Dynamics in coarse-grained models for oligomer-grafted silica nanoparticles

Type
Article

Authors
Hong, Bingbing
Chremos, Alexandros
Panagiotopoulos, Athanassios Z.

KAUST Grant Number
KUS-C1-018-02

Online Publication Date
2012-05-30

Print Publication Date
2012-05-28

Date
2012-05-30

Abstract
Coarse-grained models of poly(ethylene oxide) oligomer-grafted nanoparticles are established by matching their structural distribution functions to atomistic simulation data. Coarse-grained force fields for bulk oligomer chains show excellent transferability with respect to chain lengths and temperature, but structure and dynamics of grafted nanoparticle systems exhibit a strong dependence on the core-core interactions. This leads to poor transferability of the core potential to conditions different from the state point at which the potential was optimized. Remarkably, coarse graining of grafted nanoparticles can either accelerate or slowdown the core motions, depending on the length of the grafted chains. This stands in sharp contrast to linear polymer systems, for which coarse graining always accelerates the dynamics. Diffusivity data suggest that the grafting topology is one cause of slower motions of the cores for short-chain oligomer-grafted nanoparticles; an estimation based on transition-state theory shows the coarse-grained core-core potential also has a slowing-down effect on the nanoparticle organic hybrid materials motions; both effects diminish as grafted chains become longer. © 2012 American Institute of Physics.

Citation
Hong B, Chremos A, Panagiotopoulos AZ (2012) Dynamics in coarse-grained models for oligomer-grafted silica nanoparticles. J Chem Phys 136: 204904. Available: http://dx.doi.org/10.1063/1.4719957.

Acknowledgements
This publication is based on work supported in part by Award No. KUS-C1-018-02, made by King Abdullah University of Science and Technology (KAUST). Additional support was provided by Grant No. CBET-1033155 from the U.S. National Science Foundation (NSF).

Publisher
AIP Publishing

Journal
The Journal of Chemical Physics

DOI
10.1063/1.4719957

PubMed ID
22667588

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