Fig. 7: Formation of scarf-like SP heterostructures via hetero-seeding-induced secondary nucleation.

a Schematic illustration for formation SP heterostructures obtained by adding PE-PDI 2D platelets to 2EH-PDI dormant monomers via secondary nucleation. b Time-dependent variation in the absorbance of 2EH-PDI dormant monomers at 515 nm after adding the 50 mol% of PE-PDI seeds (blue) and spontaneous polymerization of 2EH-PDI (red) is shown for comparison. c FE-SEM image of SP heterostructures synthesized via hetero-seeding approach by adding 50 mol% PE-PDI 2D platelets seeds to 2EH-PDI dormant monomers. d log-log plot of the half-times of hetero-seeding supramolecular polymerization versus the original concentration of 2EH-PDI. Symbols represent the experimental data; solid line is a power law fit. This fit shows a linear trend with a slope of −3.46 ± 0.09 called exponent coefficient (γ), which suggests a monomer-dependent, seed-induced secondary nucleated supramolecular polymerization process. e Kinetic profiles of the concentration-dependent hetero-seeding experiments, obtained by monitoring the absorbance at 480 nm of 2EH-PDI, at constant seed concentration ((PE-PDI)_{concentration}: 25 μM) while varying the dormant monomer concentrations of 2EH-PDI to 40 μM, 45 μM, 50 μM, and 62 μM. The sigmoidal growth of the 2EH-PDI dormant monomers indicates a secondary nucleation-elongation process. f Bright-field microscopy images showing time-dependent growth of SP heterostructures after mixing the 50 mol% of PE-PDI seeds to the 2EH-PDI dormant monomers in MCH* (encircled with dashed lines of blue, pink, and magenta). g Kinetics of growth of SP heterostructures from the PE-PDI seeds encircled in blue, pink and magenta dashed lines in panel (f) was tracked via image analysis to follow the increase in pixel area corresponding to the growth of new fibrils from the seeds. The image in c is representative of four experiments, and the images in f are representative of three experiments.