Dispersion Stability and Cement Hydration of Wool Keratin-Graphene Oxide Complexes in Alkaline/Calcium Environments

Controllable setting retardation and early age strength development of concrete are prerequisites for various engineering applications. This study utilized waste wool to extract wool keratin (WK) and investigated the effect of the WK-to-graphene oxide (GO) mass ratio on the dispersion stability of GO in high-alkalinity and rich-calcium environments, as well as its impact on cement hydration thermodynamics, aiming to elucidate the multiscale regulation mechanism of WK-GO complexes under harsh conditions. Characterization via ATR-FTIR/Raman spectroscopy, UV–vis, multiple light scattering, isothermal calorimetry, and molecular dynamics (MD) simulations revealed that KG10 provides markedly improved dispersion stability in harsh environments. Specifically, MD simulations visualized that the dense WK layer significantly expands the GO interlayer spacing (>20 Å) and overcomes Ca 2+ -bridging via enhanced steric hindrance. However, it severely inhibits hydration due to a triple-action barrier (comprising solution-phase Ca 2 + chelation, active site shielding, and ion diffusion hindrance). In contrast, KG1 maintains moderate dispersion stability through π-π stacking and enhances hydration through optimized adsorption, improved nucleation, and accelerated growth via preserved GO activity. This work unveils a separable regulation mechanism between ″dispersion stability″ and ″hydration activity″, providing a paradigm for the multifunctional design of cement-based materials.