Anomalous viscosity jump during the volume phase transition of poly(N-isopropylacrylamide) particles

Research output: Contribution to journalJournal article – Annual report year: 2009Researchpeer-review

Without internal affiliation

Standard

Anomalous viscosity jump during the volume phase transition of poly(N-isopropylacrylamide) particles. / Howe, Andrew M.; Desrousseaux, Stephanie; Lunel, Laure S.; Tavacoli, Joe; Yow, Huai Nyin; Routh, Alexander F.

In: Advances in Colloid and Interface Science, Vol. 147-48, No. C, 2009, p. 124-131.

Research output: Contribution to journalJournal article – Annual report year: 2009Researchpeer-review

Harvard

APA

CBE

MLA

Vancouver

Author

Howe, Andrew M. ; Desrousseaux, Stephanie ; Lunel, Laure S. ; Tavacoli, Joe ; Yow, Huai Nyin ; Routh, Alexander F. / Anomalous viscosity jump during the volume phase transition of poly(N-isopropylacrylamide) particles. In: Advances in Colloid and Interface Science. 2009 ; Vol. 147-48, No. C. pp. 124-131.

Bibtex

@article{b8a1a9c7c44b4eb7b32dd80775dbc384,
title = "Anomalous viscosity jump during the volume phase transition of poly(N-isopropylacrylamide) particles",
abstract = "Dilute dispersions of cross-linked poly(N-isopropylacrylamide) (PNIPAM) microgels are studied by viscosity at low stress, dynamic light scattering and microelectrophoresis. The theological measurements at low stress demonstrate that upon heating through the volume phase transition temperature (VPTT) there is a stress-dependent increase in viscosity that passes through a maximum before failing close to the Value of water. On cooling only a much smaller viscosity rise is seen in the region of the VPTT. The particle size. measured in the absence of shear, decreases smoothly on increase in temperature as the microgel transitions through the VPTT from a swollen coil to a collapsed, globular latex. The magnitude of electrophoretic mobility of the swollen coil is low but of the collapsed globule is high, consistent with a charge-stabilised polymer latex. The collapse in particle size Occurs at a lower temperature than the increase in magnitude of electrophoretic mobility. The viscosity rise on heating occurs in the range of temperature over which the hydrodynamic particle size falls, then the viscosity falls as the magnitude of the electrophoretic mobility increases. We propose that the viscosity rise is a shear-induced association of microgel particles via inter-chain association and the findings are consistent with a two-stage collapse during the coil-globule transition. (C) 2008 Elsevier B.V. All rights reserved.",
keywords = "Aggregation, Aggregation during phase transition, LCST, PNIPAM, Shear-induced aggregation, Viscosity, Viscosity bump, VPTT",
author = "Howe, {Andrew M.} and Stephanie Desrousseaux and Lunel, {Laure S.} and Joe Tavacoli and Yow, {Huai Nyin} and Routh, {Alexander F.}",
year = "2009",
doi = "10.1016/j.cis.2008.07.008",
language = "English",
volume = "147-48",
pages = "124--131",
journal = "Advances in Colloid and Interface Science",
issn = "0001-8686",
publisher = "Elsevier B.V.",
number = "C",

}

RIS

TY - JOUR

T1 - Anomalous viscosity jump during the volume phase transition of poly(N-isopropylacrylamide) particles

AU - Howe, Andrew M.

AU - Desrousseaux, Stephanie

AU - Lunel, Laure S.

AU - Tavacoli, Joe

AU - Yow, Huai Nyin

AU - Routh, Alexander F.

PY - 2009

Y1 - 2009

N2 - Dilute dispersions of cross-linked poly(N-isopropylacrylamide) (PNIPAM) microgels are studied by viscosity at low stress, dynamic light scattering and microelectrophoresis. The theological measurements at low stress demonstrate that upon heating through the volume phase transition temperature (VPTT) there is a stress-dependent increase in viscosity that passes through a maximum before failing close to the Value of water. On cooling only a much smaller viscosity rise is seen in the region of the VPTT. The particle size. measured in the absence of shear, decreases smoothly on increase in temperature as the microgel transitions through the VPTT from a swollen coil to a collapsed, globular latex. The magnitude of electrophoretic mobility of the swollen coil is low but of the collapsed globule is high, consistent with a charge-stabilised polymer latex. The collapse in particle size Occurs at a lower temperature than the increase in magnitude of electrophoretic mobility. The viscosity rise on heating occurs in the range of temperature over which the hydrodynamic particle size falls, then the viscosity falls as the magnitude of the electrophoretic mobility increases. We propose that the viscosity rise is a shear-induced association of microgel particles via inter-chain association and the findings are consistent with a two-stage collapse during the coil-globule transition. (C) 2008 Elsevier B.V. All rights reserved.

AB - Dilute dispersions of cross-linked poly(N-isopropylacrylamide) (PNIPAM) microgels are studied by viscosity at low stress, dynamic light scattering and microelectrophoresis. The theological measurements at low stress demonstrate that upon heating through the volume phase transition temperature (VPTT) there is a stress-dependent increase in viscosity that passes through a maximum before failing close to the Value of water. On cooling only a much smaller viscosity rise is seen in the region of the VPTT. The particle size. measured in the absence of shear, decreases smoothly on increase in temperature as the microgel transitions through the VPTT from a swollen coil to a collapsed, globular latex. The magnitude of electrophoretic mobility of the swollen coil is low but of the collapsed globule is high, consistent with a charge-stabilised polymer latex. The collapse in particle size Occurs at a lower temperature than the increase in magnitude of electrophoretic mobility. The viscosity rise on heating occurs in the range of temperature over which the hydrodynamic particle size falls, then the viscosity falls as the magnitude of the electrophoretic mobility increases. We propose that the viscosity rise is a shear-induced association of microgel particles via inter-chain association and the findings are consistent with a two-stage collapse during the coil-globule transition. (C) 2008 Elsevier B.V. All rights reserved.

KW - Aggregation

KW - Aggregation during phase transition

KW - LCST

KW - PNIPAM

KW - Shear-induced aggregation

KW - Viscosity

KW - Viscosity bump

KW - VPTT

U2 - 10.1016/j.cis.2008.07.008

DO - 10.1016/j.cis.2008.07.008

M3 - Journal article

VL - 147-48

SP - 124

EP - 131

JO - Advances in Colloid and Interface Science

JF - Advances in Colloid and Interface Science

SN - 0001-8686

IS - C

ER -