Cationic surfactants quaternary ammonium salts

An obvious modification of the above procedure will permit the determination of long-chain amines or quaternary ammonium salts (cationic surfactants) ... 

Chou, L. C., Christensen, R. N., and Zakin, J. L., The influence of chemical composition of quaternary ammonium salt cationic surfactants on their drag reducing effectiveness, in Drag Reduction in Fluid Flows, SeUin, R. H. J., and Moses, J. T., Eds., Ellis Horwood, Chichester, UK, 1989b, pp. 141-148. 

In recent years different types of surfactants have been used, in concentrations above their cmc, forming normal micelles, to improve different aspects of chemiluminescent reactions. Though the choice of the best surfactant depends on the characteristics of the chemiluminescent reaction, the surfactants most used have been the cationic (fundamentally quaternary ammonium salts) and to a lesser degree the anionic, the nonionic, and the zwiterionic compounds. 

A broad range of information pertaining to the toxicity of several classes of surfactants including anionic (linear alkylbenzene sulfonates (LAS), alkylether sulfates (AES), alkyl sulfates (AS), non-ionic (alkylphenol ethoxylates (APEO)), cationic (ditallow dimethyl ammonium chloride (DTDMAC)—a group of quaternary ammonium salts of distearyl ammonium chloride (DSDMAC)) and amphoteric surfactants (alkyl-betaines) is available. Several reviews of the scientific literature have been published [3-5,20]. 

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]. 

Cationic surfactants produce a positively charged surfactant ion in solution and are mainly quaternary nitrogen compounds such as amines and derivatives and quaternary ammonium salts. Owing to their poor cleaning properties, they are little used as detergents rather their use is a result of their bacteriocidal qualities. Relatively little is known about the mechanisms of biodegradation of these compounds. 

Quaternary ammonium salts are well-known cationic surfactants and popular phase-transfer (FT) catalysts. In addition, these salts exhibit both antimicrobial activities and antielectrostatic effects. Another useful compound which belongs to the ammonium salt group is chinoline chloride, also known as vitamin B4 it is an essential component that ensures proper functioning of the nervous system and is widely used as a feed additive for livestock. 

Being internally neutralized, the amphoterics have minimal impact on the biocidal activity of quaternary ammonium salts. For this reason, like the nonionics, they often find use in antimicrobial preparations that are based on cationic surfactants. 

Solutes. Toluene, although polarizable, was chosen as an apolar solute. Caffeine was chosen as a polar but nonionic solute. Four ionic solutes were tested benzyltrimethylammonium bromide (BTAB) is a cationic quaternary ammonium salt. Benzoic acid acts as an anionic solute at mobile phase pH values between 5.5 and 6.5 (the pK lies between 3.7 in CTAB solutions and 4.7 in SDS solutions)(4). Sodium paraoctylbenzene sulfonate (SOBS) (pK -0.8) and cetylpyridinium chloride (CPC) were chosen as ionic solutes having surfactant properties. Their hydrophobic "tails have the same lenghts as those of SDS and CTAB, respectively. 

STEPANTEX 6530B is a cationic surfactant of quaternary ammonium salt type, having properties which are especially well adapted to the formulation of fabric softeners. STEPANTEX 6530B has been developed for making household fabric softeners with average or high active concentrations. 

The asymmetrical tertiary amines are used exclusively as starting materials for the manufacture of quaternary ammonium compounds, cationic and amphoteric surfactants, and amine oxides. Quaternary ammonium compounds used as bactericides and algicides are produced by the reaction of tertiary amines with benzyl chloride, methyl chloride, or dimethyl sulfate. Of these, the benzyl ammonium chloride salt is the most widely used. 

A third class of industrial chemical biocides consists of agents with the ability to inhibit biological film formation, also called surfactants . The term surfactant originates from the phrase surface active agent. Surfactants fall into four broad categories anionic (e.g., soaps, alkyl benzenesulfonates, alkyl sulfonates, alkyl phosphates), cationic (e.g., quaternary ammonium salts), nonionic (e.g., alkyl polyglycosides, alcohol ethoxylates, alkylphenol ethoxylates), and zwitterionic. 

Quaternary ammonium salts, in most cases trialkylmethyl ammonium salts, have been the second focal point of work in this field. These molecules are cationic amphiphiles and have been revealed to be a complement to studies on the influence of the charge of the surfactant, compared to anionic AOT. In their early studies, Luisi et (34, 35) used trimethyloctylammonium chloride (TOMAC) at low surfactant concentrations (about 12 mM) in cyclohexane. But at higher... 

Experiments typically consisted of dispersing 70 milliliters of a 2 molar solution of sodium chloride (NaCl) in 100 milliliters of an oil phase. This oil phase consisted of a paraffinic solvent (Solvent 100 Neutral, Exxon Chemical Company), a nonionic emulsion-stabilizing surfactant (Paranox 100, Exxon Chemical Company), a cationic "carrier" - a tri-capryl quaternary ammonium salt (Aliquat 336,... 

A relatively new field is the use of flotation in wet textile processes [73]. The ( -potential of cotton fibres in aqueous solutions is negative, therefore they are effectively floated by cationics like quaternary ammonium salts, e.g. dodecyl trimethyl ammonium chloride. Sysilia et al. [74] have established, by measuring the electrokinetic potential, a clear rule between the positive surface charge of chromite and flotation efficiency. At low pH, chromite was effectively floated by fatty acid soaps, the ions of which are negatively charged under these conditions. The surfactant adsorption is reversible which is indicative of its physical nature. 

Ion flotation in the presence of surfactants for the treatment of rinses and separation of metal ions is of interest since the sixties [327, 328]. Here, we take only a few examples. The recovery of silver ions from highly diluted solutions is possible by forming a silver-thiourea complex in form of a colloidal precipitate (sublate) followed by sublate flotation with sodium dodecyl benzene sulfonate [329]. Skiylev [330] has developed methods for the removal of non-ferrous metal salts from waste waters. Subject of the investigations were 0.01 - 0.001% solutions of ferrous metal salts. Typical anionic surfactants (alkyl sulfates, alkyl phosphates, alkyl xanthogenates of potassium) or cationic surfactants (quaternary ammonium salts) were used as collectors in ion flotation from diluted solutions. At certain pH, a sublate containing a non-ferrous metal ion was formed, followed by a sublate film formation at the surface due to the rise of the complexes with air bubbles stabilised by the surfactants. 

The caticHiic surfactants are used infrequently in emulsion polymerization t pli-cations since they are not compatible with the anionic surfactants and with the (typically) negatively charged latex particles. These surfactants are usually of the following types salts of long chain amines, polyamines and their salts, quaternary ammonium salts (e.g., hexadecyltrimethyl ammonium bromide), polyoxyethyle-nated long-chain amines and their quatemized doivatives, and amine oxides [89]. 

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