Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9675796 | Colloids and Surfaces A: Physicochemical and Engineering Aspects | 2005 | 6 Pages |
Abstract
The surface tension of 1,2-dimethyl-3-N-hexadecyl imidazolium tetrafluoroborate (Im BF4) as a function of concentration has been measured. Between 10â5 and 4 Ã 10â4 mol/L, the surface tension decreases with increasing imidazolium concentration. Aggregate formation appears to occur at a concentration near 4 Ã 10â4 mol/L for temperatures between 50 and 75 °C. Small angle neutron scattering measurements show the aggregates to be micelles with an aggregation number â83. Advancing and receding contact angles of Im BF4 surfactant solutions wetting pre-equilibrated mica surfaces show surfactant adsorption occurring at 10â6 mol/L. At 7 Ã 10â5 mol/L, a maximum in the hydrophobicity of the surface is measured, with a contact angle of 84° ± 2°. The results show that the Im BF4 surfactant adsorbs onto the mica surface and produces a hydrophobic surface, similar to the behavior of cetyl trimethyl ammonium bromide (CTAB). However, a hydrophobic surface forms at lower concentrations for the Im BF4 surfactant than the CTAB surfactant.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Colloid and Surface Chemistry
Authors
B.H. Cipriano, S.R. Raghavan, P.M. McGuiggan,