Graphene—the thinnest and lightest known material—is about 200 times stronger than steel, one of the best conductors of electricity and heat, and visually transparent. Yet, despite these remarkable qualities, the substance has not been available in building construction.
Ever since professors Andre Geim and Konstantin Novoselov isolated graphene at the University of Manchester in 2004—an accomplishment that won them the 2010 Nobel Prize in Physics—designers and manufacturers have sought ways to utilize this supermaterial in making commercial products. As a result, many applications are currently in development, with early successes in smartphone touchscreens, batteries, inks, composites, and filtration technologies.
Given the novelty and initial small-batch production of graphene, it is unsurprising that applications of this single-atom-thick, “harder than diamond yet more elastic than rubber” material would be limited to specialized products of a small size. However, thanks to successes in scaling industrial production, graphene is finally making its way to building products—less than two decades after the substance’s first isolation in a lab.
One proposed application enhances building glazing, allowing it to function as a tunable surface for energy-saving purposes. Researchers at Duke University’s Pratt School of Engineering in Durham, N.C., have developed graphene-enabled electrochromic glass that can switch between solar heating and radiative cooling modes. In such an application, graphene provides excellent conductivity, heat and visible light transparency, and current reversibility.
“It’s very difficult to create materials that can function in both of these regimes,” Duke materials scientist Po-Chun Hsu has said. “Our device has one of the largest tuning ranges in thermal radiation ever demonstrated.”
Another use improves the weathering performance of steel. Scientists at the University of Buffalo in New York have created a coating that incorporates graphene particles to increase protection against chemical degradation. The researchers immersed various steel samples in saltwater, a highly corrosive environment for untreated steel. The optimized graphene coating, which makes use of the material’s conductive and hydrophobic properties, allowed submerged steel to remain unchanged for a month. With the idea that the layer would last much longer in the open air, the scientists see the new surface treatment as an environmentally responsible alternative to toxic coatings like hexavalent chromium, which is carcinogenic.
A less expected building product application of graphene is concrete. Attempting to take advantage of graphene’s impressive mechanical performance, researchers at the University of Exeter in England created a new method to add the material to conventional concrete. As outlined in the paper “Ultrahigh Performance Nanoengineered Graphene–Concrete Composites for Multifunctional Applications,” the novel technique adds “water-stabilized graphene dispersions” to a concrete mix, resulting in a material with double the strength and four times the water resistance. Significantly, the researchers claim a 50% reduction in the materials needed to make concrete, translating to a savings of 446 kilograms per metric ton of CO2 emissions.
Graphene is also showing promise when combined with organic materials. Textiles made with natural fibers like jute exhibit advantageous environmental characteristics but are not sufficiently robust for some high-impact uses. Scientists at the University of Manchester in England have enhanced the mechanical performance of jute by coating the fibers with flakes of graphene as well as graphene oxide. The new jute-graphene composite reveals an increase in shear strength of 200% and flexural strength of 100% over untreated jute. Such impressive characteristics also compare favorably to many polymer-based textiles— materials of growing environmental concern due to the prevalence of plastic waste—that began to replace fibers like jute several decades ago.
“I believe our graphene-based jute fibers could play a very important role in meeting the growing demand of more environmentally friendly products for various industries,” said associate professor Nazmul Karim, a fellow at the National Graphene Institute.
As graphene makes its way into glass, steel, concrete, textiles, and many other building products, it will be essential to evaluate the potential consequences of its burgeoning utilization. The material is nontoxic, but could dispersed fibers of graphene lead to pervasive environmental waste like we now see with microplastics? This remarkable allotrope of carbon exhibits impressive performance, but its embodied energy is not insignificant, and this footprint must be considered in any material enhancement calculations. If we continue to leverage our growing collective knowledge about material life cycle performance, we can embrace the paradigm-changing capacities of this supermaterial while avoiding some of the pitfalls encountered with past substances.
The views and conclusions from this author are not necessarily those of ARCHITECT magazine or of The American Institute of Architects.
