MWCNT/rGO/natural rubber latex dispersions for innovative, piezo-resistive and cement-based composite sensors

The present study is focused on the development and characterization of innovative cementitious based composite sensors. In particular, multifunctional cement mortars with enhanced piezoresistive properties are realized by exploiting the concept of confnement of Multiwall Carbon Nanotubes (MWCNTs) and reduced Graphene Oxide (rGO) in a threedimensional percolated network through the use of a naturalrubber latex aqueous dispersion. The manufactured cementbased composites were characterized by means of Inelastic Neutron Scattering to assess the hydration reactions and the interactions between natural rubber and the hydratedcement phases and by Scanning Electron Microscopy and XRay difraction to evaluate the morphological and mineralogical structure, respectively. Piezoresistive properties to assess electromechanical behavior in strain condition are also measured. The results show that the presence of natural rubber latex allows to obtain a three dimensional rGO/MWCNTs segregate structure which catalyzes the formation of hydrated phases of the cement and increases the piezoresistive sensitivity of mortar composites, representing a reliable approach in developing innovative mortarbased piezoresistive strain sensors.