TY - JOUR
T1 - The effects of counterion exchange on charge stabilization for anionic surfactants in nonpolar solvents
AU - Smith, Gregory N.
AU - Brown, Paul
AU - James, Craig
AU - Kemp, Roger
AU - Khan, Asad Muhammad
AU - Plivelic, Tomás S.
AU - Rogers, Sarah E.
AU - Eastoe, Julian
PY - 2016/3/1
Y1 - 2016/3/1
N2 - Hypothesis: Sodium dioctylsulfosuccinate (Aerosol OT or NaAOT) is a well-studied charging agent for model poly(methyl methacrylate) (PMMA) latexes dispersed in nonpolar alkane solvents. Despite this, few controlled variations have been made to the molecular structure. A series of counterion-exchanged analogs of NaAOT with other alkali metals (lithium, potassium, rubidium, and cesium) were prepared, and it was expected that this should influence the stabilization of charge on PMMA latexes and the properties of the inverse micelles. Experiments: The electrophoretic mobilities of PMMA latexes were measured for all the counterion-exchanged AOT analogs, and these values were used to calculate the electrokinetic or ζ potentials. This enabled a comparison of the efficacy of the different surfactants as charging agents. Small-angle scattering measurements (using neutrons and X-rays) were performed to determine the structure of the inverse micelles, and electrical conductivity measurements were performed to determine the ionized fractions and Debye lengths. Findings: Sodium AOT is a much more effective charging agent than any of the other alkali metal AOTs. Despite this, the inverse micelle size and electrical conductivity of NaAOT are unremarkable. This shows a significant non-periodicity in the charging efficiency of these surfactants, and it emphasizes that charging particles in nonpolar solvents is a complex phenomenon.
AB - Hypothesis: Sodium dioctylsulfosuccinate (Aerosol OT or NaAOT) is a well-studied charging agent for model poly(methyl methacrylate) (PMMA) latexes dispersed in nonpolar alkane solvents. Despite this, few controlled variations have been made to the molecular structure. A series of counterion-exchanged analogs of NaAOT with other alkali metals (lithium, potassium, rubidium, and cesium) were prepared, and it was expected that this should influence the stabilization of charge on PMMA latexes and the properties of the inverse micelles. Experiments: The electrophoretic mobilities of PMMA latexes were measured for all the counterion-exchanged AOT analogs, and these values were used to calculate the electrokinetic or ζ potentials. This enabled a comparison of the efficacy of the different surfactants as charging agents. Small-angle scattering measurements (using neutrons and X-rays) were performed to determine the structure of the inverse micelles, and electrical conductivity measurements were performed to determine the ionized fractions and Debye lengths. Findings: Sodium AOT is a much more effective charging agent than any of the other alkali metal AOTs. Despite this, the inverse micelle size and electrical conductivity of NaAOT are unremarkable. This shows a significant non-periodicity in the charging efficiency of these surfactants, and it emphasizes that charging particles in nonpolar solvents is a complex phenomenon.
KW - Electrophoresis
KW - Nonpolar solvents
KW - Polymer latexes
KW - Small-angle scattering
KW - Surfactants
UR - http://www.scopus.com/inward/record.url?scp=84949604809&partnerID=8YFLogxK
U2 - 10.1016/j.jcis.2015.11.062
DO - 10.1016/j.jcis.2015.11.062
M3 - Article (Academic Journal)
C2 - 26688124
AN - SCOPUS:84949604809
SN - 0021-9797
VL - 465
SP - 316
EP - 322
JO - Journal of Colloid and Interface Science
JF - Journal of Colloid and Interface Science
ER -