Surface active anions

Surface-active agents iacrease the conductivity of oils quite significantly (97), and addition of water, probably dissolved at the iaterface with the surfactant, further iacreases the conductivity. Nonionic and cationic surface-active agents are preferred to anionic surface-active agents probably because of their higher solubiHty ia oils and higher hygroscopicity. Many anionic surfactants have adequate antistatic efficiency, but they are used less frequendy. 

The perspective of using consecutive reactions is grounded on the example of the analysis of isomeric mono-nitrophenols and anion surface-active substances. The variants of systematic analysis of mixtures of tri-, di- and mono-nitrophenols, anion surface-active substances, based on the combination of measurements of consecutively received extracts at different pH values are discussed. 

Anodically polished and then cathodically reduced Cd + Pb alloys have been studied by impedance in aqueous electrolyte solutions (NaF, KF, NaC104, NaN02, NaN03).827 For an alloy with 2% Pb at cNap 0.03 M, Emfo = -0.88 V (SCE) and depends on cNaF, which has been explained by weak specific adsorption of F" anions. Surface activity increases in the sequence F" < CIO4 < N02. The Parsons-Zobel plot at E is linear, with /pz = 1.33 and CT° = 0.31 F m"2. Since the electrical double-layer parameters are closer to those for pc-Pb than for pc-Cd, it has been concluded that Pb is the surface-active component in Cd + Pb alloys827 (Pb has a lower interfacial tension in the liquid state). 

In the manufacture of articles direct from latex it is necessary to stabilise the latex (to prevent premature coagulation) by the addition of protective colloids such as casein soaps, gelatine and proprietary anionic surface active agents. 

In MEKC, mainly anionic surface-active compounds, in particular SDS, are used. SDS and all other anionic surfactants have a net negative charge over a wide range of pH values, and therefore the micelles have a corresponding electrophoretic mobility toward the anode (opposite the direction of electro-osmotic flow). Anionic species do not interact with the negatively charged surface of the capillary, which is favorable in common CZE but especially in ACE. Therefore, SDS is the best-studied tenside in MEKC. Long-chain cationic ammonium species have also been employed for mainly anionic and neutral solutes (16). Bile salts as representatives of anionic surfactants have been used for the analysis of ionic and nonionic compounds and also for the separation of optical isomers (17-19). 

CNC PAL AN is an anionic surface active agent with excellent detergency and wetting properties. It is recommended in all phases of textile scouring and washing operations. It is particularly useful in those applications where relatively high amounts of alkali are used in the bath. 

CNC Product ST is an anionic surface active agent which possesses excellent wetting and scouring properties. CNC Product ST is recommended as a print wash in cases where high concentrations of residual color and print paste are to be removed from cotton, rayon or synthetic fibers. 

C8H1700CCH2CH(S03Na)C00C8H17. An anionic surface-active agent. 

Oleyl sodium sulphate Sodium oleyl p-anisidine sulphonate Anionic surface-active compound. 

The liquor is made up with 4 gallons per 100 of benzyl alcohol, 2 per cent on the weight of the goods of Irgasol NJ (an anionic surface active product), 2 per cent of acetic acid (40 per cent), and a portion of the dye. The goods are entered at 60°C (140°F) and the temperature raised to the boil and the remainder of the dye is added at intervals. Exhaustion is very rapid and level results are obtained without prolonged boiling. 

Muramoto S and Oki Y (1984) Influence of anionic surface-active agents on the uptake of heavy metals by water hyacinth (Eichomia crassipes). Bull Environ Contam Toxicol 33 444-450. 

The surface-active agent first made by man was soap, with this being an anionic surface-active agent. Indeed, soap was already known to the Sumerians (Babylonians) as early as 2500 years bc. Vegetable oils were cooked with potassium carbonate from burnt wood. The next step was the use of potassium hydroxide made from potash and calcium oxide. In this way, soap has been produced for millennia, mainly by the reaction of potassium hydroxide and tallow. During the 17th century, Marseille, in particular, was well known for its production of soap. 

The anionic surface-active compounds with the largest volume of production are the alkylbenzene sulfonates. Here, the possibility of an easy insertion of a sulfonic acid group into the benzene molecule is used to obtain inexpensive surfactants. Suitable starting materials are alkylbenzenes with an alkyl chain length of ca. 12 carbon atoms, obtained by the application of olefines or monochloroalkanes to the benzene ring. 

There are various other materials with special structures which show anionic surface-active properties. 

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