Frequency-dependent stiffening of semiflexible networks: A dynamical nonaffine to affine transition
Frequency-dependent stiffening of semiflexible networks: A dynamical nonaffine to affine transition
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DOI：
10.1103/physreve.82.061902
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发表时间：
2010-12-06
影响因子：
2.4
通讯作者：
Barkema, G. T.
中科院分区：
文献类型：
--
作者：
Huisman, E. M.;Storm, C.;Barkema, G. T.
通过将单一半柔性聚合物的力-伸长关系与朗之万方程相结合，以捕获穿过粘性介质的链的耗散动力学，我们研究了交联生物聚合物材料的动力学响应。我们发现，在低频下，网络变形是高度非仿射的，并且模量表现出较低的平台。在较高频率下，这种非亲和力会降低，而弹性模量会增加。随着频率的增加，越来越多的非仿射网络松弛模式被抑制，从而导致僵化。这种效应与单丝松弛模式导致的高频硬化有本质上的不同[F.吉蒂斯和 F.C.麦金托什，物理学家。 Rev. E 58, R1241 (1998)]，不仅在其机制方面，而且在其最终的缩放方面：G'(omega)类似于 omega(alpha)，且 alpha>3/4。这可以确定低生理相关频率下的非线性材料特性。
By combining the force-extension relation of single semiflexible polymers with a Langevin equation to capture the dissipative dynamics of chains moving through a viscous medium we study the dynamical response of cross-linked biopolymer materials. We find that at low frequencies the network deformations are highly nonaffine, and show a low plateau in the modulus. At higher frequencies, this nonaffinity decreases while the elastic modulus increases. With increasing frequency, more and more nonaffine network relaxation modes are suppressed, resulting in a stiffening. This effect is fundamentally different from the high-frequency stiffening due to the single-filament relaxation modes [F. Gittes and F.C. MacKintosh, Phys. Rev. E 58, R1241 (1998)], not only in terms of its mechanism but also in its resultant scaling: G'(omega)similar to omega(alpha) with alpha>3/4. This may determine nonlinear material properties at low, physiologically relevant frequencies.