Electromagnetic wave absorption and heat storage dual-functional cement composites incorporated with carbon nanotubes and phase change microcapsule

A novel electromagnetic (EM) wave absorption and heat storage dual-functional cement composite was developed by incorporating with carbon nanotubes (CNTs) and phase change microcapsule (PCM). The reflection loss (RL), EM parameter, latent heat, thermal inertia and mechanical properties were investigated in detail, the obtained results indicate that the PCM particles can improve the impedance matching of cement composites and introduce extra EM attenuation path of scattering and multiple reflection, broadening the bandwidth of RL less than −7 dB. An obvious heat storage capacity and better thermal inertia of cement composite can be attained by the addition of PCM, and the heating rate can be reduced approximately 47% when PCM content selected as 20%. The compressive strength and flexural strength of cement composites can be reduced observably, because of the increase of porosity and limitation of cement hydration process caused by PCM. However, considering the comprehensive properties of the developed dual-functional cement composite, the strength loss is acceptable, and it can be a candidate as plastering mortar or enclosure materials for non-bearing structure in building engineering.