Toward tough and sustainable hydrogel-cement composites via biomineralization-inspired strategy

Abstract Enhancing the toughness of cement-based materials is key to extending their service life, reducing carbon emissions, and achieving sustainable development of the building materials industry. Drawing inspiration from the biomineralization in nature, a novel hydrogel-cement composite with an interpenetrating organic-inorganic structure was developed, followed by a rapid polymerization to pre-construct a continuous organic network, and a sequential deposition of inorganic cement hydrates on that, in order, thereby endowing the obtained composites with a honeycomb-like porous structure. Compared with normal cement paste, the hydrogel-cement composites (hydrogel content: 2.4–13.7 wt %) showed more than 30 times higher flexural toughness, and 60% increase in compressive strength. Besides, the composites exhibited high porosity characteristics consisting of closed micropores, which contributed to the 90% lower thermal conductivity of the composites than normal cement paste. In conclusion, these findings open a new window to toughen and functionalize cement-based materials with hydrogels using a biomineralization-inspired strategy.