Nonaffine rubber elasticity for stiff polymer networks
Nonaffine rubber elasticity for stiff polymer networks
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DOI：
10.1103/physreve.76.031906
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发表时间：
2007-09-01
影响因子：
2.4
通讯作者：
Frey, Erwin
中科院分区：
文献类型：
--
作者：
Heussinger, Claus;Schaefer, Boris;Frey, Erwin
我们提出了一个理论的弹性交联刚性聚合物网络。刚性聚合物与柔性聚合物不同，是高度各向异性的弹性物体。类似于机械梁，刚性聚合物在弯曲时容易变形，而它们相对于拉伸力（“拉伸”）更刚性。与以前的方法不同，网络弹性来自拉伸模式，我们的理论正确地解释了软弯曲响应。一个自洽的有效介质的方法是用来计算的宏观弹性模量从微观表征的变形场的“软盘模式”-低能量的弯曲激发，保留了高度的非亲和性。表征出现的非亲和性的长度尺度由“纤维长度”l（f）给出，定义为聚合物保持直的尺度。计算的剪切模量的标度特性与最近在二维模型网络中获得的模拟结果非常一致。此外，我们的理论可用于合理化重建肌动蛋白网络中的大量流变学数据。
We present a theory for the elasticity of cross-linked stiff polymer networks. Stiff polymers, unlike their flexible counterparts, are highly anisotropic elastic objects. Similar to mechanical beams, stiff polymers easily deform in bending, while they are much stiffer with respect to tensile forces ("stretching"). Unlike in previous approaches, where network elasticity is derived from the stretching mode, our theory properly accounts for the soft bending response. A self-consistent effective medium approach is used to calculate the macroscopic elastic moduli starting from a microscopic characterization of the deformation field in terms of "floppy modes"-low-energy bending excitations that retain a high degree of nonaffinity. The length scale characterizing the emergent nonaffinity is given by the "fiber length" l(f), defined as the scale over which the polymers remain straight. The calculated scaling properties for the shear modulus are in excellent agreement with the results of recent simulations obtained in two-dimensional model networks. Furthermore, our theory can be applied to rationalize bulk rheological data in reconstituted actin networks.