Topological defects in tubular network block copolymers

Materials based on the double gyroid multicontinuous tubular structure can exhibit exotic properties due to the unique 3D network structure. The nature, frequency and potential influence of topological defects present in the interpenetrating gyroid networks on various physical properties is an open question. We examined a polystyrene - polydimethylsiloxane diblock copolymer possessing the double gyroid morphology in order to identify and classify the types of topological defects present. The large volume reconstructions were made by sequentially ion beam milling and low voltage electron beam imaging. Different types of local point-like topological defects were found including node functionality defects, network breaks and network-network joints (bridges) as well as two types of intra-network loop defects. Such topological defects will influence properties ranging from charge and mass transport, to wave propagation and band gaps, and battery performance in materials with the gyroid structure.