Mesoscale structure of nanoparticles in attractive polymer nanocomposites

Dispersing nanoparticles (NPs) into polymers results in unexpected and remarkable changes in macroscopic properties of the resulting composites (PNCs). The properties of PNCs are primarily controlled by the polymer-NP interaction that also determines the NP dispersion state. Repulsive or neutral polymer-NP interaction often leads to phase-separated or self-assembled superstructures and their percolation within the soft matrix dominates the mechanical reinforcement. Favourable polymer-NP interaction facilitates polymer adsorption on NP surfaces and, in most cases, results in good dispersion of bare particles in polymers. However, the detailed mechanism is not well-understood.We believe that a combination of SANS and SESANS can yield significant information on these structures over ~5 orders of magnitude. Our goal ss to unravel such ‘hidden network’ of particles by SANS and SESANS.