Ethoxylated alcohol surfactants

T. Stobe, Z. Lin, R. M. Hill, M. D. Ward, and H. T. Davis, Enhanced spreading of aqueous films containing ethoxylated alcohol surfactants on solid substrates, Langmuir 13, 7270-7275 (1997). 

P. Jandera, M. Holcapek, G. Theodoridis, Investigation of chromatographic behaviour of ethoxylated alcohol surfactants in NP and RP systems using LC-MS, J. Chromatogr. A, 813 (1998)299. 

ACD has been associated with ethoxylated alcohol surfactants. Though not by themselves known to cause ACD, ethoxylated surfactants are polyethers and are easily air oxidized to hydroperoxides, peroxides, and carbonyl compounds (including formaldehyde and acetaldehyde), substances that do cause ACDJ22 251 The irritant components of surfactants and other chemicals present in formulated products facilitate the absorption of the ACD causing decomposition products of ethoxylated alcohols and thus exacerbate their effects. F61 This is yet another example of lipophilic compounds enhancing the absorption of hydrophilic compounds (the decomposition products of ethoxylated alcohols) and hence increasing the toxic effect beyond that predicted. 

HLB number of 3.8, i.e. it is suitable for a W/O emulsifier. However, in many cases, accurate estimation of the saponification number is difficult, e.g. ester of tall oil, resin, beeswax and linolin. For the simpler ethoxylate alcohol surfactants, HLB can be calculated simply from the weight per cent of oxyethylene E and poly-hydric alcohol P, i.e. 

As first noted by Shinoda (7), simple three-component mixtures of nonionic ethoxylated alcohol surfactants mixed with oil and water form microemulsions. Ethoxylated alcohols, the most widely used nonionic surfactants, are prepared by the reaction of ethylene oxide... 

Figure 4.5. Schematic phase diagram of equal amounts of oil and water (a = 0.5) as a function of ethoxylated alcohol surfactant concentration (/) and temperature (T) yo denotes the critical microemulsion concentration , i.e. the surfactant concentration where the middle microemulsion phase first appears. In addition, T and Tu denote the temperature range of the three-phase region, while X, the point at which the tail and the body of the fisji meet, denotes the temperature and surfactant coordinates (T, y) for the most efficient formation of single microemulsion phases. The test tubes show the types of phase behaviour found in the various regions of the phase diagram. Reproduced by permission of the American Chemical Society (redrawn from Kahlweit and Strey (46))...

Kahlweit and Strey and their co-workers have sys-tematicall measured the dependence of X, as described by / and T, upon the chemical structure of the ethoxylated alcohol surfactants (/ and j) and hydrocarbon chain length (k) (27). The following presents a summary of the patterns observed ... 

Figure 4.6. The temperature (7) and. surfactant concentration (y) coordinates at which optimal microemulsions form when equal amounts of octane and water ot = 0.5) are mixed with a variety of ethoxylated alcohol surfactants (QE ) of different lipophilic (/) and hydrophilic (y) balances. Reproduced by permission of The Royal Society of Chemistry (from Burauer et al. (28))...

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