Solution properties, aqueous, fatty

Aqueous Solution Properties of a Fatty Dicarboxylic Acid Hydrotrope... 

TRIBOLOGICAL PROPERTIES OF AQUEOUS SOLUTIONS OF OXYETHYLATED FATTY ALCOHOLS... 

Commercially, soap is most commonly produced through either the direct saponification of fats and oils with caustic or the hydrolysis of fats and oils to fatty acids followed by stoichiometric (equal molar) neutralization with caustic. Both of these approaches yield workable soap in the form of concentrated soap solutions (- 70% soap). This concentration of soap is the target on account of the aqueous-phase properties of soap as well as practical limitations resulting from these properties. Hence, before discussing the commercial manufacturing of soap, it is imperative to understand the phase properties of soap. 

Because of their preferential use as detergents, the main interest in the physicochemical properties of the salts of a-sulfo fatty acid esters is related to their behavior in aqueous solution and at interfaces. In principle these are surface-active properties of general interest like micelle formation, solubility, and adsorption, and those of interest for special applications like detergency, foaming, and stability in hard water. 

Liposomes are artificial structures primarily composed of phospholipid bilayers exhibiting amphiphilic properties. Other molecules, such as cholesterol or fatty acids also may be included in the bilayer construction. In complex liposome morphologies, concentric spheres or sheets of lipid bilayers are usually separated by aqueous regions that are sequestered or compartmentalized from the surrounding solution. The phospholipid constituents of liposomes consist of hydrophobic lipid tails connected to a head constructed of various glycerylphosphate... 

The formation of two aqueous phases can be exploited in the recovery of proteins using liquid-liquid extraction techniques. Many factors contribute to the distribution of a protein between the two phases. Smaller solutes, such as amino acids, partition almost equally between the two phases, whereas larger proteins are more unevenly distributed. This effect becomes more pronounced as protein size increases. Increasing the polymer molecular weight in one phase decreases partitioning of the protein to that phase. The variation in surface properties between different proteins can be exploited to improve selectivity and yield. The use of more hydrophobic polymer systems, such as fatty acid esters of PEG added to the PEG phase, favors the distribution of more hydrophobic proteins to this phase. In Fig. 10.13, partition coefficients for several proteins in a dextran-PEG system are given [27]. 

Phospholipids. The phospholipids comprise approximately 1 % of the total lipid in bovine milk (ca.0.3 to 0.4 g/liter). While quantitatively minor, the ability of the phospholipids to form stable colloidal suspensions or emulsions in aqueous solution cause them to be important in the formation and secretion of milk fat. (Long and Patton 1978 Patton and Keenan 1975). Their physical properties as bipolar molecules and their relatively high concentration of unsaturated fatty acids also make them an important factor to consider during the storage and... 

Amine oxides are the reaction products of tertiary amines and hydrogen peroxide. In aqueous solutions fatty amine oxides exhibit non-ionic or cationic properties depending on pH, and under neutral or alkaline conditions they exist as non-ionised hydrates. 

The octanol - water partition coefficient, Aiow, for an organic compound is the ratio of the compound concentration in octanol saturated with water to that in water saturated in octanol. This property of the VOC can be used to estimate as it is directly related to the tendency of a compound to partition in natural organic matter from aqueous solution (Karickhoff, 1981). The octanol-water partition coefficient also provides a measure of the propensity of a compound to bioaccumulate (Rathbun, 1998) in fatty tissue of aquatic biota. Values of are provided in Table 5. 

The stratum corneum is the outermost layer of the epidermis and has a thickness of 10-15 pm. It is the principal barrier for the transport of most solutes (except for very lipophilic compounds) across the skin. The stratum corneum is a continuous heterogeneous structure that consists of approximately 10-25 layers of closely packed dead keratinized cells (corneocytes) cemented together by intercellular lipids. The intercellular lipids in the stratum corneum are in the form of multiple lamellar bilayers composed mainly of ceramides, cholesterol, and fatty acids. Proteins in the stratum corneum are largely concentrated within the corneocytes as keratin fibrils. The transport of lipophilic compounds across the stratum corneum is related to the intercellular lipids (lipoidal or intercellular pathways). On the other hand, it is believed that the transport of polar and ionic compounds is related to pathways with aqueous properties (the polar or pore pathways) when the stratum corneum is under a hydrated state. ... 

The objective of this research program was to investigate the characteristics of the interfacial films observed in our miniemulsion systems. This study of oil/aqueous mixed emulsifier solution interfacial properties included the effects of mixed emulsifier molar ratio and concentration, fatty alcohol initial location and chain length, and oil phase water solubility. The effect of equilibration on the formation of interfacial layers was also studied. 

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