Quaternary ammonium surfactant

A few commercial cationic latexes are offered, eg, by Du Pont Showa and Denki. These are stabilized with quaternary ammonium surfactants. 

Gravimetric and volumetric methods are practicable for the quantitative determination of the a-sulfo fatty acid esters. Using gravimetric methods the surfactant is precipitated with p-toluidine or barium chloride [105]. The volumetric determination method is two-phase titration. In this technique different titrants and indicators are used. For the analysis of a-sulfo fatty acid esters the quaternary ammonium surfactant hyamine 1622 (p,f-octylphenoxyethyldimethyl-ammonium chloride) is used as the titrant [106]. The indicator depends on the pH value of the titration solution. Titration with a phenol red indicator is carried out at a pH of 9, methylene blue is used in acid medium [106], and a mixed indicator of a cationic (dimidium bromide) and an anionic (disulfine blue VN150) dye can be used in an acid and basic medium [105]. 

Therefore, a C13-AE, a cationic (quaternary ammonium) surfactant (quat), an amphoteric Ci2-alkylamido betaine, and the non-ionic fatty acid diethanol amide (FADA) as presented with their FIA-MS spectra in Fig. 2.5.12(a)-(d) were analysed as pure blends and as mixtures always obtained from two blends in FIA-MS multiple ion detection mode (MID). Mixtures as well as pure blends contained identical concentrations of surfactant homologues. For AE quantitation the mass traces of all A m/z 44 equally spaced homologues (m/z 306-966) of the C13-AE were recorded. The cationic (quaternary ammonium) surfactant, the amphoteric Ci2-alkylamido betaine, and the non-ionic FADA were quantified recording the mass traces at m/z 214 and 228, or 184, 212, 240, 268, 285, 296, 313, 324 and 341, or 232,260, 288, 316 and 344, respectively. 

To recognise ion suppression reactions, the AE blend was mixed together either (Fig. 2.5.13(a) and (b)) with the cationic quaternary ammonium surfactant, (c, d) the alkylamido betaine compound, or (e, f) the non-ionic FADA, respectively. Then the homologues of the pure blends and the constituents of the mixtures were quantified as presented in Fig. 2.5.13. Ionisation of their methanolic solutions was performed by APCI(+) in FIA-MS mode. The concentrations of the surfactants in the mixtures were identical with the surfactant concentrations of the blends in the methanolic solutions. Repeated injections of the pure AE blend (A 0-4.0 min), the selected compounds in the form of pure blends (B 4.0—8.8 min) and their mixtures (C 8.8— 14.0 min) were ionised and compounds were recorded in MID mode. For recognition and documentation of interferences, the results obtained were plotted as selected mass traces of AE blend (A b, d, f) and as selected mass traces of surfactant blends (B a, c, e). The comparison of signal heights (B vs. C and A vs. C) provides the information if a suppression or promotion has taken place and the areas under the signals allow semi-quantitative estimations of these effects. In this way the ionisation efficiencies for the pure blends and for the mixture of blends that had been determined by selected ion mass trace analysis as reproduced in Fig. 2.5.13, could be compared and estimated quite easily. 

Fig. 2.12.1. Chemical structure of different classes of cationic surfactants (a) quaternary ammonium surfactants (quats) (b) dialkylcarboxyethyl hydroxyethyl methyl ammonium surfactants (esterquats) (c) alkyl polyglycol amine surfactants (d) quaternary perfluoro-alkyl ammonium surfactants (e) N, N, N1, JV -tetramethyl-iV, iV -didodecyle-l,3-propane-diyle-diammonium dibromide (cationic gemini surfactant). R = alkyl or benzyl group.

Lee YS, Surjadi D, Rathman JF (1996) Effects of aluminate and silicate on the structure of quaternary ammonium surfactant aggregates. Langmuir 12 6202-6210... 

According to this mechanism, the size of the mesopores will be in direct proportion to the chain length of the quaternary ammonium surfactants. The relation between the mean diameter of the framework pores in sol-PILB-Cn samples and the alkyl chain length of the surfactants, expressed by the number of carbon atoms in the alkyl chain of the surfactants (Cn), is shown in Figure 3. 

Powdered, particulate MCM-41 molecular sieves (Si/Al = 37) with varied pore diameters (1.80, 2.18, 2.54 and 3.04 nm) were synthesized following the conventional procedure using sodium silicate, sodium aluminate and C TMAB (n = 12, 14, 16 and 18) as the source materials for Si, A1 and quaternary ammonium surfactants, respectively [13]. Each sample was subjected to calcination in air at 560 °C for 6 h to remove the organic templates. The structure of the synthesized material was confirmed by powder X-ray diffraction (XRD) and by scanning/transmission electron microscopy. Their average pore sizes were deduced from the adsorption curve of the N2 adsorption-desorption isotherm obtained at 77 K by means of the BJH method (Table 1). 

Tetrabutylammonium bromide-quaternary ammonium surfactants Tetrapentylammonium bromide-quaternary ammonium surfactants For example, tributylammonium or tripentylammonium (better) headgroup Quaternary ammonium surfactants - >2 w-butyl, w-pentyl, isopentyl groups Replacing 1 or 2 small alkyl groups with long hydrophobic tail (8—18 carbon atoms)... 

An anionic surfactant is soluble only at a pH greater than tf pqf its ionizable group, whereas a cationic surfactant (e.g., primary, secondary, ortertiary amines) is soluble only at a pH less than its pKg. However, quaternary ammonium surfactants remain soluble at all pH values. Zwitterionic surfactants, for example, sulfobetaine surfactants, are neutral from pH 2 to 12, whereas some nonionic surfactants, for example, alkyldimethylamine oxides, are converted to cationic surfactants by protonation at acidic pH. 

Games, L.M., J.E. King, and R.J. Larson. 1982. Fate and distribution of a quaternary ammonium surfactant, octadecylammonium chloride, (OTAC), in wastewater treatment. Environ. Sci. Technol. 16, 483-488. 

Another method used to make lubricating greases, and also oil-based drilling fluids, involves the use of organic compounds to stabilize non-aqueous suspensions. For example, clays and other mineral solids can be dispersed in oils when polar organic compounds such as quaternary ammonium surfactants are adsorbed onto their surfaces, making the latter preferentially oil-wetting (see Sections 3.4 and 3.5.3). 

If the reaction takes place under basic conditions then the silica species are present as anions, that is, deprotonated silanol groups (Si-O-) in this case the surfactants have to be charged positively to ensure interactions between both components commonly cationic quaternary ammonium surfactants are used as the SDA this synthesis pathway is termed S+I (Fig. 3.6a). 

Alkoxylated quaternary ammonium surfactants have been patented recently as performance boosters for detergent formulations [71 ]. 

In their original synthesis of MCM-41, Beck et al. (1992) achieved the hydrothermal conversion of aluminosilicate gels in the presence of quaternary ammonium surfactants (e.g. hexadecyltrimethylammonium ions). The washed and air-dried products were calcined at 450°C to remove residual organic material. 

Surfactant Chain Length. Under comparable reaction conditions, the pore size generally increases with the chain length of surfactants. For example, when quaternary ammonium surfactants (C TMABr) with different alkyl tails (n = 8, 9, 10, 12, 14, and 16) were used, the pore size... 

Zirconia. Mesoporous zirconia was first reported by Knowles and Hudson with cationic aUcyltrimethylam-monium siufactants. Starting from zirconium sulfate or propoxide, Schiith and Ciesla et al. synthesized hexagonal mesoporous zirconia using aUcyltrimethylammonium surfactants as templates. Reddy and Sayari obtained hexagonal or lamellar phases of mesostructured zirconia using quaternary ammonium surfactants and acidified primary aUcylamine,... 

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