skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Intradomain Textures in Block Copolymers: Multizone Alignment and Biaxiality

; ; ;
Publication Date:
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
Grant/Contract Number:
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 118; Journal Issue: 24; Related Information: CHORUS Timestamp: 2017-06-12 22:09:44; Journal ID: ISSN 0031-9007
American Physical Society (APS)
Country of Publication:
United States

Citation Formats

Prasad, Ishan, Seo, Youngmi, Hall, Lisa M., and Grason, Gregory M. Intradomain Textures in Block Copolymers: Multizone Alignment and Biaxiality. United States: N. p., 2017. Web. doi:10.1103/PhysRevLett.118.247801.
Prasad, Ishan, Seo, Youngmi, Hall, Lisa M., & Grason, Gregory M. Intradomain Textures in Block Copolymers: Multizone Alignment and Biaxiality. United States. doi:10.1103/PhysRevLett.118.247801.
Prasad, Ishan, Seo, Youngmi, Hall, Lisa M., and Grason, Gregory M. 2017. "Intradomain Textures in Block Copolymers: Multizone Alignment and Biaxiality". United States. doi:10.1103/PhysRevLett.118.247801.
title = {Intradomain Textures in Block Copolymers: Multizone Alignment and Biaxiality},
author = {Prasad, Ishan and Seo, Youngmi and Hall, Lisa M. and Grason, Gregory M.},
abstractNote = {},
doi = {10.1103/PhysRevLett.118.247801},
journal = {Physical Review Letters},
number = 24,
volume = 118,
place = {United States},
year = 2017,
month = 6

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on June 12, 2018
Publisher's Accepted Manuscript

Save / Share:
  • No abstract prepared.
  • Block copolymers made by covalently linking two or more conjugated polymers have significant potential for organic optoelectronic applications, particularly those requiring a p/n junction. Herein, we report the structure of all-conjugated diblock copolymers poly(3-hexylthiophene)-block-poly(9,9-dioctylfluorene) and poly(3-hexylthiophene)-block-poly(9,9-dioctylfluorene-co-benzothiadiazole) in thin films and in the bulk. The diblock copolymers are prepared using a combination of Grignard metathesis polymerization and Suzuki polycondensation and purified using solvent extraction and column chromatography. 1H NMR, SEC, and UV/Visible absorbance measurements are used to characterize the materials and quantify the amount of homopolymer impurities. Thin films and bulk structure are characterized using a combination of differential scanning calorimetry,more » x-ray diffraction, small-angle x-ray scattering, and atomic force microscopy. Atomic force microscopy images reveal nanoscale lamellar domains in solvent-annealed diblock copolymer thin films, and peaks in x-ray diffraction data correspond to poly(3-hexylthiophene) crystallites. On cooling from temperatures above the crystallization temperature to below the crystallization temperature, two peaks appear in temperature-dependent small-angle x-ray scattering traces - one associated with poly(3-hexylthiophene) crystallites and a second low-angle peak indicative of a self-assembled nanostructured. These measurements show all-conjugated diblock copolymers self-assemble into nanoscale crystalline domains present throughout the bulk samples which may be useful for improving the performance of organic photovoltaics and organic light-emitting diodes.« less
  • Air–water interfacial monolayers of poly((d,l-lactic acid-ran-glycolic acid)-block-ethylene glycol) (PLGA–PEG) exhibit an exponential increase in surface pressure under high monolayer compression. In order to understand the molecular origin of this behavior, a combined experimental and theoretical investigation (including surface pressure–area isotherm, X-ray reflectivity (XR) and interfacial rheological measurements, and a self-consistent field (SCF) theoretical analysis) was performed on air–water monolayers formed by a PLGA–PEG diblock copolymer and also by a nonglassy analogue of this diblock copolymer, poly((d,l-lactic acid-ran-glycolic acid-ran-caprolactone)-block-ethylene glycol) (PLGACL–PEG). The combined results of this study show that the two mechanisms, i.e., the glass transition of the collapsed PLGA filmmore » and the lateral repulsion of the PEG brush chains that occur simultaneously under lateral compression of the monolayer, are both responsible for the observed PLGA–PEG isotherm behavior. Upon cessation of compression, the high surface pressure of the PLGA–PEG monolayer typically relaxes over time with a stretched exponential decay, suggesting that in this diblock copolymer situation, the hydrophobic domain formed by the PLGA blocks undergoes glass transition in the high lateral compression state, analogously to the PLGA homopolymer monolayer. In the high PEG grafting density regime, the contribution of the PEG brush chains to the high monolayer surface pressure is significantly lower than what is predicted by the SCF model because of the many-body attraction among PEG segments (referred to in the literature as the “n-cluster” effects). The end-grafted PEG chains were found to be protein resistant even under the influence of the “n-cluster” effects.« less
  • Block copolymers have been extensively studied due to their ability to spontaneously self-organize into a wide variety of morphologies that are valuable in energy-, medical- and conservation-related (nano)technologies. While the phase behavior of bicomponent diblock and triblock copolymers is conventionally governed by temperature and individual block masses, we demonstrate that their phase behavior can alternatively be controlled through the use of blocks with random monomer sequencing. Block random copolymers (BRCs), i.e., diblock copolymers wherein one or both blocks is a random copolymer comprised of A and B repeat units, have been synthesized, and their phase behavior, expressed in terms ofmore » the order-disorder transition (ODT), has been investigated. Our results establish that, depending on the block composition contrast and molecular weight, BRCs can microphase-separate. We also report that the predicted ODT can be generated at relatively constant molecular weight and temperature with these new soft materials. This sequence-controlled synthetic strategy is extended to thermoplastic elastomeric triblock copolymers differing in chemistry and possessing a random-copolymer midblock.« less