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P. Kuterba

Publications and source records attributed to P. Kuterba.

2 recordsLinked to original sources

Entropic force in a dilute solution of real ring polymer chains with different topological structures in a slit of two parallel walls with mixed boundary conditions

The molecular dynamics simulations were used to obtain the radius of gyration of real ring polymer chains with different topological structures consisting of 360 monomers. We focus on the entropic force which is exerted by a dilute solution of ring polymer chains of different topological structures with the excluded volume interaction (EVI) in a good solvent on the confining parallel walls of a slit geometry. We consider mixed boundary conditions of one repulsive wall and the other one at the adsorption threshold. The obtained molecular dynamics simulation results for a wide slit region demonstrate a qualitative agreement with previous analytical results for ideal ring polymers. These results could lead to interesting potential applications in materials engineering and improve understanding of some biological processes suggested in the paper. Additionally, they could be applied in micro- and nano-electromechanical devices (MEMS and NEMS) in order to reduce the static friction.

cond-mat.soft

Ring polymers in confined geometries

The investigation of a dilute solution of phantom ideal ring polymers and ring polymers with excluded volume interactions (EVI) in a good solvent confined in a slit geometry of two parallel repulsive walls and in a solution of colloidal particles of big size was performed. Taking into account the correspondence between the field theoretical $ϕ^4$ $O(n)$-vector model in the limit $n\to 0$ and the behaviour of long-flexible polymers in a good solvent, the correspondent depletion forces and the forces which exert phantom ideal ring polymers and ring polymers with EVI on the walls were obtained in the framework of the massive field theory approach at fixed space dimensions $d$=3 up to one-loop order. Besides, taking into account the Derjaguin approximation, the depletion forces between big colloidal particle and a wall and in the case of two big colloidal particles were calculated. The obtained results indicate that phantom ideal ring polymers and ring polymers with EVI due to the complexity of chain topology and for entropical reasons demonstrate a completely different behaviour in confined geometries compared with linear polymers.

physics.bio-ph