Surface treatment of halloysite nanotubes with sol-gel reaction for the preparation of epoxy composites

Halloysite nanotubes (HNTs) are naturally occurring aluminosilicates that have received attention for their high aspect ratio and low cost, which makes them suitable for commercial applications. HNTs provide good mechanical properties when applied in epoxy resins as fillers. The mechanical and thermal properties of HNTs are further enhanced by surface treatment using the sol-gel method. In this study, the modified surfaces of HNTs (m-HNTs) were investigated using scanning electron microscopy and transmission electron microscopy. The amounts of m-HNTs were varied in the epoxy composition (binder) that was comprised of a latent hardener, a reaction accelerator, and an epoxy resin. The physical properties of the cured composites with different amounts of HNTs and m-HNTs were measured using a universal testing machine (UTM) to analyze the effect of HNT and m-HNT on the flexural strength. Furthermore, the thermomechanical analysis of the cured composites with m-HNT showed that the dimensional changes of the composites were lower than those of epoxy composites with HNT particles.