Mesoscopic Morphologies in Frustrated ABC Bottlebrush Block Terpolymers
ORAL
Abstract
Bottlebrush block polymers, featuring densely grafted side chains, have garnered significant attention mainly for their large self-assembled domain spacings, up to several hundred nanometers, rarely achieved with linear counterparts. However, the structures observed in AB diblock bottlebrushes are limited to simple lamellae and cylindrical phases. We synthesized a library of ABC bottlebrush triblock terpolymers, poly(DL-lactide)-b-poly(ethylene-alt-propylene)-b-polystyrene (PLA-PEP-PS) using macromonomers and ring-opening metathesis polymerization (ROMP). This creates a frustrated system, where the mandatory interfaces (PLA/PEP) have larger interfacial energies than PLA/PS. Morphological characterization revealed intriguing mesoscopic structures, including layered microstructures, core-shell hexagonally packed cylinders (CSHEX, plane group p6mm), alternating tetragonally packed cylinders (ATET, p4mm), and an unprecedented morphology, rectangular centered cylinders-in-undulating-lamellae (RCCUL, c2mm). Varying molecular weight led to a wide range of unit cell dimensions (exemplified by RCCUL) from 40 nm to over 130 nm. This work highlights the potential of multiblock bottlebrushes for creating materials with innovative structures and diverse domain dimensions.
*This work was supported by the National Science Foundation (NSF) through the University of Minnesota MRSEC under Award DMR-2011401. Parts of this work were carried out in the Characterization Facility, University of Minnesota, which receives partial support from the NSF through the MRSEC (Award Number DMR-2011401) and the NNCI (Award Number ECCS-2025124) programs. The research reported here was partially supported by the BioPACIFIC Materials Innovation Platform of the National Science Foundation under Award No. DMR-1933487 (equipment and characterization). This research also used resources from Sector 11-BM CMS beamline of the National Synchrotron Light Source II, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract no. DE-SC0012704.
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Publication:Shuquan Cui, Elizabeth A. Murphy, Subrata Santra, Frank S. Bates, Timothy P. Lodge, Mesoscopic Morphologies in Frustrated ABC Bottlebrush Block Terpolymers, submitted to ACS Nano (under review)
