Halloysite–epoxy nanocomposites with improved particle dispersion through ball mill homogenisation and chemical treatments

This paper presents experimental studies aimed to achieve homogeneous mixtures of halloysite nanotubes (HNTs) with epoxies and halloysite–epoxy nanocomposites through ball mill homogenisation and chemical treatments. It was demonstrated that ball mill homogenisation and potassium acetate (PA) treatment were effective approaches to reduce the size of halloysite particle clusters in the epoxy matrix. However, silane and cetyl trimethyl ammonium chloride (CTAC) treatments, particularly the latter, were found to increase the possibility of particle agglomeration. With the improvement in particle dispersion in epoxies, enhancements in the mechanical properties of the halloysite–epoxy nanocomposites were achieved, which were attributed to several mechanisms including interactions between the advancing crack and halloysite particle clusters, interfacial debonding, halloysite tube breakage and pull-out.