Abstract:The disorder to order transition of comb copolymer A
m+1(BC)
m
is investigated by the self-consistent field theory. The interaction parameters between the three different blocks are considered by varying the composition of the comb triblock copolymer with the side chain number m = 1 and 3. As the side chain number m increases, the Flory–Huggins interaction parameter of disorder to order transition (DOT) increases and the lowest DOT occurs when the volume fractions of blocks A, B, and C are approximately equal… Show more
“…By comparing these three figures, we also can see that with the increasing of comb side chain number m , the χN of DOT increases largely, which corresponds to the lower temperature to microphase separate, i.e., the system becomes more stable. We can see that the χN of DOT is larger when the coil-comb copolymer has the longer block B or longer block C. This result is different from our previous research on the DOT of A m + 1 (BC) m [46] because the topological structure between these two kinds of copolymer is different. In this condition, block A is much free and only one end is confined by block B, while blocks B and C are much restricted by the junctions.Fig.…”
The disorder to order transition and the ordered patterns near the disordered state of coil-comb copolymer A-b-(Bm + 1-g-Cm) are investigated by the self-consistent field theory. The phase diagrams of coil-comb copolymer are obtained by varying the composition of the copolymer with the side chain number m = 1, 2, and 3. The disorder to order transition is far more complex compared with the comb copolymer or linear block copolymer. As the side chain number m increases, the Flory-Huggins interaction parameter of disorder to order transition (DOT) increases and the lowest DOT occurs when the volume fractions of blocks A, B, and C are approximately equal. When one component is the minority, the disorder to order transition curve is similar with binary copolymer, but the curve shows the asymmetric property. The comb copolymer is more stable with larger side chain number m and shorter side chain. The ordered patterns from the disordered state are discussed. The results are helpful for designing coil-comb copolymers and obtaining the ordered morphology.
“…By comparing these three figures, we also can see that with the increasing of comb side chain number m , the χN of DOT increases largely, which corresponds to the lower temperature to microphase separate, i.e., the system becomes more stable. We can see that the χN of DOT is larger when the coil-comb copolymer has the longer block B or longer block C. This result is different from our previous research on the DOT of A m + 1 (BC) m [46] because the topological structure between these two kinds of copolymer is different. In this condition, block A is much free and only one end is confined by block B, while blocks B and C are much restricted by the junctions.Fig.…”
The disorder to order transition and the ordered patterns near the disordered state of coil-comb copolymer A-b-(Bm + 1-g-Cm) are investigated by the self-consistent field theory. The phase diagrams of coil-comb copolymer are obtained by varying the composition of the copolymer with the side chain number m = 1, 2, and 3. The disorder to order transition is far more complex compared with the comb copolymer or linear block copolymer. As the side chain number m increases, the Flory-Huggins interaction parameter of disorder to order transition (DOT) increases and the lowest DOT occurs when the volume fractions of blocks A, B, and C are approximately equal. When one component is the minority, the disorder to order transition curve is similar with binary copolymer, but the curve shows the asymmetric property. The comb copolymer is more stable with larger side chain number m and shorter side chain. The ordered patterns from the disordered state are discussed. The results are helpful for designing coil-comb copolymers and obtaining the ordered morphology.
“…Supposing that the χ value is maintained, a higher χN is required for the microphase separation to occur, because N increases with n. Thus, the (χN) ODT values increase with both n and L C . Results from the SCFT calculations also indicate that the (χN) ODT values increase with architectural periodicity n for the A n+1 (BC) n copolymers [35]. Thus, our results are consistent with the previous theoretical and simulation results.…”
Section: The Critical Values For the Order-disorder Transitionssupporting
confidence: 91%
“…Qian and Wang [35] investigated the (χN) ODT values for the triblock comb copolymer A n+1 (BC) n . According to their results, the (χN) ODT values for copolymers with the side chain number n = 3 was approximately triple the χN for copolymers with n = 1 when the volume fractions of the three or two blocks were equal.…”
Section: The Critical Values For the Order-disorder Transitionsmentioning
The backbone of the Janus double-brush copolymer may break during long-term service, but whether this breakage affects the self-assembled phase state and microphase transitions of the material is still unknown. For the Janus double-brush copolymers with a periodicity in molecular architecture ranging from 1 to 10, the influences of the architectural periodicity on their phase diagrams and order–disorder transitions (ODT) were investigated by the self-consistent mean field theory (SCFT). In total, nine microphases with long-range order were found. By comparing the phase diagrams between copolymers of different periodicity, a decrease in periodicity or breakage along the copolymer backbone had nearly no influence on the phase diagrams unless the periodicity was too short to be smaller than 3. For copolymers with neutral backbones, a decrease in periodicity or breakage along the copolymer backbone reduced the critical segregation strengths of the whole copolymer at ODT. The equations for the critical segregation strengths at ODT, the architectural periodicity, and the volume fraction of the backbone were established for the Janus double-brush copolymers. The theoretical calculations were consistent with the previous theoretical, experimental, and simulation results.
“…[28][29][30][31][32] Russell and co-workers investigated the unconventional morphologies of symmetric, diblock copolymers as a function of film thickness, 28 and interfacial interactions as early as 1990s. 50,[57][58][59][60][61][62][63][64][65][66] Ross and co-workers successfully explored the graphoepitaxy of spherical morphological block copolymers templated by an array of posts, predicting that the formation of aperiodic templated structures gave an excellent agreement with experimental results. 32 In the following, a series of experimental studies have demonstrated the above results.…”
Section: Introductionmentioning
confidence: 84%
“…56 Especially in recent years, self-consistent field theory (SCFT) has been largely promoted to predict new-fashioned or sophisticated structures versus some phase transitions based on the self-assembly of diblock and triblock copolymers. 50,[57][58][59][60][61][62][63][64][65][66] Ross and co-workers successfully explored the graphoepitaxy of spherical morphological block copolymers templated by an array of posts, predicting that the formation of aperiodic templated structures gave an excellent agreement with experimental results. 50 Meng and Wang carried out a systematic calculation to explore the phase behaviors of symmetric diblock copolymers confined in thin films, observing complex structures of T k (k = 1, 2, 3) combined k layers of regular lamellae with a single layer of perforated lamella for asymmetric surface interactions.…”
An extensive and systematic calculation was performed to explore hierarchical cylindrical structures and the order-to-order transitions of AB diblock copolymers (f(A) = 0.3) on a saw-toothed substrate using self-consistent mean-field theory. We obtained fifteen relatively simple morphologies, including the existing morphologies observed experimentally and from simulations, and five more complicated structures, by varying the lateral periodicity of the substrate, the film thickness of diblock copolymers, the interaction between the A-block and the substrate and the tilt angles (or the shape) of the substrate. These structures show that the orientation and number of layers of cylinders can be tailored. Even lamellae and spherical microdomains were observed. Most interestingly, hierarchical structures are also observed, such as the morphology of C(ab)(//) within the upper cylinder perpendicular to the bottom cylinder, SC(b)(//) morphology that the upper is a cylinder but the bottom is a sphere. In addition, we discussed these complex hierarchical structures in detail and have analyzed the order-to-order transitions between the cylindrical morphologies with distinct orientations and layers.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
