KAUST Grant NumberKUS-C1-018-02
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AbstractPolymer nanocomposites containing nanoparticles smaller than the random coil size of their host polymer chains are known to exhibit unique properties, such as lower viscosity and glass transition temperature relative to the neat polymer melt. It has been hypothesized that these unusual properties result from fast diffusion of the nanostructures in the host polymer, which facilitates polymer chain relaxation by constraint release and other processes. In this study, the effects of addition of sterically stabilized inorganic nanoparticles to entangled cis-1,4-polyisoprene and polydimethylsiloxane on the overall rheology of nanocomposites are discussed. In addition, insights about the relaxation of the host polymer chains and transport properties of nanoparticles in entangled polymer nanocomposites are presented. The nanoparticles are found to act as effective plasticizers for their entangled linear hosts, and below a critical, chemistry and molecular-weight dependent particle volume fraction, lead to reduced viscosity, glass transition temperature, number of entanglements, and polymer relaxation time. We also find that the particle motions in the polymer host are hyperdiffusive and at the nanoparticle length scale, the polymer host acts like a simple, ideal fluid and the composites' viscosity rises with increasing particle concentration. © 2012 The Royal Society of Chemistry.
CitationKim D, Srivastava S, Narayanan S, Archer LA (2012) Polymer nanocomposites: polymer and particle dynamics. Soft Matter 8: 10813. Available: http://dx.doi.org/10.1039/c2sm26325d.
SponsorsThis work was supported by the National Science Foundation, Award no. DMR-1006323 and Award No. KUS-C1-018-02 made by King Abdullah University of Science and Technology. Use of the Sector 8-ID-I at Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract no. DE-AC02-06CH11357. Facilities available through the Cornell Center for Materials Research (CCMR) were used for this study.
PublisherRoyal Society of Chemistry (RSC)