碳纳米管表面接枝聚合物动力学的粗粒化模拟研究

Coarse-grained simulation study of polymer chain-grafted carbon nanotubes prepared via grafting-from strategy

本研究采用粗粒化分子动力学模拟结合随机聚合反应模型,对碳纳米管(CNT)表面以grafting-from方式接枝聚合物的接枝动力学进行了研究.研究结果表明,适当调控表面曲率可以有效提高接枝聚合物链的接枝密度.此外,CNT表面曲率对接枝聚合物链的多分散性指数也有一定影响.在引发剂位点密度较低时,接枝聚合物的分子量分布趋向于泊松分布特征.本研究在深入理解CNT表面grafting-from接枝过程的动力学主控因素,以及拓展grafting-from技术的应用等方面具有一定的理论指导意义.

In this article,the coarse-grained molecular dynamics simulation combined with the stochastic polymerization model was applied to study the preparation of polymer chain-grafted carbon nanotube(CNT)via the"grafting-from"'strategy.The simulation results show that it is feasible to promote the grafting density of the polymer chains by appropriately regulating the surface curvature of CNT.Moreover,the CNT surface curvature also has effect on the dispersity of grafted polymer chains.With the variation of CNT surface curvature,the response of chain propagation process on the steric repulsive effect has a sudden change,which is ascribed to the specific feature of two-dimensional confinement of the CNT surface.It is expected to obtain the polymer-grafted CNT material with high grafting density and low dispersity based on the CNT with appropriate surface curvature in experiment.Finally,by the comparison of molecular weight distribution of grafted polymer chains,we find that when the initiator density is low,the molecular weight distribution shows a Poisson form.The current investigation should be helpful on the aspects such as better understanding of the kinetics of grafting-from reaction from CNT surface,as well as extension of the application of this technique in broader fields.