Polymethacrylamide and Carbon Composites that Grow, Strengthen, and Self‐Repair using Ambient Carbon Dioxide Fixation

Abstract Plants accumulate solid carbon mass and self‐repair using atmospheric CO₂ fixation from photosynthesis. Synthetic materials capable of mimicking this property can significantly reduce the energy needed to transport and repair construction materials. Here, a gel matrix containing aminopropyl methacrylamide (APMA), glucose oxidase (GOx), and nanoceria‐stabilized extracted chloroplasts that is able to grow, strengthen, and self‐repair using carbon fixation is demonstrated. Glucose produced from the embedded chloroplasts is converted to gluconolactone (GL) via GOx, polymerizing with APMA to form a continuously expanding and strengthening polymethacrylamide. The extracted spinach chloroplasts exhibit enhanced stability and produce 12 µg GL mg⁻¹ Chl h⁻¹ after optimization of the temporal illumination conditions and the glucose efflux rate, with the insertion of chemoprotective nanoceria inside the chloroplasts. This system achieves an average growth rate of 60 µm³ h⁻¹ per chloroplast under ambient CO₂ and illumination over 18 h, thickening with a shear modulus of 3 kPa. This material can demonstrate self‐repair using the exported glucose from chloroplasts and chemical crosslinking through the fissures. These results point to a new class of materials capable of using atmospheric CO₂ fixation as a regeneration source, finding utility as self‐healing coatings, construction materials, and fabrics.