Anisotropic and enhanced self-diffusion of a macromolecular chain under simple shear flow as revealed by Monte Carlo simulation on lattices

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	Anisotropic and enhanced self-diffusion of a macromolecular chain under simple shear flow as revealed by Monte Carlo simulation on lattices
	Xu, GQ ; Ding, JD ; Yang, YL
刊名	MACROMOLECULAR THEORY AND SIMULATIONS
	1998
卷号	7 期号:1 页码:129-140
ISSN号	1022-1344
英文摘要	Two-dimensional simple shear flow of a self-avoiding macromolecular chain is simulated by a lattice Monte Carlo (MC) method with a pseudo-potential describing the flow field. The simulated velocity profile satisfies the requirements of simple shear flow unless the shear rate is unreasonably high. Some diffusion problems for a free-draining bead-spring chain with excluded volume interaction are then investigated at low and relatively high shear rates. Three diffusion coefficients are defined and examined in this paper: the conventional self-diffusivity in zero field, D-self, the apparent self-diffusivity in flow field, D-app,,, and the flow diffusivity in simulation, D-flow,, reflecting actually the transport coefficient. It is found that these three diffusivities for a flexible chain are different from each other. What is more important is that self-diffusion exhibits a high anisotropy in the flow field. The apparent self-diffusion along the flow direction is enhanced to a large extent. It is increased monotonically with the increase of shear time or shear strain, whereas the chain configuration can achieve a stationary anisotropic distribution following an interesting overshoot of the coil shape and size. Besides a single self-avoiding chain, an isolated Brownian bead and a group of self-avoiding beads with a quasi-Gaussian spatial distribution are also simulated. According to the comparison, the effects of the connectivity of the chain on the diffusion behavior are revealed. Some scaling relations of D-app versus t are consistent with the theoretical analyses in the pertinent literature.
语种	英语
出版者	WILEY-V C H VERLAG GMBH
WOS记录号	WOS:000073006000016
内容类型	期刊论文
源URL	[http://ir.iccas.ac.cn/handle/121111/74257]
专题	中国科学院化学研究所
通讯作者	Xu, GQ
作者单位	1.Fudan Univ, Dept Macromol Sci, Lab Mol Engn Polymers, Shanghai 200433, Peoples R China 2.Chinese Acad Sci, Inst Chem, Beijing 100080, Peoples R China
推荐引用方式 GB/T 7714	Xu, GQ,Ding, JD,Yang, YL. Anisotropic and enhanced self-diffusion of a macromolecular chain under simple shear flow as revealed by Monte Carlo simulation on lattices[J]. MACROMOLECULAR THEORY AND SIMULATIONS,1998,7(1):129-140.
APA	Xu, GQ,Ding, JD,&Yang, YL.(1998).Anisotropic and enhanced self-diffusion of a macromolecular chain under simple shear flow as revealed by Monte Carlo simulation on lattices.MACROMOLECULAR THEORY AND SIMULATIONS,7(1),129-140.
MLA	Xu, GQ,et al."Anisotropic and enhanced self-diffusion of a macromolecular chain under simple shear flow as revealed by Monte Carlo simulation on lattices".MACROMOLECULAR THEORY AND SIMULATIONS 7.1(1998):129-140.