Marine Coatings

Marine anticorrosion and antifouling coatings are likely to become important applications for GNP as numerous long-term testing programs wrap up. Graphene additive from Talga Group Ltd. is currently undergoing real-world marine testing on two large marine vessels. One of those ships just completed a 15-month inspection and sections coated with the GNP-enhanced primer are said to be providing comparable or better performance than the unenhanced benchmark, which is already showing corrosion marks. | Talga Group Ltd.

A number of coatings formulators and graphene producers have been hard at work developing anticorrosion/antifouling coatings for the marine industry. Given the extensive testing over a long time scale that’s required to receive approval in this segment, most companies we spoke with stated their products are still in the testing and evaluation stages and non-disclosure agreements (NDAs) prevented them from discussing their work in detail. However, they each indicated that testing to date showed significant benefits from incorporating GNP into marine coatings.

One company that couldn’t speak in detail about its work is Singapore-based 2D Materials Pte. Ltd., which began lab-scale GNP production in 2017 and commercial-scale production last year. Its graphene products are specifically formulated for the paint and coatings industry and the company says it’s worked with two of the largest suppliers of marine anticorrosion coatings since 2019 to develop both paints and coatings for that segment. 2D Materials also notes that it is working with a large steel company to integrate graphene into oils used to protect steel during transport and storage. According to Chwan Chieh Foo, 2D Materials application specialist, “Graphene has the most impact in functional coatings,” he notes. “For example, in the case of anticorrosion coatings for the marine industry, zinc is one of the main components. Graphene could be used to reduce or replace the zinc in these coatings. The addition of less than 2% graphene can greatly increase the useful lifespan of these coatings, which makes it a very attractive value proposition and one that is hard to say no to.”

Founded in 2010, Talga Group Ltd. (Perth, Australia) is a battery anode and graphene company that earlier this year announced positive results from real-world marine testing of its Talcoat graphene additive for primers. The additive was specifically formulated for use in marine coatings to boost corrosion resistance, reduce paint loss in aquatic ecosystems, and increase productivity by permitting longer intervals between drydocking. Notably, the dry dispersible additive can be incorporated into coatings on-site, which represents a significant commercial development for GNP products, which typically are supplied in liquid dispersions for good mixing.

In 2019, the additive was supplied premixed in a 2-part epoxy primer from a leading paint supplier and applied to 700 m²/7,535 ft² of a large container ship’s hull as part of a sea trial to evaluate coating performance in a rough ocean environment. (To provide a realistic benchmark, a conventional primer was used elsewhere, with markings distinguishing each product. Both primers were then topcoated.) At the time, this application was said to represent the single-largest graphene application in the world. That ship has since undergone a 15-month inspection and sections coated with the GNP-enhanced primer are said to be providing comparable or better performance than the unenhanced benchmark, which is already showing corrosion marks. A second trial involved having a paint applicator mix the powdered GNP additive on-site into a different 2-part epoxy coating from another leading paint supplier and spray it on a sizeable section of a comparably large vessel. Both trials are still ongoing. Talga notes that pandemic-related travel restrictions continue to impact international shipping, delaying news about how the coating is doing on the second ship. Encouraged by the results, Talga is said to be developing antifouling marine coatings, antibacterial coatings for metals and plastics, anticorrosion coatings for large-volume metallic parts, and barrier coatings for plastic packaging.

Outsized Impact: Graphene Nanoplatelets | Products Finishing (pfonline.com)