Microstructure and mechanical properties of carbon nanotube reinforced cementitious composites developed using a novel dispersion technique

The authors also acknowledge Centre for Textile Science and Technology (University of Minho) and FIBRENAMICS PLATFORMfor providing required conditions for this research. Sincere thanks are also due to Mr. Pedro Samuel Leite and Mr. Carlos Jesus for their kind help in sample preparation and testing.

The present paper reports the first attempt of developing carbon nanotube (CNT) reinforced cement composites through a short dispersion route using Pluronic F-127 as a novel dispersing agent. Optimum concentrations of Pluronic for various types of CNTwere determined, and the influences of Pluronic and CNT on themicrostructure and mechanical properties of cementitious composites were thoroughly investigated. Pluronic with optimized defoamer concentration significantly improved the bulk density and mechanical properties of cement mortar. Further, dispersion of 0.1% single walled nanotube (SWNT) improved flexural modulus of mortar by 72% and flexural and compressive strengths by 7% and 19%, respectively after 28 days of hydration. Flexural and compressive strengths with functionalized SWNT increased with the hydration period up to 17% and 23% after 56 days, respectively. All CNT reinforced samples exhibited significantly higher stiffness, fracture energy and ductility as compared to plain mortar and composite samples prepared using a common surfactant.