Figure 5.

Number density maps of nanocarbon-HDPE composites with fillers consisting of (a) C₆₁, (b) C₁₈₁, (c) C₁₀₈₇, and (d) C₂₁₆₁ graphene flakes, as well as (e) C₅₄₀ fullerenes. A lower cutoff is imposed on the number density to eliminate uninteresting portions of the polymer matrix and highlight only the higher-density regions. As seen in the maps, larger flakes induce increased ordering of polymer chains at the filler–matrix interface as well as higher local densification of the polymer chains in these regions. Similar but reduced local densification also is evident at the C₅₄₀–matrix interface.