Can Wood Stop Rust? Creating Cellulose-Based Coatings for Metals from Biorefining By-Products

Coated metal surfaces can be found in all aspects of modern life, including household products like kitchenware, technology such as laptops and mobile phones, tools from the hammer to the axe, and transport from ships to cars. Polymer coatings are widely used to prevent rust on metals like steel, to protect surfaces from damage, and to create beautiful surfaces. The metal industry uses a large volume of polymers for coating metal products. Currently these coatings cannot easily be recycled. As a result, the pressure for the industry to explore sustainable options to replace these non-renewable oil-based metal coatings becomes ever more intense. The challenge is to find a coating that not only prevents corrosion, but does so in a sustainable way and can aid metal recovery. Such coating would reduce not only global warming, but also the consumption of finite metal ores and other raw materials.

Aalto University's project explores whether the solution to these challenges could be sourced from Finland’s forests. Use of forestry-based materials like cellulose nanofibers – generated as a by-product of Biorefining – will be investigated as alternative metal coatings. These coatings will be evaluated for a range of applications from a fingerprint-proof alternative to Teflon to functionalised surfaces on steel and from wear-resistant PVC replacement coatings in ship cabins to surfaces with pleasing aesthetics. This new generation of sustainable surfaces will be applied using a process where electricity flows through nanocellulosic solution produces coatings – a method akin to modern day alchemy!

The resulting biosourced surfaces not only remove the need for environmentally costly petrochemicals, but also offer easier routes to recycling – cellulose is not toxic like PVC. Moreover, the process reduces the global impact of Finland’s major industries as a superfluous product of Biorefining becomes a valuable resource for metal coatings production. This is a real win-win for local industry and environment.

Aalto University Team:

Prof. Mari Lundström, Aalto University
Dr. Benjamin P. Wilson, Aalto University
Prof. Herbert Sixta, Aalto University
Dr. Michael Hummel, Aalto University