Mesoatomic distortions and subdomain morphology in DG and DD networks

Slice-and-view scanning electron microscopy tomography was used to assess the 3D structural features of double gyroid (DG) and double diamond (DD) networks formed with two strongly segregated polystyrene-b-polydimethylsiloxane samples (χN~180). Due to shrinkage forces from solvent evaporation, both nominally cubic structures showed variable-triclinic unit cells by X-ray scattering and 3D reconstruction. The deformation is accommodated by non-affine modes of sub-unit cell symmetry breaking whereby the relatively soft strut lengths and diameters deform while the angular geometry between adjacent struts is stiff. Measurements included unit cell parameters, angular geometry of the minority network skeleton, the curvatures of the Intermaterial Dividing Surface (IMDS) and the subdomain thicknesses as measured from the IMDS to the skeletal graph or to the medial surfaces for both tubular (minority) and matrix (majority) phases. The distributions of medial thickness for the minority component are much shorter and more narrowly distributed than for the corresponding skeletal metrics. These subdomains morphology metrics are compared to self-consistent field predictions, suggesting