Summary: We studied the two‐dimensional (2D) microphase‐separated morphology of linear ABCD tetrablock copolymers by self‐consistent field theory. By varying the interaction parameters and the compositions, we found at least twelve structures, two of which – “four‐color” lamellae and “three‐color” core‐shell hexagonal phase – prove the existing experimental observations. These morphologies were discussed in correlation with the volume fraction of the components and the interaction parameters. A specific behavior of symmetrical tetrablock copolymers, i.e., fA = fD and fB = fC, is that the stable phases are lamellae, which is different from symmetrical ABC triblock copolymer having order‐to‐order transition. These results are helpful for the design of new block copolymer‐based nanomaterials.
