Intermicellar Migration of Surfactant Molecules in Entangled Micellar Solutions

Kato, Tadashi; Terao, Toshiaki; Seimiya, Tsutomu

doi:10.1021/la00024a015

Cited by 55 publications

(76 citation statements)

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“…4, curve 3, may be explained by considering the convection in the aqueous solution. The same result was obtained in several studies [6,7], but they could not observe the decrease in the self-diffusion coefficient because the diffusion time in their measurement was 40-fold longer than that in this study.…”

Section: Estimation Of the Hydrodynamic Radius Of A Micellesupporting

confidence: 90%

“…Among the different physical methods to test the surfactant behavior in aqueous dispersion, pulsed field gradient nuclear magnetic resonance (PFG NMR) is a method to choose for the quantitative characterization of the molecular association and exchange processes between polymer and solvent. PFG NMR techniques give us the opportunity to measure the selfdiffusion of surfactant and solvent molecules in different spatial scales [1][2][3][4][5][6][7][8]. By PFG NMR, the surfactant aggregation and molecular exchange processes on the micelle surface may be investigated by analyzing the spin-echo attenuation or diffusional der at different diffusion times.…”

Section: Introductionmentioning

confidence: 99%

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Structural and dynamic properties of polyoxyethylene sorbitan monooleate micelle in water dispersion studied by pulsed field gradient NMR

et al. 2005

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The diffusion phenomenon of a nonionic surfactant, polyoxyethylene sorbitan monooleate (POE-SMO), micelle in aqueous solution was investigated by pulsed field gradient nuclear magnetic resonance (PFG NMR) with a high gradient strength of 17.4 T/m at the diffusion time t d varied from 3 to 300 ms. This high gradient strength allowed us to measure the slow self-diffusion coefficient of POE-SMO micelle, and the short diffusion time below 10 ms showed the restricted diffusion of the micelle. At the short t d the self-diffusion of the miceUe was restricted and the restricted sizes were 1.8, 1.5, and 0.8 gm for the POE-SMO concentration of 100, 200 and 300 mM, respectively, and 0.6 gm for the POE-SMO only. The possible reason of this restriction was assumed to be the formation of a spatial network ora micellar clustering. Furthermore, a proton exchange between water molecule and surfactant OH group on the micelle surface was proposed. With respect to this proposal, the residence time of the proton at the micelle surface and the thickness of the surface were investigated from proton self-diffusion coefficients by PFG NMR.

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Section: Estimation Of the Hydrodynamic Radius Of A Micellesupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Structural and dynamic properties of polyoxyethylene sorbitan monooleate micelle in water dispersion studied by pulsed field gradient NMR

et al. 2005

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“…3 and 4 are not consistent with the prediction of their theory. In order to explain the self-diffusion results, we have proposed a diffusion model considering intermicellar migration at entanglement points [5,6]. According to this model, the self-diffusion coefficient can be expressed as…”

Section: Methodsmentioning

confidence: 99%

“…Double-logarithmic plots of self-diffusion coefficient of Cl6E7 vs. surfactant concentration[5][6][7]. The vertical-strong correlation between D and ~s in the concentration range 2 20 wt%.…”

mentioning

confidence: 92%

“…In the previous studies [5][6][7][8], we have measured light scattering, small-angle X-ray scattering (SAXS), viscosity, and pulsed-gradient spin echo (PGSE) on semidilute solutions of nonionic surfactants C16E7, C14E6, and C14Ev (C~E,, represents a chemical formula C,H2,,+I(OCzH4)mOH). Light scattering results suggest that worm-like micelles are entangled above about To -15 K where To is the lower critical solution temperature (about 35 ~ for C16E7).…”

Section: Introductionmentioning

confidence: 99%

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Structure and dynamics of networks formed in concentrated solutions of nonionic surfactants

Kato

Taguchi

Nozu

Formation and Dynamics of Self-Organized Structures in Surfactants and Polymer Solutions

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Dynamic light scattering has been measured on semidilute solutions of nonionic surfactant (C16E7) where formation of networks of worm-like micelles is suggested from our previous studies. In addition to the diffusion mode, we have found the so-called slow mode in time correlation function of the scattered field. By comparing concentration and temperature dependence of the correlation time of the slow mode with that of the surfactant selfdiffusion coefficient, dynamics of networks are discussed.

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