Diffusion of spheres in crowded suspensions of rods

被引:58
作者
Kang, K [1 ]
Gapinski, J
Lettinga, MP
Buitenhuis, J
Meier, G
Ratajczyk, M
Dhont, JKG
Patkowski, A
机构
[1] Forschungszentrum Jul, Inst Festkorper Forsch, D-52425 Julich, Germany
[2] Adam Mickiewicz Univ, Inst Phys, PL-61614 Poznan, Poland
关键词
D O I
10.1063/1.1834895
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Translational tracer diffusion of spherical macromolecules in crowded suspensions of rodlike colloids is investigated. Experiments are done using several kinds of spherical tracers in fd-virus suspensions. A wide range of size ratios L/2a of the length L of the rods and the diameter 2a of the tracer sphere is covered by combining several experimental methods: fluorescence correlation spectroscopy for small tracer spheres, dynamic light scattering for intermediate sized spheres, and video microscopy for large spheres. Fluorescence correlation spectroscopy is shown to measure long-time diffusion only for relatively small tracer spheres. Scaling of diffusion coefficients with a/xi, predicted for static networks, is not found for our dynamical network of rods (with the mesh size of the network). Self-diffusion of tracer spheres in the dynamical network of freely suspended rods is thus fundamentally different as compared to cross-linked networks. A theory is developed for the rod-concentration dependence of the translational diffusion coefficient at low rod concentrations for freely suspended rods. The proposed theory is based on a variational solution of the appropriate Smoluchowski equation without hydrodynamic interactions. The theory can, in principle, be further developed to describe diffusion through dynamical networks at higher rod concentrations with the inclusion of hydrodynamic interactions. Quantitative agreement with the experiments is found for large tracer spheres, and qualitative agreement for smaller spheres. This is probably due to the increasing importance of hydrodynamic interactions as compared to direct interactions as the size of the tracer sphere decreases. (C) 2005 American Institute of Physics.
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页数:13
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共 53 条
[1]   Entropically driven microphase transitions in mixtures of colloidal rods and spheres [J].
Adams, M ;
Dogic, Z ;
Keller, SL ;
Fraden, S .
NATURE, 1998, 393 (6683) :349-352
[2]   HYDRODYNAMIC SCREENING AND PARTICLE DYNAMICS IN POROUS-MEDIA, SEMIDILUTE POLYMER-SOLUTIONS AND POLYMER GELS [J].
ALTENBERGER, AR ;
TIRRELL, M ;
DAHLER, JS .
JOURNAL OF CHEMICAL PHYSICS, 1986, 84 (09) :5122-5130
[3]   Multiple-particle tracking measurements of heterogeneities in solutions of actin filaments and actin bundles [J].
Apgar, J ;
Tseng, Y ;
Fedorov, E ;
Herwig, MB ;
Almo, SC ;
Wirtz, D .
BIOPHYSICAL JOURNAL, 2000, 79 (02) :1095-1106
[4]   FLUORESCENCE CORRELATION SPECTROSCOPY AS A PROBE OF MOLECULAR-DYNAMICS [J].
ARAGON, SR ;
PECORA, R .
JOURNAL OF CHEMICAL PHYSICS, 1976, 64 (04) :1791-1803
[5]   FLUORESCENCE CORRELATION SPECTROSCOPY AND BROWNIAN ROTATIONAL DIFFUSION [J].
ARAGON, SR ;
PECORA, R .
BIOPOLYMERS, 1975, 14 (01) :119-137
[6]   Translational diffusion of globular proteins in the cytoplasm of cultured muscle cells [J].
Arrio-Dupont, M ;
Foucault, G ;
Vacher, M ;
Devaux, PF ;
Cribier, S .
BIOPHYSICAL JOURNAL, 2000, 78 (02) :901-907
[7]   MODE COUPLING THEORY APPROACH TO THE LIQUID-STATE DYNAMICS [J].
Bagchi, Biman ;
Bhattacharyya, Sarika .
ADVANCES IN CHEMICAL PHYSICS <D>, 2001, 116 :67-221
[8]   SEDIMENTATION IN A DILUTE DISPERSION OF SPHERES [J].
BATCHELOR, GK .
JOURNAL OF FLUID MECHANICS, 1972, 52 (MAR28) :245-+
[9]   SHORT-TIME DIFFUSION-COEFFICIENTS AND HIGH-FREQUENCY VISCOSITY OF DILUTE SUSPENSIONS OF SPHERICAL BROWNIAN PARTICLES [J].
CICHOCKI, B ;
FELDERHOF, BU .
JOURNAL OF CHEMICAL PHYSICS, 1988, 89 (02) :1049-1054
[10]   Methods of digital video microscopy for colloidal studies [J].
Crocker, JC ;
Grier, DG .
JOURNAL OF COLLOID AND INTERFACE SCIENCE, 1996, 179 (01) :298-310