Distearyldimethylammonium chloride

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]. 

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. 

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. 

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... 

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). 

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). 

Distearyldimethylammonium chloride Sewage sludge and river sediment Extraction and alumina cleanup Derivative spectrophotometry, direct (Dragendorff reagent) or indirect (LAS/methylene blue) 157... 

Ester quat—Quaternized tallow triethanolamine esters unquater-nized mono-, di-, and triesteramine impurities and fatty acid impurities separated triester-quat, diesterquat, and monoester-quat resolved elution according to decreasing alkyl character Distearyldimethylammonium chloride, cocoalkyldimethylbenzylam-monium chloride, cetyltrimethylammonium bromide, and a quaternary imidazoline compound resolved from J S V S ier environmental analysis... 

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