Magnetic alignment of block copolymer microdomains by intrinsic chain anisotropy
- Yale Univ., New Haven, CT (United States)
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- Univ. of Wisconsin, Madison, WI (United States)
We examine the role of intrinsic chain susceptibility anisotropy in magnetic field directed self-assembly of a block copolymer using in situ x-ray scattering. Alignment of a lamellar mesophase is observed on cooling across the disorder-order transition with the resulting orientational order inversely proportional to the cooling rate. We discuss the origin of the susceptibility anisotropy, Δχ, that drives alignment and calculate its magnitude using coarse-grained molecular dynamics to sample conformations of surface-tethered chains, finding Δχ ≈ 2×10–8. From field-dependent scattering data, we estimate that grains of ≈ 1.2 μm are present during alignment. Furthermore, these results demonstrate that intrinsic anisotropy is sufficient to support strong field-induced mesophase alignment and suggest a versatile strategy for field control of orientational order in block copolymers.
- Research Organization:
- Brookhaven National Laboratory (BNL), Upton, NY (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- SC00112704; SC0012704
- OSTI ID:
- 1246786
- Alternate ID(s):
- OSTI ID: 1233966
- Report Number(s):
- BNL-111841-2016-JA; PRLTAO; R&D Project: 16077; KC0403020
- Journal Information:
- Physical Review Letters, Vol. 115, Issue 25; ISSN 0031-9007
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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