Vertical vs Lateral Macrophase Separation in Thin Films of Block Copolymer Mixtures

Computer Simulations and GISAXS Experiments

Anatoly V. Berezkin, Florian Jung, Dorthe Posselt, Detlef M. Smilgies, Christine M. Papadakis

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Mixtures of two diblock copolymers of very different lengths may feature both macro- and microphase separation; however, not much is known about the mechanisms of separation in diblock copolymer thin films. In the present work, we study thin films of mixtures of two compositionally symmetric block copolymers, both in the one-phase and in the two-phase state, combining coarse-grained molecular simulations (dissipative particle dynamics, DPD) with scattering experiments (grazing-incidence small-angle X-ray scattering, GISAXS). We reveal that the film thickness and selective adsorption of different blocks to the substrate control the distribution of macrophases within the film as well as the orientation of the lamellae therein. In thick films, the mixtures separate in the vertical direction into three layers: Two layers being rich in short copolymers are formed near the film interfaces, whereas a layer being rich in long copolymers is located in the film core. The lamellar orientation in the layers rich in short copolymers is dictated by the surface selectivity, and this orientation only weakly affects the vertical orientation of lamellae in the film core. This provides the opportunity to control the domain orientation in the copolymer films by mixing block copolymers with low-molecular additives instead of relying on a more complicated chemical modification of the substrate. In thinner films, a lateral phase separation appears.
Original languageEnglish
JournalACS Applied Materials and Interfaces
Volume9
Issue number37
Pages (from-to)31291−31301
Number of pages11
ISSN1944-8244
DOIs
Publication statusPublished - 2017

Cite this

Berezkin, Anatoly V. ; Jung, Florian ; Posselt, Dorthe ; Smilgies, Detlef M. ; Papadakis, Christine M. / Vertical vs Lateral Macrophase Separation in Thin Films of Block Copolymer Mixtures : Computer Simulations and GISAXS Experiments. In: ACS Applied Materials and Interfaces. 2017 ; Vol. 9, No. 37. pp. 31291−31301.
@article{64efe83584214f5abe21cb08271f4cb3,
title = "Vertical vs Lateral Macrophase Separation in Thin Films of Block Copolymer Mixtures: Computer Simulations and GISAXS Experiments",
abstract = "Mixtures of two diblock copolymers of very different lengths may feature both macro- and microphase separation; however, not much is known about the mechanisms of separation in diblock copolymer thin films. In the present work, we study thin films of mixtures of two compositionally symmetric block copolymers, both in the one-phase and in the two-phase state, combining coarse-grained molecular simulations (dissipative particle dynamics, DPD) with scattering experiments (grazing-incidence small-angle X-ray scattering, GISAXS). We reveal that the film thickness and selective adsorption of different blocks to the substrate control the distribution of macrophases within the film as well as the orientation of the lamellae therein. In thick films, the mixtures separate in the vertical direction into three layers: Two layers being rich in short copolymers are formed near the film interfaces, whereas a layer being rich in long copolymers is located in the film core. The lamellar orientation in the layers rich in short copolymers is dictated by the surface selectivity, and this orientation only weakly affects the vertical orientation of lamellae in the film core. This provides the opportunity to control the domain orientation in the copolymer films by mixing block copolymers with low-molecular additives instead of relying on a more complicated chemical modification of the substrate. In thinner films, a lateral phase separation appears.",
author = "Berezkin, {Anatoly V.} and Florian Jung and Dorthe Posselt and Smilgies, {Detlef M.} and Papadakis, {Christine M.}",
year = "2017",
doi = "10.1021/acsami.6b16563",
language = "English",
volume = "9",
pages = "31291−31301",
journal = "ACS Applied Materials and Interfaces",
issn = "1944-8244",
publisher = "American Chemical Society",
number = "37",

}

Vertical vs Lateral Macrophase Separation in Thin Films of Block Copolymer Mixtures : Computer Simulations and GISAXS Experiments. / Berezkin, Anatoly V.; Jung, Florian; Posselt, Dorthe; Smilgies, Detlef M.; Papadakis, Christine M.

In: ACS Applied Materials and Interfaces, Vol. 9, No. 37, 2017, p. 31291−31301.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Vertical vs Lateral Macrophase Separation in Thin Films of Block Copolymer Mixtures

T2 - Computer Simulations and GISAXS Experiments

AU - Berezkin, Anatoly V.

AU - Jung, Florian

AU - Posselt, Dorthe

AU - Smilgies, Detlef M.

AU - Papadakis, Christine M.

PY - 2017

Y1 - 2017

N2 - Mixtures of two diblock copolymers of very different lengths may feature both macro- and microphase separation; however, not much is known about the mechanisms of separation in diblock copolymer thin films. In the present work, we study thin films of mixtures of two compositionally symmetric block copolymers, both in the one-phase and in the two-phase state, combining coarse-grained molecular simulations (dissipative particle dynamics, DPD) with scattering experiments (grazing-incidence small-angle X-ray scattering, GISAXS). We reveal that the film thickness and selective adsorption of different blocks to the substrate control the distribution of macrophases within the film as well as the orientation of the lamellae therein. In thick films, the mixtures separate in the vertical direction into three layers: Two layers being rich in short copolymers are formed near the film interfaces, whereas a layer being rich in long copolymers is located in the film core. The lamellar orientation in the layers rich in short copolymers is dictated by the surface selectivity, and this orientation only weakly affects the vertical orientation of lamellae in the film core. This provides the opportunity to control the domain orientation in the copolymer films by mixing block copolymers with low-molecular additives instead of relying on a more complicated chemical modification of the substrate. In thinner films, a lateral phase separation appears.

AB - Mixtures of two diblock copolymers of very different lengths may feature both macro- and microphase separation; however, not much is known about the mechanisms of separation in diblock copolymer thin films. In the present work, we study thin films of mixtures of two compositionally symmetric block copolymers, both in the one-phase and in the two-phase state, combining coarse-grained molecular simulations (dissipative particle dynamics, DPD) with scattering experiments (grazing-incidence small-angle X-ray scattering, GISAXS). We reveal that the film thickness and selective adsorption of different blocks to the substrate control the distribution of macrophases within the film as well as the orientation of the lamellae therein. In thick films, the mixtures separate in the vertical direction into three layers: Two layers being rich in short copolymers are formed near the film interfaces, whereas a layer being rich in long copolymers is located in the film core. The lamellar orientation in the layers rich in short copolymers is dictated by the surface selectivity, and this orientation only weakly affects the vertical orientation of lamellae in the film core. This provides the opportunity to control the domain orientation in the copolymer films by mixing block copolymers with low-molecular additives instead of relying on a more complicated chemical modification of the substrate. In thinner films, a lateral phase separation appears.

U2 - 10.1021/acsami.6b16563

DO - 10.1021/acsami.6b16563

M3 - Journal article

VL - 9

SP - 31291−31301

JO - ACS Applied Materials and Interfaces

JF - ACS Applied Materials and Interfaces

SN - 1944-8244

IS - 37

ER -