Non-affinely distorted Double Gyroid structures in Solvent-vapor-annealed Polystyrene-b-Poly(methyl methacrylate) Films
발표자
()
초록
내용
In this study, we investigate symmetry-breaking nature of double gyroid structure in solvent-vapor-annealed polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA) films. During the optimized solvent vapor annealing process, as-cast morphology transforms into a cubic gyroid structure via transient cylinders in a swollen state. Immediately upon rapid deswelling, however, the PS-b-PMMA films undergo a contraction along the direction normal to the substrate. Interestingly, we reveal the non-affine distortion in the contracted gyroid structure by grazing-incidence small-angle X-ray scattering patterns that involve diffraction spots forbidden in a cubic gyroid structure. We further elucidate the symmetry-breaking features of gyroid structures by close observation of electron density difference maps. Moreover, level-set reconfiguration based on X-ray results suggest inversion symmetry-breaking in the PS-b-PMMA gyroid films that can lead to possible application of optical Weyl photonic crystals.