Properties of cement-based composites by doping nano-TiO₂

Cement-based composites were prepared by using nano-TiO₂ dispersed by ultrasonication as an additive to the composites. The uniformity of the distribution and the stability of nano-TiO₂ in the cement matrix of the composites were determined by electron probe X-ray micro-analysis and infrared spectrometry, and the structure of the composites was observed with scanning electron microscopy. The conductivity, electromagnetic parameters and wave-absorbing capability and mechanical properties of the composites were investigated. The experimental results indicate that there is greater stability of nano-TiO₂ in the cement matrix. The cement-based composite with 5.0% (in mass) nano-TiO₂ had better dielectric and wave-absorbing capabilities in the 12.5-18 GHz frequency range (KU waveband), and its conductivity reaches 57.0 × 10^-3 S·cm^-1. The least reflectivity is -16.34 dB and the bandwidth for -10 dB is 4.5 GHz.