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Title: Detachment of semiflexible polymer chains from a substrate: A molecular dynamics investigation

Using Molecular Dynamics simulations, we study the force-induced detachment of a coarse-grained model polymer chain from an adhesive substrate. One of the chain ends is thereby pulled at constant speed off the attractive substrate and the resulting saw-tooth profile of the measured mean force 〈f〉 vs height D of the end-segment over the plane is analyzed for a broad variety of parameters. It is shown that the observed characteristic oscillations in the 〈f〉-D profile depend on the bending and not on the torsional stiffness of the detached chains. Allowing for the presence of hydrodynamic interactions (HI) in a setup with explicit solvent and dissipative particle dynamics-thermostat, rather than the case of Langevin thermostat, one finds that HI have little effect on the 〈f〉-D profile. Also the change of substrate affinity with respect to the solvent from solvophilic to solvophobic is found to play negligible role in the desorption process. In contrast, a changing ratio ε{sub s}{sup B}/ε{sub s}{sup A} of the binding energies of A- and B-segments in the detachment of an AB-copolymer from adhesive surface strongly changes the 〈f〉-D profile whereby the B-spikes vanish when ε{sub s}{sup B}/ε{sub s}{sup A}<0.15. Eventually, performing an atomistic simulation of (bio)-polymers, we demonstratemore » that the simulation results, derived from our coarse-grained model, comply favorably with those from the all-atom simulation.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5]
  1. Leibniz-Institut of Poslymer Research Dresden, 01069 Dresden (Germany)
  2. (Poland)
  3. Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States)
  4. Institute for Physical Chemistry, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)
  5. Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz (Germany)
Publication Date:
OSTI Identifier:
22413283
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 141; Journal Issue: 21; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ADHESIVES; AFFINITY; BENDING; BINDING ENERGY; COPOLYMERS; DESORPTION; FLEXIBILITY; INTERACTIONS; MOLECULAR DYNAMICS METHOD; PARTICLES; SIMULATION; SOLVENTS; SUBSTRATES; SURFACES; THERMOSTATS