By a News Reporter-Staff News Editor at Science Letter -- Researchers detail new data in Science. According to news reporting from Zurich, Switzerland, by NewsRx journalists, research stated, "The effect of nanoscale surface roughness on the lubrication properties of a polymer brush in a good solvent has been investigated. Friction and adhesion forces were measured by means of polyethylene colloidal-probe AFM across a 12 nm silica particle gradient before and after the adsorption of a poly(L-lysine)-g-poly(ethylene glycol) (PLL-g-PEG) polymer brush."
The news correspondents obtained a quote from the research from the Swiss Federal Institute of Technology, "The adsorption and conformation of the polymer chains were studied with multiple transmission and reflection infrared (MTR-IR) spectroscopy. The results show that prior to the adsorption of PLL-g-PEG on the gradient surface, the friction is high at the smooth end of the gradient while it decreases toward the rough end. Moreover, there is a direct correlation between friction and adhesion. Upon adsorption of the brushes, adhesion vanishes. In this case, a higher frictional force between the PEG-coated particle gradient substrate and the polyethylene sphere is observed at the rough end of the gradient in comparison to the smooth end."
According to the news reporters, the research concluded: "In spite of the increased adsorbed mass of PLL-g-PEG at the rough end of the gradient, theory and simulations show that the high curvature of the nanoparticles leads to a less swollen PEG brush in comparison to PEG brushes adsorbed on a planar surface, resulting in a lower repulsion, which can explain the observed increase in friction with particle density."
For more information on this research see: Adhesion and Friction Properties of Polymer Brushes on Rough Surfaces: A Gradient Approach. Langmuir, 2013;29(49):15251-15259. Langmuir can be contacted at: Amer Chemical Soc, 1155 16TH St, NW, Washington, DC 20036, USA. (American Chemical Society - www.acs.org; Langmuir - www.pubs.acs.org/journal/langd5)
Our news journalists report that additional information may be obtained by contacting S.N. Ramakrishna, Swiss Fed Inst Technol, Dept. of Mat, Lab Surface Sci & Technol, CH-8093 Zurich, Switzerland. Additional authors for this research include R.M. Espinosa-Marzal, V.V. Naik, P.C. Nalam and N.D. Spencer (see also Science).
Keywords for this news article include: Zurich, Europe, Science, Switzerland
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