Durable cement/cellulose nanofiber composites prepared by a facile approach

This study developed a facile methodology for preparation of nanoscale dispersion of cellulose nanofibers (CNFs). A suite of methodologies was proposed for the first time to gauge the dispersion quality of CNFs, which was crucial to the subsequent compounding with cement to prepare nanocomposites. Being compatible with cement through interfacial bonding between –COO ^- of CNFs and Ca ²⁺ of cement, CNFs improved the compressive strength of cement by 18% at 0.096 wt% and flexural strength by 21% at 0.480 wt%. Reinforcing mechanisms were explained in terms of the hydration, pore structure and morphologies of the nanocomposites. CNFs at 0.096 wt% significantly decreased the pore volume of cement from 72.66 mm ³/g to 51.39 mm ³/g and reduced the cement water absorption from 17.23% to 10.60%, which was attributed to the enhanced microstructural densification and pore-size refinement.