Betaines amphoteric surfactants

The tested amphoteric surfactants (betaine and sulfobetaine) are highly salt-tolerant and are excellent foamers. Adsorption of these surfactants is less dependent on salinity than adsorption of anionic surfactants, and the trends are not monotonic (Figure 13b). Adsorption of amphoteric surfactants may proceed by a complex interplay of mechanisms involving electrostatic and complexation mechanisms of both the cationic and the anionic group in the surfactant molecule (12, 87, 88). The trends in ad-... 

The behavior of anionic polysaccharides with nonionic and amphoteric surfactants (betaines) is more complex. For example, nonionic surfactants can form charge transfer complexes with highly charged polysaccharides. Amphoteric surfactants can have various charges and various degrees of interaction with anionic polysaccharides depending on the... 

MIRANOL Amphoteric Surfactants - Betaines and Sultaines (Continued) ... 

Anionic surfactants are the most commonly used class of surfactant. Anionic surfactants include sulfates such as sodium alkylsulfate and the homologous ethoxylated versions and sulfonates, eg, sodium alkylglycerol ether sulfonate and sodium cocoyl isethionate. Nonionic surfactants are commonly used at low levels ( 1 2%) to reduce soap scum formation of the product, especially in hard water. These nonionic surfactants are usually ethoxylated fatty materials, such as H0CH2CH20(CH2CH20) R. These are commonly based on triglycerides or fatty alcohols. Amphoteric surfactants, such as cocamidopropyl betaine and cocoamphoacetate, are more recent surfactants in the bar soap area and are typically used at low levels (<2%) as secondary surfactants. These materials can have a dramatic impact on both the lathering and mildness of products (26). 

Amphoteric surfactants are those that are an acid and a base at the same time (like water is). Cocamidopropyl betaine, for example, is used in shampoos to stabilize foam and thicken the mixture. 

Ethoxylated products can also feature as amphoteric surfactants an example is compound 9.55, an alkylamine poly(oxyethylene) sulphate. Of particular interest in textile processing are the trisubstituted alkylamino acids known as betaines N-alkylbetaines (9.56 R = C8-C16 alkyl) and acylaminoalkylbetaines (9.57 R = C10-C16 alkyl) are typical [30]. 

Cocamidopropyl betaine (Table 1.4) is the most prominent representative of the class of amphoteric surfactants. Due to the synergism with other surfactants and its gentleness to the skin and mucous membranes, cocamidopropyl betaine performs well in shampoo and cosmetics where its dosage lies in the order of 1-5% [27]. 

AES type surfactants were examined qualitatively in the ESI—FLAMS mode but, from the result, the presence of AES seemed to be doubtful. After a LC separation presenting the TIC in the form of a contour plot the identification of AES surfactants in parallel with an amphoteric surfactant mixture of alkylamido propyl betaine type was possible [50]. 

Only limited data have been published on the degradability of betaines, such as cocamidopropyl betaine (CAPB, Fig. 5.1.22), and the limited information available is somewhat contradictory. Swisher reported that total degradability was rather poor (45-58%) [10], whilst Brunner et al. [138] obtained mixed results with a series of the amphoteric surfactants in an extended OECD 302B test and a laboratory trickling test filter. While the two compounds cocoampho diacetate and cocoampho dipropionate were mineralised only to a minor extent, CAPB and cocoampho acetate proved to be nearly totally degradable. 

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]. 

Corresponding to the type of surfactant the hydrophobic group consists of an anion (anionics), a cation (cationics) or segment in nonionic or related polymer surfactants. Also, in amphoteric surfactants or betaine structures the fluorocarbon tail is extremely hydrophobic. 

Mona Industries received a series of patents in the 1980s for betaines and imidazoline-based surfactants similar to the hydroxysultaines and hydroxypropylsulfonates discussed earlier but alkylated with a propanechlorohydrin phosphate rather than the CHPS [9]. These amphoteric surfactants were demonstrably mild and were thought to have some... 

Amphoteric surfactants. These compounds have the characteristics of both anionic detergents and cationic fabric softeners. They tend to work best at neutral pH, and are found in shampoos, skin cleaners, and carpet shampoos. They are very stable in strong acidic conditions and are favorably used with hydrofluoric acid. For example, compounds of alkyl-betain or alkylsulfobetaine type possess both anionic and cationic groups in the same molecule even in aqueous solution. These surfactants are rarely employed in laundry detergents because of their high costs [3, 4]. 

Amphoteric Surfactants. Amphoteric surfactants in aqueous solution contain both positive and negative charges in the same molecule. Thus, a hydrophobic fatty chain is attached to a hydrophilic group that contains both positive and negative charges. Its behavior depends on the condition of the medium or its pH value. Examples of this type are the alkyl betaines. 

Cocamidopropyl betaine is the most commonly used amphoteric surfactant in shampoos, bath products, and other cosmetic products. It is popular because of its relatively low irritation potential. 

Surfactants anionics sodium lauryl ether sulfate (SLES) and sodium lauryl sulfate (SLS) amphoteric cocamidopropyl betaine (CAPB) nonionic alkyl polyglucoside (APG). 

Amphoteric surfactants, in particular betaines, especially cocoamidopropyl betaine, typically provide synergistic benefits with anionic surfactants [18]. Similar to the benefits of amine oxides, they have been found to mitigate the inherent... 

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