By a News Reporter-Staff News Editor at Physics Week -- Researchers detail new data in Chemical Physics. According to news reporting originating in Dresden, Germany, by VerticalNews journalists, research stated, "Using a numerical quasi off-lattice self-consistent field method which describes heterogeneous chains of spherical monomers we study the case of a densely grafted polymer brush with a fraction of free chain ends being replaced by a modified end-group differing in size and solvent selectivity. We can confirm the observation from molecular dynamics simulations that upon changing the solvent conditions, a switching in location of end-groups which are bigger than monomers from a state 'exposed' to the solvent (on the top of the brush) to a 'hidden' state (inside the brush) takes place."
The news reporters obtained a quote from the research from Technical University, "Our numerical method allows a detailed study of the switching effect as a function of the relevant parameters, such as grafting density, chain length, size of end-groups and their volume fraction. We find that the switching effect is enhanced for long chains, low fractions of modified chains, and big end-groups. We consider the case of low fraction of modified chains in more detail using a test chain method. Here, we explore the optimal grafting density as a function of the size of the end-groups, where the switching is most sensitive. These values can be in the experimental range for end-groups which are at least 3-4 times bigger than the monomers."
According to the news reporters, the research concluded: "The end-groups can be realized by attaching nano-particles to the last monomer of a brush-chain."
For more information on this research see: Conformational switching of modified guest chains in polymer brushes. Journal of Chemical Physics, 2013;139(4):759-769. Journal of Chemical Physics can be contacted at: Amer Inst Physics, Circulation & Fulfillment Div, 2 Huntington Quadrangle, Ste 1 N O 1, Melville, NY 11747-4501, USA. (American Institute of Physics - www.aip.org/; Journal of Chemical Physics - jcp.aip.org/)
Our news correspondents report that additional information may be obtained by contacting D. Romeis, Technical University of Dresden, Inst Theoret Phys, D-01069 Dresden, Germany.
Keywords for this news article include: Europe, Dresden, Germany, Chemical Physics
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