UC uses eggshell waste to develop innovative radon-sealing paint

A research team from the Faculty of Science and Technology of the University of Coimbra (FCTUC), in collaboration with the Instituto Pedro Nunes (IPN), has developed an innovative paint by adding eggshell waste, capable of sealing the passage of radon gas.

According to Teresa Vieira, Professor at the Department of Mechanical Engineering (DEM) at FCTUC, "The ShellutionPlus project aimed to find an innovative and sustainable biogenic mineral filler for new paint and paper formulations, addressing the challenges of food waste management and processing while enhancing the technical performance of the new products."

The difference between the calcium carbonate in a hen's egg and that which occurs in nature or is synthetically produced "is the nanoporosity in the eggshell, which is maintained during the ink's production. This helps to improve specific optical properties and enhances the barrier effect against the passage of radon gas," explains João Duarte, a researcher at IPN, noting that this new ink formulation has been patented.

"In the paper industry, the potential of biogenic mineral fillers to improve mechanical resistance properties has been demonstrated," said Paulo Ferreira, a professor at the Chemical Engineering Department (DEQ), who coordinated the FCTUC project regarding paper applications.

Despite the promising results, this innovation still faces several challenges and requires further optimisation. Market entry is hampered by insufficient production of eggshells and the challenge of separating their organic and inorganic components.

"Nevertheless, in the future, the impact should be positive both for those who produce the waste, who can dispose of it and avoid it going to landfill, and for those who receive it, who get an improved product made from waste, placing the industry at the forefront of sustainability," they conclude.

The project "SHELLUTIONPLUS - Application of nanoporous eggshell in paints and paper fillers" was coordinated by researcher João Duarte and FCTUC professors Paulo Ferreira and Teresa Vieira.