Decylammonium chloride

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. 

Fig. 4 Variation of the order parameter S with the position cf the earbon atom on the alkyl chain of decylammonium chloride for spherical (s) and elongated (s) mieelles. Reproduced from Kef [211 with permission cf the Anicrican Chemical Society.

The need to add either salt or a long-chain alcohol in order to prepare nematic phases from classical surfactants (e.g., SDS-decanol-water [154] decylammonium chloride-ammonium chloride-water [237]) may be understood in terms of this model. These additives shift the liquid crystalline phases away from their optimum concentration ranges and leading to a buildup of frustration. This frustration is resolved by the introduction of local structural fluctuations that destabilize the mesophases and lead to finite micelles of the appropriate sizes [177]. For instance, decanol limits the domains of existence of the mesophases for the system SDS-decanol-water [238]. The addition of NH4CI to the decylammonium chloride-water system suppresses the hexagonal phase and enhances the stability of the discotic phase [239]. 

CAS 107-64-2 EINECS/ELINCS 203-508-2 Synonyms Ammonium, dimethyidioctadecyl-, chloride Dimelhyldiocla-decylammonium chloride N,N-Dimethyl-N-ocladecyl-1-octadecan-aminium chloride Dioctadecyl dimethyl ammonium chloride Disteaiyl dimethyl ammonium chloride Octadecanaminium, N,N-dimethyl-N-octadecyl-, chloride Quatemium-5 Classiffcation Quaternary ammonium salt Empirical C3,H N Cl... 

An example of this phenomenon is given in Fig. 3.20, which shows the force curve obtained for a nematic solution of surfactants in water (molar concentration water 95%, decylammonium chloride 0.75%, potassium lam-ate 4.25%). The solution forms biaxial micelles and it is a nematic discotic at 29°C, where the micelles freely rotate about their shortest principal axis, defining the director orientation [53]. In bulk nematic there is a short-range... 

In nature, many other polymethylene systems-also of practical relevance-can be found which show phase transitions that need to be accounted for. More theoretical and experimental spectroscopic work needs to be done. We have studied the spectra of intercalated layered alkylammonium zirconium phosphates [ 128] and of the solutions of decylammonium chloride [129]. The spectroscopic data present unusual features with temperature which need further theoretical and experimental studies using the techniques presented in this chapter. 

Measurements also in sodium decyl sulfate, decylammonium chloride. 

Vanin et al. [40] used dopants with different locations of mesophase environments they found that only when the dopant is solubilized mainly in the bulk water its structure is important with respect to the twist sense of different host phases. The use of strongly water soluble sugars exhibited a very low twisting efficiency. In their studies hydrophobic dopants lead to the same handedness in all investigated hosts (decylammonium chloride, potassium alkanoates, sodium, and cesium alkylsulfates). To discuss their results they proposed three different situations ... 

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