Unlocking the Potential of CO₂ Capture: A Synergistic Hybridization Strategy for Polymeric Hydrogels with Tunable...

Unlocking CO₂ capture potential remains a complex and challenging endeavor. Here, a blueprint is crafted for optimizing materials through CO₂ capture and developing a synergistic hybridization strategy that involves synthesizing CO₂-responsive hydrogels by integrating polymeric networks interpenetrated with polyethyleneimine (PEI) chains and inorganic CaCl₂. Diverging from conventional CO₂ absorbents, which typically serve a singular function in CO₂ capture, these hybrid PEAC hydrogels additionally harness its presence to tune their optical and mechanical properties once interacting with CO₂. Such synergistic functions entail two significant steps: (i) rapid CO₂-fixing through PEI chains to generate abundant carbamic acid and carbamate species and (ii) mineralization via CaCl₂ to induce the formation of CaCO₃ micro-crystals within the hydrogel matrix. Due to the reversible bonding, the PEAC hydrogels enable the decoupling of CO₂ through an acid fumigation treatment or a heating process, achieving dynamic CO₂ capture-release cycles up to 8 times. Furthermore, the polyethyleneimine-acrylamide-calcium chloride (PEAC) hydrogel exhibits varying antibacterial attributes and high interfacial adhesive strength, which can be modulated by fine-tuning the compositions of PEI and CaCl₂. This versatility underscores the promising potential of PEAC hydrogels, which not only unlocks CO₂ capture capabilities but also offers opportunities in diverse biological and biomedical applications.