Seeing mesoatomic distortions in soft-matter crystals of a double-gyroid block copolymer. Academic Article uri icon

abstract

  • Supramolecular soft crystals are periodic structures that are formed by the hierarchical assembly of complex constituents, and occur in a broad variety of 'soft-matter' systems1. Such soft crystals exhibit many of the basic features (such as three-dimensional lattices and space groups) and properties (such as band structure and wave propagation) of their 'hard-matter' atomic solid counterparts, owing to the generic symmetry-based principles that underlie both2,3. 'Mesoatomic' building blocks of soft-matter crystals consist of groups of molecules, whose sub-unit-cell configurations couple strongly to supra-unit-scale symmetry. As yet, high-fidelity experimental techniques for characterizing the detailed local structure of soft matter and, in particular, for quantifying the effects of multiscale reconfigurability are quite limited. Here, by applying slice-and-view microscopy to reconstruct the micrometre-scale domain morphology of a solution-cast block copolymer double gyroid over large specimen volumes, we unambiguously characterize its supra-unit and sub-unit cell morphology. Our multiscale analysis reveals a qualitative and underappreciated distinction between this double-gyroid soft crystal and hard crystals in terms of their structural relaxations in response to forces-namely a non-affine mode of sub-unit-cell symmetry breaking that is coherently maintained over large multicell dimensions. Subject to inevitable stresses during crystal growth, the relatively soft strut lengths and diameters of the double-gyroid network can easily accommodate deformation, while the angular geometry is stiff, maintaining local correlations even under strong symmetry-breaking distortions. These features contrast sharply with the rigid lengths and bendable angles of hard crystals.

published proceedings

  • Nature

altmetric score

  • 40.33

author list (cited authors)

  • Feng, X., Burke, C. J., Zhuo, M., Guo, H., Yang, K., Reddy, A., ... Thomas, E. L.

citation count

  • 39

complete list of authors

  • Feng, Xueyan||Burke, Christopher J||Zhuo, Mujin||Guo, Hua||Yang, Kaiqi||Reddy, Abhiram||Prasad, Ishan||Ho, Rong-Ming||Avgeropoulos, Apostolos||Grason, Gregory M||Thomas, Edwin L

publication date

  • November 2019

published in