Electrical Conductivity Improvement of Polyvinyl Alcohol Nanofiber by Solvent Vapour Treatment

Abstract

The electrical conductivity of polyvinyl alcohol (PVA) electrospun nanofibers is naturally low. For an electrical device application, it requires high enough conductivity. The objective of this study is to improve the electrical conductivity of electrospun PVA nanofibers with and without poly (3,4-ethylenedioxytriophene): polystyrene sulfonate (PEDOT:PSS) by exposure polar solvent of dimethyl sulfoxide (DMSO). For this purpose, the nanofibers were deposited on a substrate with patterned electrodes. The distance between two electrodes is 2 mm. The sheet resistance of the PVA nanofibers was measured by using two-point probe connected to a source measurement unit of Keithley SMU-2400.  As a result, the conductivity of PVA electrospun nanofibers increases from 0.03 μS/cm to 1.20 μS/cm by increasing the PVA concentration from 8 to 10 wt%. More significant improvement is also achieved by mixing PVA and PEDOT:PSS to be 110 μS/cm after being exposure DMSO. This improvement has been confirmed using the scanning electron microscopy (SEM) images, where a  solvent-induced fusion occurs at the nanofiber junction points after DMSO treatment. The stability of electrical conductivity, however, of electrospun PVA nanofibers is better than that of electrospun PVA/PEDOT:PSS nanofibers after exposure DMSO