Polymer Institute, Slovak Academy of Sciences, Dubravská Cesta 9, Bratislava 842 36, Slovakia.
J Chem Phys. 2009 Dec 14;131(22):224903. doi: 10.1063/1.3271830.
We compare in detail the channel confinement of flexible and semiflexible chains over a broad range of confinements and chain lengths using molecular simulations. Flexible and semiflexible chains differ over the regimes involved under confinement. For the stiff chain we confirm a transition between strong and weak confinement at the tube diameter approximately equal to the chain persistence length. Deviations from the predicted behavior for confined semiflexible macromolecules in the tubelike channel under the weak confinement are explained by a tendency of chains toward ideal chain behavior. There are several indicators of this ideality based on the shape of chain extension R-confinement D curves, on the scaling of R with the chain length, on the structure factor of coil in the range of individual blobs in the channel, on ambiguity in introduction of excluded volume for confined stiff chains in theoretical treatments as well as on the reported experimental observation.
我们使用分子模拟详细比较了在广泛的约束和链长范围内柔性链和半柔性链的通道限制。在约束下，柔性链和半柔性链的区别很大。对于刚性链，我们在管直径约等于链持久长度的情况下证实了强约束和弱约束之间的转变。在管状通道中，在弱约束下，与受限半柔性大分子的预测行为的偏差可以通过链向理想链行为的趋势来解释。有几个基于链延伸 R-约束 D 曲线形状、R 与链长的标度、通道中单个斑点范围内线圈结构因子、受限刚性链在理论处理中排除体积的引入的不明确性以及报道的实验观察的理想性的指标。
