Comparison of Various Correlation Times in Polymer Melts by Molecular Dynamics Simulation

Pestryaev, E. M.

doi:10.1088/1742-6596/324/1/012031

Cited by 12 publications

(11 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A by-product of this strategy is furthermore that the time scales of molecular-dynamics computer simulations can be extended in this way to account for practically relevant dynamic features (see, e.g., Ref. [28], for example).…”

Section: Classification and Terminologymentioning

confidence: 99%

Molecular Dynamics in Polymers

Kimmich

2012

Principles of Soft-Matter Dynamics

View full text Add to dashboard Cite

Suitably modified versions of the Langevin equation introduced in Chap. 2 will be taken as a general basis for analytical explanations of macromolecular-chain motions. The reader will straightforwardly be led from the dynamics of freely draining polymer chains as the simplest case to entangled-chain phenomena and finally to mesoscopic confinement effects. The Langevin equation-based treatments will be supplemented step by step by additional force terms specific for the diverse model scenarios. The restriction to this equation-of-motion strategy is expected to favor the comprehensibility of this demanding field. The relaxation-mode solutions will be expressed in the form of predictions for diverse experimental techniques outlined in Chap. 3. This in particular refers to spin-lattice relaxation, coherent and incoherent neutron scattering, and mechanical relaxation.

show abstract

Section: Classification and Terminologymentioning

confidence: 99%

Molecular Dynamics in Polymers

Kimmich

2012

Principles of Soft-Matter Dynamics

View full text Add to dashboard Cite

show abstract

“…Note that force F tube increases exponentially when any particle leaves the tube. Note also that, if the tube walls are replaced with periodic boundary conditions, model 2 satisfactorily describes the dynamic proper ties of unentangled melts of macromolecules (i.e., the melts of chains with molecular masses lower than the critical molecular mass) in bulk [32][33][34][35].…”

Section: Abstract-mentioning

confidence: 99%

Computer-aided simulation of the influence of collective effects on polymer-melt dynamics in a straight cylindrical tube: Observation of the onset stage of the corset effect

et al. 2012

View full text Add to dashboard Cite

The dynamics of polymer melts confined in porous nano and mesoscale media has been intensively stud ied in recent years . These studies were to a large extent stimulated by the unusual phenomena detected at frequencies of 0.1-100 MHz that were first observed in the experiments devoted to the frequency dependence of the nuclear spin-lattice relaxation rate of polymer melts in porous systems [5,7,16,24]. These phenomena are known as the corset effect. In general, the basis of the corset effect is as follows. The dynamic properties of polymer melts in porous sys tems may considerably differ from the corresponding properties of polymer melts without any spatial con straints at high frequencies (small times ), when the rms displacements of polymer segments 1 This work was supported by the Russian Foundation for BasicResearch (project no. 10 03 00739 a) and the DAAD program Mikhail Lomonosov II ω 1 t ∝ ω are much smaller than the squared characteris tic radius of a tube, . Note that the specified differ ences were observed even for tubes whose radii were several times larger than the characteristic lengths of polymer chains. In other words, a mutual noncross ability of polymer chains and a low compressibility of the polymer melt lead to the specific collective effect: Polymer segments span the medium via rapidly prop agating acoustic waves and respond to the presence of impermeable tube walls by changing the character of thermal fluctuations relative to those of the common melt much earlier than the direct physical contact with the tube wall ensues.At present, controversial opinions about the possi bility of the corset effect can be found in the literature. In studies denying the existence of the corset effect, it is assumed that the influence of confinements due to tube walls on the dynamics of polymer chains can be 2 ( ) r t tube 2 r Abstract-The results of the computer aided simulation of the dynamics of a polymer melt consisting of Fraenkel chains in straight cylindrical tubes and in bulk are discussed. Two different models are studied. In the first model, the dynamics of the polymer melt is simulated via the molecular dynamics simulation. The interaction of unbound polymer segments is described by the Lennard Jones potential, which excludes any chain crossing of macromolecules and generates collective acoustic waves. In the second model, which serves as a reference, the system is studied via the Brownian dynamics method, in which intermolecular interactions are allowed for phenomenologically via friction and stochastic Langevin forces. In this case, cooperative effects are absent and the effect of spatial confinements makes itself evident only in a narrow near wall layer. For the two models under consideration, there is a significant difference in the decay of dynamic correlation functions = , where averaging is performed over all macromolecular segments and is the component of the end to end segment vector ( , and the cylindrical axis of the tube is directed along the z axis). For the first model allowing for col...

show abstract

“…Olgun studied the basic mechanisms of the polymers wall slip by focusing on the dynamics of the polymer behavior at the wall for three different polymers . Pestryaev investigated the crossover from Rouse‐like dynamics for short chains to Reptation‐like dynamics for long chains and its influence on the various translational and orientational correlation times . Kremer and Grest presented an extensive molecular dynamics simulation for a bead spring model of a linear polymer melt .…”

Section: Introductionmentioning

confidence: 99%

Study the effects of nanofiber on the polymer chain orientation using molecular dynamic in the circular duct flow

Kanvisi

2018

Polymer Engineering & Sci

View full text Add to dashboard Cite

In this article, the effects of nanofiber on the polymer chain orientation are studied using molecular dynamic techniques in the circular duct flow. The conformational tensor models, which have root in the molecular dynamic, applied to simulate the polymer chain orientation in suspension of nanofibers. The effects of nanofiber aspect ratio are also investigated on the polymer chain orientation. The results show that the polymer chains are less oriented along the flow direction for more nanofiber concentration and consequently, the extensibility of the polymer chains decrease. In fact, the nanofibers prevent to stretch of polymer chains along the flow direction. Moreover, the results indicate that as increasing the aspect ratio of nanofibers, the c zz components decrease but c rr , c hh , and c zr components increase. It reveals that the polymer chains are less oriented along the flow direction for higher aspect ratio of nanofibers, and consequently, the length of polymer chains is reduced. POLYM. ENG. SCI., 00:000-000, FIG. 5. Effect of nanofiber aspect ratio on the mean square chain extension; nanofiber aspect ratio is (-) 1, (ÁÁÁ) 6, (--) 10, (--) 15.

show abstract

Comparison of Various Correlation Times in Polymer Melts by Molecular Dynamics Simulation

Cited by 12 publications

References 61 publications

Molecular Dynamics in Polymers

Molecular Dynamics in Polymers

Computer-aided simulation of the influence of collective effects on polymer-melt dynamics in a straight cylindrical tube: Observation of the onset stage of the corset effect

Study the effects of nanofiber on the polymer chain orientation using molecular dynamic in the circular duct flow

Contact Info

Product

Resources

About