The Size Effect of Strenthening for Dispersion-Filled Polymer Nanocomposites

In the case of dispersion-filled polymer nanocomposites, it is assumed that a decrease in the size of dispersed nanoparticles leads to a strong increase in their degree of amplification. However, it is known that reducing the size of nanofiller particles intensifies the process of their aggregation, which ultimately dramatically increases the effective size of the nanofiller in the polymer matrix. Therefore, the question arises which nanofiller is more effective from a practical point of view – one having a small size of the initial particles, but highly aggregated, or another having a relatively large size of nanoparticles, but poorly aggregated. The aim of this work is to answer the above question. We have used two dispersion-filled polymer nanocomposites having the same polymer matrix, but filled with a dispersed filler, which size of the original particles differed by about 15 times. It is shown that the level of aggregation of dispersed nanofiller particles in the polymer matrix of the nanocomposite is controlled by two main factors: the size of its initial particles and the conditions for obtaining the nanomaterial, and the influence of the first factor prevails. The process of nanofiller aggregation significantly affects the level of interfacial adhesion and, as a consequence, the final properties of nanocomposites.