Electrical Percolation Threshold In Oxidized Single Wall Carbon Nanohorn-Polyvinylpyrrolidone Nanocomposite: A Possible Application For High Sensitivity Resistive Humidity Sensor

The objective of this study is to design and synthetize an oxidized single wall carbon nanohorns (SWCNHs) - polyvinylpyrrolidone (PVP) composite film as potential sensing material for resistive humidity sensor. Raman spectroscopy is used to investigate the nanohybrid formation and components interaction. Comparative results are presented for the percolation threshold values determined for 2 study-cases: carbon nanohorns in PVP film deposited on either rigid (Si / SiO 2 ) or flexible substrate (polyimide). While in the first case, the percolation threshold occurs at a concentration of oxidized SWCNHs in the nanocomposite matrix in the range (0.05-0.1)% (w/w), in the second instance, the concentration of SWCNHs for the percolation threshold is between (2-3.5)% (w/w). Experimental findings are explained in terms of size effects in the geometry of the studied structures. The key role played by the electrical percolation threshold in the resistive sensing capabilities of the synthesized nanocomposite towards water molecules is described.