Oleic acid surfactant

All the models mentioned thus far are based on autopoietic self-reproduction experiments. The experimental implementation of a homeostatic mode of the autopoietic minimal system, which is also illustrated in Figure 8.3, proved to be much more difficult, and was realized only in 2001 (Zepik et al., 2001). It is based on the oleic acid surfactant system and is schematized in Figure 8.5 (respecting the theoretical scheme of Figure 8.3) there are two competitive reactions, the reaction Up forms oleate surfactant from the hydrolysis of the anhydride and the other reaction destroys oleate via oxidation of the double bond. 

Figure 11. Effect of packing density on ligand chain length of surfactant molecules for 3 nm diameter FePt spheres, cylinders and cubes. Current state-of-the-art spherical 3nm diameter particles use / = lnm oleic acid surfactant molecules and have a packing fraction of only p — 19%. Cubic or cylindrical structures with shorter chains are needed to increase p to acceptable levels.

Highly active PtRu nano-alloys supported on Vulcan XC72 were also produced by colloidal methods, including the co-reduction of Pt(acac)2 and Ru(acac)2 (where acac = acetylacetonate) with 1,2-hexadecanediol in octyl ether with oleylamine and oleic acid surfactants controlling the particle growth [105]. The average particle size was 2.4 nm 0.5 nm and the Pt Ru atomic ratio was 1 1. The mass activity of the PtRu nano-alloy at 0.45 V vs. SHE was 32.9 mA mg compared to 11.7 mA mg" for the commercial E-TEK Inc. catalyst [105]. 

The most commonly used emulsifiers are sodium, potassium, or ammonium salts of oleic acid, stearic acid, or rosin acids, or disproportionate rosin acids, either singly or in mixture. An aLkylsulfate or aLkylarenesulfonate can also be used or be present as a stabilizer. A useful stabilizer of this class is the condensation product of formaldehyde with the sodium salt of P-naphthalenesulfonic acid. AH these primary emulsifiers and stabilizers are anionic and on adsorption they confer a negative charge to the polymer particles. Latices stabilized with cationic or nonionic surfactants have been developed for special apphcations. Despite the high concentration of emulsifiers in most synthetic latices, only a small proportion is present in the aqueous phase nearly all of it is adsorbed on the polymer particles. 

Sulfated Natural Oils and Fats. Sulfated natural triglycerides were the first nonsoap commercial surfactants introduced in the middle of the nineteenth century. Since then sulfates of many vegetable, animal, and fish oils have been investigated (see also Fats AND FATTY oils). With its hydroxyl group and a double bond, ricinoleic acid (12-hydroxy-9,10-octadecenoic acid) is an oil constituent particularly suited for sulfation. Its sulfate is known as turkey-red oil. Oleic acid is also suited for sulfation. Esters of these acids can be sulfated with a minimum of hydrolysis of the glyceride group. Polyunsaturated acids, with several double bonds, lead to dark-colored sulfation products. The reaction with sulfuric acid proceeds through either the hydroxyl or the double bond. The sulfuric acid half ester thus formed is neutralized with caustic soda ... 

The reaction of olefin sulfation and its possibilities has been extensively studied [3-10] and it was used to produce alcohol sulfates. Dry distillation of spermaceti gives palmitic acid and cetene-1, which can be sulfated with sulfuric acid to give cetyl-2 sulfate [11]. Other surfactants were obtained from olefins produced from natural substances, such as alcohol sulfates by sulfation of olefins from decarboxylation of oleic acid [12], by sulfation of olefins made by dehydrating hydroabietyl alcohol, by direct sulfation of abietyl alcohol [13,14], or by sulfation of natural terpenes [15]. 

Even today renewable resources play a dominant role as raw materials for surfactants, but only because of the great contribution made by soaps to the production of surfactants. If the soaps are left out of consideration as native surfactants, petrochemistry holds 65-70% of the production of synthetic surfactants [2]. But for the future a further increase of renewable raw materials is expected in surfactant production [3]. The main reason for this development is the superior digestibility in the environment of products produced from natural materials. The future importance of the renewable raw materials becomes evident from the fact that even now new plants are cultivated or plants are modified to obtain an improved yield. A new type of sunflower has been cultivated to obtain a higher proportion of monounsaturated oleic acid compared with doubly unsaturated linoleic acid [4],... 

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%. 

BAM showed bright regions due to the Ag particles and dark regions occupied primarily by oleic acid (Fig. 10b). TEM showed monolayer domains of surfactant-coated silver particles within regions of oleic acid. Vertical transfer onto quartz plates of up to eight layers with good linearity was reported. 

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-... 

A cosolvent, typically ethanol, may be used to bring drug into solution. A small number of surfactants (sorbitan trioleate, oleic acid, and lecithin) may be dispersed in propellant systems and can aid in suspension stability and in valve lubrication. 

Fig. 2.9.33. ESI-FIA-MS-MS(+) (CID) product ion mass spectrum of parent ion with m/z 370 of industrial blend of unsaturated FADA surfactant compound could be identified as diethanolamide derivative of oleic acid (CH3-C7H14-CH=CH-C7H14-C(0)-N(CH2-CH2-OH)2) (inset) fragmentation scheme observed under CID conditions [16].

The traditional major source for the nonionic surfactant industry is fatty acid triglycerides from both animal and vegetable sources as the saturated or unsaturated acids. The saturated acids include lauric acid (w-dodecanoic), myristic acid (n-tetradecanoic), palmitic acid ( -hexadecanoic),and stearic acid (n-octadecanoic). The unsaturated acids include oleic acid (Z-9-octadecenoic) and linoleic acid (Z,Z-9,12-octadecadienoic). Of the 200 non-ionic surfactants... 

Several ehemical enhancers, such as sodium ethylenediaminetetraacetate and sodium taurocholate, oleic acid [37], polyoxyethylated nonionic surfactants, citric acid, and dihydroxy bile salts open the paracellular route, presumably by disruption of the intraeellular OJC funetion [37], The use of nitrie oxide is another approach [39], Moreover, manipulation of the cyclooxygenase pathway activities to trigger the release of eompounds like substance P may provide another means for altering colonic permeability [40],... 

Enhancers proposed for potential use for the buccal route include those studied for transdermal delivery [102], such as dimethyl sulfoxide (DMSO), dimethylformamide, ethanol, propylene glycol, 2-pyrxolidones, decylmethyl sulfoxide, azone, sodium lauryl sulfate, oleic acid, bile salts, and nonionic surfactants (polysorbates). These enhancers fall into six categories [103] ... 

C] and 6% Cj g) was used as the anionic surfactant. Oleic Acid (Extra pure reagent, Kanto Chemical Co., Tokyo, Japan), Triolein (glycerol trioleate (Cj 2H33C00)3C3H5, Technical, BDH Chemicals, England) and n-decane (E. Merck, G.C., 95%) were used as oil. Sodium chloride (E. Merck, purity 100 0.05%) was used as electrolyte. 

Solubilization in Nonionic Surfactant. Figure 2 shows the solubilization of oleic acid in Newcol nonionic surfactants. Turbidity was plotted against shaking time. The first number on the curve represents the surfactant. 1102 means dodecanol ethoxylate containing 2 EO. The second number on the curve represents the amount of oleic acid added to the surfactant solution. 

Figure 2. Solubilization of Oleic Acid in Nonionic Surfactant.

From the lower turbidity values shown in Figures 3 and 4, one may estimate that the solubilization of oleic acid is higher than triolein or n-decane in Newcol surfactant solutions. It is difficult to make further distinction between triolein and n-decane from Figures 3 and 4. 

Solubilization in Anionic Surfactant. Figures 5 and 6 show the solubilization of oleic acid in SDS solutions. The surfactant... 

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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