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

Abstract Unlocking CO 2 capture potential remains a complex and challenging endeavor. Here, a blueprint is crafted for optimizing materials through CO 2 capture and developing a synergistic hybridization strategy that involves synthesizing CO 2 ‐responsive hydrogels by integrating polymeric networks interpenetrated with polyethyleneimine (PEI) chains and inorganic CaCl 2 . Diverging from conventional CO 2 absorbents, which typically serve a singular function in CO 2 capture, these hybrid PEAC hydrogels additionally harness its presence to tune their optical and mechanical properties once interacting with CO 2 . Such synergistic functions entail two significant steps: ( i ) rapid CO 2 ‐fixing through PEI chains to generate abundant carbamic acid and carbamate species and ( ii ) mineralization via CaCl 2 to induce the formation of CaCO 3 micro‐crystals within the hydrogel matrix. Due to the reversible bonding, the PEAC hydrogels enable the decoupling of CO 2 through an acid fumigation treatment or a heating process, achieving dynamic CO 2 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 CaCl 2 . This versatility underscores the promising potential of PEAC hydrogels, which not only unlocks CO 2 capture capabilities but also offers opportunities in diverse biological and biomedical applications.