Yethiraj Arun
Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin, Madison, WI 53706, USA.
J Chem Phys. 2006 Nov 28;125(20):204901. doi: 10.1063/1.2374884.
Monte Carlo simulations are presented for the static properties of highly branched polymer molecules. The molecules consist of a semiflexible backbone of hard-sphere monomers with semiflexible side chains, also composed of hard-sphere monomers, attached to either every backbone bead or every other backbone bead. The conformational properties and structure factor of this model are investigated as a function of the stiffness of the backbone and side chains. The average conformations of the side chains are similar to self-avoiding random walks. The simulations show that there is a stiffening of the backbone as degree of crowding is increased, for example, if the branch spacing is decreased or side chain length is increased. The persistence length of the backbone is relatively insensitive to the stiffness of the side chains over the range investigated. The simulations reproduce most of the qualitative features of the structure factor observed in experiment, although the magnitude of the stiffening of the backbone is smaller than in experiment.
本文给出了关于高度支化聚合物分子静态性质的蒙特卡罗模拟。这些分子由硬球单体构成的半柔性主链以及同样由硬球单体组成的半柔性侧链组成,侧链连接到每个主链珠子或每隔一个主链珠子上。研究了该模型的构象性质和结构因子随主链和侧链刚度的变化情况。侧链的平均构象类似于自回避随机行走。模拟结果表明,随着拥挤程度的增加,主链会变硬,例如,如果支链间距减小或侧链长度增加。在所研究的范围内,主链的持久长度对侧链的刚度相对不敏感。尽管主链变硬的程度比实验中的小,但模拟结果再现了实验中观察到的结构因子的大部分定性特征。