FAQ

According to the international standards organization ISO, graphene refers to a single plane of sp2 carbon bonded atoms in a hexagonal honeycomb crystal lattice.

In addition, the term "graphene" can be applied to material that is up to, and including, 10 layers of carbon and includes graphene related materials such as graphene oxide, reduced graphene oxide, functionalized graphene and graphene quantum dots.

As a nano-material, graphene imparts extraordinary properties, often multiple positive characteristics in combination, when used in devices or embedded in other materials. 

It is the thinnest material known to man, so thin that it is considered to be 2 dimensional.

• Exceptional Strength: Despite being incredibly thin, graphene is remarkably strong and can withstand significant mechanical stress.

• High Electrical Conductivity: It exhibits excellent electrical conductivity, allowing electrons to move through it with minimal resistance.

• Exceptional Thermal Conductivity: Graphene is also an excellent conductor of heat, making it useful for applications requiring efficient heat dissipation.

• Flexibility: It is extremely flexible and can be bent and folded without losing its properties.

• Transparency: A single atomic layer of Graphene is nearly transparent, allowing it to be used in transparent conductive films and touchscreens.

• Impermeability: Despite its thinness, graphene is impermeable to all gases and liquids, making it an effective barrier material.

Graphene is the same basic material that is found in ordinary pencil lead.

As a universal caveat, precautions should be taken when handling ANY nano-material when in a dry powder form. The greatest exposure risk with nanomaterials involves potential inhalation which can be managed with operational controls and the proper use of personal protective equipment.

However, once graphene has been added to a liquid or has been embedded in a host material, it is quite safe to handle and provides no risk in dermal contact. We recommend that companies that wish to use graphene work with a qualified supplier to ensure graphene is safely applied.

For more information on the use of graphene and use in human contact, please refer to this paper.

Cement-based concrete represents the most heavily used material in the construction industry owing to its low-cost and excellent compressive strength. However, cement and concrete are responsible for as much as 8% of all CO² emissions globally.

Graphene as an additive offers attractive properties to address some of the issues facing cement-based concrete. For example, adding graphene in a concrete formulation can reduce the amount of cement needed by as much as almost 50%, reducing the main source of embedded CO².

In addition, because of graphene’s inherent strength properties it can increase concrete’s overall durability and resistance to cracking, reduce water permeability and thereby, the corrosion of reinforcing steel.

Graphene makes concrete stronger and cure faster with less embedded CO².

Because of the way cement reacts with water, graphene plays a unique and critical role in the curing process. When cement comes in contact with water more than 70 different crystals (part of the calcium – silicate – hydrate group, which are responsible for concrete’s hardening and mechanical properties) change shape and size during their evolution.

Graphene is capable of mechanically interlocking with these crystals because of its significant surface area and its nano dimensions. During this process, the nanomaterial interacts with the crystals adding strength and accelerating the rate of cure.

Different types and forms of graphene enable a range of improved performance characteristics for cement and concrete applications;

• Faster cure rate
• Increased load and compressive strength
• Reduced water permeation
• Reduced micro-cracking and fractures
• Effective for use in repair compounds and mortars
• Requires less cement in a concrete mix reducing embedded CO²
• Requires less concrete to achieve the same engineering performance, providing a further reduction in CO²

Because concrete is so complex and is used in so many different applications, it would be wrong to assume that there will be one-size-graphene-fits-all solution, unlike other graphene applications where for example graphene oxide (GO) is needed and nothing else works. Commercial graphene producers are working with innovative engineering firms and builders to deliver low carbon, high performance concrete solutions.

It is important to remember that only a very small amount of graphene is needed, as little as hundredths of a percent by weight per ton of concrete, making graphene a commercially viable additive. It is also important to note that graphene can be used as a liquid admixture or a dry additive, much like other commercially available cement and concrete additives. 

Companies that are producing concrete slabs, pre-cast concrete products, Ultra-High-Performance Concrete (UHPC) and Ultra-High Strength Concrete (UHSC), high traffic roadways, marine or other harsh exposure environments are all prime candidates to use graphene to meet your unique concrete engineering challenges.

Graphene has proved itself as a great concrete additive through research and experimentation conducted by various teams of researchers. The concrete made up of ordinary cement provides excellent compressive strength; however, the poor tensile strength necessitates reinforcement which necessitates a more robust concrete variant.

Graphene-Concrete Composites

Graphene can be added as an additive in concrete to make it more robust, durable, and flexible. This incorporation of graphene can increase the lifespan of buildings by reducing cracks and corrosion.

In the years since this initial discovery, scientists have been working on perfecting the process and making it commercially viable. A team of researchers at the University of Exeter published an article in the journal Advanced Functional Materials that reveals the enhanced properties of graphene-concrete composites.

Researchers incorporated graphene into concrete to develop a composite material that they believe can easily be scaled up for use with modern manufacturing processes. The fragile characteristics of concrete can be addressed in a variety of ways. Graphene concrete enhances compressive strength, flexural strength, and split tensile strength all at the same time.

Ordinary concrete is usually made up of cement, and modifications tend to take place within the cement structure.

The cement particles are made up of multiple elements such as calcium silicates, aluminum, silicon, iron, and alu-minoferrites. The hydration reaction causes the cement particles to transition from powder to fibrous crystals when exposed to water.

The development and bonding of cement particles over time are the most important variables in determining the material qualities of concrete. Nanomaterials’ remarkable chemical and physical properties make them the most effective means of improving the internal matrix of the concrete.

The method used by the researchers is known as the high-shear exfoliation of graphene in water. This method allows the water to be replaced directly in a concrete mixture. The process entails preparing graphene suspensions in water by high-shear exfoliation with the surfactant sodium cholate, resulting in surfactant functionalized graphene (FG).

The surfactant functionalized graphene was then mixed in concrete using a high-shear mixer. The experimental results revealed that the graphene reinforcement not only enhances the compressive strength of concrete but also the flexural strength.

It was observed that the graphene reinforced concrete structures serve as a water barrier which ultimately enhances its durability. It has high resistivity, which prevents the steel rebars from corrosion and high thermal stability, increasing the heat capacity of a material.

It was also found that graphene reinforced concrete structures positively impact the environment since it significantly reduces the emissions of carbon dioxide. All these experimental findings make graphene reinforced concrete a promising construction material for a greener and eco-friendlier construction industry.

The biggest challenges for real-world applications are the difficulty in finding a reliable graphene supplier and a lack of confidence in graphene in the supply chain.

Extensive research is still needed to fully maximize the potential of graphene composites without endangering the environment or human health. However, graphene reinforced composites will most certainly become a part of cities and homes in the next years, bringing considerable improvements to daily life.