This research work deals with the surface behavior of mixed protein/surfactant systems and its relation foam stability. In particular, a novel procedure analysis experimental data is proposed, which provides direct correlation between both phenomena. Accordingly, results presented might constitute promising tool in control stability, has crucial technological application. The characterization performed by studying pressure isotherms systems. qualitative information extracted from curves...

In this work, we have performed explicit coarse-grained Monte Carlo simulations of thermo-responsive nanogels in salt-free solutions with the help bead-spring model polyelectrolytes and a solvent-mediated hydrophobic interaction potential that captures swelling behavior real microgels. As far as know, such not been applied to temperature-sensitive charged yet. Monovalent divalent counterions considered. Charge profiles inside outside nanogel computed from simulations, revealing an attractive...

In this work, a quantitative comparison between experimental swelling data of thermo-sensitive microgels and computer simulation results obtained from coarse-grained model polyelectrolyte network the primitive electrolyte is carried out. Polymer-polymer hydrophobic forces are considered in through solvent-mediated interaction potential whose depth increases with temperature. The qualitative agreement experiment very good. particular, our simulations predict gradual shrinkage temperature,...

In this paper, the structure of electric double layer in presence (mostly) multivalent counterions is investigated through Monte Carlo simulations. Unlike previous similar studies addressing matter, difference study lies use realistic hydrated ion sizes. Additionally, two different methods for calculating energies Metropolis algorithm are applied. The obtained results show that conclusions preceding papers must be revised. particular, our simulations suggest existence certain layering...

Lipoplexes constituted by calf-thymus DNA (CT-DNA) and mixed cationic liposomes consisting of varying proportions the lipid 3β-[N-(N',N'-dimethylaminoethane)-carbamoyl]cholesterol hydrochloride (DC-Chol) zwitterionic lipid, 1,2-dioleoyl-sn-glycero-3-phosphoetanolamine (DOPE) have been analyzed means electrophoretic mobility, SAXS, fluorescence anisotropy experiments, as well theoretically calculated phase diagrams. Both experimental theoretical studies run at several liposome lipoplex...

In this work, thermo-responsive polyelectrolyte gels have been simulated using polymer networks of diamond-like topology in the framework primitive model. Monte Carlo simulations were performed canonical ensemble and a wide collection situations has systematically analysed. Unlike previous studies, our model includes an effective solvent-mediated potential for hydrophobic interaction between non-bonded beads. This predicts that strength attractive forces increases with temperature, which...

In this work, coarse-grained simulations of two charged thermo-shrinking nanogels (with degrees ionization 0.125 and 0.250) in the presence 1:1 3:1 electrolytes have been explicitly performed through bead-spring model polyelectrolyte. a first set simulations, salt concentrations for ranged from 1 to 100 mM 0.167 16.7 mM, respectively, whereas temperature remained fixed at value which hydrophobic forces were negligible our case (288 K). The sizes swollen are smaller when trivalent cations...

Both experiments and theory have evidenced that multivalent cations can mediate the interaction between negatively charged polyelectrolytes like-charged objects, such as anionic lipoplexes (DNA-cation-anionic liposome complexes). In this paper, we use Monte Carlo simulations to study electrostatic responsible for trivalent-counterion-mediated adsorption of onto a planar surface. The evaluation Helmholtz free energy allows us characterize both magnitude range function polyelectrolyte charge,...

The equilibrium distribution of monovalent and trivalent ions within a thermo-responsive charged nanogel is investigated using Monte Carlo simulations Ornstein–Zernike equations.

Poly(N-vinylcaprolactam) (PVCL) is a new temperature-responsive type of polymer microgel with improved biocompatibility as compared to more commonly used poly(N-isopropylacrylamide) (PNIPAM). Both polymers swell at low temperatures and collapse high ones, showing volume phase transition temperature (VPTT) around the physiological temperature. Exploring interfacial characteristics thermoresponsive microgels important due their potential application in emulsion based systems tailored...

Some theories claim that the Poisson–Boltzmann approach could fail to describe electric double layer of colloids under certain conditions as a result neglecting ion size correlations. For instance, if surface charge density and/or electrolyte concentration are high enough, counterion local in vicinity charged become so large particle would be overcompensated. This phenomenon is theoretically known overcharging and, sometimes, should involve ζ-potential reversal. Accordingly, this work looks...

In this work we test the validity of a recent modified Poisson–Boltzmann (MPB) theory that includes ion size effects through Langmuir-type correction. particular, will focus on an analytic charge–potential relationship accounting for such effects. Previous electric double layer (EDL) surveys have demonstrated inclusion ions in classical EDL theories, based (PB) equation, can yield considerable improvements. sense, analyze assumes that, as result excluded volume, concentration close to...

The compaction of DNA by cationic liposomes constituted a mixture lipid, dioctadecyldimethylammonium bromide (DODAB), and zwitterionic 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine (DOPE) or 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC), has been evaluated means experimental studies (electrophoretic mobility, conductometry, cryogenic electron transmission microscopy cryo-TEM, fluorescence spectroscopy) as well theoretical calculations. This information reveals that DODAB/DOPE...

A new mechanism for charge inversion of colloids in electrolyte solutions based on the hydrophobic effect is presented. We show that this able to induce at low concentrations (∼mM) monovalent ions containing functional groups and present first time experimental evidence prediction. provide a simple mean field theoretical model successfully describes data up inversion. Saturation effects appearing higher are also discussed.

We present experimental and simulation evidence for a new mechanism of charge reversal operating only ions capable to penetrate into soft interfaces. It is based on the preferential solvation counterions by amphiphilic molecules hydration water rather than bulk water. This does not require high surface densities it affected addition 1:1 salt. behavior opposite that observed in systems as diverse microfluidic channels or latex colloids. The robustness physiological amounts salt suggests...

Lipoplexes constituted by plasmid DNA pEGFP-C3 (pDNA) or linear double-stranded calf thymus (ctDNA) and mixed cationic liposomes consisting of several percentages the lysine derived lipid C6(LL)2 zwitterionic 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) have been analyzed both experimental theoretical approaches. Experimental studies, electrophoretic mobility/zeta potential, small angle X-ray scattering (SAXS), cryogenic transmission electron microscopy (cryo-TEM), negatively stained...

In this work, the effect of counterion valence on behavior thermo-sensitive gels and microgels is studied through computer simulations. The polyelectrolyte gel described within a bead–spring model ions are explicitly considered. thermo-shrinking simulated with help phenomenological solvent-mediated polymer–polymer interaction that captures essential features experimental swelling data. Our results show multivalent species smaller than in case monovalent counterions therefore lower...

In this work, we study the effect of steric excluded-volume interactions between counterions and thermoresponsive ionic heterogeneous microgel particles. With aim, perform Monte Carlo simulations to calculate effective net charge conunterion distribution function inside around for different degrees swelling. These results are compared ones obtained solving Ornstein–Zernike integral equations within HNC approximation. For purpose, equilibrium polymer mass resulting from used as input...

Specific ion effects have been observed in the magnetite/water interface. Monte Carlo simulations qualitatively explain them terms of size and ionic polarizabilities.