Nanoparticle Motion in Entangled Melts of Linear and Nonconcatenated Ring Polymers

Abstract

The motion of nanoparticles (NPs) in entangled melts of linear polymers and nonconcatenated ring polymers are compared by large-scale molecular dynamics simulations. The comparison provides a paradigm for the effects of polymer architecture on the dynamical coupling between NPs and polymers in nanocomposites. Strongly suppressed motion of NPs with diameter d larger than the entanglement spacing a is observed in a melt of linear polymers before the onset of Fickian NP diffusion. This strong suppression of NP motion occurs progressively as d exceeds a and is related to the hopping diffusion of NPs in the entanglement network. In contrast to the NP motion in linear polymers, the motion of NPs with d > a in ring polymers is not as strongly suppressed prior to Fickian diffusion. The diffusion coefficient D decreases with increasing d much slower in entangled rings than in entangled linear chains. NP motion in entangled nonconcatenated ring polymers is understood through a scaling analysis of the coupling between NP motion and the self-similar entangled dynamics of ring polymers.

RETRACTED ARTICLE: Comparing ion transport in ionic liquids and polymerized ionic liquids

“…Compared to the IL, the polyIL has short ballistic regime. In the ballistic regime, anions fly freely, having no bounces with other ions 60,61 . Hence the results show that in the polyIL, the average cavity size is smaller than that in the IL and an anion is constrained more stringently in the polyIL than in the IL.…”

“…The subdiffusive regime of the polyIL is longer than the IL. The hindrance influence of surrounding units on anions lead to the subdiffusion phenomena 60 , so studying the subdiffusive regime is essential for clarify the mechanisms behind.…”

A Review of the Synthesis and Applications of Polymer–Nanoclay Composites

“…The melting conditions, such as feed rate, temperature profile, rotor/screw speed, mixing time, oxidative environment, die pressure, material grades and contents, as well as the chemical nature of the nanoclay filler and polymers, are important parameters for the synthesis of the composites [77]. An enthalpic driving force for the functionalized macromolecules, a relatively large interlayer spacing for the macromolecular Gaussian coil, and sufficient time for the diffusion process of the center-stacked layers are three essential elements in the melt-blending method [78]. The melt-blending process can either be static or dynamic.…”

Polymer and spherical nanoparticle diffusion in nanocomposites

“…Nanoparticle diffusion in a medium is predicted theoretically by the Stokes -Einstein formula 61 in a dilute nanoparticle regime. Nanoparticles smaller than the tube diameter [62][63][64][65] do not follow the Stokes-Einstein relation 62,[66][67][68][69][70][71][72][73][74] . To the best of our knowledge there is not any simulation study that investigates the polymer (except Ref.…”