Figure 1.

Morphologies of SF nanoparticles and the assembled nanofibers on GO nanosheets. (A–H) AFM morphology of SF nanoparticles (A,B), GO nanosheets (C,D), and SF/GO solutions with GO contents of 2% (E,F) and 10% (G,H). (B,D,F,H) Magnified view of a typical area in (A,C,E,G), respectively. When the GO content was 2%, the schematic of necklace-like SF nanofibrils was shown at the bottom left of (F), and the schematic of solid SF nanofibrils when GO contents was 10% was shown at the bottom left of (H). The section analysis in (I) shows that SF nanoparticles had a height of 3.7 or 1.8 nm. The section analysis in (J) shows that a GO nanosheet had an extremely thin and smooth characteristic surface with the height about 1 nm. The section analysis in (K) shows that at 2% of GO, the height of necklace-like SF particle assemblies at the thicker area [purple dotted line in (F)] can reach up to 4 nm (as shown by the purple dotted curve) and the height of those at the thinner area [green line in (F)] was about 1.5 nm (as shown by the green curve). The section analysis in (L) shows that when GO content is increased to 10%, the newly formed SF nanofibrils had a height of 0.3 nm.