Synthesis and characterization of nano-fibres graphene oxide for sensing humidity

Abstract

Relative humidity is the prime parameter in industrial processes which are measured through ceramic, metal oxide and polymeric sensors. Ceramic and metal oxide sensors shows nonlinear resistive behaviours with increasing relative humidity and high sintering temperature for hydro-desorption. Transformation of ceramic and metallic sensors with the polymeric sensors is due to its eco-friendly synthesis fabrication, less heat intensive and high sensitivity. In this research work, a polymeric sensor of enhanced electric properties with sustainable captive and resistive response was synthesised from nano-fibres graphene oxide for sensing humidity. The synthesized graphene oxide through modified Hammer method was mixed with poly-vinyl alcohol (GO/PVA) in the ratio of 5 wt % for four hours at 90 ºC. Nano fibres of graphene oxide and poly-vinyl alcohol (GO/PVA) solutions were obtained at the 24V DC electric field; 0.5 ml/h feed rate and 10 cm tip-to-collector distance through electrospinnig. GO/PVA fibres were deposited on the silver inter-digited electrodes of 8mm and five combs of 20Îm consecutive distance. SEM analysis shows that the fibres were in nano-range with no major cracks while XRD and FTIR spectrum investigated the finger prints and functional groups of GO and GO/PVA respectively. Parametric study of resistive and capacitive were analysed at difference response and recovery time at various frequency in the range of 0 % to 82% relative humidity.