Morphology of ABCD Tetrablock Copolymers Predicted by Self‐Consistent Field Theory

Abstract

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. magnified image

Theoretical study on morphology of ABCD 4-miktoarm star block copolymer

“…2 have such a high symmetry. But when it comes to the linear copolymers, situations change [28]. There are many different morphologies like LAM 4 (''four-color lamellae''), CSH (coreeshell hexagonal lattice), CST 2 (coreeshell two interpenetrating tetragonal lattice), LAM þ BD (lamellae with beads inside), CS 3 H (''threecolor'' coreeshell hexagonal phase), LAM þ BD 2 (lamellae with ''two-color'' beads inside).…”

“…Meanwhile, many morphologies occurred in the present case disappear, such as, HEX, HEX 2 , HEX 3 , HEX 3i , TET 2 , TET 3 , TET 4 , HEX þ PEP 2 , and HEX þ TET 2 . That shows that the morphology not only depends on the composition of the block copolymer but also relies on its architecture [28].…”

“…After that, Dotera et al [24,25] found that a monodisperse symmetric ABCD star block copolymer melt undergoes a microphase separation by using Monte Carlo simulations. Among these complicated tetrablock copolymers, to our knowledge, the morphologies for the linear ABCA tetrablock terpolymer have been studied theoretically [26,27] and that the end block A is substituted by a different block D has been reported as well, that is ABCD tetrablock quarterpolymer [28]. Takano et al [19] and Takahashi et al [18,29] have synthesized the complex tetrablock quarterpolymer of ABCD type, and the four-phase triple coaxial cylindrical morphology and the four-phase six-layer lamellar structure were observed.…”

Periodic and Aperiodic Tiling Patterns from a Tetrablock Terpolymer System of the A1BA2C Type

“…Takano et al reported a noncentrosymmetric lamellar structure of an ABCA terpolymer, while an O 52 network structure was reported for a tetrablock terpolymer of the ABAC type . Moreover, a four-phase lamellar structure has been found for an ABCD tetrablock quarterpolymer, whereas complex morphologies have been predicted for an ABCD quarterpolymer by SCFT . Furthermore, Meuler et al reported on the O 70 ( Fddd ) network structure of a pentablock terpolymer of the ABCBA type …”

“…14 Moreover, a four-phase lamellar structure has been found for an ABCD tetrablock quarterpolymer, 15 whereas complex morphologies have been predicted for an ABCD quarterpolymer by SCFT. 16 Furthermore, Meuler et al reported on the O 70 (Fddd) network structure of a pentablock terpolymer of the ABCBA type. 17 On the other hand, star-shaped terpolymers of the ABC type have very peculiar structures due to their restricted molecular architectures, and they tend to have structures with assemblies of rods, whose cross sections can produce periodic tiling structures.…”