Emergence of a C15 Laves Phase in Diblock Polymer/Homopolymer Blends

Andreas J. Mueller; Aaron P. Lindsay; Ashish Jayaraman; Timothy P. Lodge; Mahesh K. Mahanthappa; Frank S. Bates

doi:10.1021/acsmacrolett.0c00124

Emergence of a C15 Laves Phase in Diblock Polymer/Homopolymer Blends

Andreas J. Mueller, Aaron P. Lindsay, Ashish Jayaraman, Timothy P. Lodge, Mahesh K. Mahanthappa, Frank S. Bates

Research output: Contribution to journal › Article › peer-review

65 Scopus citations

Abstract

The observation of complex, Frank-Kasper (FK) particle packings in diblock polymer melts has until recently been limited to low molecular weight, conformationally asymmetric polymers. We report temperature-dependent small-angle X-ray scattering (SAXS) studies of blends of a sphere-forming poly(styrene-block-1,4-butadiene) (SB) diblock polymer (M _n = 33.3 kg/mol, Ð = M _w/M _n = 1.08, f _B = 0.18) with two different poly(1,4-butadiene) (B) homopolymer additives. When the B additive M _n is the same as that of the diblock core-forming B segment, these blends remarkably form tetrahedrally close-packed FK s and Laves C14 and C15 phases with increasing B content. However, binary blends in which the B additive M _n is 60% of that of the diblock B segment form only the canonical body-centered cubic (BCC) particle packing and hexagonally-packed cylinders (HEXc). The observed phase behavior is rationalized in terms of "wet" and "dry" brush blending, whereby higher B M _n drives stronger localization of the homopolymer in the particle cores while preserving the interfacial area per SB diblock chain. The consequent packing constraints in these blends destabilize the BCC packing, and FK phases emerge as optimal minimal surface solutions to filling space at constant density while maximizing local particle sphericity.

Original language	English (US)
Pages (from-to)	576-582
Number of pages	7
Journal	ACS Macro Letters
Volume	9
Issue number	4
DOIs	https://doi.org/10.1021/acsmacrolett.0c00124
State	Published - Apr 21 2020

Bibliographical note

Funding Information:
We thank Ronald Lewis III for providing the diblock copolymers utilized in this study. Financial support for this work was under National Science Foundation Grants DMR-1801993 (A.J.M., F.S.B.) and CHE-1807330 (A.J., M.K.M.) and a National Science Foundation Graduate Research Fellowship under Grant No. 00039202 (A.P.L.). SAXS experiments were conducted at the Advanced Photon Source (APS), Sector 5 DuPont-Northwestern-Dow Collaborative Access Team (DND-CAT). DND-CAT is supported by E.I. DuPont de Nemours & Co., the Dow Chemical Company, and Northwestern University. Additional SAXS experiments were also carried out at Sector 12 of the APS. Use of the APS, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357. Parts of this work, including lab source SAXS analyses, were carried out in the Characterization Facility at the University of Minnesota, which receives partial support from NSF through the UMN MRSEC (DMR-1420013). We acknowledge the Minnesota Supercomputing Institute (MSI) at the University of Minnesota ( www.msi.umn.edu ) for providing computational resources for calculation of electron density maps.

Publisher Copyright:
Copyright © 2020 American Chemical Society.

MRSEC Support

Shared

Publisher link

10.1021/acsmacrolett.0c00124

https://pubs.acs.org/doi/10.1021/acsmacrolett.0c00124

Find It

Find It at U of M Libraries

Cite this

@article{d618892d36904734a89f346cf4c1fe2e,

title = "Emergence of a C15 Laves Phase in Diblock Polymer/Homopolymer Blends",

abstract = "The observation of complex, Frank-Kasper (FK) particle packings in diblock polymer melts has until recently been limited to low molecular weight, conformationally asymmetric polymers. We report temperature-dependent small-angle X-ray scattering (SAXS) studies of blends of a sphere-forming poly(styrene-block-1,4-butadiene) (SB) diblock polymer (M n = 33.3 kg/mol, {\DH} = M w/M n = 1.08, f B = 0.18) with two different poly(1,4-butadiene) (B) homopolymer additives. When the B additive M n is the same as that of the diblock core-forming B segment, these blends remarkably form tetrahedrally close-packed FK s and Laves C14 and C15 phases with increasing B content. However, binary blends in which the B additive M n is 60% of that of the diblock B segment form only the canonical body-centered cubic (BCC) particle packing and hexagonally-packed cylinders (HEXc). The observed phase behavior is rationalized in terms of {"}wet{"} and {"}dry{"} brush blending, whereby higher B M n drives stronger localization of the homopolymer in the particle cores while preserving the interfacial area per SB diblock chain. The consequent packing constraints in these blends destabilize the BCC packing, and FK phases emerge as optimal minimal surface solutions to filling space at constant density while maximizing local particle sphericity. ",

author = "Mueller, {Andreas J.} and Lindsay, {Aaron P.} and Ashish Jayaraman and Lodge, {Timothy P.} and Mahanthappa, {Mahesh K.} and Bates, {Frank S.}",

note = "Funding Information: We thank Ronald Lewis III for providing the diblock copolymers utilized in this study. Financial support for this work was under National Science Foundation Grants DMR-1801993 (A.J.M., F.S.B.) and CHE-1807330 (A.J., M.K.M.) and a National Science Foundation Graduate Research Fellowship under Grant No. 00039202 (A.P.L.). SAXS experiments were conducted at the Advanced Photon Source (APS), Sector 5 DuPont-Northwestern-Dow Collaborative Access Team (DND-CAT). DND-CAT is supported by E.I. DuPont de Nemours & Co., the Dow Chemical Company, and Northwestern University. Additional SAXS experiments were also carried out at Sector 12 of the APS. Use of the APS, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357. Parts of this work, including lab source SAXS analyses, were carried out in the Characterization Facility at the University of Minnesota, which receives partial support from NSF through the UMN MRSEC (DMR-1420013). We acknowledge the Minnesota Supercomputing Institute (MSI) at the University of Minnesota ( www.msi.umn.edu ) for providing computational resources for calculation of electron density maps. Publisher Copyright: Copyright {\textcopyright} 2020 American Chemical Society.",

year = "2020",

month = apr,

day = "21",

doi = "10.1021/acsmacrolett.0c00124",

language = "English (US)",

volume = "9",

pages = "576--582",

journal = "ACS Macro Letters",

issn = "2161-1653",

publisher = "American Chemical Society",

number = "4",

}

TY - JOUR

T1 - Emergence of a C15 Laves Phase in Diblock Polymer/Homopolymer Blends

AU - Mueller, Andreas J.

AU - Lindsay, Aaron P.

AU - Jayaraman, Ashish

AU - Lodge, Timothy P.

AU - Mahanthappa, Mahesh K.

AU - Bates, Frank S.

N1 - Funding Information: We thank Ronald Lewis III for providing the diblock copolymers utilized in this study. Financial support for this work was under National Science Foundation Grants DMR-1801993 (A.J.M., F.S.B.) and CHE-1807330 (A.J., M.K.M.) and a National Science Foundation Graduate Research Fellowship under Grant No. 00039202 (A.P.L.). SAXS experiments were conducted at the Advanced Photon Source (APS), Sector 5 DuPont-Northwestern-Dow Collaborative Access Team (DND-CAT). DND-CAT is supported by E.I. DuPont de Nemours & Co., the Dow Chemical Company, and Northwestern University. Additional SAXS experiments were also carried out at Sector 12 of the APS. Use of the APS, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357. Parts of this work, including lab source SAXS analyses, were carried out in the Characterization Facility at the University of Minnesota, which receives partial support from NSF through the UMN MRSEC (DMR-1420013). We acknowledge the Minnesota Supercomputing Institute (MSI) at the University of Minnesota ( www.msi.umn.edu ) for providing computational resources for calculation of electron density maps. Publisher Copyright: Copyright © 2020 American Chemical Society.

PY - 2020/4/21

Y1 - 2020/4/21

N2 - The observation of complex, Frank-Kasper (FK) particle packings in diblock polymer melts has until recently been limited to low molecular weight, conformationally asymmetric polymers. We report temperature-dependent small-angle X-ray scattering (SAXS) studies of blends of a sphere-forming poly(styrene-block-1,4-butadiene) (SB) diblock polymer (M n = 33.3 kg/mol, Ð = M w/M n = 1.08, f B = 0.18) with two different poly(1,4-butadiene) (B) homopolymer additives. When the B additive M n is the same as that of the diblock core-forming B segment, these blends remarkably form tetrahedrally close-packed FK s and Laves C14 and C15 phases with increasing B content. However, binary blends in which the B additive M n is 60% of that of the diblock B segment form only the canonical body-centered cubic (BCC) particle packing and hexagonally-packed cylinders (HEXc). The observed phase behavior is rationalized in terms of "wet" and "dry" brush blending, whereby higher B M n drives stronger localization of the homopolymer in the particle cores while preserving the interfacial area per SB diblock chain. The consequent packing constraints in these blends destabilize the BCC packing, and FK phases emerge as optimal minimal surface solutions to filling space at constant density while maximizing local particle sphericity.

AB - The observation of complex, Frank-Kasper (FK) particle packings in diblock polymer melts has until recently been limited to low molecular weight, conformationally asymmetric polymers. We report temperature-dependent small-angle X-ray scattering (SAXS) studies of blends of a sphere-forming poly(styrene-block-1,4-butadiene) (SB) diblock polymer (M n = 33.3 kg/mol, Ð = M w/M n = 1.08, f B = 0.18) with two different poly(1,4-butadiene) (B) homopolymer additives. When the B additive M n is the same as that of the diblock core-forming B segment, these blends remarkably form tetrahedrally close-packed FK s and Laves C14 and C15 phases with increasing B content. However, binary blends in which the B additive M n is 60% of that of the diblock B segment form only the canonical body-centered cubic (BCC) particle packing and hexagonally-packed cylinders (HEXc). The observed phase behavior is rationalized in terms of "wet" and "dry" brush blending, whereby higher B M n drives stronger localization of the homopolymer in the particle cores while preserving the interfacial area per SB diblock chain. The consequent packing constraints in these blends destabilize the BCC packing, and FK phases emerge as optimal minimal surface solutions to filling space at constant density while maximizing local particle sphericity.

UR - http://www.scopus.com/inward/record.url?scp=85082967032&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85082967032&partnerID=8YFLogxK

U2 - 10.1021/acsmacrolett.0c00124

DO - 10.1021/acsmacrolett.0c00124

M3 - Article

C2 - 35648489

SN - 2161-1653

VL - 9

SP - 576

EP - 582

JO - ACS Macro Letters

JF - ACS Macro Letters

IS - 4

ER -

Emergence of a C15 Laves Phase in Diblock Polymer/Homopolymer Blends

Abstract

Bibliographical note

MRSEC Support

Publisher link

Find It

Other files and links

Fingerprint

University of Minnesota MRSEC (DMR-1420013)

MRSEC IRG-3: Hierarchical Multifunctional Macromolecular Materials

MRSEC SEED Projects DMR-1420013

Cite this