Innovative coatings mitigate effects of deepening climate change

Companies and researchers are increasingly offering innovative coatings to help businesses and governments combat climate change by providing insulation, heat reflection and other energy-saving functionalities. These products also support compliance with growing legislation targeting net zero emissions by 2050, and address intensifying consumer concerns about the impact of climate change. With more frequent record-breaking heatwaves, devastating floods and wildfires, among other disasters, a Deloitte Consumer Industry Centre report published in January 2024 stated that “individuals who experienced extreme weather were statistically more likely to believe climate change is an emergency compared to those who didn’t” (Source).

As for regulatory pressure, sustainability reporting is now mandatory in the European Union (EU), with the US potentially following suit soon (though its rules are currently on hold), further increasing the compliance utility of climate-resistant coatings (Source 1, Source 2). Moreover, in April 2024, the EU approved a directive aimed at reducing emissions and energy use in buildings by 16 per cent by 2030 and by 20-22 per cent by 2035 (Source 3), with climate-resistant coatings potentially playing a significant role.

Additionally, in 2021, the United Nations Framework Convention on Climate Change (UNFCCC) launched a compendium on greenhouse gas baselines and monitoring for the building and construction sector. It promoted, for example, the use of reflective coatings on roofs and facades to enhance the thermal performance of existing buildings (Source).

Furthermore, the 2024 International Green Construction Code (IgCC), developed by the Washington DC-based International Code Council (ICC), specifies that IgCC-certified architectural coatings must comply with requirements for volatile organic compound (VOC) content or carbon emissions reduction requirements (Source).

Moreover, in the US island state of Hawaii, which experiences hot weather and high humidity, a compliance credit is available for the installation of highly reflective exterior wall materials on residential and commercial buildings (Soruce).

Additionally, the European Commission’s ‘EU-level technical guidance on adapting buildings to climate change’ recommends best practices such as plaster-based coatings to waterproof walls, and special surface coatings that use nanotechnology to create tiny mirrors for sunlight, helping to reflect energy and maintain lower temperatures in buildings (Source).

David Park, spokesperson for the British Coatings Federation (BCF), sees “constant innovation occurring in R&D [research and development] labs across the industry.” This includes “everything from reformulating to use more sustainable inputs, such as bio-based materials, to developing coatings that actively preserve energy and fuel, like heat-reflecting paints.”

“This is both necessary for the global drive for net zero and a good commercial opportunity for companies that can bring these new technologies to market,” he told PPCJ. The application of coatings to combat climate change extends beyond the construction sector. Park noted that “much of the new green and renewable energy infrastructure relies on coatings to function effectively,” because “wind turbines need protection from the weather, and solar panels require specialist coatings to operate.”

Additionally, he mentioned that “food packaging coatings use preservatives to extend the shelf life of foodstuffs and minimise food waste.” Regarding materials, companies are increasingly using bio-based inputs to reduce the climate footprint of the coatings sector, he said. Furthermore, he added that “the EU’s move to a ‘safe and sustainable by design’ (SSbD) approach means companies are examining all the inputs they use from a longer-term and end-of-life perspective” (Source).

For instance, the Netherlands-based AkzoNobel received approval from the internationally recognised and UN-backed Science Based Targets initiative in 2021, which empowers companies to combat the climate crisis (Source). This approval was granted due to its carbon reduction target of 50% by 2030 across its full value chain, according to a company note sent to PPCJ.

“The built environment is responsible for around 39 per cent of global energy-related carbon emissions,” with 28% coming from “the energy usage (mainly from heating and lighting) in operating buildings,” while around 11% results from “carbon emissions related to energy use during the construction and renovation phases, as well as from the building materials used,” the company emphasised. Therefore, AkzoNobel’s ‘Cool Chemistry’ paints and coatings help to “reduce the operational carbon footprint of buildings in hot climates,” as they can reflect sunlight and thus “reduce the amount of energy that buildings consume.”

“Given the rate and spread of global warming, our heat-reflective products will also become an increasingly viable solution in other parts of the world,” the company predicted. In 2023, the company introduced its Interpon D2525 Low-E range, “designed to withstand conditions in more extreme and challenging locations,” thereby extending the product’s lifespan (Source). AkzoNobel told PPCJ that these low-energy, high-performance powder coatings help “customers reduce their energy consumption” and are “capable of curing at temperatures as low as 150°C.”

Tackling weather conditions with functional coatings is not new, of course. The Georgia, US-based firm ThermaCote began developing such products in 1985, and its weather barrier coating, sold under the ThermaCote brand, still conserves energy, seals structures, and prevents corrosion.

A company note claims that with its “thermal coating solution,” “no matter what environmental conditions arise, your property will remain safe” (Source). Its ceramic-based formula is suitable for a range of substrates, including wood, steel, concrete, sheetrock and plastic.

CEO and president Tommy Sharp told PPCJ: “Our high-performance advances in ‘envelope’ airtightness and moisture mitigation, combined with resistance to thermal bridging, certainly elevate ThermaCote above the competition.” He added, “ThermaCote weighs just 0.6 kilos per litre in its wet state and dries even lighter, so it won’t add significant weight to the substrates it’s applied to. Despite its light weight, ThermaCote is a heavyweight champion in advanced coating systems.”

ThermaCote is one of the founding members of the Wall Rating Programme, launched by the Oregon, US-based Cool Roof Rating Council, which provides product ratings for coated exterior wall products based on their surface radiative performance, including solar reflectance and thermal emittance (Source).

Universities have also been investing in this promising sector. For instance, in June 2023, Rachith S. N. Kumar, Wim Deferme, and other researchers from the Institute for Materials Research (IMO-IMOMEC) — a joint research entity of Belgium’s Hasselt University and the Interuniversity Microelectronics Centre (IMEC) — presented an innovative technique that makes ultra-thin coatings more affordable and strongly adhesive due to a dynamic wetting process (Source).

However, as Kumar explained to PPCJ, depositing ultra-thin films of less than 15 nanometres (nm) over large areas (up to metres) remains “quite challenging” for the sector. Most existing techniques either cannot achieve the required thinness or are not scalable. For example, spin coating can deposit ultra-thin films, but it cannot be scaled up for roll-to-roll processes at the industrial level, he said.

To tackle this challenge, Kumar developed a uniform ultra-thin coating technique capable of depositing films less than 5 nanometres thick, using spray-on-screen (SoS) technology, which is compatible with roll-to-roll processes. “Our results are comparable to those of the most expensive deposition techniques, such as thermal evaporators, which are currently the global standard,” Kumar said, adding that their technology is patented in both the US and the European Union.

By Andreia Nogueira