Two‐Dimensional Seeded Self‐Assembly of a Complex Hierarchical Perylene‐Based Heterostructure

Abstract

A complex two‐dimensional (2D) hierarchical heterostructure was fabricated by a sequential two‐dimensional seeded self‐assembly, which consisted of laterally grown nanotubes from one perylene monomer and terminally elongated nanocoils from a similar perylene monomer on microribbon seeds from a third perylene. Because the nanotube and nanocoil monomers can form kinetically trapped off‐pathway aggregates to prevent self‐nucleation and have similar molecular organizations to different facets of the seeds, the nanotube and nanocoil monomers preferentially nucleate and grow on the seed sides and terminal ends, respectively, to form a complex 2D hierarchical heterostructure. The strategy used in this work can be extended to fabricate other complex nanoarchitectures from small molecules.

Emergent Self‐Assembly Pathways to Multidimensional Hierarchical Assemblies using a Hetero‐Seeding Approach

“…In ap revious work, we demonstrated the formation of nanocoils of PDI 2 from the terminio fm icroribbon seeds of PDI 4. [34] Unseeded self-assembly of 2 yieldeda similar nanocoil morphology from metastable ribbons (Figure 1b and FigureS18) which indicated that the same pathway was followedu nder both sets of conditions. In contrast, seededg rowth of PDI 2 in 1:15 (v/v) chloroform/ethanol using nanotube seeds from PDI 3 in 1:15 (v/v) chloroform/ethanol that have lengthsr anging from 0.2 to 1.2 mm ( Figure 5b)e nabled the nucleation at one terminus of the nanotube seed and epitaxial growth into the nanotubulars tructure ( Figure 5 and FigureS19).…”

“…However, through the use of homo-seeding methodswhichinvolve the addition of as eed with the same compositiona nd morphology as the assembled molecular building block, the nucleation barrier can be bypassed. [14,15,[25][26][27][30][31][32][33][34] In such cases the morphology of the resulting thermodynamically stable assemblies is independento fw hetherg rowth proceeds in the presence or absence of seeds. The analogous use of heteroseeds,w hich possessadifferent composition or morphology to the assembled molecular buildingb lock, is much less explored.…”

“…We previouslyr eported the 1D and 2D self-assembly of PDI 3 in the absence of seeds, the presence of homo-seeds, and hetero-seeds consistingo fm icroribbons from PDI 4.I ne ach case, 3 self-assembled into as imilarn anotube morphology. [34,35] This suggests that PDI 3 likelyh as no other accessible self-assembly pathways between kinetically-trapped microribbons and thermodynamically stable nanotubes. Given that the competition betweenm olecular interactions determines the energy landscape that governs the self-assembly pathways, [28,37] we anticipated that the reduction of the steric hindrance of the substituents in PDI 3 might lead to more relatively stable states.…”

Hierarchical 2D–1D micelles self-assembled from the heterogeneous seeded-growth of rod-coil block copolymers

“…Generally, the hybrid micelles with crystalline cores are realized by adding block copolymers with different core-forming or corona-forming blocks in the seed micelle solution. [25][26][27][28][29] This heteroepitaxial growth process can result in hierarchical nanoassemblies with various morphological features, such as scarf-like micelles with different core-forming blocks in the disk region and tassels. [17][18][19][20][21][22] As for the seeded-growth behavior of the present work, there are several unique qualities.…”

“…The structures can be regulated by varying the corona-forming blocks or the block ratios of added block copolymers. [25][26][27][28][29] However, obtaining the hierarchical hybrid nanoassemblies from the seeded-growth of one identical copolymer system is challenging. In addition, the growth mechanisms of hybrid hierarchical structures, especially the origin of branches and their growth kinetics, still need to be clarified.…”