Effect of Size Asymmetry of Latex Nanoparticles on Formation and Properties of Nanocolloidal Gels

The study of the fundamental principles of gelation of colloidal nanoparticles (NPs) advances the understanding of the formation of colloidal systems of living organisms. In this paper, the effect of particle size for a binary system of oppositely charged latexes on the experimental parameters of the system, including the gelation region, rheological parameters and cluster size, is considered for the first time. It is shown that the gelation regions in the phase diagrams for asymmetric particles are symmetric with respect to the ratio of charge and surface area of the particles. It was found that asymmetric particles form denser gels compared with the same concentration of symmetrical particles. This work provides insight into the gelation of asymmetric NPs, which is important for numerous applications, including their utilization in colloidal gels as ink for additive manufacturing and as scaffolds for cell growth, as well as understanding the fundamental aspects of the formation of bio-colloids.