TY - JOUR
T1 - The effect of solvent and counterion variation on inverse micelle CMCs in hydrocarbon solvents
AU - Smith, Gregory N.
AU - Brown, Paul
AU - James, Craig
AU - Rogers, Sarah E.
AU - Eastoe, Julian
PY - 2016/4/5
Y1 - 2016/4/5
N2 - Critical micelle concentrations (CMCs) for the formation of inverse micelles have been determined for anionic surfactants in nonpolar, hydrocarbon solvents. Sodium dioctylsulfosuccinate (Aerosol OT or AOT) was chosen as the model surfactant, with systematic variations in both the solvent (benzene, cyclohexane, and dodecane) and the surfactant counterion (sodium and tetrapropylammonium). Recent work (Langmuir 29 (2013) 3352-3258) has shown that high-resolution small-angle neutron scattering (SANS) measurements can be used to directly determine the presence or absence of aggregates in solution. No variation in the value of the CMC was found within the resolution of the measurements for changing either solvent or counterion; some effects on the structure of inverse micelles were observed. This lack of a significant difference in the onset of inverse micellization with changes to the molecular species is surprising, and the implications on the solvophobic effect in nonpolar solvents are discussed.
AB - Critical micelle concentrations (CMCs) for the formation of inverse micelles have been determined for anionic surfactants in nonpolar, hydrocarbon solvents. Sodium dioctylsulfosuccinate (Aerosol OT or AOT) was chosen as the model surfactant, with systematic variations in both the solvent (benzene, cyclohexane, and dodecane) and the surfactant counterion (sodium and tetrapropylammonium). Recent work (Langmuir 29 (2013) 3352-3258) has shown that high-resolution small-angle neutron scattering (SANS) measurements can be used to directly determine the presence or absence of aggregates in solution. No variation in the value of the CMC was found within the resolution of the measurements for changing either solvent or counterion; some effects on the structure of inverse micelles were observed. This lack of a significant difference in the onset of inverse micellization with changes to the molecular species is surprising, and the implications on the solvophobic effect in nonpolar solvents are discussed.
KW - Inverse micelles
KW - Nonpolar solvents
KW - Small-angle neutron scattering
UR - http://www.scopus.com/inward/record.url?scp=84956600061&partnerID=8YFLogxK
U2 - 10.1016/j.colsurfa.2016.01.020
DO - 10.1016/j.colsurfa.2016.01.020
M3 - Article (Academic Journal)
AN - SCOPUS:84956600061
VL - 494
SP - 194
EP - 200
JO - Colloids and Surfaces A. Physicochemical and Engineering Aspects
JF - Colloids and Surfaces A. Physicochemical and Engineering Aspects
SN - 0927-7757
ER -