Oleic acid effect

Rehbinder and co-workers were pioneers in the study of environmental effects on the strength of solids [144], As discussed by Frumkin and others [143-145], the measured hardness of a metal immersed in an electrolyte solution varies with applied potential in the manner of an electrocapillary curve (see Section V-7). A dramatic demonstration of this so-called Rehbinder effect is the easy deformation of single crystals of tin and of zinc if the surface is coated with an oleic acid monolayer [144]. 

Brevib. thiogenitalis oleic acid production from acetic acid and Cu " is effective 66, 50% ... 

Sulfated Acids, Amides, and Esters. Reaction with sulfuric acid may be carried out on fatty acids, alkanolamides, and short-chain esters of fatty acids. The disodium salt of sulfated oleic acid is a textile additive and an effective lime soap dispersant. A typical sulfated alkanolamide stmcture is CiiH23C0NHCH2CH20S03Na. Others include the sulfates of mono and diethanolamides of fatty acids in the detergent range. The presence of... 

Sulfosuccinates are not only less irritating to skin and mucus membranes than other surfactants, but it was also found that they reduce skin irritation of other surfactants used in skin and hair care products. In particular, the effect on sodium lauryl ether sulfate was found to be most pronounced [103]. Figure 14 shows the mollifying effect of disodium oleic acid monoethanol amide sulfo-succinate when blended with anionic surfactant at a total concentration of 15%. 

Addition of oleic acid to PCL caused a significant increase in the rate of chain scission, the effect being proportional to the amount of acid added (Fig. 26). The effect of added base, e.g., n-decylamine, was even more substantial, reducing the molecular weight of PCL from 60,000 to 20,000 in 20 days (Fig. 26). This reduction in mo-... 

Powdered aluminium had been added to oleic acid. The mixture detonated after being prepared. Such an accident could not be repeated and it was thought that it was caused by the presence of a peroxide formed by the effect of air on oleic acid. In fact, the acid functional group has obviously nothing to do with the peroxidation. It is more likely that the chain s double bond that activates p hydrogen atoms (ally position) was involved in it. This is a well-known phenomenon since it is responsible for the rancidity of some oils and greases. 

Both PC and TEC have been used as analytical methods for QC of oleamide production from urea and oleic acid [383]. Polyamide-impregnated PC is effective in separating fatty amides of different carbon contents [384],... 

Surfactants. The use of surfactants is greatly restricted in formulating ophthalmic solutions. The order of surfactant toxicity is anionic > cationic >> nonionic. Several nonionic surfactants are used in relatively low concentrations to aid in dispersing steroids in suspensions and to achieve or to improve solution clarity. Those principally used are the sorbitan ether esters of oleic acid (Polysorbate or Tween 20 and 80), polymers of oxyethylated octyl phenol (Tyloxapol), and polyoxyl 40 stearate. The lowest concentration possible is used to perform the desired function. Their effect on preservative efficacy and their possible binding by macromolecules must be taken into account, as well as their effect on ocular irritation. The use of surfactants as cosolvents for an ophthalmic solution of chloramphenicol has been described [271]. This com-... 

Monazite is readily floatable using cationic collectors such as oleic acid and sodium oleate in the pH region of 7-11. Monazite does not float readily using, for example, laurel amine or anionic collectors. Adsorption of the sodium oleate on the monazite increases with an increase in pH, indicating that monazite does not float in acid pH, while pyrochlore is readily floatable and is depressed at a pH greater than 10. Figure 24.1 shows the effect of pH on flotation of monazite, pyrochlore and zircon. 

Figure 25.1 Effect of pH on ilmenite flotation from different ore types using oleic acid as collector.

Infusion of fat into the ileum has been shown to cause a lengthening of the SITT—a phenomenon known as the ileal brake (27,28). However, the effect is generally modest (causing a delay of 30-60 min) and attempts to exploit this mechanism in drug delivery have had limited success. Dobson et al. (29,30) studied the effect of co-administered oleic acid on the small intestinal transit of non-disintegrating tablets. They showed a delay in SITT in over half of all cases, and a doubling of SITT in some instances, but in the other cases SITT was either unaffected or even reduced. Lin et al. (31) have also showed slowed GI transit in patients with chronic diarrhea by administration of emulsions containing 0, 1.6, and 3.2 g of oleic acid. Small intestinal transit in normal subjects was measured at 102 11 min, while the transit times in the patients treated with the three emulsions were, respectively, 29 3, 57 5 and 83 5 min. 

Dobson CL, Davis SS, Chauhan S, Sparrow RA, Wilding IR. The effect of oleic acid on the human ileal brake and its implications for small intestinal transit of tablet formulations. Pharm Res 1999 16 92-96. 

V. H. W. Mak, R. O. Potts, and R. H. Guy. Oleic acid concentration and effect in human stratum corneum Non-invasive determination by attenuated total reflectance infrared spectroscopy in vivo. J. Control. Release 12 67-75 (1990). 

Lee J, Kellaway IW (2000) Combined effect of oleic acid and polyethylene glycol 200 on buccal permeation of [D-ala2, D-leu5]enkephalin from a cubic phase of glyceryl monooleate. Int J Pharm 204 137-144... 

Since oleic acid is relatively polar, it may become emulsified by the surfactant monomer. The removal of oleic acid comes mainly from two contributions monomer emulsification and micellar solubilization. Although the Vgjj has been decreased with increasing EO number in dodecanol ethoxylates, in higher EO numbers than 5, this factor has been compensated by the Increase of monomer with increasing EO number (CMC decreases with EO number). The levelling of detergency of dodecanol ethoxylates from EO number 5 to EO number 8 has been interpreted by these reasons. The monomer emulsification of oleic acid has been clearly shown in this paper in SDS solution. The nonionic surfactants we used here have low EO numbers and show mainly the effect of solubilization. 

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