3D Nanometer-Scale Study of Coexisting Bicontinuous Morphologies in a Block Copolymer/Homopolymer Blend

• Published in: Macromolecular rapid communications. Vol. 27; no. 17; pp. 1424 - 1429
• Main Authors: Jinnai, Hiroshi, Hasegawa, Hirokazu, Nishikawa, Yukihiro, Sevink, G. J. Agur, Braunfeld, Michael B., Agard, David A., Spontak, Richard J.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 04.09.2006; WILEY‐VCH Verlag; Wiley
• Subjects: Applied sciences; bicontinuous networks; block copolymers; Exact sciences and technology; Organic polymers; phase separation; Physicochemistry of polymers; Properties and characterization; simulations; Structure, morphology and analysis; TEM; block copolymers; Polymer blends; Nanostructure; Experimental study; Heterogeneous mixture; simulations; phase separation; Transmission electron microscopy; Three dimensional structure; Morphology; Isoprene copolymer; bicontinuous networks; Diblock copolymer; Styrene polymer; TEM; Styrene copolymer
• ISSN: 1022-1336; 1521-3927
• DOI: 10.1002/marc.200600344

Coexisting bicontinuous morphologies, one ordered and one disordered, are investigated in a macrophase‐separated poly(styrene‐block‐isoprene) diblock copolymer/homopolystyrene (SI/hS) blend. Two‐phase behavior is attributed to the relatively high hS/S mass ratio (0.92). According to its crystallographic signature and channel coordination as discerned from three‐dimensional (3D) images generated by transmission electron microtomography (TEMT), the ordered morphology is classified as gyroid. The 3D local and global topological characteristics of both bicontinuous morphologies as measured directly from TEMT images are reported. The disordered morphology is further compared with molecular‐field simulations to ascertain the spatial distribution of the constituent species within the blend, thereby demonstrating the utility of high‐resolution 3D imaging coupled with molecular‐level simulations.