What is a coating?

A coating is a covering that is applied to the surface of an object. The purpose of applying the coating may be decorative, functional, or both. Coatings are ubiquitous and can be found on walls, furniture, on all sorts of wires and printed circuits, the outside of houses and cars, and much more. In addition, the decorative duties of coatings span quite a broad spectrum.

Decorative coatings are mainly used for their color, texture or other visual property. Functional coatings are applied to change the surface properties of the substrate, such as adhesion, wettability, corrosion resistance, wear resistance and more. In some cases, the coating adds an entirely new property such as a magnetic response or electrical conductivity and forms an essential part of the finished product.

Coatings may be used in various processes, that are roughly divided into: vapor deposition, spraying, chemical and electrochemical techniques, roll-to-roll coating processes and other, less prominent techniques.

What is graphene?

Graphene is a two dimensional layer of carbon atoms, arranged in the form of a honeycomb lattice. It is touted as a “miracle material” because it is endowed with an abundance of astonishing traits - this thin, one atom thick substance is the lightest, strongest, thinnest material known to man, as well as the best heat and electricity conductor ever discovered - and the list does not end there. Graphene is the subject of relentless research and is thought to be able to revolutionize whole industries, as researchers work on many different kinds of graphene-based materials - each one with unique qualities and purpose.

Graphene for coatings

The vast selection of extraordinary properties that graphene possesses can open the door to many interesting types of coatings, paints, inks and more. Graphene's high resistivity can make for durable coatings that do not crack and are resistant to water and oil; its excellent electrical and thermal conductivity can be used to make various conductive paints, and a strong barrier effect can contribute to extraordinary anti-oxidant, scratch-resistant and anti-UVA coatings.

Graphene enables a wide array of functional coatings and paints, for many possible applications. Among these can be high performance adhesives enabled by graphene's high adhesion property, anti-bacterial coatings, solar paints (capable of absorbing solar energy and transmitting it), paints that provide isolation for houses, anti-rust coatings, anti-fog paints and UV ray blockers, non-stick coatings for various domestic applications (like frying pans and countertops) and even a much-hyped possibility (currently under scientific examination) of a coating that turns a regular wall into a screen.

Commercial activity

Graphene-enhanced products are yet to reach widespread commercialization. Nonetheless, given graphene’s impressive array of properties and the vigorous R&D that is taking place, graphene-enhanced coatings should not be too far away.

The Sixth Element Materials, a Chinese company that focuses on R&D, mass production and sales of graphene and related materials, showcased its graphene-zinc anti-corrosion primer used for offshore wind power tower, that can come at a competitive price compared with zinc rich epoxy primer.

Garmor, the University of Central Florida spin-off formed to develop a new graphene oxide flakes production process, has developed graphene oxide-based coatings useful for limiting UV radiation damage to sensors and polymers. Garmor's transparent GO-films are reportedly derived from a commercially-viable and scalable process that can be readily implemented with minimal constraints.

Four layers of GO coating on polycarbonateFour layers of GO coating on polycarbonate

The Spain-based Graphenano announced the launch of a graphene-based series of paints and coatings called Graphenstone in 2014. These are said to be very strong and also acts as a protective layer against environmental damage. Graphenstone is made from a graphene powder and limestone powder.

The British Electro Conductive Products released a sprayable transparent conductive coating based on a CNT and graphene platelets (GNP) hybrid material. TBA are targeting the food, electronics, pharmaceuticals and petrochemicals markets.The new ATEX-compliant product is available as a clear, anti-static aerosol, and it should also be available as bulk paint. Its application will safeguard electronic equipment used in explosive environments and bring it up to European standards.

Further reading

Latest Graphene coating news

G3 and Lanka Graphite enter agreement to develop graphene-enhanced products

Apr 19, 2017

Global Graphene Group (G3), a holding company for subsidiaries like Angstron Materials, has signed Heads of Agreement with Lanka Graphite, a graphite exploration company. The joint venture entity (LGR 50%, G3 50%) will develop a range of commercial graphene projects.

G3 is reportedly scaling a broad range of commercial platforms of graphene applications in several , areas like energy storage, coatings, and thermal management. Lanka Graphite will supply vein graphite product into the joint venture in addition to assisting with sourcing investment, marketing and administration. G3 proposes to supply its experience in developing IP and research grants, commercialization planning and manufacturing infrastructure.

A graphene-based coating changes color upon deformation warns of cracks in buildings and bridges

Apr 06, 2017

Researchers at the Germany-based Leibniz Institute of Polymer Research have developed a structurally colored coating based on graphene flakes, that changes color depending on deformation of the colored surface. Inspired by natural iridescence in fish skin, this coating could provide a simple way to warn of hidden damage in buildings, bridges and other structures.

GNP-enhanced coating changes color when deformed image

The team made the coating in an initial red, but when deformed, it appears yellow, and when cracked at the micrometer scale, green. This color-changing ability comes from a careful alignment of the graphene flakes in semi-transparent, parallel layers, coating a glass fibre. Under stress, the layers compress and flatten, changing the interference and color of reflected light. In fact, by overlapping graphene nanoplatelets (GNPs) with ordered and disordered features using a special deposition approach, unique “fish scale” like structures are achieved. Variable structural coloration is observed through the mechanical tuning of fine parallel multilayers.

The Graphene Catalog - find your graphene material here

Talga enters agreement with Chemetall to develop graphene-based coatings

Mar 29, 2017

Talga Resources has announced the signing of a joint development agreement with Chemetall, a global business unit of BASF Coatings Division, to co-develop and commercialize graphene-enhanced metal surface coatings.

Talga joins Chemetal in developing graphene coating image

Under the terms of the Agreement, Talga and Chemetall will cooperate to develop Talga value-added graphene products for use in Chemetall surface treatment products. The joint development program aims to set new industry standards for eco-friendly, high performance, corrosion resistant surface treatments.

A new graphene oxide coating to improve the performance of lithium-sulfur batteries

Mar 21, 2017

Researchers at Yale University have developed an ultra-thin coating material, based on graphene oxide, that has the potential to extend the life and improve the efficiency of lithium-sulfur batteries. The newly developed material is a dendrimer-graphene oxide composite film, that can be applied to any sulfur cathode.

GO coating to improve Li-sulfur batteries performance image

The researchers state that sulfur cathodes coated with the material can be stably discharged and recharged for more than 1,000 cycles, enhancing the battery’s efficiency and number of cycles. In addition, they said “the developed film is so thin and light it will not affect the overall size or weight of the battery, and thus it will function without compromising the energy and power density of the device”.

Thomas Swan launches a high-performance graphene intermediate product for coatings

Mar 15, 2017

Thomas Swan logoThomas Swan has announced the launch of a high-performance graphene intermediate product for coatings formulators. The new Elicarb Graphene product is a cost effective, stable, easy to handle dispersion of Elicarb Materials Grade Graphene powder for formulation into epoxy-based coating formulations. The product is available now in liter quantities for testing and evaluation.

Thomas Swan has established a 20 tonne per year capability for the manufacture of Elicarb Graphene and Elinova Boron Nitride products at its UK manufacturing site in Consett, County Durham. Elicarb Graphene Epoxy Dispersion is a high performance intermediate product which is intended for further optimization and incorporation into customers’ existing proprietary coating systems. The graphene dispersion is targeted at improving corrosion resistance, thermal conductivity, chemical barrier and mechanical resistance in industrial coatings.