Abstract The influence of systematic perturbation input interaction parameters on thermodynamic equilibrium properties is studied employing dissipative particle dynamics (DPD) simulations. values both the excess pressure and surface tension are found to be very sensitive soft repulsion parameter between unlike DPD particles for high coarse-graining level (number water molecules per particle). For case in which a molecular surfactant present at interface we have determined dependence these...

The interfacial tension between organic solvents and water at different temperatures is predicted using coarse-grained, mesoscopic Dissipative Particle Dynamics (DPD) simulations. temperature effect of the DPD repulsive interaction parameters, aij, for components calculated from dependence Flory-Huggins χ parameter on temperature, by means solubility parameters. Atomistic simulations were carried out calculation parameters compounds in order to estimate then aij coefficients. We validate...

The influence of the chain degree ionization on adsorption weak polyelectrolytes neutral and oppositely likely charged surfaces is investigated, by means Monte Carlo simulations with a mesoscopic interaction model known as dissipative particle dynamics. electrostatic interactions are calculated using three-dimensional Ewald sum method, an appropriate modification for confined systems. Effective wall forces confine linear polyelectrolytes, electric charges included. solvent, which included...

The adsorption and disjoining pressure isotherms of polymers confined by planar walls are obtained using Monte Carlo (MC) simulations in the Grand Canonical (GC) ensemble combination with mesoscopic technique known as dissipative particle dynamics (DPD). Two models effective potentials for confining surfaces used: one both an attractive a repulsive term purely term. As polymer, seven-bead linear model polyethylene glycol (PEG) dissolved water is used. results indicate remarkably good...

We undertake the investigation of sheared polymer chains grafted onto flat surfaces to model liposomes covered with polyethylene glycol brushes as a case study for mechanisms efficient drug delivery in biologically relevant situations, example, carriers topical treatments illnesses human vasculature. For these applications, specific rheological properties are required, such low viscosity at high shear rates, improve transport liposomes. Therefore, extensive non-equilibrium, coarse-grained...

The viscosity increase of carbon dioxide by copolymers is predicted using dissipative particle dynamics simulations, as a function polymer concentration. Three types direct viscosifying polymers are simulated: fluorinated acrylate polymerized with styrene and two nonfluorinated copolymers. latter the hydrocarbon-based poly(1-decene), which branched, linear poly(vinyl ethyl ether). These associate differently in CO2 because their different molecular chemical characteristics. effect...

The shear viscosity (η) and kinetic friction coefficient (μ) of highly confined, quasi-two-dimensional ionic liquids (2D ILs) subject to stationary linear flow at constant temperature are studied in this work through coarse-grained numerical simulations. Using state under increasing rate (γ̇), η μ predicted as functions γ̇ for growing coupling values (Γ*). structural changes the fluid due charged particles found yield coefficient. Shear-thinning is all systems, regardless value Γ*....

We have performed dissipative particle dynamics (DPD) simulations to evaluate the effect that finite size of transversal area has on stress anisotropy and interfacial tension. The were carried out in one phase two phases parallelepiped cells. In one-phase there is no finite-size when simulation using repulsive forces. However, an oscillatory function found for attractive-repulsive interactions. case liquid-liquid interfaces with interaction between molecules, only a small surface tension are...

We review briefly the concept of colloidal dispersions, their general properties and some most important applications, as well basic molecular interactions that give rise to in equilibrium. Similarly, we revisit Brownian motion hydrodynamic associated with viscosity dispersion. It is argued use modern research tools, such computer simulations, allows one predict accurately macroscopically measurable by solving relatively simple models for a large number particles. Lastly, case study, report...

A proper treatment of electrostatic interactions is crucial for the accurate calculation forces in computer simulations. Electrostatic are typically modeled using Ewald based methods, which have become one cornerstones upon many other methods numerical computation based. However, their use with charge distributions rather than point charges requires inclusion ansatz solutions Poisson equation, since there no exact solution known smeared out charges. The interest incorporating at scales...

A scaling law for the osmotic pressure of quasi-two-dimensional polymer melts as a function concentration is obtained, which shows fractal characteristics. Structural properties such chains' contour length and their inner-monomer pair distribution display well. These predictions are confirmed with mesoscale numerical simulations. The chains swollen highly entangled, yet Flory's exponent always ν = 1/2. melt can be considered fluid "blobs" whose size becomes renormalized in terms contour's...

The thermodynamic properties of a simple fluid confined by effective wall forces are calculated using Monte Carlo simulations in the grand canonical ensemble. solvation force produced polymer brushes two different lengths is obtained also. For particular type model interactions used, known as dissipative particle dynamics method, we find that it possible to obtain an exact, expression for induced planar composed identical particles interact with those fluid. We show despite short range all...

The transport of hydrophobic drugs in the human body exhibits complications due to low solubility these compounds. With purpose enhancing bioavailability and biodistribution such drugs, recent studies have reported use amphiphilic molecules, as phospholipids, for synthesis nanoparticles or nanocapsules. Given that phospholipids can self-assemble liposomes micellar structures, they are ideal candidates function vehicles molecules. In this work, we report mesoscopic simulations nanoliposomes,...

The need to extract oil from wells where it is embedded on the surfaces of rocks has led development new and improved enhanced recovery techniques. One those injection surfactants with water vapor, which promotes desorption that can then be extracted using pumps, as encapsulate in foams. However, mechanisms lead optimal best type carry out are not well known yet, warrants basic research this topic. In work, we report non equilibrium dissipative particle dynamics simulations model molecules...

The increase of the effective solid–liquid interfacial tension between pure liquids and surfaces with random features is due to variations local pressure adsorbed liquid in solid.

The influence of a logarithmic Van Hove singularity in the electronic density states is studied framework BCS theory. We use simplified model, neglecting effects such as interlayer coupling and pair breaking. Through analytic numerical analyses it found that although model can give rise to high temperatures, there are other properties, isotope effect specific-heat jump at transition temperature, which cannot be explained properly with this recent experimental data...

We report a model for atomic force microscopy by means of computer simulations molecular brushes on surfaces biological interest such as normal and cancerous cervical epithelial cells. Our predicts that the needed to produce given indentation can move surface cell (called "liquid" brushes) is same required whose ends are fixed cell's "solid" brushes), long tip microscope covers entire area brush. Additionally, we find cells softer than ones, in agreement with various experiments. Moreover,...

Viscosification of CO2 by a low concentration functional molecules is prized task. It has two important applications. One in fracturing shale formation and the other sweep efficiency improvement on subsurface hydrocarbon production. Toward that goal, we investigate molecular structure copolymers based simulations at atomistic mesoscopic scales various copolymer concentrations, pressure, temperature. The effect small amount water also investigated. Three types polymers are examined:...