Macroparticle diffusion in dextran solutions

Phillies, George D. J.; Gong, Jiaju; Li, Liyang; Rau, Anand; Zhang, Ker; Yu, Li Ping; Rollings, J. E.

doi:10.1021/j100353a050

Cited by 36 publications

(54 citation statements)

References 3 publications

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“…Agreement or disagreement with the effective viscosity approach is often rationalized using the model of Langevin and Rondolez ͓6,11,12,15,17,24,25͔, which treats the host rod medium as a static network ͑on the time scale of tracer motion͒ with an average pore size . Large tracers (RϾ ) will see a continuous fluid with viscosity ( ), while small tracers (RϽ ) experience a much smaller microviscosity which is close to 0 .…”

Section: Discussionmentioning

confidence: 99%

Self-diffusion and sedimentation of tracer spheres in (semi)dilute dispersions of rigid colloidal rods

2000

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Long-time self-diffusion and sedimentation of fluorescent tracer spheres in electrostatically stabilized dispersions of rigid colloidal host rods have been measured in situ with fluorescence recovery after photobleaching, and gravitational and ultracentrifugal sedimentation. The dynamics of silica tracer spheres of 39 and 370 nm radius was monitored in dispersions of host rods with aspect ratios 9.6 and 25.7 at various rod volume fractions. The translational and rotational diffusion coefficient of the host rods was obtained independently with dynamic light scattering and birefringence decay measurements. Our results indicate that sedimentation and long-time self-diffusion are determined by the same friction factor. Furthermore we find that, as long as the host rods are relatively mobile, tracer sphere sedimentation and long-time self-diffusion are governed by the macroscopic solution viscosity, regardless of the tracer and host rod size. However, when the host rods are immobilized, due to rod entanglements at higher volume fractions, tracer sphere dynamics depends strongly on the tracer size relative to the pore size of the host rod network. The large tracers are completely trapped in the network whereas the small tracer spheres remain mobile. Current models for tracer sphere motion in rod assemblies do not satisfactorily explain the complete dynamic regime covered by our experimental model system because the effect of host rod mobility is not properly taken into account.

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Section: Discussionmentioning

confidence: 99%

Self-diffusion and sedimentation of tracer spheres in (semi)dilute dispersions of rigid colloidal rods

2000

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“…The models include those 35 based on the obstruction effect [5-8], on hydrodynamic theories [9][10][11][12][13][14][15][16], on the free volume theory [17][18][19][20][21][22][23], and on anomalous diffusion [24,25]. The motion of bigger probes (r p in the range from fractions to several micrometers), is usually described in terms of microrheology [26,27].…”

Section: Accepted Manuscriptmentioning

confidence: 99%

Motion of nanoprobes in complex liquids within the framework of the length-scale dependent viscosity model

Kalwarczyk

Sozański

Ochab-Marcinek

et al. 2015

Advances in Colloid and Interface Science

118

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“…22,23 In their place, empirical relationships have been derived from studies of spherical probe diffusion in polymeric solutions, which, although based on a number of different physical models, all lead to formulas where the reduced diffusion coefficient (D/D 0 ) is a stretched exponential function of the polymer matrix concentration. [24][25][26] Although there are reservations about using such a model, its general applicability and utility have been demonstrated, for example in the cited references.…”

Section: Diffusion Coefficients In Starchmentioning

confidence: 99%

Fluorescence Recovery after Photobleaching as a Probe of Diffusion in Starch Systems

2006

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The diffusion coefficients of dextran probes of various molecular weights in starch solutions over a wide concentration range were carried out using fluorescent recovery after photobleaching (FRAP), combined with a confocal microscope and tracer probe diffusion. The technique is simple to implement and can be carried out using increasingly common microscopy apparatus, giving access to a wide variety of new structural and kinetic information. The data can be rationalized in terms of the effects of probe molecular weight and on matrix starch concentration and structure. This provides a new tool to investigate the behavior of systems where starch is an ingredient that contributes to the processing and textural properties of food.

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Macroparticle diffusion in dextran solutions

Abstract: A limiting current under concentration polarization J flux and A. At, electron, anion, proton, and cation flux, respectively Ce.d = (H°) ~f-M) (A.II.7b) At, 7m M cation reduced concentration, (M+)/C with Ox, Re oxidized, reduced forms site charge with sign

Cited by 36 publications

References 3 publications

Self-diffusion and sedimentation of tracer spheres in (semi)dilute dispersions of rigid colloidal rods

Self-diffusion and sedimentation of tracer spheres in (semi)dilute dispersions of rigid colloidal rods

Motion of nanoprobes in complex liquids within the framework of the length-scale dependent viscosity model

Fluorescence Recovery after Photobleaching as a Probe of Diffusion in Starch Systems

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