Institute for Computational Mechanics, Technische Universität München, 85748 Garching, Germany.
Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095-1596, USA and Department of Physics and Astronomy, UCLA, Los Angeles, California 90095-1596, USA.
Phys Rev Lett. 2014 Jun 13;112(23):238102. doi: 10.1103/PhysRevLett.112.238102. Epub 2014 Jun 10.
We present a theoretical and computational analysis of the rheology of networks made up of bundles of semiflexible filaments bound by transient cross-linkers. Such systems are ubiquitous in the cytoskeleton and can be formed in vitro using filamentous actin and various cross-linkers. We find that their high-frequency rheology is characterized by a scaling behavior that is quite distinct from that of networks of the well-studied single semiflexible filaments. This regime can be understood theoretically in terms of a length-scale-dependent bending modulus for bundles. Next, we observe new dissipative dynamics associated with the shear-induced disruption of the network at intermediate frequencies. Finally, at low frequencies, we encounter a region of non-Newtonian rheology characterized by power-law scaling. This regime is dominated by bundle dissolution and large-scale rearrangements of the network driven by equilibrium thermal fluctuations.
我们提出了一个理论和计算分析的粘弹性的网络组成的束半刚性细丝结合瞬变的交联剂。这种系统是无处不在的细胞骨架，可以形成体外使用丝状肌动蛋白和各种交联剂。我们发现，他们的高频流变学的特点是一种缩放行为，是从网络的研究很好的单丝截然不同。这一制度可以在理论上的依赖于长度尺度的弯曲模量束。接下来，我们观察到新的耗散动力学与剪切诱导的网络在中间频率的破坏。最后，在低频时，我们遇到了一个非牛顿流变学的特点是幂律标度的区域。这一制度是由束溶解和网络的大尺度重排为主的平衡热波动驱动。
