High-Strength, Waterproof, Corrosion-Resistant Nano-Silica Carbon Nanotube Cementitious Composites

This study aims to prepare a nano-silica-carbon nanotube (NS-CNT) elastic composite using NS (nano-silica), CNTs (carbon nanotube), and (D₃F) trifluoropropyltrimethoxysilane. The results show that the activated NS could promote the hydrolysis of D₃F. Polymerization products of nano-silica and D₃F are uniformly adhered onto the surfaces of CNTs, thereby forming a NS-CNT composite. The composite is composed of irregular ellipsoids of 3-12 μm in length and 2-10 μm in diameter. The activated NS-CNT composite material effectively promotes the further hydration of (CaOH)₂ in the cement to form hydrated calcium silicate, and further dehydration-condensation between the surface hydroxyl group of the composite material and the inherent hydroxyl group of (CaOH)₂. The cementitious composite-based composites containing the activated NS-CNT exhibit high mechanical strengths, high water resistances, and good durability and corrosion resistance. The chemical characterizations reveal the morphology, nucleation mode of the composite, and its influence on the hydration structure and products of cementitious composite.