|
New Pathways in Block Copolymer Order-Order Transitions.
The installation of an in situ rheometer on the new 6m SAXS line at the University of Minnesota allows preparation of "single crystal" like habits in ordered copolymer solutions. The temperature-induced transformation to other ordered phases can be followed in detail. For example, we have demonstrated that the fcc-bcc and hcp-bcc transitions follow exactly the same epitaxial relationships as in simple metals [T.P. Lodge, J. Bang, and X. Wang, Phys. Rev. Lett., submitted]. Also, the transformation from cylinders (image A) to gyroid (image C) sometimes involves the metastable intermediate perforated layer phase (image B). [C.-Y. Wang, and T.P. Lodge, Macromol. Rapid Commun. 2002, 23, 49)]
|
Last
modified on April 3, 2008