SCIENCE@home

The Effect of Nanoparticle Shape on Polymer-Nanocomposite Rheology and Tensile Strength

Scott T. Knauert,J. Douglas,F. Starr

Published 2007 in Journal of Polymer Science Part B

ABSTRACT

Nanoparticles can influence the properties of polymer materials by a variety of mechanisms. With fullerene, carbon nanotube, and clay or graphene sheet nanocom- posites in mind, we investigate how particle shape influences the melt shear viscosity ! and the tensile strength " , which we determine via molecular dynamics simula- tions. Our simulations of compact (icosahedral), tube or rod-like, and sheet-like model nanoparticles, all at a volume fraction # ! 0.05, indicate an order of magnitude increase in the viscosity ! relative to the pure melt. This finding evidently can not be explained by continuum hydrodynamics and we provide evidence that the ! increase in our model nanocomposites has its origin in chain bridging between the nanopar- ticles. We find that this increase is the largest for the rod-like nanoparticles and least for the sheet-like nanoparticles. Curiously, the enhancements of ! and " exhibit opposite trends with increasing chain length N and with particle shape anisotropy. Evidently, the concept of bridging chains alone cannot account for the increase in " and we suggest that the deformability or flexibility of the sheet nanoparticles con- tributes to nanocomposite strength and toughness by reducing the relative value of the Poisson ratio of the composite. The molecular dynamics simulations in the present work focus on the reference case where the modification of the melt structure associ- ated with glass-formation and entanglement interactions should not be an issue. Since many applications require good particle dispersion, we also focus on the case where the polymer-particle interactions favor nanoparticle dispersion. Our simulations point to a substantial contribution of nanoparticle shape to both mechanical and processing prop- erties of polymer nanocomposites. © 2007 Wiley Periodicals, Inc." J Polym Sci Part B: Polym

PUBLICATION RECORD

CITATION MAP

EXTRACTION MAP

CLAIMS

  • No claims are published for this paper.

CONCEPTS

  • No concepts are published for this paper.

REFERENCES

Showing 1-71 of 71 references · Page 1 of 1

CITED BY

Showing 1-100 of 219 citing papers · Page 1 of 3

123
Next