1 Introduction The design and construction of metal-organic polymers has been a field of rapid growth in materials chemistry because of their intriguing topologies and potential applications as functional materials. ...1 Introduction The design and construction of metal-organic polymers has been a field of rapid growth in materials chemistry because of their intriguing topologies and potential applications as functional materials. In this regard, every effort has been devoted to the deliberate design and control of self-assembly infinite coordination networks via selecting the chemistry structures of ligands, Multidentate carboxylate ligands are widely adopted for construction of coordination frameworks due to their rich coordination modes.展开更多
A coarse-grained model is proposed to study the dynamics of a nano-chain diffusing in porous media. The simulation utilizes a hybrid method which combines stochastic rotation dynamics with molecular dynamics. Solvent ...A coarse-grained model is proposed to study the dynamics of a nano-chain diffusing in porous media. The simulation utilizes a hybrid method which combines stochastic rotation dynamics with molecular dynamics. Solvent molecules are explicitly taken into account to represent the hydrodynamic interactions and random fluctuations. The conformation, relaxation, and diffusion properties of a polymer chain are investigated by changing the density degree of the obstacle matrix. It is found that the average size of the chain is a non- monotonic function of the obstacle volume faction Ф. A dense environment may contribute to extending a linear chain, which can be characterized by larger exponents in the corresponding power law. The relaxation behavior of a stretched chain to a steady state shows dramatic crossover from exponent to power-law relaxation when the values of φ are increased. The dependence of the diffusion coefficient on the chain size is also studied. Various kinds of scaling properties are presented and discussed. The results can give additional insight into the density effect of porous media on polymer structure and dynamics.展开更多
采用Tersoff势与L-J势的分子动力学(MD)方法,模拟了4C60富勒烯链/(10,10)碳管纳米豆荚(nanopeapod)的拉伸与压缩过程,并将其与(10,10)碳纳米管以及4C60富勒烯链的拉伸与压缩力学特性进行了比较。研究结果表明,碳纳米管中置入C60富勒烯链...采用Tersoff势与L-J势的分子动力学(MD)方法,模拟了4C60富勒烯链/(10,10)碳管纳米豆荚(nanopeapod)的拉伸与压缩过程,并将其与(10,10)碳纳米管以及4C60富勒烯链的拉伸与压缩力学特性进行了比较。研究结果表明,碳纳米管中置入C60富勒烯链后,其拉伸性能并无明显改善;4C60富勒烯链所能承受的拉伸载荷很小,且无承受压缩载荷的能力;由于4C60富勒烯与(10,10)碳管之间存在Van der Waals作用,纳米豆荚的压缩性能较(10,10)碳管有显著提高。展开更多
基金Supported by the National Natural Science Foundation of China(Nos. 20601007, 50472020 and 20773034)the Natural Science Foundation of Hebei Education Department, China(No.ZH2006002)+1 种基金the Natural Science Foundation of Hebei Province, China(No.B2008000143)the Doctoral Foundation of Hebei Normal University, China(No.103261).
文摘1 Introduction The design and construction of metal-organic polymers has been a field of rapid growth in materials chemistry because of their intriguing topologies and potential applications as functional materials. In this regard, every effort has been devoted to the deliberate design and control of self-assembly infinite coordination networks via selecting the chemistry structures of ligands, Multidentate carboxylate ligands are widely adopted for construction of coordination frameworks due to their rich coordination modes.
基金Supported by the National Natural Science Foundation of China under Grant No 51176044the Natural Science Foundation of Zhejiang Province under Grant No LY13A040007the China Postdoctoral Science Foundation under Grant Nos 2013M541634and 2014T70498
文摘A coarse-grained model is proposed to study the dynamics of a nano-chain diffusing in porous media. The simulation utilizes a hybrid method which combines stochastic rotation dynamics with molecular dynamics. Solvent molecules are explicitly taken into account to represent the hydrodynamic interactions and random fluctuations. The conformation, relaxation, and diffusion properties of a polymer chain are investigated by changing the density degree of the obstacle matrix. It is found that the average size of the chain is a non- monotonic function of the obstacle volume faction Ф. A dense environment may contribute to extending a linear chain, which can be characterized by larger exponents in the corresponding power law. The relaxation behavior of a stretched chain to a steady state shows dramatic crossover from exponent to power-law relaxation when the values of φ are increased. The dependence of the diffusion coefficient on the chain size is also studied. Various kinds of scaling properties are presented and discussed. The results can give additional insight into the density effect of porous media on polymer structure and dynamics.
文摘采用Tersoff势与L-J势的分子动力学(MD)方法,模拟了4C60富勒烯链/(10,10)碳管纳米豆荚(nanopeapod)的拉伸与压缩过程,并将其与(10,10)碳纳米管以及4C60富勒烯链的拉伸与压缩力学特性进行了比较。研究结果表明,碳纳米管中置入C60富勒烯链后,其拉伸性能并无明显改善;4C60富勒烯链所能承受的拉伸载荷很小,且无承受压缩载荷的能力;由于4C60富勒烯与(10,10)碳管之间存在Van der Waals作用,纳米豆荚的压缩性能较(10,10)碳管有显著提高。
