Hydrophobic Forces in the Foam Films Stabilized by Sodium Dodecyl Sulfate: Efect of Electrolyte
نویسنده
چکیده
Further studies of the hydrophobic force in foam films were carried out, including the effect of added inorganic electrolyte. We used a thin film balance of Scheludko-Exerowa type to obtain the disjoining pressure isotherms of the foam films stabilized by 10-4 M sodium dodecyl sulfate in varying concentrations of sodium chloride. The results were compared with the disjoining pressure isotherms predicted from the extended Derjaguin-Landau-Verwey-Overbeek theory, which considers contributions from hydrophobic force in addition to those from double layer and van der Waals dispersion forces. The double layer forces were calculated from the surface potentials (ψs) obtained using the Gibbs adsorption equation and corrected for the counterion binding effect, while the dispersion forces were calculated using the Hamaker constant (A232) of 3.7 × 10-20 J. The hydrophobic forces were calculated from the equilibrium film thickness as described previously. The predicted disjoining pressure isotherms were in good agreement with the experimental ones. It was found that the hydrophobic force is dampened substantially by the added electrolyte.
منابع مشابه
Hydrophobic forces in the foam films stabilized by sodium dodecyl sulfate: effect of electrolyte.
Further studies of the hydrophobic force in foam films were carried out, including the effect of added inorganic electrolyte. We used a thin film balance of Scheludko-Exerowa type to obtain the disjoining pressure isotherms of the foam films stabilized by 10(-4) M sodium dodecyl sulfate in varying concentrations of sodium chloride. The results were compared with the disjoining pressure isotherm...
متن کاملReply to comment on "hydrophobic forces in the foam films stabilized by sodium dodecyl sulfate: effect of electrolyte" and subsequent criticism.
متن کامل
Role of Hydrophobic Forces in the Thinning of the Foam Films in the Presence of Sodium Dodecyl Sulfate
The thin film pressure balance (TFPB) technique was used to study the kinetics of film thinning in the presence of sodium dodecyl sulfate (SDS) and sodium chloride (NaCl). The experimental results were compared with the predictions of the Reynolds equation. During the initial stages, the film thinning was controlled by the capillary pressure. As the film thickness is reduced, the process is con...
متن کاملFoam superstabilization by polymer microrods.
Few foam systems stabilized by solid particles have been reported, and usually the particles have been used in combination with surfactants. We report how foams can be stabilized solely with a new class of anisotropic particles, hydrophobic polymer microrods of diameter less than 1 mum and length of a few tens of micrometers. The obtained foams were extraordinary stable, retaining a constant vo...
متن کاملSurface Forces in Foam Films
Fundamental studies of surface forces in foam films are carried out to explain the stability of foams and froths in froth flotation. The thin film pressure balance (TFPB) technique was used to study the surface forces between air bubbles in water from equilibrium film thickness and dynamic film thinning measurements. The results were compared with the disjoining pressure predicted from the Derj...
متن کامل