Stability of hierarchical lamellar morphologies formed in ABC star triblock copolymers

• Published in: Journal of polymer science. Part B, Polymer physics Vol. 48; no. 10; pp. 1101 - 1109
• Main Authors: Xu, Yuci, Li, Weihua, Qiu, Feng, Zhang, Hongdong, Yang, Yuliang, Shi, An-Chang
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15.05.2010; Wiley
• Subjects: Applied sciences; Block copolymers; Blocking; Exact sciences and technology; Free energy; Internal energy; Morphology; Organic polymers; phase behavior; Physicochemistry of polymers; Properties and characterization; Reproduction; self-assembly; Stability; Stars; Structure, morphology and analysis; theory; Terpolymer; Self assembly; Theoretical study; Thermodynamic stability; Modeling; Star copolymer; self-assembly; Triblock copolymer; Lamellar structure; phase behavior; SCF method; Domain structure; theory
• ISSN: 0887-6266; 1099-0488; 1099-0488
• DOI: 10.1002/polb.22000

The stability of hierarchical lamellar morphologies formed in ABC star triblock copolymers, is studied using the self-consistent mean-field theory. The hierarchical lamellae consist of repeating period of the largest block A-formed layer and B/C coformed layer where B and C domains are arranged alternatively. An angle, which is used to characterize the shifting magnitude between two neighbor B/C coformed layers, varies from 0 to 180 degrees. By comparing the free energy among the lamellar morphologies with various shift angle, their relative stability is analyzed. Our results show that the morphology with larger shift has lower entropic energy and higher internal energy. In general, the morphology with the largest shift of 180-degree is stable compared with those with smaller shift as the entropic energy dominates the internal energy. However, the relative stability can be tuned by the interactions among the three components as well as their relative compositions. PACS numbers: 61.25.Hq, 64.60.Cn, 64.75.+g.