The Use of Graphene Oxide for the Protection of Concrete

The degradation of concrete constructions and the resulting need for regular maintenance and repair has driven interest in methods to better protect concrete, particularly from the negative impacts of water and precipitation.

One approach to protecting concrete to extend its lifetime and lower maintenance costs has been the application of surface protection materials. These materials are hydrophobic and block the penetration of damaging chloride ions found in community water supplies

Concrete surface treatments generally fall into three different categories:

1.Coatings that establish a continuous film on top of a concrete surface
2.The use of a coating to ‘impregnate’ soluble surface constituents to create a protective barrier
3.The ‘hydrophobic impregnation’ of surface constituents to make water-repellent concrete

Existing coating materials have shown varying degrees of effectiveness. There currently is no single coating that is capable of protecting all kinds of concrete from deterioration.Concrete researchers have recently focused on using nanomaterials to develop superior coating materials. In particular, graphene oxide, produced by the chemical exfoliation of graphite, has emerged as a promising candidate.

Due to the superior mechanical properties conveyed by its high surface area and strength, as well as its excellent dispersibility in water, graphene oxide appears to be an excellent candidate for the surface protection of concrete.In one recent study, researchers looked at the protective effect of a graphene oxide coating on concrete, focusing on its ability to prevent water and ions penetration.

To apply a 9 mg layer of graphene oxide on concrete samples, the study team used three application methods: brushing, spraying and submerging.Researchers evaluated 90-day old samples for water absorption, capillary absorption and water vapor permeability. They also performed Fourier-transform infrared spectroscopy (FTIR) to assess any molecular changes, and a rapid chloride permeability test (RCPT) to evaluate the degree of corrosion due to chloride penetration.