Hartmann Markus A, Fratzl Peter
Institute of Physics, University of Leoben, Franz-Josef Strasse 18, A-8700 Leoben, Austria.
Nano Lett. 2009 Oct;9(10):3603-7. doi: 10.1021/nl901816s.
Multivalent ions are known to allow for reversible cross-linking in soft biological materials, providing stiffness and extensibility via sacrificial bonds. We present a simple model where stiff nanoscale elements carrying negative charges are coupled in shear by divalent mobile cations in aqueous media. Such a shear coupling through a soft glue has, indeed, been proposed to operate in biological nanocomposites. While the coupling is elastic and brittle when the negative charges are periodically arranged, sufficient randomness in their distribution allows for large irreversible deformation.
已知多价离子可使软生物材料发生可逆交联，通过牺牲键提供刚度和可拉伸性。我们提出了一个简单模型，其中带有负电荷的刚性纳米级元件在水性介质中通过二价移动阳离子在剪切力作用下相互耦合。事实上，已经有人提出这种通过软胶水的剪切耦合作用存在于生物纳米复合材料中。当负电荷呈周期性排列时，这种耦合是弹性且脆性的，而其分布中足够的随机性则允许发生大的不可逆变形。
