Plant-Based Polymer Repairs Self Through CO2 Reaction

A gap is created in the self-healing polymer that is composed of a hydrogel (dark green) with plant-derived chloroplasts (light green) embedded within it. Bottom: The polymer is exposed to light and its reaction to the carbon dioxide in the air repairs the gap. Photo courtesy of MIT News.

A team made up of chemical engineers from the Massachusetts Institute of Technology (MIT) (Cambridge, Massachusetts, USA) and University of California, Riverside (Riverside, California, USA) has developed a polymer that reacts with carbon dioxide (CO2) in the air in order to regenerate itself. This “self-healing material,” which is designed to mimic the CO2 absorption properties of green plants, has potential applications in a variety of construction and protective coatings projects.

“Imagine a synthetic material that could grow like trees, taking the carbon from the carbon dioxide and incorporating it into the material’s backbone,” says Michael Strano, MIT’s Carbon P. Dubbs Professor of Chemical Engineering and a member of the research team.

The new polymer developed by the MIT and UC Riverside research team is a synthetic gel-like substance made from an aminopropyl methacrylamide (APMA) and glucose-based polymer, an enzyme called glucose oxidase, and chloroplasts. The team obtained the chloroplasts—the specialized subunits, or organelles, within plants that enable them to conduct photosynthesis—from spinach leaves that catalyze the reaction of CO2 to glucose. In addition to its ability to repair itself through exposure to CO2 in the air, this liquid material also hardens and solidifies when exposed to sunlight or indoor lighting, which has the added benefit of making it lightweight enough to save on energy and transportation costs.

The researchers say that the self-repair material could soon be used commercially as a self-healing coating or crack filling, although there is further work to be done before the material is a suitable construction or composite material. Moreover, according to Strano, the material’s ability to consume CO2, as well as the lack of fossil fuels used in its production, has added environmental benefits.

“Our work shows that carbon dioxide need not be purely a burden and a cost,” Strano says. “Making a material that can access the abundant carbon all around us is a significant opportunity for materials science. In this way, our work is about making materials that are not just carbon neutral, but carbon negative.”

The findings from Strano’s team can be found in an article entitled “Polymethacrylamide and Carbon Composites that Grow, Strengthen, and Self‐Repair using Ambient Carbon Dioxide Fixation” in the October 9 edition of Advanced Materials magazine. Their research was supported by the U.S. Department of Energy (Washington, D.C., USA), which will also sponsor a new program directed by Strano to further develop this work.

Source: MIT News,