Impedance-Based Characterization of Functional Carbon Nano-Tube/Cement Composites

Abstract

Carbon-based materials allows for their derivatives such as fullerenes, carbon nano-tubes (CNTs), and graphenes in addition to the conventional bulk carbon materials. The high conductive feature of carbon-based derivatives can be exploited as the conduction path of the carbon/inorganic mixture. In this work, carbon-based materials are combined with cement-based materials in order to being fabricated as the pressure-sensors under the high-impact condition. In particular, the CNTs are combined with cement-based materials. The corresponding hydration is monitored as a function of time using impedance spectroscopy. The addition of CNTs into the cement matrix system modifies the conventional conduction path, forming a conductive one, leading to the significant change in impedance spectra. The frequency-dependent impedance information allows for an equivalent circuit model which reflects the microstructure composed of CNTs and cement-based products. Based on the microstructural/electrical understanding, a possibility of being a piezoresistive sensor is discussed as a novel application involving the peculiar features of 1-dimensional CNT materials.