6533b831fe1ef96bd1299b18
RESEARCH PRODUCT
On the effect of the nature of counterions on the self-assembly of polyoxyethylene alkyl ether carboxylic acids
Giuseppe LazzaraChiara CrivelloLeonardo Chiappisisubject
inorganic chemicalschemistry.chemical_classificationEthylene oxideCharge density02 engineering and technologyGeneral ChemistryNeutron scattering010402 general chemistry021001 nanoscience & nanotechnologyCondensed Matter Physics01 natural sciences0104 chemical scienceschemistry.chemical_compoundPulmonary surfactantchemistrySodium hydroxideCounterion condensationSurfactantPolymer chemistryCounterion0210 nano-technologyAlkylSettore CHIM/02 - Chimica Fisicadescription
In this contribution, we investigate the effect of the type of counterion on the properties of dilute solutions of polyoxyethylene alkyl ether carboxylic acids. Two different surfactants, presenting an oleic acid alkyl chain and on-average five and nine ethylene oxide units, and terminated by a weakly anionic carboxymethyl group were studied. The surfactants were gradually ionized with sodium hydroxide, arginine, and choline hydroxide. The solutions properties were probed by light scattering, electrophoretic mobility, density and sound velocity measurements, as well as by small-angle neutron scattering. To our initial surprise, no specific effect arising from the nature of the counterion could be determined. We ascribe this phenomenon to the fact that the presence of the ethylene oxide units markedly dilutes the surfactant head group charge density, reducing counterion condensation and subsequent counterion specific effects. This journal is
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2020-07-15 | Soft Matter |