Research progress of different kinds of nanocellulose-modified cementitious materials: a review

Nanocellulose, a nanostructured cellulose with high modulus, large specific surface area, and excellent mechanical properties, has shown great potential in cementitious materials. This study first presents a bibliometric analysis of research on nanocellulose-modified cementitious materials and then comprehensively reviews four nanocellulose types, namely, cellulose nanofibers, cellulose nanocrystals, bacterial cellulose, and cellulose filaments. Their effects on the mechanical performance, hydration, shrinkage, rheological behaviour, microstructure, and durability of cementitious materials are compared and discussed. The results indicate that different nanocellulose types influence cementitious materials in different ways. Appropriate incorporation of nanocellulose, together with suitable mixture parameters such as water-to-cement ratio, supplementary cementitious materials, and mix design, can effectively improve the mechanical, rheological, and durability-related properties of cementitious composites. Finally, promising application scenarios, such as oil well cement and dental materials, are highlighted, while major technical bottlenecks, including dispersion difficulties caused by nanoscale agglomeration and alkaline instability due to glycosidic bond hydrolysis, are discussed.