Surfactant content remaining

Effect of Surfactant Concentration. Raising the surfactant concentration increases the stability of adsorption layer which enhances resistance of the emulsion to coalescence. The radius of the aqueous internal phase droplets in the emulsion initially diminishes with the increase in surfactant concentration and then remains constant. This results from the tendency of the dispersed phase to minimize the interfacial area for a given amount of surfactant. Despite a high degree of dispersion of the internal phase, the droplets coalesce until they attain a surfactant content at the interface which is close to the limiting value of adsorption. When the surfactant is present in an amount sufficient for stabilization of all of the drops of internal phase formed as a result of the dispersion, a maximum stability of the emulsion (Figure 1) and a minimum coalescence rate constant (Figure 2, curve 1) are attained. 

Patterns of ordered molecular islands surrounded by disordered molecules are common in Langmuir layers, where even in zero surface pressure molecules self-organize at the air—water interface. The difference between the two systems is that in SAMs of trichlorosilanes the island is comprised of polymerized surfactants, and therefore the mobihty of individual molecules is restricted. This lack of mobihty is probably the principal reason why SAMs of alkyltrichlorosilanes are less ordered than, for example, fatty acids on AgO, or thiols on gold. The coupling of polymerization and surface anchoring is a primary source of the reproducibihty problems. Small differences in water content and in surface Si—OH group concentration may result in a significant difference in monolayer quahty. Alkyl silanes remain, however, ideal materials for surface modification and functionalization apphcations, eg, as adhesion promoters (166—168) and boundary lubricants (169—171). 

Industrial effluents Organic compounds chloro- and nitrophenols, nonionic surfactants, linear alkylated benzene sulfonates, benzene and naphthalene sulfonates, estradiol, ethinyl estradiol V. fischeri (ToxAlert 10, ToxAlert 100) There were certain correlations between the results of the chemical analyses and bioassays to a large extent, however, the composition of the samples remained unknown Distinct correlations were found between the inhibition of bioluminescence and compound content, but only in the case of nonylphenol, nonylphenol carboxylate, nonylphenol ethoxylate, and chlorophenols 84... 

The removal of mineral oils from sea sand was studied in [323] in presence of aqueous solutions of nonionic surfactants (Triton X-100, Triton X-114, Alconox) with and without solid additives, such as granular activated carbon, powder activated carbon. The process was conducted in a scrubber by froth flotation. Contaminants and fine sand particles were transferred, together with sorbents, into the water-froth stream, whereas clean sand remained in the tails . Without addition of sorbent, the content of contaminants (total oil and grease -TOG) was 4000 ppm, while the additives reduced the TOG content to less than 1000 ppm. 

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