By a News Reporter-Staff News Editor at Science Letter -- Investigators discuss new findings in Macromolecular Research. According to news reporting originating from Ithaca, New York, by NewsRx correspondents, research stated, "Above a critical surface chemistry-dependent particle loading associated with nanoscale interparticle spacing, ligand-ligand interactions-both electrostatic and steric-come into play and govern the structure and dynamics of charged oligomer-functionalized nanoparticle suspensions. We report in particular on the structure, ion transport, and rheology of suspensions of nanoparticle salts created by cofunctionalization of silica particles with tethered sulfonate salts and oligomers."
Our news editors obtained a quote from the research from Cornell University, "Dispersion of the hairy ionic particles into medium and high dielectric constant liquids yields electrolytes with unique structure and transport properties. We find that electrostatic repulsion imparted by ion dissociation can be tuned to control the dispersion state and rheology through counterion size (i.e., Li+, Na+, and K+) and dielectric properties of the dispersing medium. Analysis of small-angle X-ray scattering (SAXS) structure factors and the mechanical modulus shows that when the interparticle spacing approaches nanometer dimensions, weakly entangled anchored ligands experience strong and long-lived topological constraints analogous to those normally found in well-entangled polymeric fluids. This finding provides insight into the molecular origins of the surprisingly similar rubbery plateau moduli observed in hairy nanoparticle suspensions and entangled polymers of the same chemistry as the tethered ligands. Additionally, we find that a time-composition superposition (TCS) principle exists for the suspensions, which can be used to substantially extend the observation time over which dynamics are observed in jammed, soft glassy suspensions."
According to the news editors, the research concluded: "Application of TCS reveals dynamical similarities between the suspensions and entangled solutions of linear polymer chains; i.e., a hairy particle trapped in a cage appears to exhibit analogous dynamics to a long polymer chain confined to a tube."
For more information on this research see: Structure, Ion Transport, and Rheology of Nanoparticle Salts. Macromolecules, 2014;47(13):4479-4492. Macromolecules can be contacted at: Amer Chemical Soc, 1155 16TH St, NW, Washington, DC 20036, USA. (American Chemical Society - www.acs.org; Macromolecules - www.pubs.acs.org/journal/mamobx)
The news editors report that additional information may be obtained by contacting Y.H. Wen, Cornell University, Sch Chem & Biomol Engn, Ithaca, NY 14853, United States. Additional authors for this research include Y.Y. Lu, K.M. Dobosz and L.A. Archer (see also Macromolecular Research).
Keywords for this news article include: Ithaca, New York, Chemicals, Chemistry, United States, Macromolecular Research, North and Central America
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