The salt effects of 10 transition metal cations on nonionic surfactants were investigated by the action of their salts (nine nitrates, two sulfates) on the cloud point (CP) of octoxynol 9. All cations investigated raised the CP of octoxynol 9 by complexation with its ether groups, which represents s
Effect of inorganic additives on solutions of nonionic surfactants II
โ Scribed by Hans Schott; Suk Kyu Han
- Publisher
- John Wiley and Sons
- Year
- 1975
- Tongue
- English
- Weight
- 646 KB
- Volume
- 64
- Category
- Article
- ISSN
- 0022-3549
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โฆ Synopsis
The effect of electrolytes and urea on the cloud points of the following three nonionic polyoxyethylated surfactants was studied: cetyl, stearyl, and oleyl alcohol adducts containing 10 ethylene oxide units. The results were similar to those obtained previously with polyethylene oxide and with a polyoxyethylated alkylphenol. Nitrates of cations capable of forming stable solid complexes with model ethers like dioxane raised the cloud points in proportion to their concentrations by up to 35 degrees. They salted the surfactants in through complexation with the ether oxygens. The order of effectiveness in raising the cloud points was lead nitrate greater than hydrochloric acid greater than cadmium nitrate greater than sulfuric acid approximately equal to to magnesium nitrate greater than aluminum nitrate greater than nickel nitrate greater than lithium nitrate greater than calcium nitrate. Only the nitrates of sodium, potassium, ammonium, and cesium lowered the cloud points, salting the surfactants out. These cations do not form complexes with ether oxygens. Urea, sodium perchlorate, and sodium iodide, which break the structure of water, raised the cloud points. This salting-in process is ascribed to increased hydration of the ether groups of the polyoxyethylated surfactants due to depolymerization of water by urea and the perchlorate and iodide anions. The bromide, chloride, and sulfate of sodium lowered the cloud points. The surfactant with the alkylaryl moiety was salted in more extensively but salted out only slightly more than the three surfactants with the linear hydrocarbon chain. The data indicate the need for revising the theories of the effects of salts on the solubility of nonelectrolytes in water. None of the theories takes into account the interaction between electrolytes and nonelectrolytes, even though many nonelectrolytes compete with water as ligands for the cations.
๐ SIMILAR VOLUMES
As an alternative, salt effects for NS are measured by The effect of salts on the nonionic surfactant octoxynol 9 was changes in CMC or in CP. Most NS have small CMC values. studied by the changes they produced in its cloud point (CP): CP Therefore, the increases in CMC through salting in and the in
Continuing work on the interaction of inorganic additives with nonionic surfactants in aqueous solution dealt with their effect on the CMC and surface tension. The surfactants were octoxynol and polyoxyethylated oleyl alcohol, containing an average of 9.5 and 10 ethylene oxide units, respectively. T