Heterogeneous structures in self-assembled bicontinuous networks

Amphiphilic macromolecules and block copolymers form bicontinuous network phases, such as double gyroid and double diamond, held together by supramolecular interactions. Recent advances in nanoscale microscopy allow the visualization of large volumes (beyond ~μm³) containing thousands of unit cells, revealing large-scale features of these networks. However, existing molecular simulations are spatially limited, often covering only a few unit cells. Furthermore, experiments have also identified well-ordered grains exhibiting inhomogeneous strain and defects, such as local changes in network structure (“coordination defects”). To address these limitations, we introduce a coarse-grained model that links network structure to generic features governing self-assembly, namely: (i) mass transport, (ii) space-filling constraints and the associated (iii) steric interactions. We show how model parameters shape individual molecular packing environments, enabling comparisons with molecular theory, as well as predictions of structural correlations and collective response to network inhomogeneities. This approach ultimately allows us to address the assembly of complex network morphologies across scales, including predictions of supramolecular defect interactions.