Surfactants general classification

Surface acoustic waves (SAWs), acoustic wave sensors and, 22 270 Surface-active agent(s), 12 33. See also Surfactant entries cmc values of, 24 121t general classification of, 24 144-153 nonionic, 10 665 organic esters as, 10 519 Surface-active molecules, 12 1 foaming and, 12 3... 

In this overview, I start with the general classification of surfactants and their unusual properties. This is followed by some examples to illustrate the application of surfactants in some chemical industries. 

Effect of Demulsifier Mixture. In previous studies (27) Duo-meen C, which was effective in causing flocculation of the water droplets, was not very effective in breaking the interfacial film formed between the water droplets, which inhibits coalescence. (Duomeen C is a mixture of many types of surfactants the general classification is a fatty acid ester nitrogen derivative.) However, Duomeen C in combination with docusate sodium (Aerosol OT), a hydrophilic surfactant, was much more effective in causing water separation compared to the individual chemicals. This effect is shown in Figure 16 for a 6 vol% water-in-oil (Leduc crude) emulsion in which both the UVP signal (20 min after chemical addition) and the volume... 

The first section of this chapter describes the solution properties of polymers, and this is followed by a general classification of polymeric surfactants. Examples are provided of polymeric surfactants and polyelectrolytes that are used as dispersants and emulsifiers. 

In this overview, the first section will on general classification of polymeric surfactants. This is followed by a section on preparation of polymeric snrfactants, with particular reference to sugar-based molecules. This is followed by a discussion of their solntion properties. The next section will be devoted to the adsorption of polymeric snrfactants at the solid/liquid (S/L) interface, whereby a summary will be given to some of the theoretical treatments and the methods that... 

In Structure 3.11, R is the alkyl group containing 8 to 12 carbons and n the number of ethylene oxide units ranging from 1 to 30, most typically 6 to 15. A surfactant based on an ethoxylated alkylphenol falls into the general classification of a nonionic (benzenoid) type. The alkylphenol ethoxylate is most commonly referred to as APE in the industry. 

In this section we describe the general classification of dispersing agents. The adsorption of surfactants and polymers at the solid/liquid interface was treated in Chapter 5. The various classes can be summarised as follows. 

This chapter will start with a short account of the general classification and description of polymeric surfactants. This is followed by a summary on then-solutions properties. The adsorption and conformation of polymeric surfactants at the solid-liquid interface will be discussed at a fundamental level and some experimental results will be presented to illustrate the prediction of the theories. The interaction energies between particles or droplets containing adsorbed polymeric surfactants will be briefly described. The final section will give some applications of polymeric surfactants in suspensions, emulsions, and multiple emulsions. 

The test classifies all the N-acyl ED3A salts tested as non-irritants with the next-mildest substance tested being Na Lauroyl glutamate a surfactant generally recognized as being very mild with a score of 4200 and a classification of mild. Not surprisingly the Baby Shampoo was also rated as mild with a score of > 2000. 

The adsorption of snrfactants at liquid interfaces and their applications were described in many pnbhcations. Also books have been dedicated to this subject. For example in [1] not only the general classification of snrfactants and the synthesis and application of the main types of surfactants were discnssed but also the adsorption characteristics for a large number of homologous series of surfactants were snmmarized. hi various technologies the action of snrfactants is essential, snch as in the formation for foams and emulsions [2]. 

An unknown commercial detergent may contain some combination of anionic, nonionic, cationic, and possibly amphoteric surfactants, inorganic builders and fillers as weU as some minor additives. In general, the analytical scheme iacludes separation of nonsurfactant and inorganic components from the total mixture, classification of the surfactants, separation of iadividual surfactants, and quantitative determination (131). 

The surfactants used as textile auxiliaries can be divided into four major groups, depending on the type and distribution of the polar forces, an arrangement broadly resembling the ionic classification of dyes. The general scheme is shown in Table 8.1. 

The general behavior described above was experimentally observed in Kunieda s lab for numerous new systems, and the results were diffused through several papers and congress communications. These works suppose an important contribution in extending the potential applications of new surfactants and cosurfactants, and are now, in the following text, briefly reviewed. The systems studied by Professor Kunieda are reviewed according to his own classification given in his review paper [25]. 

As is the case in most discussions of interfacial systems and their applications, definitions and nomenclature can play a significant role in the way the material is presented. The definition of an emulsion to be followed here is that they are heterogeneous mixtures of at least one immiscible liquid dispersed in another in the form of droplets, the diameters of which are, in general, greater than 0.1 (.m. Such systems possess a minimal stability, generally defined rather arbitrarily by the application of some relevant reference system such as time to phase separation or some related phenomenon. Stability may be, and usually is, enhanced by the inclusion of additives such as surfactants, finely divided solids, and polymers. Such a definition excludes foams and sols from classification as emulsions, although it is possible that systems prepared as emulsions may, at some subsequent time, become dispersions of solid particles or foams. 

Surfactant Structure. Surfactants in this section are defined as amphipolar or amphipathic molecules composed of a hydrophilic head and a hydrophobic tail group. A detailed description of surfactants and surfactant structure can be found in Chapter 1. Surfactants are generally classified according to their hydrophilic head group. Common classifications are ... 

The initial step in the fabrication of a multiple emulsion (W/OAV) is to prepare a primary emulsion (W/0). It is generally agreed that the surfactant for the primary emulsion should have an HLB value of 3-6 (in the hydrophilic-lipophilic balance system of surfactant classification). Surfactants that have successfully been utilized include Span 80 (sorbitan oleate Nianxi et al, 1992 Zheng et al, 1993 Omotosho et al, 1990), E644 (polyamine Nianxieia/., 1992),N205 (polyamine Nianxi eta/., 1992), TX-4 (polyoxyethylene aUcylphenol ether Nianxi et al, 1992), MO A3 (polyoxyethylene aliphatic alcohol ether Nianxi et al, 1992), Brij 93 (Nianxi et al, 1992), polyoxamers [poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer Law et al, 19861, and egg lecithin. The surfactant or combination of surfactants is then dissolved in the oil... 

Some classification of parameters in their connection with physical or mechanical processes is to be done. The main parameter connecting hydrodynamic and diffusion parts of the film flow problem with surfactant is Marangoni number Ma. The both variants of positive (Ma > 0) and negative (Ma < 0) solutal systems are considered. The main hydrodynamic parameters are Re, 7 or equivalently S. 7. This two values determine the mean film thickness i/, mean velocity and flow rate as well as parameter k. The diffusion parameters Pe,co determine the local thickness of diffusion boundary layer h and smallness parameter e. Two values T, Di characterize the masstransfer of surfactant by the adsorption-desorption and the intensity of dissipation by the surface diffusion. Besides the limiting case of fast desorption (T = 0) the more general case (T 1) are considered. Intensity of the surfactant evaporation by parameter Bi is determined. The remaining parameter G gives an indication to the typical value of surface excess concentration A in comparison with c. ... 

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