## Abstract

Original language | Undefined/Unknown |
---|---|

Pages (from-to) | 2159-2169 |

Number of pages | 11 |

Journal | Soft Matter |

Volume | 8 |

Issue number | 7 |

DOIs | |

Publication status | Published - 2012 |

## Keywords

- OXIDE) TRIBLOCK COPOLYMERS
- STRONG-SEGREGATION THEORY
- BLOCK-COPOLYMERS
- MICROPHASE SEPARATION
- BICONTINUOUS PHASES
- DIBLOCK COPOLYMERS
- POLY(ISOPRENE-B-STYRENE-B-ETHYLENE OXIDE)
- MICRODOMAIN MORPHOLOGY
- EQUILIBRIUM MORPHOLOGY
- LENGTH SCALES

## Cite this

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*Soft Matter*,

*8*(7), 2159-2169. https://doi.org/10.1039/c1sm06688a

**The diamond and other non-conventional morphologies in two-scale multiblock AB copolymers**. In: Soft Matter. 2012 ; Vol. 8, No. 7. pp. 2159-2169.

}

*Soft Matter*, vol. 8, no. 7, pp. 2159-2169. https://doi.org/10.1039/c1sm06688a

**The diamond and other non-conventional morphologies in two-scale multiblock AB copolymers.** / Erukhimovich, Igor; Kriksin, Yury; ten Brinke, Gerrit.

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

TY - JOUR

T1 - The diamond and other non-conventional morphologies in two-scale multiblock AB copolymers

AU - Erukhimovich, Igor

AU - Kriksin, Yury

AU - ten Brinke, Gerrit

PY - 2012

Y1 - 2012

N2 - We revisit the idea of the existence of the ordered block copolymer phase possessing diamond symmetry Fd (3) over barm (space group No. 227), which was first put forward within the framework of the strong segregation approach. For this purpose we study the order-disorder and order-order transitions in molten two-scale multiblock copolymers A(mN/2)(B(N/2)A(N/2))(n)B-mN/2 via the pseudo-spectral numerical procedure of the self-consistent field theory (SCFT). The phase diagram in the plane (f(C), (chi) over tilde), where f(C) = n/(m + n) and (chi) over tilde = chi N(m + n) is the effective energetic Flory-Huggins parameter, is built and some accompanying quantities are analyzed. Near the order-disorder transition line the phase diagram contains the regions where the lamellar, alternating gyroid, diamond and simple cubic phase, respectively, exist. With an increase of the degree of segregation, the diamond phase is replaced by a tetragonal array of cylinders (simple square) phase, which agrees with the preceding results obtained within the Leibler-like weak segregation theory, and with the SCFT calculations for a physically similar melt of linear ABC triblock copolymers with a non-selective middle block. Thus, the diamond morphology in the system under study is shown to exist as an essentially weak or moderately (not strongly) segregated phase. The ways to visualize the patterns of ordering in such morphologies are discussed. A new quantity (topological permeability) to characterize the transport properties in 3D bicontinuous morphologies is introduced and first calculated for real block copolymer ordered morphologies. Some implications of the results obtained for the design of the block copolymer thin films with improved permeability are discussed.

AB - We revisit the idea of the existence of the ordered block copolymer phase possessing diamond symmetry Fd (3) over barm (space group No. 227), which was first put forward within the framework of the strong segregation approach. For this purpose we study the order-disorder and order-order transitions in molten two-scale multiblock copolymers A(mN/2)(B(N/2)A(N/2))(n)B-mN/2 via the pseudo-spectral numerical procedure of the self-consistent field theory (SCFT). The phase diagram in the plane (f(C), (chi) over tilde), where f(C) = n/(m + n) and (chi) over tilde = chi N(m + n) is the effective energetic Flory-Huggins parameter, is built and some accompanying quantities are analyzed. Near the order-disorder transition line the phase diagram contains the regions where the lamellar, alternating gyroid, diamond and simple cubic phase, respectively, exist. With an increase of the degree of segregation, the diamond phase is replaced by a tetragonal array of cylinders (simple square) phase, which agrees with the preceding results obtained within the Leibler-like weak segregation theory, and with the SCFT calculations for a physically similar melt of linear ABC triblock copolymers with a non-selective middle block. Thus, the diamond morphology in the system under study is shown to exist as an essentially weak or moderately (not strongly) segregated phase. The ways to visualize the patterns of ordering in such morphologies are discussed. A new quantity (topological permeability) to characterize the transport properties in 3D bicontinuous morphologies is introduced and first calculated for real block copolymer ordered morphologies. Some implications of the results obtained for the design of the block copolymer thin films with improved permeability are discussed.

KW - OXIDE) TRIBLOCK COPOLYMERS

KW - STRONG-SEGREGATION THEORY

KW - BLOCK-COPOLYMERS

KW - MICROPHASE SEPARATION

KW - BICONTINUOUS PHASES

KW - DIBLOCK COPOLYMERS

KW - POLY(ISOPRENE-B-STYRENE-B-ETHYLENE OXIDE)

KW - MICRODOMAIN MORPHOLOGY

KW - EQUILIBRIUM MORPHOLOGY

KW - LENGTH SCALES

U2 - 10.1039/c1sm06688a

DO - 10.1039/c1sm06688a

M3 - Article

VL - 8

SP - 2159

EP - 2169

JO - Soft Matter

JF - Soft Matter

SN - 1744-683X

IS - 7

ER -