Polymerization-induced polymer aggregation or polymer aggregation-enhanced polymerization? A computer simulation study
Polymerization-induced polymer aggregation or polymer aggregation-enhanced polymerization? A computer simulation study
复制标题
聚合诱导的聚合物聚集还是聚合物聚集增强的聚合？
DOI：
10.1039/c8cp03069c
复制
发表时间：
2018
影响因子：
3.3
通讯作者：
Cui Feng-Chao
中科院分区：
文献类型：
--
作者：
Kong Si-Min;Liu Hong;Xue Yao-Hong;Liu Xiao-Li;Jia Xiao-Xi;Cui Feng-Chao
在本研究中，利用耗散粒子动力学模拟与随机反应模型相结合，通过简单地将溶剂的溶解度调整为一种共聚，研究了二元溶液中聚合诱导的聚合物聚集过程和聚合物聚集增强的聚合过程。我们的模拟表明，这是共聚对聚集体形成的复杂相互作用，即，一方面聚合可能引起一种物质的聚集；另一方面，聚合可能引起一种物质的聚集。另一方面，它具有将两种物质混合在一起的作用。我们还发现聚合过程基本上遵循一级反应动力学。随着溶液中B物种不溶性的增加，其不断偏离一级反应动力学。在对称共聚体系中，我们发现共聚物的分散度随着反应概率的增加而单调降低。这种违反直觉的结果可以通过扩散控制动力学和反应控制动力学的比较来理解。在不对称体系中，对于优先共聚的体系，质量分布形状呈类高斯分布，并具有一定的峰。作为比较，对于优先均聚的体系，质量分布形状显示出明显的双峰形式。该研究有助于更好地理解共聚物材料制备过程中反应动力学和扩散动力学之间的协同竞争，并可为实验室和工业中更好地设计和改进共聚技术提供指导。
In this study, using dissipative particle dynamics simulations coupled with the stochastic reaction model, we investigate the polymerization-induced polymer aggregation process and the polymer aggregation-enhanced polymerization process in a binary solution, by simply tuning the solubility of the solvent to one species of copolymerization. Our simulations indicate that it is a complicated interplay of the copolymerization on the formation of aggregates, namely, on one hand the polymerization may induce the aggregation of one species; on the other hand it has an effect of mixing the two species together. We also find that the polymerization process basically follows the first order reaction kinetics. With the increase of insolubility of B species in the solution, it continuously deviates from the first order reaction kinetics. In the symmetric copolymerization system, we find that the dispersity of copolymers monotonically decreases with the increase of reaction probability. This counterintuitive result can be understood via the comparison of diffusion-controlled kinetics and reaction-controlled kinetics. In the asymmetric system, for systems with preferential copolymerization, the mass distribution shapes are Gaussian-like with certain peaks. For comparison, for systems with preferential homopolymerization, the mass distribution shape shows an obviously bimodal form. This study helps to better understand the cooperative competition between the reaction dynamics and the diffusion dynamics during the preparation of copolymer materials, and could act as a guide to better design and improve the copolymerization technologies in laboratories and in industry.