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 mortar composites with enhanced functional, piezo-resistive, properties are designed with Multiwall Carbon Nanotube-MWCNTs and reduced Graphene Oxide-rGO dispersed in a natural-rubber latex aqueous dispersion, by exploiting both the concept of confining of the conductive filler in the polymeric phase. The manufactured cement-based composites were characterized by means of Inelastic Neutron Scattering to assess the hydration reactions and the interactions of natural rubber with the hydrated cement phases and by Electron Scanning Microscopy and X-Ray diffraction to evaluate the morphological and mineralogical structure, respectively. Piezo-resistive properties to assess electro-mechanical behavior in strain condition are also measured. The results show that the presence of natural-rubber latex permits to obtain a three-dimensional rGO/MWCNTs segregate structure which catalyzes the formation of hydrated phases of the cement and increases the piezo-resistive sensitivity of mortar composites, representing a reliable approach in developing innovative mortar-based piezoresistive strain sensors.