Investigating the healing-mechanical behavior of glass fibers/epoxy self-healing composites containing microcapsules and silica nanoparticles under the shear loading

In this research work, the simultaneous effect of silica nanoparticles and microcapsules containing healing agent on the healing-mechanical behavior of glass fibers/epoxy self-healable composites was investigated. To do so, the silica nanoparticles with the different percentages (1, 3 and 5 wt.%) into the smart composite containing the 14 wt.% capsulated healing agent were dispersed. For destructing the smart composites, the quasi-static penetration test with the damage force of 3300 N was used. Also, for assessing the healing mechanical performances, the interlaminar shear strength test was used. As well as, the field emission scanning electron microscope (FESEM) was used for characterizing the related mechanisms, healing performance and interaction of nanoparticles into the composite structure. The obtained results from quasi-static penetration test showed that adding the silica nanoparticles caused to reduce the level of created damages into the composite under damage force, which finally resulted to improve the healing performance. The lowest created damage was seen in the sample containing 1 wt.% silica nanoparticles. Based on the obtained results, the composite containing 5 wt.% silica nanoparticles with healing efficiency of 118.2% had the maximum healing efficiency, as compared with other composites. The creation of V shape lines and agglomeration of silica nanoparticles as effective mechanisms on the shear strength of self-healable composites were characterized by FESEM.