Crystallization of finite-extensible nonlinear elastic Lennard-Jones coarse-grained polymers.
Crystallization of finite-extensible nonlinear elastic Lennard-Jones coarse-grained polymers.
复制标题
有限可扩展非线性弹性伦纳德-琼斯粗粒聚合物的结晶。
作者：
J. Morthomas;C. Fusco;Zengqiang Zhai;O. Lame;M. Perez
用分子动力学模拟方法研究了一个简单的粗粒有限可伸展非线性弹性（FENE）Lennard-Jones（LJ）聚合物模型的结晶能力。最佳的FENE Lennard-Jones参数组合（FENE和LJ平衡距离之间的比率）和最佳的晶格参数计算为五种不同的完美的微晶结构：简单的四面体，体心四面体，体心斜方晶系，六方原始，和六方密堆积。结果发现，最积极有利的结构是体心正交。从平衡的聚合物液体开始，并采用针对体心斜方晶系找到的最佳参数，等温处理导致形成具有典型链拓扑结构的大片状微晶：折叠链、环链和系链，结晶度约为60%-70%，类似于真实的半结晶聚合物。这个简单的粗粒度Lennard-Jones模型为研究聚合物的半结晶微结构提供了一个定性的工具。
The ability of a simple coarse-grained finite-extensible nonlinear elastic (FENE) Lennard-Jones (LJ) polymer model to be crystallized is investigated by molecular dynamics simulations. The optimal FENE Lennard-Jones parameter combinations (ratio between FENE and LJ equilibrium distances) and the optimal lattice parameters are calculated for five different perfect crystallite structures: simple tetragonal, body-centered tetragonal, body-centered orthorhombic, hexagonal primitive, and hexagonal close packed. It was found that the most energetically favorable structure is the body-centered orthorhombic. Starting with an equilibrated polymer liquid and with the optimal parameters found for the body-centered orthorhombic, an isothermal treatment led to the formation of large lamellar crystallites with a typical chain topology: folded, loop, and tie chains, and with a crystallinity of about 60%-70%, similar to real semicrystalline polymers. This simple coarse-grained Lennard-Jones model provides a qualitative tool to study semicrystalline microstructures for polymers.