microscopy studies demonstrated evidence for successful surface modification of carbon nanofibers and covalent grafting of PVA. Thermogravimetric analysis (TGA) and contact angle studies also demonstrated improved thermal stability and wettability. Because of the excellent structural flexibility, high electrical conductivity, and biodegradability of PVA/mCF@PLA nanofiber mats, they could be used in biofuel cell electrodes, biomedical devices, and wearable electronics applications.