Symmetry-breaking in double gyroid block copolymer films by non-affine distortion

Seungyun Jo, Haedong Park, Taesuk Jun, Kwangjin Kim, Hyunsoo Jung, Sungmin Park, Byeongdu Lee, Seungwoo Lee, Du Yeol Ryu

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


Soft-matter bicontinuous networks find a double gyroid structure from block copolymer (BCP) self-assembly. A gyroid structure composed of dissimilar blocks has proven its potential as a soft crystal capable of tuning structural periodicity and symmetry, of which the lattice dimension is variable with molecular weight of the polymer. Using an asymmetric polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA), here we show that the self-assembled gyroid films formed via a solvent vapor annealing (SVA) process undergo unique structural distortion due to directional deformation immediately upon deswelling. During the SVA process with PS-b-PMMA films, transient cylinders developed from the as-cast morphology transform into a cubic gyroid structure in a swollen state. Rapid and spontaneous deswelling processes ̶ the manners in which the films contract along the z-direction while retaining an enlarged lateral dimension of the cubic form ̶ lead to triclinic gyroid structures with z-directional contraction ratios (Cz) of 2.5 and 2.0, respectively. Our X-ray analysis reveals that the deswelling process of the swollen gyroid films produces a notable symmetry-breaking in non-affine gyroid structure that elicits several forbidden reflections such as {110} and {200} reflections. For further characterization of the symmetry-breaking, we delineate the structural features of noncubic gyroid films by computing electron-density difference maps assisted with X-ray measurements. Level-set approach is accordingly developed to quantitate the structural characteristics of the maps in terms of inversion symmetry-breaking, suggesting its possible application to optical Weyl photonic crystals.

Original languageEnglish
Article number101006
JournalApplied Materials Today
Publication statusPublished - 2021 Jun

Bibliographical note

Funding Information:
GISAXS measurements were performed at Pohang Accelerator Laboratory (Korea) and Argonne National Laboratory (US) supported by the US department of Energy , Office of Basic Energy Sciences, under contract no. DE-AC0206CH11357 . This research was supported by Samsung Research Funding & Incubation Center of Samsung Electronics under Project Number SRFC-MA1801-04.

Publisher Copyright:
© 2021 Elsevier Ltd


  • Gyroid
  • Non-affine distortion
  • Solvent vapor annealing
  • Symmetry-breaking
  • Weyl point
  • Z-directional contraction

ASJC Scopus subject areas

  • Materials Science(all)


Dive into the research topics of 'Symmetry-breaking in double gyroid block copolymer films by non-affine distortion'. Together they form a unique fingerprint.

Cite this