Direct measurement of interfacial curvature distributions in a bicontinuous block copolymer morphology

Self-consistent field theory predicts that the complex phase behavior of block copolymers does not originate solely from the interface seeking constant mean curvature as once thought, but instead reflects competing minimization of interfacial tension and packing frustration. To test this prediction, we directly measure interfacial curvature distributions from a 3D image reconstruction of the bicontinuous gyroid morphology. Results obtained here reveal that the gyroid interface is not constant mean curvature and confirm the importance of packing frustration in the stabilization of such complex nanostructures. PACS numbers: 68.35.Ct, 42.30.Wb, 47.20.Hw, 83.70.Hq.