Journal article
Stability of the A15 phase in diblock copolymer melts
Proceedings of the National Academy of Sciences - PNAS, v 116(27), pp 13194-13199
02 Jul 2019
PMID: 31209038
Featured in Collection : UN Sustainable Development Goals @ Drexel
Abstract
Block copolymers are prevalent throughout industry and academe due to their self-assembly into well-ordered nanostructures, but only a handful of morphologies are known with the simplest materials built from two chemically distinct blocks. In this article, we report that AB diblock copolymers can also self-assemble into a structure known as the A15 phase. Theory and experiments indicate A15 occurs throughout a substantial region of phase space with suitable differences in the space-filling characteristics of each block. The observed temperature-dependent phase transitions can only be explained using fully fluctuating field-theoretic simulations, which provide evidence that composition fluctuations play a key role in the self-assembly of block copolymers into the larger class of tetrahedrally close-packed sphere phases.
The self-assembly of block polymers into well-ordered nanostructures underpins their utility across fundamental and applied polymer science, yet only a handful of equilibrium morphologies are known with the simplest AB-type materials. Here, we report the discovery of the A15 sphere phase in single-component diblock copolymer melts comprising poly(dodecyl acrylate)−
block
−poly(lactide). A systematic exploration of phase space revealed that A15 forms across a substantial range of minority lactide block volume fractions (
f
L
= 0.25 − 0.33) situated between the σ-sphere phase and hexagonally close-packed cylinders. Self-consistent field theory rationalizes the thermodynamic stability of A15 as a consequence of extreme conformational asymmetry. The experimentally observed A15−disorder phase transition is not captured using mean-field approximations but instead arises due to composition fluctuations as evidenced by fully fluctuating field-theoretic simulations. This combination of experiments and field-theoretic simulations provides rational design rules that can be used to generate unique, polymer-based mesophases through self-assembly.
Metrics
Details
- Title
- Stability of the A15 phase in diblock copolymer melts
- Creators
- Morgan W. Bates - University of California, Santa BarbaraJoshua Lequieu - University of California, Santa BarbaraStephanie M. Barbon - University of California, Santa BarbaraRonald M. Lewis - University of MinnesotaKris T. Delaney - University of California, Santa BarbaraAthina Anastasaki - University of California, Santa BarbaraCraig J. Hawker - University of California, Santa BarbaraGlenn H. Fredrickson - University of California, Santa BarbaraChristopher M. Bates - University of California, Santa BarbaraUniv. of California, Santa Barbara, CA (United States)
- Publication Details
- Proceedings of the National Academy of Sciences - PNAS, v 116(27), pp 13194-13199
- Publisher
- National Academy of Sciences
- Grant note
- DE-SC0019001 / U.S. Department of Energy (DOE) DE-SC0019272 / U.S. Department of Energy (DOE)
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Chemical and Biological Engineering
- Web of Science ID
- WOS:000473427900013
- Scopus ID
- 2-s2.0-85068259073
- Other Identifier
- 991020950771304721
UN Sustainable Development Goals (SDGs)
This publication has contributed to the advancement of the following goals:
InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Collaboration types
- Domestic collaboration
- Web of Science research areas
- Polymer Science