Development of Electrospinning System for Synthesis of Polyvinylpyrrolidone Thin Films for Sensor Applications

Abstract

Electrospinning is a systematic process of elaborating nanofibers by forcing a polymer fluid through a spinneret by the application of electric field. Polyvinylpyrrolidone (PVP) is a hydrophilic polymer that has good film formation properties.PVP thin films are widely used as a sensitive layer in Surface Acoustic Wave (SAW) sensors in order to detect the volatile organic compounds.The present study was aimed at development of cost effective electrospinning system for production of quality thin films and parametric optimization. Experimental investigation was performed by electrospinning of PVP considering 7.5wt %, 10wt %,12.5wt %,15wt %,dissolved in Di-MethylFormamide (DMF). The process parameters considered were voltage of 20kV, flow rate 0.5ml/hr, needle dimension 21 gauge and tip-to-collector distance 100 mm. It was found that concentration of polymer is a critical factor in controlling the beads formation and fiber diameters although applied voltage and tip-to-collector distance also influenced the fiber diameter.With increase in concentration of the polymer solution the formation of beads formation reduced significantly with increase in fiber diameter. The fiber diameter varied between 25.50 nm to 113.84 nm. Minimum fiber diameter obtained was 25.5 nm whereas the corresponding bead diameter was 647.39 nm for 10 wt % polymer concentration. Maximum fibre diameter obtained was for 15 wt % polymer concentration with 135.85 nm and the corresponding bead diameter of 1208.35 nm. Morphological studies of electrospun thin films by Scanning Electron Microscope (SEM) revealed the formation of fibres in nano dimension, PVP with 10 wt % dissolved in DMF and suitable process parameters can result in nanofibres with lesser bead formation.