Amphoteric surfactants alkyl betaines

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]. 

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]. 

These are surfactants containing both cationic and anionic groups. The most common amphoterics are the A-alkyl betaines, which are derivatives of trimethyl-glycine, (CH3)3NCH2COOH (which was described as betaine). An example of a betaine surfactant is laurylamido-propyldimethylbetaine, Ci2H25CON(CH3)2CH2COOH. 

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. 

These synergistic effects play an important role with regard to the use of betaines and amphoteric surfactants in dermatologically compatible formulations. Results from the Draizetest (determination of the irritation capacity in the rabbit eye) clearly show the synergistic effect of sodium lauryl ether sulfate/betaine with respect to mucous membrane compatibility. The initial level of the dermatological irritation potential of the disodium cocoamphodiacetate is lower than that of the betaine. Depending on the ratio of alkyl ether sulfate/amphoteric surfactant or alkyl ether sulfate/betaine combinations, a minimum in the irritation potential can be achieved. 

Amphoteric surfactants are divided into two groups based on their response to pH. One class of compounds that contain carboxylated imidazoles and A-alkyl betaines are zwitterionic at pHs at, and above, their isoelectric points and cationic at lower pHs. Sulfobetaines and phosphobetaines, on the other hand, exhibit zwitterionic characteristics as the anionic portion is dissociated at all pHs. Although the former are the major ingredients in many baby shampoos or those products that provide mildness, they also function as foam and viscosity enhancers when utilized as secondary surfactants, having good water solubility over a wide pH range. ° ... 

Alkanolamides Alkyl sulfonates Amine oxides Amphoteric surfactants Anionic surfactants Cocoamidopropyl betaine Betaine derivatives Amido guanidines Disulfonates... 

Amphoteric surfactants Alkyl betaine, alkylamido betaine, alkylamphoacetate <10... 

Owing to their compatibility with cationic biocides, amphoteric and amine oxide surfactants continue to be used widely in the development and formulation of disinfectants and sanitizers for personal care, household, industrial, and institutional markets. For instance, substituted imidazoline amphoteric surfactants, in combination with didecyl dimethyl ammonium chloride, have been found to display unexpected synergistic irritation reduction compared to formulas with alkyl dimethyl benzyl ammonium chlorides [57]. Also, imidazoline derivatives and betaines are known to impart moderate cleansing without causing skin roughness, stickiness, or irritating reactions with cationic disinfectants [58], Amphoteric surfactants are also suitable for use in antimicrobial medications requiring subcutaneous, cutaneous, or mucosal membrane administration [36]. 

The workhorse amphoteric surfactants are the alkyl- and alkylamidopropyl betaines, containing C8-C18 linear chain distributions that are derived from coconut or palm kernel oil, or ethylene-based alpha olefins. The alkyl betaines are prepared from ADMA feedstocks that are typically derived from alpha olefins and dimethyl amine throngh hydrohalogenation and alkylation reaction steps. The alkylamidopropyl betaines are based on tertiary amines derived from whole triglycerides or their fractionated derivative fatty acids or methyl esters reacted with DMAPA. 

The amphoteric surfactants are relatively expensive products compared to anionic surfactants. Thus, it is not surprising that they are primarily being utilized at low concentrations in cosmetic formulations. A review of 438 shampoos of the U.S. market reveals that appreciable quantities, for example, >5% of alkylamido betaines and imidazolinium surfactants were found in only 8.7% and 13.5%, respectively, of the investigated shampoos. Alkyl betaines were found in a limited number of cases, whereas sulfo betaines were not found in this stndy [4,5]. Since these studies were made, the market has focused on mild products. The change in the U.S. market from bar to liquid soaps has increased the use of alkylamidopropyl betaines. 

Anionic Surfactant Blend and Amphoteric Surfactants onto Berea Sandstone, Indiana Limestone, Baker Dolomite, and Quartz. The first study to be presented examined the adsorption behavior of two amphoteric surfactants, a betaine (Empigen BT) and a sulfobetaine (Varion CAS) and a 50 50 blend of a Cio diphenyl ether disulfonate (DOWFAX 3B2), and a Ci4 i6 ot-olefm sulfonate [11]. The anionic surfactant blend was designated as DOW XS84321.05. The Cio diphenyl ether disulfonate surfactant is one isomer in a suite of surfactants which differ in their degree of alkylation and sulfonation and in their chain lengths. This suite consists of monoalkyl disulfonates (MADS), dialkyl disulfonates (DADS), monoalkyl monosulfonates (MAMS), and... 

These surfactant classes are a subset of those used in cleaning applications, and there are classes that are noticeably absent from the list above, such as alcohol sulfates, salts of fatty acids (soaps), alkanolamides, aliphatic sulfonates, betaines (amphoterics), methyl ester sulfonates and the relatively new alkyl polyglycosides. All of these have seen various applications in the petroleum industry, but perhaps lesser importance in EOR. Cost, availability and performance are the obvious issues in determining the potential use of surfactants in EOR. 

The polymer-surfactant complex has high surfeice viscosity and elasticity (i.e. surfeice viscoelasticity), both will enhance the foam stability (see below). The amphoteric surfactants such as betaines and the phospholipid surfeictants when used in conjunction with alkyl sulfeites or alkyl ether sulfeites can also enhance the foam stability. All these molecules strengthen the film of surfactant at the air/water interface, thus modifying the lather from a loose lacy structure to a rich, dense, small bubble size, luxurious foam. Several foam boosters have been suggested and these include fatty acid alkanolamide, amine oxides. Fatty alcohol and fatty acids can also act as foam boosters when used at levels of 0.25-0.5 %. Several approaches have been considered to explain foam stability (a) Surface viscosity and elasticity theory The adsorbed surfeictant film is assumed to control the mechanical-dynamical properties of the surface layers by virtue of its surface viscosity and elasticity. This may be true for thick films (> 100 nm) whereby intermolecular forces are less dominant. Some correlations... 

Amphoteric surfactants by definition are chimeric, exhibiting anionic character in alkaline solution, nonionic character near their isoelectric point, and cationic character in acidic solution [73]. As a result of their complex charge characteristics, their interactions with interfaces must be examined iudividually and as a function of pH. For example, the adsorption of alkyl betaines firom solution onto wool keratin is much greater at acidic than alkalide pH values. Although amphoteric surfactants are used extensively to improve the cosmetic attributes of many consmner products [74], their interactions with skin have received little attention. 

Five amphoteric surfactants (cocoamidopropyl betaine, cocoamidopropyl sultaine, lau-roamphoglycinate, dihydroxyethyl tallow glycinate and isostearoamphopropionate) were separated by reversed-phase LC. According to the anthors (Cozzoli et al, 1989), this method could be applied to cosmetic matrices. Tegeler et al (1995) set out to determine amphoteric surfactants in typical cleansing formulation, which could contain anionic (e.g. alkyl ether... 

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