By a News Reporter-Staff News Editor at Physics Week -- Researchers detail new data in Styrenes. According to news reporting out of Darmstadt, Germany, by VerticalNews editors, research stated, "Performing coarse-grained molecular dynamics simulations, the local dynamics of free and grafted polystyrene chains surrounding a spherical silica nanoparticle has been investigated, where the silica nanoparticle was either bare or grafted with 80-monomer polystyrene chains. The effect of the free (matrix) chain molecular weight and grafting density on the relaxation time of both the free and grafted polystyrene chains has been investigated."
Our news journalists obtained a quote from the research from Technical University, "Furthermore, we have analyzed the local mobility of the grafted chains at different separations from the nanoparticle surface, as well as on the mean square displacement of the nanoparticles. Proximity to the surface, confinement by the surface, increased grafting density and increased matrix chain length were found to slow down the dynamics of the chain monomers and hence to increase the corresponding relaxation times. 'Drying' of the grafted network of the nanoparticle via increasing the free chain lengths, which is known to shrink the brush-height, was found to slow down the relaxation of the brushes, too. The thickness of the interphase, beyond which the polymers showed bulklike behavior, was similar to 2 nm for a bare nanoparticle, corresponding to four monomer layers, for all matrix chain lengths investigated."
According to the news editors, the research concluded: "It increased to similar to 3 nm for grafted nanoparticles depending on the grafting density and the matrix chain molecular weight."
For more information on this research see: Influence of Surface Grafted Polymers on the Polymer Dynamics in a Silica-Polystyrene Nanocomposite: A Coarse-Grained Molecular Dynamics Investigation. Journal of Physical Chemistry C, 2013;117(47):25069-25076. Journal of Physical Chemistry C can be contacted at: Amer Chemical Soc, 1155 16TH St, NW, Washington, DC 20036, USA. (American Chemical Society - www.acs.org; Journal of Physical Chemistry C - www.pubs.acs.org/journal/jpccck)
Our news journalists report that additional information may be obtained by contacting A. Ghanbari, Technical Univ Darmstadt, Center Smart Interfaces, D-64287 Darmstadt, Germany. Additional authors for this research include M. Rahimi and J. Dehghany.
Keywords for this news article include: Europe, Germany, Physics, Darmstadt, Nanoparticle, Polystyrenes, Nanotechnology, Molecular Dynamics, Benzene Derivatives, Silicon Nanocrystals, Benzylidene Compounds, Emerging Technologies
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