Dodecylammonium chloride

Another collector examined for flotation of ilmenite was dodecylammonium chloride. Using this collector, ilmenite readily floated at a pH region between 3.5 and 6.5. 

T. Tchaliovska, P. Herder, R. Pugh, P. Stenius, and J.C. Ericksson Studies of the Contact Interaction Between an Air Bubble and a Mica Surface Submerged in Dodecylammonium Chloride Solution. Fangmuir 6, 1535 (1990). 

Typical procedure used was to take 1.0 g of alumina (as an example) powder and add 10 mL of solution of detergent with varying concentration. The mixture was shaken, and the concentration of detergent was estimated by a suitable method. It was found that equilibrium was obtained after 2-4 h. The detergent such as dodecylammonium chloride was found to adsorb 0.433 mM/g of alumina with a surface area of 55 m2/g. The surface area of alumina, as determined from stearic acid adsorption (and using the area/molecule of 21 A2 from monolayer), gave this value of 55 m2/g. These data can be analyzed in more detail ... 

In this paper, dodecylammonium chloride (DAC) and decylainmoniuin chloride (DeAC) are chosen to reveal the fundamental behavior of surfactants in the mixed adsorbed film and micelle. The surface tension of their aqueous solution is measured as a function of their concentrations in the neighborhood of the CMC and the comparison between the mixed adsorbed film and the mixed micelle is made in terms of the composition evaluated. 

Dodecylammonium chloride and decylammonium chloride were synthesized and purified by the method described previously. Water was... 

The surface tension y of the aqueous solution of dodecylammonium chloride — decylammonium chloride mixture was measured as a function of m at a given value of the mole fraction X of DeAC at 298.15 K under atmospheric pressure. The results are shown in Figure 1. It is seen that the y vs. m curves are similar in appearance. This behavior is in harmony with that observed previously in a low concentration range (9). Moreover, the formation of micelle is found to cause the curves to break sharply at the CMC which increases with X. It should be noted, however, that the y vs. m curve of a mixture has a very shallow minimum in the immediate vicinity of the CMC. 

Mixed Adsorbed Film of 1-Octadecanol and Dodecylammonium Chloride at the Hexane-Water Interface... 

The interfacial tension of mixed adsorbed films of 1-octadecanol and dodecylammonium chloride has been measured as a function of temperature at various bulk concentrations under atmospheric pressure. The transition interfacial pressure of 1-octadecanol film has been observed to increase with the addition of dodecylammonium chloride and then to disappear. The interfacial pressure vs mean area per adsorbed molecule curves have been illustrated at a constant mole fraction of adsorbed molecules. With the aid of the thermodynamic treatment developed previously, we find that the mutual interaction between 1-octadecanol and dodecylammonium chloride molecules in the expanded state is similar in magnitude to the interaction between the scime kind of film-forming molecules. 

It is interesting to employ the system consisting of mixed adsorbed film of 1-pctadecanol and dodecylammonium chloride because the former shows the phase transition from an expanded to a condensed state ( ). The interfacial tension was measured as a function of temperature at various bulk concentrations under atmospheric pressure and the molecular interaction between film-forming components was considered. 

HAYAMI AND MOTOMURA I-Octadecanoland Dodecylammonium Chloride 313 Experimental... 

Octadecanol was recrystallized from hexane after fractionation by vacuum distillation, and its purity was checked by gas-liquid chromatography. Dodecylammonium chloride was recrystallized from a mixture of ethanol and water, and its purity was confirmed by the fact that it had no minimum near the critical micelle concentration on the surface tension vs concentration curve. Hexane was distilled after passing through an activated alumina column. Water was distilled from alkaline permanganate solution of distilled water after refluxing for one day. The purity of hexane and water was confirmed by the value of the interfacial tension between them. 

The interfacial tension Y was measured as a function of temperature T, molality of 1-octadecanol in hexane, and molality of dodecylammonium chloride in water under atmospheric pressure. The molality was increased up to the solubility limit. 

Figure 1 shows the plots of the interfacial tension against temperature at various values for = 7.54 mmol kg". All the curves except for the concentrated solution of dodecylammonium chloride have a break point which represents the phase transition from the condensed to expanded state. The phase transition temperature lowers with increasing and disappears above a certain ni2 value. 

The interfacial densities of 1-octadecanol and of dodecylammonium chloride F are evaluated, respectively, by... 

Figure 4. Interfacial density of dodecylammonium chloride vs curves at constant and 298.15 K (1) = 0 mmol kg (2)...

We are interested in the behavior of surfactant molecules in the mixed adsorbed film. The nonideal behavior of a mixed adsorbed film is correlated to activity coefficients of surface-active components with reference to the pure adsorbed film of each component. In the same manner as the previous paper ( ), we can express the chemical potentials of 1-octadecanol and dodecylammonium chloride in the mixed adsorbed film as follows ... 

Figure 10.3 The dependence of the flotation properties of goethite (FeO(OH)) on surface charge. Lower curves show the flotation recoveryin 10 5 M solutions of dodecylammonium chloride, sodium dodecyl sulphate, and sodium dodecyl sulphonate. From Fuerstenau [623], Copyright 1962, American Institute of Mining, Metallurgical and Petroleum Engineers.

CFSE Crystal Field Stabilization Energy CMC Critical micelle concentration DDAC1 N-Dodecylammonium Chloride DEDTC Diethyl Dithiocarbamate EDL Electric Double Layer GChSG Gouy/Chapman/Stern/Grahame IP Isoelectric Point... 

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