Soik Samuel M, Sharp Tristan A
Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Phys Rev E. 2019 May;99(5-1):052505. doi: 10.1103/PhysRevE.99.052505.
We use molecular simulations to study jamming of a crumpled bead-spring model polymer in a finite container and compare to jamming of repulsive spheres. After proper constraint counting, the onset of rigidity is seen to occur isostatically as in the case of repulsive spheres. Despite this commonality, the presence of the curved container wall and polymer backbone bonds introduce new mechanical properties. Notably, these include additional bands in the vibrational density of states that reflect the material structure as well as oscillations in local contact number and density near the wall but with lower amplitude for polymers. Polymers have fewer boundary contacts, and this low-density surface layer strongly reduces the global bulk modulus. We further show that bulk-modulus dependence on backbone stiffness can be described by a model of stiffnesses in series and discuss potential experimental and biological applications.
我们使用分子模拟来研究有限容器中皱缩的珠簧模型聚合物的堵塞情况，并与排斥性球体的堵塞进行比较。经过适当的约束计数后，发现刚性的起始如同排斥性球体的情况一样以等静压方式发生。尽管有这种共性，但弯曲的容器壁和聚合物主链键的存在引入了新的力学性能。值得注意的是，这些包括反映材料结构的振动态密度中的附加能带，以及壁附近局部接触数和密度的振荡，但聚合物的振荡幅度较低。聚合物的边界接触较少，并且这种低密度表面层强烈降低了整体体积模量。我们进一步表明，体积模量对主链刚度的依赖性可以用串联刚度模型来描述，并讨论了潜在的实验和生物学应用。
