Specific ion effects on the interfacial tension of water/hydrocarbon systems

Abstract

-Specific ion effects -also known as Hofmeister effects -are ubiquitous in several areas of chemistry, chemical engineering and biology. The interfacial tension corresponds to the energy per unit of area at the interface. Thus, the presence of different salts in different concentrations changes the interfacial tension of a system containing an aqueous phase. This effect can be explained based on the concentration profile of different ions in the vicinity of the interface. In order to study this effect we measured the surface tension of aqueous electrolyte solutions and the interfacial tension of various systems containing hydrocarbons and different aqueous electrolyte solutions as a function of the ionic strength of the aqueous phase. We classify the tested ions for their ability to alter the interfacial tension of each system. These data provide valuable information that can be related to the stability of the corresponding emulsions, since the ions with higher capability of increasing the interfacial tension tend to be more effective in destabilizing the corresponding emulsion.

Characterization of partial pore wetting in hollow fiber gas absorption membrane contactors: An EDX analysis approach

“…As can be seen, the trend of the solution surface tension is ascending as a result of increasing NaCl concentration [33,34]. Also, NaCl concentration marginally influences the solution surface tension.…”

Emulsification at the Liquid/Liquid Interface: Effects of Potential, Electrolytes and Surfactants

“…[16] For the aqueous (with LiCl)/GTOs ystem, the g 0 value measured was 17.3 AE 0.1 mN m À1 ,c ompared with 31.08 mN m À1 for aG TO/saline (tris-hydrochloride, 150 mm sodium chloride) interface. [19] Kakiuchie tal. Lima et al have shown that as the concentrationo f sodium chloride was enhanced from 0-1.5 mol L À1 in the aqueous phase of the water/hydrocarbon oil system, the interfacial tension of the aqueouse lectrolyte solution also increased linearly.…”

“…Lima et al have shown that as the concentrationo f sodium chloride was enhanced from 0-1.5 mol L À1 in the aqueous phase of the water/hydrocarbon oil system, the interfacial tension of the aqueouse lectrolyte solution also increased linearly. [19] Kakiuchie tal. have exhibited, theoreticallya nd practically, using 0.5 mmoldm À3 of sodium dodecylsulfonate in an aqueous phase containing 10 mm of LiCl and 20 mm of tetrapentylammonium tetraphenylborate (TPATPB) in the 1,2-DCE phase, that the electrocapillary curve maximad ips in the presence of the anionic surfactant, giving rise to ar egion of negative capacitance where the system is unstable.…”

Morphological differences in transparent conductive indium-doped zinc oxide thin films deposited by ultrasonic spray pyrolysis

“…The decrease of the film thickness due to adding 2% InCl 3 into the zinc acetate solution was relatively substantial compared to the thickness decreases in the range of 2-8 at.% InCl 3 concentration. Adding InCl 3 and zinc acetate to methanol generally increased the interfacial tension due to the repulsion of ions at the dielectric air/liquid interface [22,23].…”