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(1.2) to be consistent with the plumber's nightmare(3) morphology. The solvent casting process used to form the material caused it to shrink uniaxially by similar to 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.