Mechanical Strength of Graphene Reinforced Geopolymer Nanocomposites: A Review

Abstract

The emergence of high-strength graphene marks a new milestone in the material science field. With only a small percentage inclusion into the matrix system, this organic nanoparticle could tremendously improve the strength in vast arrays of composites. At the same time, there is a growing interest in using the low-cost, lightweight, and high early strength geopolymer as the new binder for concrete. Compared to the traditional Ordinary Portland Cement (OPC), geopolymer emits 80% less CO2 during its production while exerting similar strength. Thus, the geopolymer has the potential to commercialize as new and green concrete. Geopolymer is a mixture of aluminosilicate powders and alkaline solutions. When incorporated with nano-sized graphene, the material forms a composite known as Graphene Reinforced Geopolymer Nanocomposite (GRGN). The addition of graphene enhances the strength of geopolymer, which can further improve its competitiveness. However, this depends on several factors, including the types of graphene, the surface modification of graphene, and the concentration of alkaline solutions. Generally, the presence of graphene alters the porous structure of geopolymer into a substantially filled porous structure, thus increasing compressive strength and flexural strength. On the other hand, Graphene Oxide (GO) undergoes a chemical reduction in the alkaline solution, producing epoxy functional groups. The chemical treatment results in two conditions which are weak interaction between graphene and geopolymer matrix, and better graphene dispersibility in geopolymer matrix. This review also highlights the analytical modelling aspect of GRGN. The dissolution of Si(OH)4 and Al(OH)4- from the aluminosilicate source was consistent with experimental work and analytical modeling, while the dissolution of Si–OH on the surface-modified graphene indicated otherwise. Therefore, this paper will provide an insightful review of the GRGN mechanical properties.

Geopolymers and Functionalization Strategies for the Development of Sustainable Materials in Construction Industry and Cultural Heritage Applications: A Review

“…As recently reported in the literature, incorporating nano-sized graphene into the geopolymeric paste enhanced the resistance and the hardness of these green concretes [ 99 , 101 ]. This improvement in the mechanical properties is probably due to several factors, such as the concentration of the alkaline solution, the type of graphene and the surface graphene changes that occur after the treatment with basic solutions.…”

“…Nanomaterials can create intelligent materials with improved rheological and mechanical properties, thanks to their small size and high surface-to-volume ratio [ 94 ]. The addition of these agents, such as nano-silica, nano alumina, TiO 2 , ZnO and graphene oxide, plays a key role in the consolidation of the innovative material, acting as nanofillers, and leading to a reduction of the inner water together with an increase in the compressive strength [ 95 , 96 , 97 , 98 , 99 , 100 ]. Recently, a study investigated the effect of a geopolymer treated with Al 2 O 3 and multi-walled carbon nanotubes (MWCNT) functionalized with hydroxyl groups [ 94 ].…”

“…Moreover, these nanoparticles, aging as fillers, occupying the voids in the polymeric porous structure, make the material more compact and resistant. From a chemical point of view, using an alkaline solution causes the reduction of graphene oxide, providing an epoxy group, which can weakly interact with the geopolymeric structure, dispersing in the matrix more efficiently [ 99 ].…”

Effect of bismuth oxide nanoparticle on the electromagnetic interference shielding and thermal stability of industrial waste based-geopolymer composites

“…Several research has incorporated various conductive fillings and loading to cement-based, such as carbon nanotubes with controllable silica shells 9 , graphene-coated CNT’s 10 , 11 , nickel fiber 12 , stainless-steel furnace dust 13 and metallic nanoparticles such as cobalt, nickel, and iron oxide 14 . One potential metallic nanoparticle that could be used as a conductive admixture is Bismuth Oxide (Bi 2 O 3 ), due to its good absorbing properties 15 .…”

Effects of graphene content on the microstructure and mechanical properties of alumina-based composites

“…Graphene is a two-dimensional material with large specific surface area, good electrical and thermal conductivity (Lee et al, 2008;Soldano et al, 2010;Novoselov et al, 2012;Tay and Norkhairunnisa, 2021), which has attracted great attention. The graphene has been used to prepare the Al 2 O 3 matrix based composites (Centeno et al, 2013;Chen et al, 2014;Liu et al, 2015;Asiq Rahman et al, 2018).…”