A Re-Evaluation of the Morphology of a Bicontinuous Block Copolymer−Ceramic Material

The structures of a poly(isoprene-block-ethylene oxide) (PI-b-PEO) block copolymer-directed aluminosilicate mesostructure and the resulting ceramic material obtained from calcination were studied via small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). The PI minority phase (volume fraction 0.36) formed a continuous network of channels, previously reported , to be consistent with the plumber's nightmare morphology. The solvent casting process used to form the material caused it to shrink uniaxially by ∼30%, deforming the network structure within it. Calculated structure factors for constant-curvature and constant-thickness models of a distorted double gyroid structure are consistent with SAXS from the material, while [100] and [111] projections of the distorted double gyroid structure match the TEM data. Because the structural data from the material is most consistent with a distorted version of the double gyroid morphology, the previous assignment of the plumber's nightmare morphology must be reconsidered. Approaches for structural assignment are also discussed.