Polymer-mediated entropic forces between scale-free objects
arXiv:1208.5778 · doi:10.1103/PhysRevE.86.061801
Abstract
The number of configurations of a polymer is reduced in the presence of a barrier or an obstacle. The resulting loss of entropy adds a repulsive component to other forces generated by interaction potentials. When the obstructions are scale invariant shapes (such as cones, wedges, lines or planes) the only relevant length scales are the polymer size R_0 and characteristic separations, severely constraining the functional form of entropic forces. Specifically, we consider a polymer (single strand or star) attached to the tip of a cone, at a separation h from a surface (or another cone). At close proximity, such that h<<R_0, separation is the only remaining relevant scale and the entropic force must take the form F=AkT/h. The amplitude A is universal, and can be related to exponents ηgoverning the anomalous scaling of polymer correlations in the presence of obstacles. We use analytical, numerical and epsilon-expansion techniques to compute the exponent ηfor a polymer attached to the tip of the cone (with or without an additional plate or cone) for ideal and self-avoiding polymers. The entropic force is of the order of 0.1 pN at 0.1 micron for a single polymer, and can be increased for a star polymer.
LaTeX, 15 pages, 4 eps figures
References in corpus (6)
- Bayesian estimates of free energies from nonequilibrium work data in the presence of instrument noise
- Casimir force between sharp-shaped conductors
- Entropic force of polymers on a cone tip
- Kinetics of First Passage in a Cone
- What is the order of 2D polymer escape transition?
- Apex Exponents for Polymer--Probe Interactions
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