采用粗粒化模型,应用分子动力学方法研究了单个纳米粒子对聚合物结晶行为的影响。通过改变纳米粒子与聚合物单体之间作用方式(吸引作用或排斥作用)、纳米粒子与聚合物单体之间作用强度和聚合物分子链的长度,计算整个系统和局部区域的有序参数,研究了三个不同因素下纳米粒子对聚合物结晶行为的不同影响。研究表明,在聚合物基体中添加单个纳米粒子,纳米粒子对整个系统的结晶影响不明显,但是纳米粒子对其周围聚合物单体的结晶存在局部强化作用。当纳米粒子与聚合物单体之间为吸引作用且作用强度较大时,纳米粒子对聚合物结晶表现出明显的局部强化作用,聚合物分子链长度也有着一定的影响,在较大吸引作用强度下,长链样本比短链样本有着更为显著的局部强化作用。
Molecular dynamics simulation with a coarse grain model is performed to study the influence of single nanoparticle on the polymer crystallization behavior. By changing the mode of action of the polymer-nanoparticle (i.e. attraction or repulsion), the strength of the polymer-nanoparticle interactions, as well as the chain length of the polymer molecular, and by calculating the bond order parameter to characterize the influence in the cooling process, different effects of single nanoparticle on the polymer crystallization behavior are studied. This study has shown that the nanoparticle has no obvious effect on the whole polymer system composed of single nanoparticles. However, nanoparticles can promote the degree of order of polymer chains in crystallization process and enhance partially the polymer crystallization. Under the attraction and strong strength of the polymer-nanoparticle interaction, it is found that obviously the nanoparticle enhances the polymer crystallization partially. Furthermore, the chain length of the polymer molecular also shows some effect on the crystallization and the long-chain sample has a better enhancement for the polymer crystallization than the short-chain one under a strong attraction strength.