in this study, a new adsorbent, silver nanoparticle loaded on activated carbon (ag˗np˗ac) was used for removal of acid yellow199 (ay 199) dye. this novel material was characterized and identified by different techniques such as brunauer, emmett and teller (bet), field emission scanning electron microscopy (fesem), x-ray diffraction (xrd) analysis. unique properties of this adsorbent such as hig...

When simulating protein adsorption behavior, decisions must first be made regarding how the protein should be oriented on the surface. To address this problem, we have developed a molecular simulation program that combines an empirical adsorption free energy function with an efficient configurational search method to calculate orientation-dependent adsorption free energies between proteins and ...

Experimental evidence suggests that proteins adsorbed to hydrophobic surfaces at low coverages are stabilized relative to the bulk. For larger coverages, proteins unfold and form beta-sheets. We performed computer simulations on model proteins and found that: 1), For weakly adsorbing surfaces, unfolded conformations lose more entropy upon adsorption than folded ones. 2), The melting temperature...

A hybrid statistical mechanical model, which is fully consistent with the bulk perturbed-chain statistical associating fluid theory (PC-SAFT) in describing properties of fluids, was developed by coupling density functional theory with PC-SAFT for the description of the inhomogeneous behavior of real chain molecules in nanopores. In the developed model, the modified fundamental measure theory wa...

Flexible metal-organic frameworks, also known as soft porous crystals, have been proposed for a vast number of technological applications, because they respond by large changes in structure and properties to small external stimuli, such as adsorption of guest molecules and changes in temperature or pressure. While this behavior is highly desirable in applications such as sensing and actuation, ...

An expression for the surface tension of an aqueous mixed solution of surfactants and electrolyte ions in the presence of the common ions was derived from the Helmholtz free energy of an air/water surface. By applying the equation to experimental data for the surface tension, the adsorption constant of surfactant ions onto the air/water interface, the binding constant of counterions on the surf...

The hydrophobic effect, i.e., the poor solvation of nonpolar parts of molecules, plays a key role in protein folding and more generally for molecular self-assembly and aggregation in aqueous media. The perturbation of the water structure accounts for many aspects of protein hydrophobicity. However, to what extent the dispersion interaction between molecular entities themselves contributes has r...

Equilibrium properties of dilute binary fluid mixtures are studied in two-phase states on the basis of a Helmholtz free energy including the gradient free energy. The solute partitioning between gas and liquid (Henry's law) and the surface tension change Delta gamma are discussed. A derivation of the Gibbs law Delta gamma = -T Gamma is given with Gamma being the surface adsorption. Calculated q...

Equilibrium constants for the adsorption of the first water molecule onto a variety of unsolvated alanine-based peptides have been measured and Delta H degrees and DeltaS degrees have been determined. The studies were designed to examine the effects of conformation, charge, and composition on the propensity for peptides to bind water. In general, water adsorption occurs significantly more readi...