Synthesis and characterization of cement- CNT composite produced by CVD process

Reinforcing of materials using carbon nanotubes are new approach for development of new and or advanced composites. In the meantime, the use of carbon nanotubes to reinforce cementitious materials, especialy reconstructing cement, is considered. The synthesis process of nanotubes on cement is the main problem in making the composite. In the paper, synthesis and characterization of cement-CNT composite produced by CVD process was investigated. The CVD process at 800°C using acetylene gas as a carbon source, argon as carrier gas and hematite iron oxide as a catalyst was performed. Wet impregnation method for preparing the catalyst bed of cement and iron oxide particles were used. FESEM, EDX, TEM and Raman spectroscopy were used to characterization CNTs/Cement composite and the size, morphology and quality of CNTs respectively. The growth yield of carbon nanotubes was determined by TGA. The results showed that the chemical vapor deposition method allows the deposition of carbon nanotubes with proper distribution of diameters and quality. It was also observed that most of the synthesized carbon nanotubes have open ends that represent the end growth of the carbon nanotubes. Finally the result of mechanical tests indicated that CNTs addition to the cement paste dramatically the increased compressive strength by bridging between cracks and filling pores.