Carbonated-water-based paint acts like high-performance coating

Replacing solvent-based paints with greener, water-based counterparts sounds nice, but the performance of those alternatives just doesn’t cut it for demanding applications in the furniture or automotive industry. Now, researchers have come up with a waterborne coating that behaves more like a solvent-based paint. In a refreshing twist, the solvent is carbonated water.

Unlike environmentally harmful oil- or solvent-based paints, in which the film-forming polymer that coats a surface starts fully dissolved, water-based latex paints are a suspension of microparticles. “In theory those particles are supposed to merge together to make a continuous film, but they don’t do it very well,” says Philip G. Jessop, who led the work. It’s hard to get a glossy finish with latex paints, and the coatings are damage prone.

To make their new paint, Jessop, graduate student Jaddie Ho, and their colleagues at Queen’s University started with a carbon dioxide-responsive polymer (Green Chem. 2018, DOI: 10.1039/c8gc00130h). Its charged side chains allow it to dissolve in carbonated water, but once applied to a surface, the water and CO₂ evaporate and the polymer becomes neutral, creating a glossy, hydrophobic coating. The team added cross-links between polymer chains to further improve durability, and that coating had better resistance to water and abrasion than a commercial latex paint purchased at Home Depot.

Because of its increased toughness, this paint might be suitable for a broader range of applications compared with traditional latex paints, including appliances and office furniture, says Phillip G. Phillips, president of coatings consulting group Chemark. Coatings expert Mohamed S. El-Aasser of Lehigh University praised the novelty of the carbonated solvent. While he notes there’s a long way to go between a proof-of-concept study and industrial-scale production, he’s optimistic the team can address formulation and other challenges.

The researchers have applied for a patent on the coatings and are collaborating with color technology firm Lorama Group. Jessop notes that because the paint’s CO₂ pressure is equal to atmospheric pressure, any future containers of the product sadly won’t make that satisfying soda-can hiss when opened.