Viscoelastic properties of semiflexible filamentous bacteriophage fd
Viscoelastic properties of semiflexible filamentous bacteriophage fd
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DOI：
10.1103/physreve.62.5509
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发表时间：
2000-10-01
影响因子：
2.4
通讯作者：
Tang, JX
中科院分区：
文献类型：
--
作者：
Schmidt, FG;Hinner, B;Tang, JX
在最近的一些研究中，细胞骨架蛋白丝F-肌动蛋白已被视为半柔性丝的模型物理系统。在这项工作中，我们研究了纠缠的解决方案的丝状噬菌体FD作为替代F-肌动蛋白具有相似的物理参数的粘弹性。我们提出了在0.01 < f < 4 Hz的频率范围内，对浓度范围为5 < c < 15 mg/ml的fd溶液，分别测量粘弹性储存模量和损耗模量G '（f）和G双撇（f）的微观流变学和宏观流变学方法。G '（f）的狭窄且倾斜的平台状区域的开始位于2 Hz左右。平台模量随浓度的变化服从幂律G（N）/（1.4+/-0.3），与F-肌动蛋白的缠结溶液相似。在低频区域，粘弹性模量的频率依赖性可以用幂律G '（f）比例tof（0.9-1.2）和G双素数（f）比例tof（0.7-0.9）来描述，这明显偏离了G'（f）比例tof（2）和G双素数（f）比例tof（1）的简单理论预测。后一种行为在当前的半柔性细丝网络理论框架内还无法理解。对于低剪切速率极限下的动态粘度，发现η（0）与浓度成正比于c（2.6），最后，观察到末端弛豫时间T（d）与浓度成正比于c。
The cytoskeletal protein filament F-actin has been treated in a number of recent studies as a model physical system for semiflexible filaments. In this work, we studied the viscoelastic properties of entangled solutions of the filamentous bacteriophage fd as an alternative to F-actin with similar physical parameters. We present both microrheometric and macrorheometric measurements of the viscoelastic storage and loss moduli, G'(f) and G double prime (f), respectively, in a frequency range 0.01 < f < 4 Hz, for fd solutions in the concentration range 5 < c < 15 mg/ml. The onset of a narrow and slanted plateaulike region of G'(f) is located at around 2 Hz. The variation of the plateau modulus with concentration obeys a power law G(N)'proportional toc(1.4+/-0.3), similar to that found for entangled solutions of F-actin. In the low-frequency regime, the frequency dependence of the viscoelastic moduli can be described by power laws G'(f)proportional tof(0.9-1.2) and G double prime (f)proportional tof(0.7-0.9), which deviate significantly from the simple theoretical predictions of G'(f)proportional tof(2) and G double prime (f)proportional tof(1). The latter behavior cannot yet be understood within the framework of current theories of semiflexible filament networks. For the dynamic viscosity at the low sheer rate limit, a concentration dependence of eta (0)proportional toc(2.6) was found. Finally, a linear scaling of the terminal relaxation time with concentration, T(d)proportional toc, was observed.