Adsorption of polyelectrolytes on charged microscopically patterned surfaces

Abstract

In the present study we have investigated ,using Monte Carlo simulations (MC), the adsorption of polyelectrolytes on the charged nanopatterned surfaces. Different surface's patterns were considered and we noticed that the amount of adsorption is directly dependent on the size of the domains. Also in the case of checkerboard configuration it was observed that the polyelectrolytes are aligned along the diagonal of square domains.

Equilibrium Conformations and Surface Charge Regulation of Spherical Polymer Brushes in Stretched Regimes

“…The monomers are connected in sequence via a harmonic spring potential U b ( R ), which models the molecular bonds between neighboring monomers ,,− where A = 0.97 k B T ( T being the temperature and k B being the Boltzmann constant), r is the distance between monomers, and r 0 represents the equilibrium distance between adjacent monomers, which we here take to be r 0 = 0.5 nm. The active sites, randomly placed at the core surface, are modeled as spheres of 0.4 nm diameter.…”

“…Polymer brushes are a special class of polymer systems in which one end of the linear polymers is attached to either flat or curved substrates. ,, There are basically two experimental routes in which this grafting process may take place: one in which the whole chain is attached at the surface via chemical bonds (the so-called grafting-to process) and a second one in which free monomers are first attracted to specific surface sites, followed by a polymerization process in which the remaining free monomers are progressively linked together to these initially formed monolayers (e.g., via highly directional, short-ranged interactions) until the fully assembled chains are found in equilibrium with the free, dissociated monomers (the so-called grafting-from process , ). Electrostatic interactions are usually of great relevance for driving (and further stabilizing) these processes. − They are one of the main driven forces that control the so-called charge-regulation mechanisms, responsible for the binding/dissociation of ions into/from the surface functional groups in an aqueous environment containing acidic/basic dissociated ions. − …”

Widom insertion method in simulations with Ewald summation

“…To efficiently account for the periodicity of the replicated systems, the usual approach is to use Ewald summation methods. [5][6][7][8][9][10][11][12][13][14][15][16] In the thermodynamic limit, the system must be charge neutral, and the GCMC must, therefore, be implemented in such a way as to respect this requirement. The simple way to do this is to insert charge neutral clusters into the simulation box.…”

Equilibrium conformations and surface charge regulation of spherical polymer brushes in stretched regimes

“…There are basically two experimental routes in which this grafting process may take place: one in which the whole chain is attached at the surface via chemical bonds (the socalled grafting-to process) and a second one in which free monomers are first attracted to specific surface sites, followed by a polymerization process in which the remaining free monomers are progressively linked together to these initially formed monolayers (e. g., via highly directional, short-ranged interactions), until the fully assembled chains are found in equilibrium with the free, dissociated monomers (the so-called grafting-from process 55,56 ). Electrostatic interactions are usually of great relevance for driving (and further stabilizing) these processes [57][58][59][60][61][62][63] . They are one of the main driven forces that controls the so-called charge-regulation mechanisms, responsible for the binding/dissociation of ions into/from surface functional groups in an aqueous environment containing acidic/basic dissociated ions [64][65][66][67][68][69][70][71][72] .…”