Enhanced self-healing performance of cementitious materials using nano-SiO2 modified ethyl cellulose microcapsules

This study investigates the enhancement of self-healing properties in cementitious materials through the integration of nano-SiO 2 (NS)-modified ethyl cellulose (EC) microcapsules (MC). By utilizing an organic-inorganic hybridization approach, we created a stable three-dimensional cross-linked structure composed of NS and EC, resulting in a controllable system that enhances the triggering efficiency of the microcapsules. Comprehensive microscopic characterization of the material composite MC was performed, encompassing evaluations of morphology, elemental composition, chemical structure, and particle size. The results demonstrate that the incorporation of NS significantly increases both the surface roughness and particle size of the MC, thereby improving mechanical interlocking with the cement matrix. Optimal self-healing performance was observed with an NS content of 6 % of EC, achieving an impressive compressive strength recovery rate of 151.2 % under pre-damage conditions corresponding to 80 % σ max . Moreover, the pore healing rate also peaked at this NS concentration, highlighting a synergistic effect on the self-healing capabilities of the cementitious composites. Furthermore, observations regarding crack healing confirm that the self-healing mortar formulated with NS-modified MC demonstrates superior crack closure performance compared to unmodified MC. These findings highlight the positive correlation between NS content and enhanced self-healing capabilities, offering valuable insights for the advancement of self-healing systems in cement-based materials.