高分子在受限稀溶液中的结构和动力学性质  

Structure and Dynamics of Confined Polymer Chain in Dilute Solution

作　　者：何彦东[1] 尤莉艳[1] 王晓琳[1] 吕中元[1] 李泽生[1] 

机构地区：[1]吉林大学理论化学研究所,理论化学计算国家重点实验室,长春130021

出　　处：《高等学校化学学报》2009年第1期191-195,共5页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:20490220;20774036);霍英东教育基金会(批准号:114018)资助

摘　　要：利用平衡态及非平衡态耗散粒子动力学模拟方法,分别研究了平衡态和流场作用下受限高分子在稀溶液中的链结构和动力学.采用没有滑移和密度涨落的边界条件模拟纳米管道环境,进而研究了高分子回转半径和扩散系数对受限强度及高分子与溶剂间相互作用的依赖关系.在非平衡态模拟中,分别考虑了Poi-seuille和Couette两种流场.研究发现,在这两种流场作用下,高分子都随着溶剂与高分子排斥作用的降低而向管道中心迁移.在强流场下,在Poiseuille流场中高分子密度呈现出双峰分布,而在Couette流场中则呈现为单峰分布.The structure and dynamics of confined single polymer chain in dilute solution, either in equilibrium or subjected to different flow fields, are investigated by means of dissipative particle dynamics simulations. The no-slip boundary condition without density fluctuation near the wall is taken into account to mimic the environment of a nanochannel. The dependence of the radius of gyration and the diffusion of the chain on the strength of the confinement and the solvent quality is studied. In non-equilibrium systems, both the Couette flow and the Poiseuille flow acting on a dilute polymer solution are investigated. The effect of the interaction between polymer and solvent under these two flow conditions are found to be the same ： the polymer migrates to the center of the channel when the interaction was reduced. With increasing the flow strength, there are two peaks with a dip in the center of the polymer density profile in the Poiseuille flow and only one peak in the center in the Couette flow, which are in agreement with the previous investigations.

关 键 词：耗散粒子动力学 受限高分子 稀溶液 Poiseuille流场 Couette流场 

分 类 号：O631[理学—高分子化学]