Monte Carlo simulation of polymer brushes in narrow pores

Abstract

We present the model of a cylindrical pore with chains tethered by one end to its inner surface. The conformational and “quasistatic” (under low and medium shear rates) hydrodynamic properties of the system are studied. Since it was shown by other researchers that the density profile of the polymer layer is only slightly affected by flow in the region of low and medium shear rates, we do not take flow into account when calculating chain conformations. The conformational properties of the concave layer are very similar to those of the flat one. They are characterized by the layer thickness h. The hydrodynamic properties are characterized by the hydrodynamic thickness Lh. We show that Lh depends strongly on the chain surface density σ under conditions of the “mushroom” regime in contrast to h. Finally, we predict that the net permeability of the cylinder could decrease with the increasing temperature. It enables us, principally, to control the pore permeability with temperature.

Computer Study of Chromatographic Separation Process: A Monte Carlo Study of H-Shaped and Linear Homopolymers in Good Solvent

“…The number of simulation papers is very high, and it is why we included only several interesting papers published recently − to demonstrate progress in this field and further we focus only on articles devoted directly to the studied topic. The behavior of various polymer chains close to planar surfaces, in narrow slits and in the pores, and the mechanism of the chromatographic separation of polymer chains have already been studied theoretically − by scaling approaches, , by mean-field calculations, − and particularly by lattice Monte Carlo (MC) simulations. − A number of individual studies concerning the effects of chain architecture , and flexibility, , molar mass, polymer concentration, , solvent quality, temperature, , polymer–wall interaction, ,, and smoothness versus roughness of the surface have been published recently. However, the mosaic of knowledge is still incomplete, and there exists a vast room for new systematic studies.…”

Structural properties of concave cylindrical brushes interacting with free chains

“…By comparison, brushes on concave surfaces (e.g., in cylindrical pores) have received relatively little attention. [12][13][14][15][16][17][18] Nevertheless, these systems belong to the class of ''smart materials'', and, as such, hold a substantial promise for practical applications, e.g. for flow control through nanofluidic channels and nanopores [19][20][21][22][23] as well as reversed-phase 24 and size-exclusion 25,26 chromatography.…”

“…So far, most theoretical studies of concave cylindrical brushes have relied on methods of computer simulations. [14][15][16][17][18] While these methods yield essentially exact answers for a given microscopic model, the computational costs impose certain restrictions on the size of systems and range of parameters that can be studied. An alternative is provided by mean-field methods 13,20,21,27,28 which are computationally very efficient but necessarily involve approximations, and, therefore, their accuracy needs to be tested against simulation results.…”

Spherical brushes within spherical cavities: A self-consistent field and Monte Carlo study

“…Since the seminal works of de Gennes 11 and Alexander 12 a remarkable progress has been done in the understanding and design of new applications involving flat brushes. [13][14][15][16][17][18][19][20][21][22][23][24] In a subsequent stage polymer brushes grafted at curved interfaces either concave [25][26][27][28][29][30][31] or convex [32][33][34][35] have been studied. In concave ͑respectively convex͒ brushes the volume available to the polymer chains decreases ͑respectively in-creases͒, as the chains move away from the interface.…”