Effect of Solvent Composition on Calcium–Silicon Ratio, Particle Size, and Morphology of C─ S─ H Nanomaterials and Cement Properties

Synthesized nanocalcium-silicate-hydrate (C─ S─ H) was successfully employed as an accelerator in portland cement. C─ S─ H nanomaterials were produced in this study utilizing a process that used separate nucleation and growth steps with varied solvent compositions. The effects of the water/alcohol volume ratio (W/A) in the combined solvent on the calcium silicon ratio, particle size, morphology of C─ S─ H nanomaterials, and compressive strength of portland cement were studied. The results reveal that when the W/A ratio decreased, the calcium to silicon (Ca/Si) molar ratio reduced, and the morphology of the C─ S─ H nanomaterials turned from micalike to mixed lamellar and granular, then to granular with a wrinkled surface, and finally to foillike. When the W/A was 3∶1, the small particles (100 nm) of C─ S─ H nanomaterials had the highest W/A, whereas the large particles (>200 nm) had the highest W/A. C─ S─ H nanomaterials offered calcium silicate hydrate nucleation sites, altered C─ S─ H gel development modes, and enhanced the number of hydration products. The composition, particle size, and shape of C─ S─ H nanomaterials all influenced the compressive strength of the cement paste.