Effects of Polymer Helical Chain Shape on Block Copolymer Self-Assembly
ORAL
Abstract
While helical chain shapes in block copolymers have been shown to produce unique morphologies, the details of how chain shape influences the thermodynamics of self-assembly are unclear. Here, we utilize model coil–coil and coil–helix block copolymers based on polypeptoids, for which the chain shape can be tuned from helix to coil via monomer chirality with constant chemistry. This model block copolymer system is used to probe the effects of chain helicity on block copolymer self-assembly. With identical domain spacings in the lamellar morphology, the coil–helix block copolymer has a lower order–disorder transition temperature (TODT) than its coil–coil analogue. There is minimal difference in the enthalpic contribution to mixing. The most significant contribution in lowering the TODT of the coil–helix block copolymer is the helical chain experiencing larger chain stretching penalties in the lamellar morphology, which leads to a larger entropic gain upon disordering. This yields insight into the importance of space filling and chain stretching of polymer chains in block copolymer self-assembly.
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Presenters
Beihang Yu
University of California, Santa Barbara
Authors
Beihang Yu
University of California, Santa Barbara
Scott Danielsen
University of California, Santa Barbara
Anastasia Patterson
University of California, Santa Barbara
Emily C Davidson
Department of Materials Science and Mechanical Engineering, Harvard University, University of California, Santa Barbara
Glenn Fredrickson
University of California, Santa Barbara, Chemical Engineering, University of California, Santa Barbara, Department of Chemical Engineering, University of California, Santa Barbara
Rachel Segalman
Materials Department and Department of Chemical Engineering, University of California, Santa Barbara, University of California, Santa Barbara, Department of Chemical Engineering, University of California, Santa Barbara
