Associative thickeners: NMR self-diffusion and rheology studies of aqueous solutions of hydrophobically modified poly(oxyethylene) polymers

Walderhaug, Harald; Hansen, Finn Knut; Abrahmsen, Susanna; Persson, Karin; Stilbs, Peter

doi:10.1021/j100133a033

Cited by 90 publications

(105 citation statements)

References 10 publications

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“…We would like to point out that the correlation between the ''macroscopic'' viscos-relaxation time for both polymers, is present in the whole concentration range. Note that the relaxation rate, G, of this ity and the ''microscopic'' D NMR is in good accord with previous studies (9,10,12). According to the Stokes-Ein-mode was proportional to the square of the scattering vector (q Å (4pn 0 /l 0 )sin u/2, where n 0 is the solvent refractive stein relation the viscosity should be inversely related to the D NMR , at least in the dilute concentration region.…”

Section: Resultssupporting

confidence: 91%

A Comparison between Hydrophobically End-Capped Poly(ethylene oxide) with Ether and Urethane Bonds

Alami

Abrahmsén-Alami

Vasilescu

et al. 1997

Journal of Colloid and Interface Science

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Section: Resultssupporting

confidence: 91%

A Comparison between Hydrophobically End-Capped Poly(ethylene oxide) with Ether and Urethane Bonds

Alami

Abrahmsén-Alami

Vasilescu

et al. 1997

Journal of Colloid and Interface Science

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“…For the first time, Pulsed Field Gradient-Nuclear Magnetic Resonance, a powerful noninvasive tool for studying the dynamics and structure of complex gels, has been used to measure diffusion of probe molecules in aqueous solutions/gels of noncommercial purified pig polymer matrices [3][4][5][6][7][8] and to obtain information regarding biological systems. For example, an investigation focused on cartilage (a dense and bone-like, yet soft, connective tissue in the body) illustrates the strength of PFG-NMR and that structural information related to different length scales of the matrix can be provided.…”

Section: Introductionmentioning

confidence: 99%

PFG‐NMR diffusometry: A tool for investigating the structure and dynamics of noncommercial purified pig gastric mucin in a wide range of concentrations

et al. 2007

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For the first time, Pulsed Field Gradient-Nuclear Magnetic Resonance, a powerful noninvasive tool for studying the dynamics and structure of complex gels, has been used to measure diffusion of probe molecules in aqueous solutions/gels of noncommercial purified pig gastric mucin (PGM), in a concentration range up to 5 wt %. Complementary data were obtained from rheology measurements. The combination of techniques revealed a strong pH dependency of the structure of the PGM samples while changes in concentration, ionic strength, and temperature appeared to induce less pronounced alterations. Viscosity was found to vary in a nonmonotonous way with pH, with the more viscous solutions found at intermediate pH. We propose that this finding is due to a reduced charge density at lower pH, which is expected to continuously increase the relative importance of hydrophobic associations. The results suggest a loose network of expanded fully charged PGM molecules with considerable mobility at neutral pH (pH 7.4). At intermediate pH (pH 4), a three-dimensional expanded network is favored. At pH 1, the charge density is low and microphase separation occurs since hydrophobic associations prevail. This leads to the formation of clusters concentrated in PGM molecules separated by regions depleted in PGM. The results obtained increase our knowledge about the gastric mucosal layer, which in vivo contains mucin in the same concentration range as that of the samples investigated here.

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“…This is essentially identical to the suggestion of Semenov et al 9 At sufficiently high concentration, the flower-like micelles link into a progressively growing network that eventually spans the entire solution, forming a three-dimensional network. 6,[8][9][10][11][12] These polymers are used as rheology modifiers in water-born coatings such as paints and paper coatings, adhesives, in sealants, and in oil-recovery applications. When these polymers are added to water in small amounts, the viscosity greatly increases and the solution thickens.…”

Section: Introductionmentioning

confidence: 99%

Self-diffusion of hydrophobically end-capped polyethylene oxide urethane resin by using pulsed-gradient spin echo NMR spetroscopy

et al. 2003

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Hydrophobically End-capped polyethylene oxide Urethane Resin(HEUR)-associating polymers, HEUR 35(8), HEUR 35 (12), and HEUR 35 (18), comprise a polyethylene oxide (PEO) having a molecular weight of 35,000 that is end capped with two C 8 H 17 , C 12 H 25 , and C 18 H 37 alkyl chains, respectively. These associating polymers were synthesized by condensation reactions with polyethylene oxides and alkyl isocyanates. The self-diffusion coefficients of HEUR-associating polymers were measured in aqueous solution by pulsed-gradient spin-echo (PGSE) nuclear magnetic resonance (NMR) spectroscopy. All polymers underwent a decrease in their mean diffusion coefficients as the concentration was increased. However, the dispersion of the diffusion coefficients, β, about the mean fluctuated with changes in concentration. The large dispersion at low concentrations of HEUR 35(8) and HEUR 35 (12) is related to the interaction between hydrophobic end groups, and the large dispersion at high concentrations of HEUR 35(18) is correlated with transient network formation. These results are valuable for predicting the associating mechanism of the large aggregates before and after their critical micelle concentration.

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Associative thickeners: NMR self-diffusion and rheology studies of aqueous solutions of hydrophobically modified poly(oxyethylene) polymers

Cited by 90 publications

References 10 publications

A Comparison between Hydrophobically End-Capped Poly(ethylene oxide) with Ether and Urethane Bonds

A Comparison between Hydrophobically End-Capped Poly(ethylene oxide) with Ether and Urethane Bonds

PFG‐NMR diffusometry: A tool for investigating the structure and dynamics of noncommercial purified pig gastric mucin in a wide range of concentrations

Self-diffusion of hydrophobically end-capped polyethylene oxide urethane resin by using pulsed-gradient spin echo NMR spetroscopy

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