Temperature-Dependent Phase Behaviors in Cylinder-Forming Block Copolymers

International Journal of Molecular Sciences

Dae Up Ahn¹ 

[1] Department of Mechanical Engineering, University of Colorado, Boulder, CO 80309-0427, USA

关键词: block copolymers;    block copolymer self-assembly;    dynamic mechanical properties;    orientation transition of block copolymer nano-cylinders;    order-disorder transition of block copolymers;   

DOI  :  10.3390/ijms10052169

来源: mdpi

【 摘 要 】

We demonstrate that the temperature-dependent phase behaviors of parallel and perpendicular cylinder-forming block copolymers are governed by domain-domain segregation forces inherently present in block copolymer material itself. With increasing temperature, a parallel cylinder-forming block copolymer experienced a parallel cylinder straightening process before the order-disorder transition (ODT) and did not show long-range composition fluctuations near the ODT temperature due to the weak segregation forces between the block domains. A perpendicular cylinder-forming block copolymer with a strong segregation force between the block domains displayed cylinder orientation transition from perpendicular to parallel below the ODT temperature. On the other hand, a perpendicular cylinder-forming block copolymer material with an exceptionally strong segregation force between the block domains maintained its initial perpendicular cylinder orientation up to near the ODT temperature. In both cases of perpendicular cylinder-forming block copolymers, submicrometer-scale long-range composition fluctuations were observed well above the ODT temperature due to their intrinsically strong segregation forces between the block domains.

【 授权许可】

CC BY   
© 2009 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.