摘要
向聚合物基底中添加纳米粒子可用来制备聚合物纳米复合材料,而纳米粒子在基底中的分散性和稳定性问题是多年来制约其大规模应用的关键因素.采用聚合物配体链来修饰纳米粒子,是实现对纳米粒子稳定性调节的一种可行方案.在众多接枝聚合物链的纳米粒子中,双峰聚合物刷接枝的纳米粒子在聚合物基底中表现出超强的分散性和稳定性.本文采用分子动力学方法,模拟研究了双峰聚合物链接枝到纳米粒子表面的grafting-to反应过程.模拟研究表明,影响grafting-to反应过程的因素是多重的,包括双峰聚合物链中短链所占的比例、聚合物链的浓度等因素.研究表明,反应前期聚合物链长度影响很微弱,但反应后期长链的反应速率、接枝效率都会明显降低.此外,在低浓度体系中,接枝过程并不受聚合物链长度的影响,遵循"就近原则"接枝;但在高浓度体系中,纳米粒子明显表现出"选择性"地接枝短链的行为.该研究的结论对实现聚合物纳米复合材料性能的精细调控具有一定的指导意义.
Filling nanoparticles into the polymer matrix is a feasible way to prepare polymer nanocomposite material.Dispersion and stabilization of the nanoparticles in the polymer matrix are crucial factors affecting the wide application of this material.By grafting the polymer ligand chains onto the nanoparticles,it is possible to regulate the stabilization of the nanoparticles in the polymer matrix.Among the various kinds of nanoparticles grafted with polymer chains,bimodal polymer chain-grafted nanoparticles demonstrate super-strong abilities of dispersion and stabilization in the polymer matrix.In this paper,the process of bimodal polymer chains grafted onto nanoparticles using a grafting-to reaction was investigated by the molecular dynamics simulation method.The results show that there were multiple factors that influenced the grafting process.These involved the fraction of short chains in the feeding bimodal chains and the concentration of the polymer chains,etc.The simulation indicated that the chain length of the polymers had a somewhat weak influence on the grafting-to process in the early stage of reaction.However,in the late stage,the reaction rate and grafting efficiency of the long chains became obviously lower than those of the short chains.Besides,in the system with a low polymer concentration,the grafting process was almost unaffected by the polymer chain length,which basically obeyed the principle of"vicinity".However,in the system with high polymer concentration,the nanoparticles always selectively adopted the short chains as their grafting candidates.Our study can serve as a guide to achieving fine regulation in the performance of polymer nanocomposite materials.
作者
薛耀红
邢继媛
钟俊东
贺敏伟
刘鸿
XUE YaoHong;XING JiYuan;ZHONG JunDong;HE Min Wei;LIU Hong(Information Science School,Guangdong University of Finance and Economics,Guangzhou 510320,China;Laboratory of Theoretical and Computational Chemistry,Institute of Theoretical Chemistry,Jilin University,Changchun 130023,China;Key Laboratory of Theoretical Chemistry of Environment,Ministry of Education,School of Chemistry and Environment,South China Normal University,Guangzhou 510006,China)
出处
《中国科学：技术科学》
EI
CSCD
北大核心
2019年第12期1507-1513,共7页
Scientia Sinica(Technologica)
基金
国家自然科学基金(批准号:21774051,21474042,51403022)资助项目
