New insights into sustainable cementitious composites doped with a hybrid system based on zinc oxide and a designable deep eutectic solvent

Deep eutectic solvents (DESs) are an emerging class of materials that show promise for applications as inexpensive “designer” solvents with tunable properties. A detailed review of the current literature reveals a lack of predictive understanding of the microscopic mechanisms that govern the structure−property relationships in this class of solvents. They can dissolve both organic and inorganic compounds, including salts and metal oxides. Zinc oxide is used as a substrate for the synthesis of various task-specific materials, and has excellent antibacterial properties. In this work, both DES and a DES + ZnO combination were used for the first time as admixtures for cement composites, and were shown to improve the final properties of the cement matrix. The materials obtained exhibit good antibacterial properties, even with small amounts of zinc oxide, improved mechanical properties, and good durability when subjected to freezing–thawing cycles.