Direct visualization of the nanoparticle rearrangement of polymer nanocomposites under deformation by scanning electron microscopy

Understanding the influence of the external deformation on the microstructure rearrangement of polymer nanocomposites is crucial for polymer nanocomposites processing. Although small angle scatterings provide an important characterization on the dispersion state of NPs, they offer little insights on the structural changes of the PNCs at the single nanoparticle level that directly link to the polymer-nanoparticle interaction. In this work, the roles of the external deformation on the spatial rearrangement of individual particles or nanoparticle clusters will be mapped out through a combination of scanning electron microscopy and rheology. While the affine deformation of PNCs holds macroscopically, the presence of nanoparticles significantly modifies the movement of the trace particles deviating from the applied strain field. These results imply a strong distortion and highly heterogeneous deformation field for PNCs at the nanoscale and highlight the complex polymer-nanoparticle interactions at the nanoscale.