Enhancing effect of KMnO4 oxidation of carbon nanotubes network embedded in elastic polyurethane on overall electro-mechanical properties of composite

The effect of functionalization of multiwalled carbon nanotubes using KMnO4 oxidation and oxygen plasma treatment on the electrical resistance of nanotube network/polyurethane composite subjected to elongation has been studied. The layered composite is prepared by taking a non-woven polyurethane filtering membrane which is made by electrospinning, enmeshing it with carbon nanotubes and melding them into one. The testing has shown tenfold composite resistance increase for the composite prepared from KMnO4 oxidized nanotubes in comparison to the network prepared from pristine nanotubes. The evaluated sensitivity of the treated composite in terms of the gauge factor increases linearly with strain from values around five at the start of deformation to nearly 45 at the strain 12%. This is a substantial increase, which put the composite prepared from KMnO4 oxidized nanotubes among ranges the materials and strain gauges with the highest sensitivity of electrical resistance measurement.