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.
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.
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.
The latest graphene coating news:
XG Sciences, designer and manufacturer of graphene nanoplatelets and advanced materials containing graphene nanoplatelets, and Terrafilum, an eco-friendly, high quality filament producer for the 3D printing industry, announced a joint development agreement to develop, produce and market 3D printing filaments and coatings using graphene-based materials.
Chris Jackson, President of Terrafilum, points out, "The full potential for 3D printing is starting to be unlocked. The addition of XG's graphene formulations into our eco-friendly filaments will transform products allowing a greater variety of parts to be created at faster production rates using less energy."
PC gear company Cryorig has introduced its low-profile CPU graphene-enhanced cooling system for small form-factor PCs that can dissipate up to 125 W. The Cryorig C7 G is among the smallest coolers for higher-end processors available today. To make C7 G's high performance possible, Cryorig applied graphene coating on the heatsink.
As demands arise for higher-performance components, cooling designers are creating low-profile coolers rated for TDP levels of 95 W of higher. To maximize efficiency of such devices, manufacturers use copper for heatsinks, many heat pipes, and large fans. Cryorig decided to go one step further and applied graphene coating to the radiator’s fins. Thermal conductivity of graphene is considerably higher than thermal conductivity of aluminum or copper, so applying it on the fins could theoretically improve cooling performance.
The Tata group is a global enterprise, headquartered in India, comprising over 100 independent operating companies. Tata Steel, the flagship company of the Tata group, is a Fortune 500 Company with immense global reach. TV Narendran, Managing Director of Tata Steel, provided updates on the Company's graphene R&D business.
Tata Steel is working with graphene as part of its plan of focusing on developing advanced material to protect its margin and bottom line. Its Graphene Development Center has recently produced corrosion-resistant graphene paint and supplied graphene powder to renowned tyre companies. It has also demonstrated the potential of graphene inks, which are used in the printing of train tickets, plane boarding passes, and RFID (radio-frequency identification) tags.
Australia-based graphene and data analytics company, Imagine Intelligent Materials, has developed an integrated sensing solution that uses graphene coatings and edge-based signal processing devices to collect data from objects with large surface areas.
Proven over areas as large as 4,000 square meters, the system gathers data such as pressure, moisture, stress and temperature and is aimed at industrial and consumer applications in the IoT market.
Project "HEA2D", which started in 2016 and set out to investigate the production, qualities, and applications of 2D nanomaterials, recently demonstrated end-to-end processing chain of two-dimensional nanomaterials. The project is a collaboration between AIXTRON, AMO, Coatema, Fraunhofer and Kunststoff-Institut für die mittelständische Wirtschaft (K.I.M.W.).
It was stated that the "HEA2D" consortium successfully demonstrated an end-to-end processing chain of two-dimensional nanomaterials as part of its results. 2D materials integrated into mass production processes have the potential to create integrated and systemic product and production solutions that are socially, economically and ecologically sustainable. Application areas for the technologies developed and materials investigated in this project are mainly composite materials and coatings, highly sensitive sensors, power generation and storage, electronics, information and communication technologies as well as photonics and quantum technologies.