A new method inspired by coral reefs can capture carbon dioxide from the atmosphere and transform it into durable, fire-resistant building materials, offering a promising solution for carbon-negative construction. The approach, developed by University of Southern California researchers draws inspiration from the coral reefs’ natural ability to create robust structures by sequestering carbon dioxide.
“This is a pivotal step in the evolution of converting carbon dioxide,” said a spokesman for the team. “Unlike traditional carbon capture technologies that focus on storing carbon dioxide or converting it into liquid substances, we found this new electrochemical manufacturing process converts the chemical compound into calcium carbonate minerals in 3D-printed polymer scaffolds. As an organism, coral can use photosynthesis to capture carbon dioxide from the atmosphere and convert it into a structure.”
The research team created 3D-printed polymer scaffolds that mimicked coral’s organic templates. They then coated them with a thin conductive layer. These coated structures were then connected to electrochemical circuits as cathodes and immersed in a calcium chloride solution. When carbon dioxide was added to the solution, it underwent hydrolysis to be broken down into bicarbonate ions. These ions reacted with calcium in the solution to form calcium carbonate, which gradually filled the 3D-printed pores. This resulted in the final product, a dense mineral-polymer composite.
“The manufacturing method revealed a natural fire-suppression mechanism of 30 minutes of direct flame exposure,” the spokesman said. “When exposed to high temperatures, the calcium carbonate minerals release small amounts of carbon dioxide that appear to have a fire-quenching effect. This built-in safety feature provides significant advantages for construction and engineering applications where fire resistance is critical.”
Cracked fabricated structures can be repaired by connecting them to low-voltage electricity. Such treatment can rejoin the cracked interfaces and restore the mechanical strength.
After a rigorous life cycle assessment, the researchers found that the manufactured structures featured a negative carbon footprint, revealing that the carbon capture exceeded the carbon emissions associated with manufacturing and operations. The researchers also demonstrated how the manufactured composites could be assembled into larger structures using a modular approach, creating large-scale load-bearing structures; the composite materials could potentially be used in construction and other applications requiring high mechanical resistance.
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