Hexadecyltrimethylammonium decyl sulfate

FIG. 5 Thermograms of hexadecyltrimethylammonium decyl sulfate (CTADeS), hexa-decyltrimethylammonium dodecyl sulfate (CTADDS), and hexadecyltrimethylammonium tetradecyl sulfate (CTATDS) obtained by differential scanning calorimetry during heating (full line) and cooling (dashed hne) scans. 

Figure 6.6. Changes in the MTR with pressure for typical ionic surfactants (a) sodium decyl sulfate, (b) sodium dodecyl sulfate, (c) sodium tetradecyl sulfate, (d) sodium hexadecyl sulfate, (e) hexadecyltrimethylammonium bromide. (Reproduced with permission of the American Chemical Society.)...

Tamura and Aida reported the unique influence of shape and volume of inner micellar space on product distribution. They irradiated ACN in aqueous sodium octyl sulfate, decyl sulfate, dodecyl sulfate, and hexadecyltrimethylammonium bromide under pressures up to 150 MPa. Pressure enhanced the dimerization reaction in all micellar systems due to the formation of a van der Waals dimer in the ground state. Plots of the consumed ACN vs. concentration of micelles exhibited a minimum under constant concentration (9.7 mmol kg" ) of ACN. Thus, the number of micelles in the solution increases with increase of surfactant concentration and, as a result, the number of ACN molecules solubilized per micelle decreases. This leads to a decrease of probabihty of collision between ACN molecules that undergo bimolecular reaction. Viscosity measurements indicate that spherical micelles start to aggregate and form rod-shaped micelles with larger volumes at ca. 9 wt% of micelle, which exactly coincides with the minimum concentration of micelles. At concentrations of micelles higher than the minimum, the number of ACN molecules included in a micelle increases due to aggregation of spherical micelles into rod-shaped micelles, leading to enhanced dimerization of ACN. 

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