Solubility nonionic surfactants

Thomas, Gomes, Drapier, Church Colgate-Palmolive Light-duty liquid cleaning compositions especially for dishwashing Contains a water-soluble nonionic surfactant... 

Arenas et al. [54] report the solubilization of polychlorocarbon solvents by alkanoylglycamines, a phenomenon that is to be expected of highly water-soluble nonionic surfactants. Miyagishi et al. [55] report determination of the CMC s of these surfactants using measurements of the fluorescence of benzophenone imine. Such determinations using, for example, pyrene have long been known the use of this particular fluorescent dye is unusual. 

This class of surfactant has been extensively investigated because it has the potential to combine the advantages of both the anionic and nonionic surfactant types. In general the ethoxylation of the fatty alcohol is not carried sufficiently far to produce a truly water-soluble nonionic surfactant usually five or fewer molecules of ethylene oxide are added and the unsulfated material is still of limited solubihty in water. The water-insoluble nonionic material, however, can then be sulfated with chlorosulfonic acid or SO3 and neutralized, usually with sodium hydroxide, to yield the desired product. Other counterions may be employed by slight modifications of the reaction or by the use of alternative reaction schemes. 

The Kraft point (T ) is the temperature at which the erne of a surfactant equals the solubility. This is an important point in a temperature-solubility phase diagram. Below the surfactant cannot fonn micelles. Above the solubility increases with increasing temperature due to micelle fonnation. has been shown to follow linear empirical relationships for ionic and nonionic surfactants. One found [25] to apply for various ionic surfactants is ... 

Solvents. The most widely used solvent is deionized water primarily because it is cheap and readily available. Other solvents include ethanol, propjdene glycol or butylene glycol, sorbitol, and ethoxylated nonionic surfactants. There is a trend in styling products toward alcohol-free formulas. This may have consumer appeal, but limits the formulator to using water-soluble polymers, and requires additional solvents to solubilize the fragrance and higher levels of preservatives. 

Emulsifiers. Removing the remover is just as important as removing the finish. For water rinse removers, a detergent that is compatible with the remover formula must be selected. Many organic solvents used in removers are not water soluble, so emulsifiers are often added (see Emulsions). Anionic types such as alkyl aryl sulfonates or tolyl fatty acid salts are used. In other appHcations, nonionic surfactants are preferred and hydrophilic—lipophilic balance is an important consideration. 

In most cases, these active defoaming components are insoluble in the defoamer formulation as weU as in the foaming media, but there are cases which function by the inverted cloud-point mechanism (3). These products are soluble at low temperature and precipitate when the temperature is raised. When precipitated, these defoamer—surfactants function as defoamers when dissolved, they may act as foam stabilizers. Examples of this type are the block polymers of poly(ethylene oxide) and poly(propylene oxide) and other low HLB (hydrophilic—lipophilic balance) nonionic surfactants. 

Emulsions stabilized with a nonionic surfactant and catalyzed with a monomer soluble initiator were found to foUow kinetics dependent on initiator concentration (17). 

At low temperature, nonionic surfactants are water-soluble but at high temperatures the surfactant s solubUity in water is extremely smaU. At some intermediate temperature, the hydrophile—Hpophile balance (HLB) temperature (24) or the phase inversion temperature (PIT) (22), a third isotropic Hquid phase (25), appears between the oil and the water (Fig. 11). The emulsification is done at this temperature and the emulsifier is selected in the foUowing manner. Equal amounts of the oil and the aqueous phases with aU the components of the formulation pre-added are mixed with 4% of the emulsifiers to be tested in a series of samples. For the case of an o/w emulsion, the samples are left thermostated at 55°C to separate. The emulsifiers giving separation into three layers are then used for emulsification in order to find which one gives the most stable emulsion. 

Phosphoric acid esters of nonionic surfactants have a greater solubility and compatibility than the nonionics from which they are derived, as shown in Table 3 [37]. 

Surfactants greatly improve the performance of trans-cinnamaldehyde as a corrosion inhibitor for steel in HCl [741,1590,1591]. They act by enhancing the adsorption at the surface. Increased solubility or dispersibility of the inhibitor is an incidental effect. N-dodecylpyridinium bromide is effective in this aspect far below its critical micelle concentration, probably as a result of electrostatic adsorption of the monomeric form of N-dodecylpyridinium bromide. This leads to the formation of a hydrophobic monolayer, which attracts the inhibitor. On the other hand, an ethoxylated nonylphenol, a nonionic surfactant, acts by incorporating the inhibitor into micelles, which themselves adsorb on the steel surface and facilitate the adsorption of trans-cinnamaldehyde. 

H Schott. Solubility parameter and hydrophilic lipophilic balance of nonionic surfactants. J Pharm Sci... 

These esters of p-hydroxybenzoic acid have been used primarily to prevent growth of molds but in higher concentrations possess some weak antibacterial activity. Their effective use is limited by low aqueous solubility and by reports of stinging and burning sensations related to their use in the eye. They bind to a number of nonionic surfactants and polymers, thereby reducing their bioactivity. They are used in combination, with the methyl ester at 0.03-0.1% and the propyl ester at 0.01-0.02%. Parabens have also been shown to promote corneal absorption [140]. 

The absorption of drugs from the rectal [32] cavity has been studied in some detail. Muranishi et al. [34] have shown that a significant increase in the absorption and lymphatic uptake of soluble and colloidal macromolecules can be achieved by pretreating the rectal mucosal membrane with lipid-nonionic surfactant mixed micelles. They found no evidence of serious damage of the mucosal membrane. Davis [30] suggested that the vaginal cavity could be an effective delivery site for certain pharmaceuticals, such as calcitonin, used for the treatment of postmenopausal osteoporosis. 

Takahashi, S., Ikkai, Y., Rodriguez-Ahreu, C., Aramaki, K., Ohsuna, T. and Sakamoto, K. (2007) Application of a water soluble alkoxysilane for the formation of mesoporous silica from nonionic surfactant micelles hearing cholesterol. Chemistry Letters, 36, 182— 183. 

Hayashi, M., Sasaki, T. (1956) Measurements of solubilities of sparingly soluble liquids in water and aqueous detergent solutions using nonionic surfactant. Bull. Chem. Soc. Jpn. 29, 857. 

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