Rheological and mechanical behavior of blend-based polymer nanocomposites containing Janus and non-Janus silica nanoparticles

In this study, the effects of Janus and non-Janus silica nanoparticles on the rheological and mechanical properties of blend-based polymer nanocomposites were investigated. The Janus nanoparticles were synthesized in O/W Pickering emulsion via desymmetrization process in two stages while a simple surface modification stage was used to prepare homogenously modified nanoparticles. The blend samples were prepared using polystyrene (PS) and polymethylmethacrylate (PMMA), and accordingly, (3-aminopropyl)triethoxysilane (APTES) and hexadecyltrimethoxysilane (HDTMS) were used, as surface modification agents, to enhance the compatibility of the nanoparticles with polymer phases. After molding into suitable pieces, the samples were subjected to rheology and tensile tests in order to investigate their characteristics in both melt and glassy states. The morphology and dispersion location of the nanoparticles were investigated using light microscopy, and the results were compared to some related data from the literature. Comparing the results of the samples containing Janus and non-Janus nanoparticles revealed that the Janus nanoparticles were very effective in enhancing the processibility and mechanical properties (e.g., tensile modulus and strength) of the PS/PMMA blend. Moreover, it was found that the negative effects of the aggregation/agglomeration of the nanoparticles were more significant in the case of Janus nanoparticles located at the polymer/polymer interface.