Morphological stabilization efficiencies of nanoparticles toward flowing polymer blends: Role of roughness and viscosity ratio

Compatibilization efficiency of nanoparticles (NPs) toward polymer blends has been reported to depend on the viscosity ratio. However, this effect is seldom considered in the case of rough NPs. In this study, fluorescently labeled hydrophobic silica (SiO 2 ) NPs with different roughness were synthesized, and the morphological stabilization efficiencies of these NPs toward flowing polyisobutylene/polyethylene glycol blends were evaluated in-situ by confocal laser scanning microscopy . The surface roughness was found to affect the stacking behavior of NPs at the blend interface and NPs with larger roughness were more effective in stabilizing the morphology of flowing blends. Moreover, the morphological stabilization efficiencies of rough NPs were found to depend largely on the viscosity contrast of blend components, which determined the coverage of NPs at the interfacial area of blends and could be tailored by the strength of the shear flow. Therefore, the viscosity ratio should be an important parameter to be considered when evaluating the compatibilization efficiency of rough NPs.