Distearyldimethylammonium

Cationic quaternary ammonium compounds such as distearyldimethylammonium-chloride (DSDMAC) used as a softener and as an antistatic, form hydrated particles in a dispersed phase having a similar structure to that of the multilayered liposomes or vesicles of phospholipids 77,79). This liposome-like structure could be made visible by electron microscopy using the freeze-fracture replica technique as shown by Okumura et al. 79). The concentric circles observed should be bimolecular lamellar layers with the sandwiched parts being the entrapped water. In addition, the longest spacings of the small angle X-ray diffraction pattern can be attributed to the inter-lamellar distances. These liposome structures are formed by the hydrated detergent not only in the gel state but also at relatively low concentrations. 

The only cationic surfactant (Fig. 23) found in any quantity in the environment is ditallow dimethylammonium chloride (DTDMAC), which is mainly the quaternary ammonium salt distearyldimethylammonium chloride (DSDMAC). The organic chemistry and characterization of cationic surfactants has been reported and reviewed [330 - 332 ]. The different types of cationic surfactants are fatty acid amides [333], amidoamine [334], imidazoline [335], petroleum feed stock derived surfactants [336], nitrile-derived surfactants [337], aromatic and cyclic surfactants [338], non-nitrogen containing compounds [339], polymeric cationic surfactants [340], and amine oxides [341]. 

Mel nikov, S.M., Sergeyev, V.G., Melnikova, Yu.S. and Yoshikawa, K. (1997b) Folding of long DNA chains in the presence of distearyldimethylammonium bromide and unfolding induced by neutral liposomes. J. Chem. Soc. Faraday Trans., 93, 283-288. 

Polymer films have been obtained by plasma polymerization of hexafluorobenzene, N-vinylpyrrolidine, and chloracrylonitrile (Munro). Higuchi et al. have shown that irradiation of an azobenzene-modified poly(Y-methyl-L-glutamate-CO-L-glutamic acid) in bilayer membrane vesicles of distearyldimethylammonium chloride leads to trans-cis isomerization of the polymer this leads to transfer of the polypeptide from the hydrophobic bilayer membrane interior to the hydrophilic surface. As a result, there was a decrease in the ion permeability through the bilayer membrane and the formation of intervesicular adhesion. Eisner and Ritter have prepared photosensitive membranes from an aromatic polyamide and a cinnamate that incorporates a liquid crystalline component. 

U.S. 4719104 (1988) Patel (Helene Curtis) 0.25-4% static-reducing agent 0.05-1% cationic film-forming polymer 0.25—4% distearyldimethylammonium static-reducing agent/catonic polymer = 2 1-20 1... 

Existing substances regulation (793/93). Distearyldimethylammonium has been put on first priority list and a risk assessment for humans has been carried out (CAS 107-64-2). 

Berenbold, H., Additional use benefits of fabric softeners based on distearyldimethylammonium chloride (DSDMAC). Comun. Jorn. Com. Esp. Deterg. 18 49-63,1987. 

Distearyldimethylammonium chloride or dihydrogenated tallow dimethylammonium chloride, also known as Quaternium-18, exhibits strong conditioning properties. However, these compounds exhibit very poor biodegradability. 

Some Pd-Pt bimetallic colloids protected by polymers [162-165] have been prepared by the coreduction of the metal salts with aqueous alcohols. Similar bimetallic sols in nonpolar organic solvents were obtained by N2H4 or NaBH4 reduction of palladium and platinum salt mixtures after their extraction into the organic phase (cyclohexane or chloroform) with such surfactants as trioctylphos-phine oxide or distearyldimethylammonium chloride. [166]... 

To produce organically-modified montmorillonite, the montmorillonite clay was mixed in water with distearyldimethylammonium chloride. The resulting solid was extracted and washed with sodium chloride solution and ethanol, to remove excess ammonium salt, and freeze dried. To combine with the PCL, the organically-modified montmorillonite was dispersed in chloroform the unmodified montmorillonite would not disperse in this way. Samples with up to 30 wt % clay were produced. 

M., and Paradies, H. H. (1994). Micellar behavior of distearyldimethylammonium hydroxide and chloride in aqueous solutions. J. Phys. Chem. 98, 11143-11162. 

DTDMAC and distearyldimethylammonium chloride (DSDMAC), which have long been amongst the most important cationic surfactants, are traditionally analyzed by normal phase HPLC with conductivity detection [4,73,74]. However, with conductivity detection an isocratic elution mode is mandatory resulting in a steady broadening of the peaks with... 

DNA from chicken erythrocytes (800-3000 b.p.) (DNAc) and DNA from salmon sperm (300-500 b.p.) (DNAl) was purchased from Soyuzkhimreaktiv Russia. Cetyl-trimethylammonium bromide (CTAB) and distearyldimethylammonium chloride (DD AC) were obtained from Tokio Kasei. CTAB was recrystallized twice from acetone and dried under vacuum DDAC was used without... 

Miyamae et al. (2002) Lauryldimethylamine oxide C]8 trimethylammonium distearyldimethylammonium Cosmetic lotions creams LC/MS... 

Other methods that enable more than two subclasses of cationic surfactants to be separated were proposed by Choi et al. (1997) and Okumura (1992). Six cationic surfactants (cetylpyridinium chloride, Cis and Cig trimelhylammonium chloride, behenyllrimethylam-monium chloride, benzalkonium chloride and benzyldimethylcetylammonium chloride) were separated by Choi et al. using an octadecylsilica column, with an acetonittile/HCl solution as a mobile phase and UV detection, except in the case of cetylpyridinium chloride and Ci5 trimethylammonium. In the case of these last compounds, they were quantified using both UV and suppressed conductivity detector in series. Analytical recovery values from a hair-treatment cream and hair rinse were good. The method proposed by Okumura enabled C15 ig-trimethylammonium and benzyldimethylammoniun, cetylpyridinium chloride and distearyldimethylammonium to be determined by reversed-phase LC at acid pH using a RI detector in shampoos and rinses. 

May and Neufahrt [81] have reported on the behaviour of the cationic surfactant distearyldimethylammonium chloride (DSDAC) in sludge-activating units. In the OECD Confirmatory Test, they obtained elimination rates of between 91% and 93% at a feed rate of 2.78 mg of DSDAC/1 or 1.75 mg of DSDAC/1, with an... 

For the cationic surfactant distearyldimethylammonium chloride, an acute fish toxicity of about 2 mg/1 is indicated by a 48 hour laboratory test under conditions... 

Electrospray MS. Analysis of methanol solutions in the positive ion mode gives molecular ions of distearyldimethylammonium chloride. Strong ions are seen for the Cj / Cis, Cis/Ci6, and Cifi/Cig homologs, as well as some minor components (15,120). It must be noted that the response factors differ sharply for similar compounds. For example, the response factor for hexadecyltrimethylammonium bromide is only 45% of that for dode-cyltrimethylammonium bromide (117). The same observations on calibration with deuter-ated analogs and fragments for MS-MS analysis made above for FAB also apply to electrospray (117). Electrospray MS was demonstrated for detection of benzalkonium chloride on human skin, using a triple quadrupole instmment in multiple reaction monitoring mode (121). 

Motomizu, S., M. Oshima, Y. Gao, S. Ishihara, K. Uemura, Indicator system for the photometric titration of ionic surfactants in an aqueous medium determination of anionic surfactants with distearyldimethylammonium chloride as titrant and tetrabromophenolphthalein ethyl ester as indicator, Ana/ysr, 1992,117,1775-1780. 

Because other UV-absorbing compounds are present in environmental matrices, direct UV measurement has little value for determination of LAS (74). Derivative UV spectroscopy eliminates many interferences, especially if more than one wavelength is used (75). Hellmann describes determination of LAS concentrations along the length of German rivers by second-derivative UV spectrophotometry of extracts of the water made with trichlorotrifluoroethane/chloroform and distearyldimethylammonium chloride. In most cases, additional cleanup was unnecessary (55). A similar method has been proposed for LAS determination in sewage without preliminary sample cleanup, but a rigorous comparison to results from standard methods is yet to be made (76,77). 

Klotz determined that quantitative removal of cationics from clay minerals is quite difficult (147). He based his conclusions on experiments with a synthetic montmorillonite made with 34% distearyldimethylammonium ion rather than sodium ion. The most complete extraction was obtained with methanolic HCl, but even this resulted in only 72% recovery. Essentially complete recovery was obtained by destroying the clay matrix by evaporation with hydrofluoric acid. Similar behavior is observed with dodecylpyridinium ion (144). 

Supercritical fluid extraction with CO2 containing at least 10% methanol is effective for removing distearyldimethylammonium chloride from sediment and sewage sludge as an ion pair. Because anionic surfactants are already present in sludge, no anion need be added to insure ion pair formation. SEE is not more complete than conventional liquid-solid extraction with methanolic HCl, but is more rapid. There is some indication that less of materials other than cationic surfactants is extracted by SEE compared to conventional extraction (150,151). 

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