Rheology of aqueous solutions of hydrophobically modified polyacrylamides and surfactants

Evis K. Penott-Chang, Laura Gouveia, Iraima J. Fernández, Alejandro J. Müller, Antonio Díaz-Barrios, Avelino E Saez

Research output: Contribution to journalArticle

58 Citations (Scopus)

Abstract

Hydrophobically modified polyacrylamides (HMPAM) were synthesized by aqueous micellar copolymerization using as hydrophobic monomers n-decylacrylamide and t-octyl-acrylamide. The synthesized polymers contained between 0.5 and 1.5 mol.% of the hydrophobic groups. Shear rheology experiments showed a viscosity enhancement for most copolymers in comparison with the homopolymers due to intermolecular hydrophobic associations, which lead to shear thickening for copolymers with 1 mol.% or more hydrophobic groups. An increase in the ionic strength of the solutions strengthens these hydrophobic associations. The addition of an anionic surfactant (sodium dodecyl sulfate, SDS) produced viscosity increases due to intermolecular bridging caused by the formation of mixed micelles between the hydrophobic groups and the surfactant. Higher surfactant concentrations lead to a viscosity reduction due to electrostatic screening of associations between hydrophobic side groups of different chains. The same behavior was observed in the spherical micelle concentration regime for the cationic surfactant cetyltrimethylammonium p-toluenesulfonate (CTAT), but at higher surfactant concentrations, entanglements between the copolymers and worm-like micelles lead to further increases in solution viscosity.

Original languageEnglish (US)
Pages (from-to)99-106
Number of pages8
JournalColloids and Surfaces A: Physicochemical and Engineering Aspects
Volume295
Issue number1-3
DOIs
StatePublished - Mar 1 2007

Fingerprint

Polyacrylates
Rheology
rheology
Surface-Active Agents
Micelles
Surface active agents
surfactants
Viscosity
aqueous solutions
Copolymers
viscosity
micelles
copolymers
Acrylamide
Anionic surfactants
Cationic surfactants
shear
Sodium dodecyl sulfate
Ionic strength
Homopolymerization

Keywords

  • Associating polymers
  • Hydrophobically modified polymers
  • Worm-like micelles

ASJC Scopus subject areas

  • Colloid and Surface Chemistry
  • Physical and Theoretical Chemistry

Cite this

Rheology of aqueous solutions of hydrophobically modified polyacrylamides and surfactants. / Penott-Chang, Evis K.; Gouveia, Laura; Fernández, Iraima J.; Müller, Alejandro J.; Díaz-Barrios, Antonio; Saez, Avelino E.

In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, Vol. 295, No. 1-3, 01.03.2007, p. 99-106.

Research output: Contribution to journalArticle

Penott-Chang, Evis K. ; Gouveia, Laura ; Fernández, Iraima J. ; Müller, Alejandro J. ; Díaz-Barrios, Antonio ; Saez, Avelino E. / Rheology of aqueous solutions of hydrophobically modified polyacrylamides and surfactants. In: Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2007 ; Vol. 295, No. 1-3. pp. 99-106.
@article{ff717633989c4d3b811d149f2df3f484,
title = "Rheology of aqueous solutions of hydrophobically modified polyacrylamides and surfactants",
abstract = "Hydrophobically modified polyacrylamides (HMPAM) were synthesized by aqueous micellar copolymerization using as hydrophobic monomers n-decylacrylamide and t-octyl-acrylamide. The synthesized polymers contained between 0.5 and 1.5 mol.{\%} of the hydrophobic groups. Shear rheology experiments showed a viscosity enhancement for most copolymers in comparison with the homopolymers due to intermolecular hydrophobic associations, which lead to shear thickening for copolymers with 1 mol.{\%} or more hydrophobic groups. An increase in the ionic strength of the solutions strengthens these hydrophobic associations. The addition of an anionic surfactant (sodium dodecyl sulfate, SDS) produced viscosity increases due to intermolecular bridging caused by the formation of mixed micelles between the hydrophobic groups and the surfactant. Higher surfactant concentrations lead to a viscosity reduction due to electrostatic screening of associations between hydrophobic side groups of different chains. The same behavior was observed in the spherical micelle concentration regime for the cationic surfactant cetyltrimethylammonium p-toluenesulfonate (CTAT), but at higher surfactant concentrations, entanglements between the copolymers and worm-like micelles lead to further increases in solution viscosity.",
keywords = "Associating polymers, Hydrophobically modified polymers, Worm-like micelles",
author = "Penott-Chang, {Evis K.} and Laura Gouveia and Fern{\'a}ndez, {Iraima J.} and M{\"u}ller, {Alejandro J.} and Antonio D{\'i}az-Barrios and Saez, {Avelino E}",
year = "2007",
month = "3",
day = "1",
doi = "10.1016/j.colsurfa.2006.08.038",
language = "English (US)",
volume = "295",
pages = "99--106",
journal = "Colloids and Surfaces A: Physicochemical and Engineering Aspects",
issn = "0927-7757",
publisher = "Elsevier",
number = "1-3",

}

TY - JOUR

T1 - Rheology of aqueous solutions of hydrophobically modified polyacrylamides and surfactants

AU - Penott-Chang, Evis K.

AU - Gouveia, Laura

AU - Fernández, Iraima J.

AU - Müller, Alejandro J.

AU - Díaz-Barrios, Antonio

AU - Saez, Avelino E

PY - 2007/3/1

Y1 - 2007/3/1

N2 - Hydrophobically modified polyacrylamides (HMPAM) were synthesized by aqueous micellar copolymerization using as hydrophobic monomers n-decylacrylamide and t-octyl-acrylamide. The synthesized polymers contained between 0.5 and 1.5 mol.% of the hydrophobic groups. Shear rheology experiments showed a viscosity enhancement for most copolymers in comparison with the homopolymers due to intermolecular hydrophobic associations, which lead to shear thickening for copolymers with 1 mol.% or more hydrophobic groups. An increase in the ionic strength of the solutions strengthens these hydrophobic associations. The addition of an anionic surfactant (sodium dodecyl sulfate, SDS) produced viscosity increases due to intermolecular bridging caused by the formation of mixed micelles between the hydrophobic groups and the surfactant. Higher surfactant concentrations lead to a viscosity reduction due to electrostatic screening of associations between hydrophobic side groups of different chains. The same behavior was observed in the spherical micelle concentration regime for the cationic surfactant cetyltrimethylammonium p-toluenesulfonate (CTAT), but at higher surfactant concentrations, entanglements between the copolymers and worm-like micelles lead to further increases in solution viscosity.

AB - Hydrophobically modified polyacrylamides (HMPAM) were synthesized by aqueous micellar copolymerization using as hydrophobic monomers n-decylacrylamide and t-octyl-acrylamide. The synthesized polymers contained between 0.5 and 1.5 mol.% of the hydrophobic groups. Shear rheology experiments showed a viscosity enhancement for most copolymers in comparison with the homopolymers due to intermolecular hydrophobic associations, which lead to shear thickening for copolymers with 1 mol.% or more hydrophobic groups. An increase in the ionic strength of the solutions strengthens these hydrophobic associations. The addition of an anionic surfactant (sodium dodecyl sulfate, SDS) produced viscosity increases due to intermolecular bridging caused by the formation of mixed micelles between the hydrophobic groups and the surfactant. Higher surfactant concentrations lead to a viscosity reduction due to electrostatic screening of associations between hydrophobic side groups of different chains. The same behavior was observed in the spherical micelle concentration regime for the cationic surfactant cetyltrimethylammonium p-toluenesulfonate (CTAT), but at higher surfactant concentrations, entanglements between the copolymers and worm-like micelles lead to further increases in solution viscosity.

KW - Associating polymers

KW - Hydrophobically modified polymers

KW - Worm-like micelles

UR - http://www.scopus.com/inward/record.url?scp=33846811729&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33846811729&partnerID=8YFLogxK

U2 - 10.1016/j.colsurfa.2006.08.038

DO - 10.1016/j.colsurfa.2006.08.038

M3 - Article

AN - SCOPUS:33846811729

VL - 295

SP - 99

EP - 106

JO - Colloids and Surfaces A: Physicochemical and Engineering Aspects

JF - Colloids and Surfaces A: Physicochemical and Engineering Aspects

SN - 0927-7757

IS - 1-3

ER -