Director orientation of nematic side-chain liquid crystalline polymers under shear flow: Comparison of a flow-aligning and a non-flow-aligning polysiloxane

Hartmut Siebert; Isabel Quijada-Garrido; Jan Vermant; Laurence Noirez; Wesley R. Burghardt; Claudia Schmidt

doi:10.1002/macp.200700248

Director orientation of nematic side-chain liquid crystalline polymers under shear flow: Comparison of a flow-aligning and a non-flow-aligning polysiloxane

Hartmut Siebert, Isabel Quijada-Garrido, Jan Vermant, Laurence Noirez, Wesley R. Burghardt, Claudia Schmidt^*

^*Corresponding author for this work

Chemical and Biological Engineering

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

10 Scopus citations

Abstract

The flow behavior and phase structure of two side-chain liquid-crystalline polysiloxanes with the same mesogens but different spacers of either four (PSi4) or six (PSi6) methylene groups are studied in the nematic phase by ²H NMR, polarization microscopy, and scattering of light, neutrons, and X-rays. PSi4 is flow-aligning, forming a monodomain with the director close to the flow direction, whereas PSi6 is non-flow-aligning showing a polydomain structure with a preferred director orientation corresponding to the log-rolling state. The flow behavior of PSi6 is related to the presence of strong smectic clusters. The director tilt in the smectic clusters of both polymers is reported.

Original language	English (US)
Pages (from-to)	2161-2172
Number of pages	12
Journal	Macromolecular Chemistry and Physics
Volume	208
Issue number	19-20
DOIs	https://doi.org/10.1002/macp.200700248
State	Published - Oct 24 2007

Keywords

Liquid-crystalline polymers (LCP)
NMR
Phase behavior
Scattering
Shear

ASJC Scopus subject areas

Condensed Matter Physics
Physical and Theoretical Chemistry
Polymers and Plastics
Organic Chemistry
Materials Chemistry

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10.1002/macp.200700248

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title = "Director orientation of nematic side-chain liquid crystalline polymers under shear flow: Comparison of a flow-aligning and a non-flow-aligning polysiloxane",

abstract = "The flow behavior and phase structure of two side-chain liquid-crystalline polysiloxanes with the same mesogens but different spacers of either four (PSi4) or six (PSi6) methylene groups are studied in the nematic phase by 2H NMR, polarization microscopy, and scattering of light, neutrons, and X-rays. PSi4 is flow-aligning, forming a monodomain with the director close to the flow direction, whereas PSi6 is non-flow-aligning showing a polydomain structure with a preferred director orientation corresponding to the log-rolling state. The flow behavior of PSi6 is related to the presence of strong smectic clusters. The director tilt in the smectic clusters of both polymers is reported.",

keywords = "Liquid-crystalline polymers (LCP), NMR, Phase behavior, Scattering, Shear",

author = "Hartmut Siebert and Isabel Quijada-Garrido and Jan Vermant and Laurence Noirez and Burghardt, {Wesley R.} and Claudia Schmidt",

year = "2007",

month = oct,

day = "24",

doi = "10.1002/macp.200700248",

language = "English (US)",

volume = "208",

pages = "2161--2172",

journal = "Macromolecular Chemistry and Physics",

issn = "1022-1352",

publisher = "Wiley-VCH Verlag",

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}

Director orientation of nematic side-chain liquid crystalline polymers under shear flow: Comparison of a flow-aligning and a non-flow-aligning polysiloxane. / Siebert, Hartmut; Quijada-Garrido, Isabel; Vermant, Jan et al.
In: Macromolecular Chemistry and Physics, Vol. 208, No. 19-20, 24.10.2007, p. 2161-2172.

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

TY - JOUR

T1 - Director orientation of nematic side-chain liquid crystalline polymers under shear flow

T2 - Comparison of a flow-aligning and a non-flow-aligning polysiloxane

AU - Siebert, Hartmut

AU - Quijada-Garrido, Isabel

AU - Vermant, Jan

AU - Noirez, Laurence

AU - Burghardt, Wesley R.

AU - Schmidt, Claudia

PY - 2007/10/24

Y1 - 2007/10/24

N2 - The flow behavior and phase structure of two side-chain liquid-crystalline polysiloxanes with the same mesogens but different spacers of either four (PSi4) or six (PSi6) methylene groups are studied in the nematic phase by 2H NMR, polarization microscopy, and scattering of light, neutrons, and X-rays. PSi4 is flow-aligning, forming a monodomain with the director close to the flow direction, whereas PSi6 is non-flow-aligning showing a polydomain structure with a preferred director orientation corresponding to the log-rolling state. The flow behavior of PSi6 is related to the presence of strong smectic clusters. The director tilt in the smectic clusters of both polymers is reported.

AB - The flow behavior and phase structure of two side-chain liquid-crystalline polysiloxanes with the same mesogens but different spacers of either four (PSi4) or six (PSi6) methylene groups are studied in the nematic phase by 2H NMR, polarization microscopy, and scattering of light, neutrons, and X-rays. PSi4 is flow-aligning, forming a monodomain with the director close to the flow direction, whereas PSi6 is non-flow-aligning showing a polydomain structure with a preferred director orientation corresponding to the log-rolling state. The flow behavior of PSi6 is related to the presence of strong smectic clusters. The director tilt in the smectic clusters of both polymers is reported.

KW - Liquid-crystalline polymers (LCP)

KW - NMR

KW - Phase behavior

KW - Scattering

KW - Shear

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JO - Macromolecular Chemistry and Physics

JF - Macromolecular Chemistry and Physics

IS - 19-20

ER -

Director orientation of nematic side-chain liquid crystalline polymers under shear flow: Comparison of a flow-aligning and a non-flow-aligning polysiloxane

Abstract

Keywords

ASJC Scopus subject areas

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