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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 40: Focus: Polymer Crystallization - from Model Systems to New Materials II
CPP 40.4: Vortrag
Mittwoch, 22. März 2017, 16:00–16:15, ZEU 222
Aligned crystallization within a single gyroid network of a semicrystalline triblock terpolymer — •James A. Dolan1, Raphael Dehmel1, Bodo D. Wilts2, Alessandro Sepe2, Yibei Gu3, Timothy D. Wilkinson1, Jeremy J. Baumberg1, Ulrich Wiesner3, Ullrich Steiner2, and Ilja Gunkel2 — 1University of Cambridge, Cambridge, UK — 2Adolphe Merkle Institute, Fribourg, CH — 3Cornell University, Ithaca, NY, USA
Semicrystalline block copolymers are an interesting model system for studying the crystallization of polymers under nanoscale confinement. Confined crystallization takes place if the crystallization temperature of the semicrystalline block is lower than the glass transition temperature of the amorphous block. This confinement is often found to induce aligned crystallization. In this work, the crystallization of semicrystalline poly(ethylene oxide) (PEO) confined within a single gyroid morphology was studied in solvent-annealed polyisoprene-b-polystyrene-b-poly(ethylene oxide) (ISO) triblock terpolymer films by means of GISAXS, GIWAXS, SEM, and optical microscopy. PEO is shown to crystallize preferentially in the direction of the least tortuous pathways of the gyroid, leading to a preferential alignment of the PEO crystallites within the self-assembled morphology. Strikingly, this gives rise to an optical birefringence of individual gyroid domains that allows mapping of the grain structure in self-assembled ISO films by means of optical microscopy.