Supramolecular Polymer Self‑Assembly Modulated by Gradient‑Like Monomer Architectures

Supramolecular polymerization offers a powerful strategy for creating soft nanomaterials with diverse applications by leveraging steric repulsions and directional interactions. However, the thermodynamics of polymerization typically favors high-aspect-ratio motifs, that are incapable of self-termination, limiting the formation of complex morphologies. Here, we present a general approach to achieve self-regulating supramolecular self-assembly by tailoring molecular architectures with gradients of grafted side chains. Specifically, amphiphiles consisting of branched hydrophobic aromatic residues and peptide backbones are spatially patterned with oligoethylene glycol (OEG) side chains. Experimental results show that forward gradients of OEG yield finite-length filaments, while the backward gradients lead to long, bundled structures. Molecular dynamics simulations reveal that gradient-induced modulations of local steric interactions between amphiphiles alter OEG domain packing, which ultimately influence assembly. Finally, we combine the obtained insights into a scaling theory to enable a priori prediction of gradient-mediated supramolecular polymerization. This integrated experimental, simulation, and theoretical approach establishes a critical link between amphiphile architecture and packing compatibility, enabling the design of functional supramolecular materials with tunable properties.