Dodecyl ammonium chloride

The specific case to be considered is that of the Cl" counterion surface in contact with a dilute salt solution—e.g., at 10 2N NaCl where 0 = 28° (Table II). Data of Stigter (33) show that the fraction of Cl" counterions outside the shear surface of dodecyl ammonium chloride micelles is about 0.4 in the range 0.02-0.05M NaCl plus surfactant at the critical micelle concentration (CMC). This value appears to rise toward 0.5-0.6 as NaCl concentration is lowered. Conductance data of Robins and Thomas (30) indicate that 73% of Cl" counterions are bound to 2-dodecyl aminoethanol hydrochloride micelles at the CMC in the absence of added salt. 

In fact, experimental surface tensions of mixtures of sodium decyl sulphate SDeS (component 1) and sodium dodecyl sulphate SDS (component 2) are described satisfactorily by Eq. (2.48) whereas the application of Eq. (2.51) leads to large differences between theory and experiment [67]. The best agreement between experimental and theoretical values of n was received by using the Frumkin analogue of Eqs. (2.48)-(2.50) with ai=0.7, a2=0.85 and ai2=(ai+a2)/2=0.77. Similarly, mixtures of decyl ammonium chloride and dodecyl ammonium chloride were very well described by these equations with ai=1.2, a2=1.56 and ai2=(ai+a2)/2=1.38 [16]. The latter system also reveals a reverse salting-out effect as an excess of inorganic counterions in the solution increases the adsorption activity of an ionic surfactant, by the same token such an excess in the surface decreases the adsorption activity. As a result, the effect of a second ionic surfactant with a common counterion on the surface pressure is smaller than it would have been according to the additivity rule for non-ionic surfactants expressed in Eq. (2.51). 

Figure 3.57 presents experimental data for decyl ammonium chloride (CioACl) and dodecyl ammonium chloride (C12ACI) in presence of 0.005 M HCl [33]. The molar area to, is somewhat lower than that for C TAB. At the same time, the Frumkin constant a is somewhat higher which underlines the interrelation of these parameters. The dependencies of b on n, for CnACl and CnTAB are compared with the data for fatty acids in Fig. 3.58. 

Mixture of decyl ammonium chloride and dodecyl ammonium chloride in 5 mmol/1 solution of NaCl. This system is discussed in Section 3.7.1. 

Figure 7.7. Experimental (points) and theoretical (lines) values of surface tension for mixtures of decyl ammonium chloride and dodecyl ammonium chloride solutions in 0.01 M NaCl with ratios 15 1, 5 1 and 5 3, calculated fora, = 1.5.

VDAC Vinylbenzyl dimethyl dodecyl ammonium chloride... 

This is the case for a drop of water hanging in toluene containing acetone which "kicks" as long as the acetone is being trans-ferred from toluene to water. But, when dodecyl ammonium chloride (4.10 mol.1 ), a compound much more surface active than acetone and very similar to those which we used in our experiments is added, the drop does not start "kicking". 

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