相关论文: Theory of the Observed Ultra-Low Friction between …
By solving the equilibrium equations for a polymer in a neutral polymer brush, the degree of interpenetration of two polymer brushes in contact and near contact is calculated. These results are used to calculate values of the force of…
We experimentally and theoretically consider highly condensed planar brushes made of charged polymers. Using x-ray reflectivity on polyelectrolytes which are anchored at the water-air interface, it is shown that such strongly stretched…
We investigate polyelectrolyte brushes in the osmotic regime using both theoretical analysis and molecular dynamics simulation techniques. In the simulations at moderate Bjerrum length, we observe that the brush height varies weakly with…
Modeling ion correlations in inhomogeneous polymers and soft matters with spatially varying ionic strength or dielectric permittivity remains a great challenge. Here, we develop a new theory which systematically incorporates electrostatic…
Friction between ring-polymer brushes at melt densities sliding past each other are studied using extensive course-grained molecular dynamics simulations and scaling arguments, and the results are compared to the friction between…
We develop a theory of static friction by modeling the homogeneous surfaces of contact as being composed of a regular array of compressible elastic smooth microscopic inclines. Static friction is thought of as the resistance due to having…
In this paper, we study electrostatic and structural properties between pH-responsive polyelectrolyte brushes by using a strong stretching theory accounting for excluded volume interactions, the density of polyelectrolyte chargeable sites…
Neutral or charged polymers that are densely end-grafted to surfaces form brush-like structures and are highly stretched under good-solvent conditions. We discuss and compare relevant results from scaling models, self-consistent-field…
We formulate a self-consistent field theory for polyelectrolyte brushes in the presence of counterions. We numerically solve the self-consistent field equations and study the monomer density profile, the distribution of counterions, and the…
We consider a polymer brush grafted to a surface (acting as an electrode) and bearing a charged group at its free end. Using a second distant electrode, the brush is subject to a constant electric field. Based on a coarse-grained continuum…
Polyelectrolyte (PE) brushes are widely used in biomaterials and nanotechnology to regulate surface properties and interactions. Here, we apply the electrostatic correlation augmented self-consistent field theory to investigate the…
Polymer brushes have found extensive applications as responsive surfaces, particularly in achieving tunable friction in solvent environments. Despite recent interest in extending this technology to air environments, little is known about…
A model of rod-like polyelectrolyte brushes in the presence of monovalent and multivalent counterions but with no added-salt is studied using Monte Carlo simulation. The average height of the brush, the histogram of rod conformations, and…
Brush-like structures emerge from stretching of long polymer chains, densely grafted on to the surface of an impermeable substrate. They arise due to the competition between conformational entropic elasticity of polymer chains and excluded…
We investigate electro-osmosis in aqueous solutions of polyelectrolytes using mean-field equations. A solution of positively charged polyelectrolytes is confined between two negatively charged planar surfaces, and an electric field is…
The properties of ionic solutions between charged surfaces are often studied within the Poisson-Boltzmann framework, by finding the electrostatic potential profile. For example, the osmotic pressure between two charged planar surfaces can…
We study theoretically the osmotic pressure of a suspension of charged objects (e.g., colloids, polyelectrolytes, clay platelets, etc.) dialyzed against an electrolyte solution using the cell model and linear Poisson-Boltzmann (PB) theory.…
We investigate the effect of counterion fluctuations in a single polyelectrolyte brush in the absence of added salt by systematically expanding the counterion free energy about Poisson-Boltzmann mean field theory. We find that for strongly…
We present a theory of the hydrodynamic forces in the drainage flow of an electrolyte between a sphere and a plane with charged surfaces. Our theory considers a thin electrolyte film which is at all times in local equilibrium across its…
The persistence length of a single, strongly charged, stiff polyelectrolyte chain is investigated theoretically. Path integral formulation is used to obtain the effective electrostatic interaction between the monomers. We find significant…