The synergistic effect of CNTs-polymeric surfactant on the properties of concrete nanocomposites: Comparative study

Abstract

Carbon nanotubes (CNTs) have been used as reinforcing material for many different matrices. There are many studies in the literature reporting that reinforcement of CNTs into concrete matrix improved the properties of the concrete. In this study, first unmodified CNTs were reinforced to concrete and it was seen that there were partial decreases in strength despite the increasing rate of CNTs. Thereon, the surfaces of CNTs to be used as reinforcing material were modified with water-soluble surfactants (Polyvinyl alcohol-PVA, Polyvinylpyrrolidone-PVP, Poly (ethylene glycol)-PEG, Dodecylamine-DDA) and reinforced with concrete. In previous studies, many different surfactants were tried to functionalise the surfaces of CNTs. However, in this study, water-soluble polymeric surfactants were preferred without the need for an additional process in order to modify the surfaces of CNTs. In addition, the effect of the surfactants used on the mechanical properties of concrete was examined comparatively. Although the amount of CNTs reinforcement is very low like 0.05 wt%, the increase in strength was seen to be above 60%. The highest strength values were obtained in the sample in which PVA was used as surfactant. Through the surfactants used, bundles of CNTs were fully opened and distributed homogeneously into the concrete matrix, and all of the CNTs were embedded into the matrix by getting wet by the matrix. In the real application, it will be possible to use new generation concretes with higher strength and lighter weight by providing the ease of reinforcing CNTs to the concrete matrix.

Mechanical Characteristics of Cement Paste in the Presence of Carbon Nanotubes and Silica Oxide Nanoparticles: An Experimental Study

“…The negative effect of CNT can be addressed by modifying the CNT’s polymeric matrices in concrete. For instance, Güler et al [ 72 ] modified the surface of CNT using polymeric surfactants such as Poly (ethylene glycol) (PEG), Polyvinyl alcohol (PVA), Dodecylamine-(DDA), and Polyvinylpyrrolidone (PVP) in an attempt to enhance concrete’s mechanical properties. The use of such polymeric surfactants avoids the requirement for additional proves of CNT’s surface, compared to other recommended different surfactants [ 73 , 74 ].…”

Nanotechnology in Concrete: a Bibliometric Review

“…In this application, nanoparticles can be a potent ally, improving the related properties (76). For this, many organic agents, such as polymers (77), and inorganic agents, such as minerals (78), can be used. Coatings containing nano agents are also a form to promote corrosion resistance .…”

Enhancement of Cement Paste with Carboxylated Carbon Nanotubes and Poly(vinyl alcohol)

“…In this study, CNTs-COOH and PVA are used to enhance the cement paste, according to the application precedents of PVA and CNTs. − The hydroxyl group of PVA can form hydrogen bonding or ionic bonding with the carboxyl group of CNTs-COOH and C–S–H of cement-based materials. − In addition, well-dispersed CNTs-COOH can optimize the pore structure of cement-based materials. , Based on the above two points, this paper hypothesizes that PVA could improve the dispersion and enhance the interface of CNTs-COOH, while CNTs-COOH could fill the pores introduced by PVA, thereby synergistically enhancing the performance of cement paste. This hypothesis is systematically studied from multiple perspectives.…”