Emulsion sodium chloride

It is quite clear, first of all, that since emulsions present a large interfacial area, any reduction in interfacial tension must reduce the driving force toward coalescence and should promote stability. We have here, then, a simple thermodynamic basis for the role of emulsifying agents. Harkins [17] mentions, as an example, the case of the system paraffin oil-water. With pure liquids, the inter-facial tension was 41 dyn/cm, and this was reduced to 31 dyn/cm on making the aqueous phase 0.00 IM in oleic acid, under which conditions a reasonably stable emulsion could be formed. On neutralization by 0.001 M sodium hydroxide, the interfacial tension fell to 7.2 dyn/cm, and if also made O.OOIM in sodium chloride, it became less than 0.01 dyn/cm. With olive oil in place of the paraffin oil, the final interfacial tension was 0.002 dyn/cm. These last systems emulsified spontaneously—that is, on combining the oil and water phases, no agitation was needed for emulsification to occur. 

In converting ESBR latex to the dry mbber form, coagulating chemicals, such as sodium chloride and sulfuric acid, are used to break the latex emulsion. This solution eventually ends up as plant effluent. The polymer cmmb must also be washed with water to remove excess acid and salts, which can affect the cure properties and ash content of the polymer. The requirements for large amounts of good-quaUty fresh water and the handling of the resultant effluent are of utmost importance in the manufacture of ESBR and directly impact on the plant operating costs. 

The choice of coagulant for breaking of the emulsion at the start of the finishing process is dependent on many factors. Salts such as calcium chloride, aluminum sulfate, and sodium chloride are often used. Frequentiy, pH and temperature must be controlled to ensure efficient coagulation. The objectives are to leave no uncoagulated latex, to produce a cmmb that can easily be dewatered, to avoid fines that could be lost, and to control the residual materials left in the product so that damage to properties is kept at a minimum. For example, if a significant amount of a hydrophilic emulsifier residue is left in the polymer, water resistance of final product suffers, and if the residue left is acidic in nature, it usually contributes to slow cure rate. 

Severe attack frequently occurs at a water-line, which in practice can range from structural steel partly immersed in a natural water to a lacquered tin can used for containing emulsion paint. This can be illustrated by adding increeising amounts of sodium carbonate to a sodium chloride solution in which a steel plate is partly immersed (Fig. 1.48c, d and e). With increase in concentration of the inhibitor, attack decreases and becomes confined to the water-line. The attack at the water-line is intense and is characterised by a triangular pasty mass of corrosion products bounded on the upper surface by a dark-brown membrane that follows the contour of the water-line. The mechanism of water-line attack is not clear, but it is likely that the membrane of corrosion products results in the formation of an occluded cell, in which the anolyte and catholyte are prevented from mixing. These occluded cells are discussed in more detail subsequently. 

Energy substrates include dextrose solutions and fat emulsion. Solutions used to supply energy and fluid include dextrose (glucose) in water or sodium chloride, alcohol in dextrose, and IV fat emulsion. Dextrose is a carbohydrate used to provide a source of calories and fluid. Alcohol (as alcohol in dextrose) also provides calories. Dextrose is available in various strengths (or percent of the carbohydrate) in a fluid, which may be water or sodium chloride (saline). Dextrose and dextrose in alcohol are available in various strengths (or percent of the carbohydrate and percent of the alcohol) in water. Dextrose solutions also are available with electrolytes, for example, Plasma-Lyte 56 and 5% Dextrose. Calories provided by dextrose and dextrose and alcohol solutions are listed in Table 58-1. 

During improved oil-recovery processes, waterflooding of the oil is applied. The entrained water forms a water-in-oil emulsion with the oil. In addition, salts such as sodium chloride, calcium chloride, and magnesium chloride may be dissolved in the emulsified water. 

Commonly administered LVPs include such products as Lactated Ringers Injection USP, Sodium Chloride Injection USP (0.9%), which replenish fluids and electrolytes, and Dextrose Injection USP (5%), which provides fluid plus nutrition (calories), or various combinations of dextrose and saline. In addition, numerous other nutrient and ionic solutions are available for clinical use, the most popular of which are solutions of essential amino acids or lipid emulsions. These solutions are modified to be hypertonic, isotonic, or hypotonic to aid in maintaining both fluid, nutritional, and electrolyte balance in a particular patient according to need. Indwelling needles or catheters are required in LVP administration. Care must be taken to avoid local or systemic infections or thrombophlebitis owing to faulty injection or administration technique. 

One advance in the area of LLE is the use of solid supports that facilitate the partitioning of the analyte(s) of interest. LLE extraction methods involving nonpolar matrices often suffer from the formation of emulsions, and using the solid support is a possible solution. In one study, polychlorinated biphenyls, dioxins, and furans were extracted from the lipid fraction of human blood plasma [32], using diatomaceous earth as the solid support. Long glass columns (30 cm) were packed with several layers of Chem-Elut (a Varian product) and sodium chloride. The plasma samples were diluted with water and ethanol and passed over the columns. A mixture of isopropanol and hexane (2 3) was passed over the column and the LLE was performed. It can be concluded that the LLE with the solid support is easier to perform and can be applied to other lipid heavy matrices such as milk [32]. 

Addition of Monovalent and Divalent Ions Relatively simple emulsions are broken by adding monovalent salts like sodium chloride whereas charge-stabilized emulsions are specifically sensitive to the divalent ions, such as CaCl2 MgCl2 etc. 

If an emulsion forms at this stage, it may be broken by acidifying with sulfuric acid and adding 50 g. of sodium chloride. 

Excellent separations of corticosteroids can be achieved on an ODS column with a suitable ratio of methanol/water as an eluent. In this assay hydrocortisone is quantified using betamethasone as an internal standard. The structure of betamethasone is close to that of hydrocortisone but since it is more lipophilic it elutes from the ODS column after hydrocortisone (Fig. 12.12). The assay is a modification of the BP assay for hydrocortisone cream. In the assay described here the internal standard is added at the first extraction step rather than after extraction has been carried out in order to ensure that any losses in the course of sample preparation are fully compensated for. Extraction is necessary in the case of a cream because the large amount of oily excipients in the basis of the cream would soon clog up the column if no attempt was made to remove them. The corticosteroids are sufficiently polar to remain in the methanol/water layer as they have a low solubility in hexane, while the oily excipients are removed by extraction into hexane. The sodium chloride (NaCl) is included in the sample extraction solution to prevent the formation of an emulsion when the extract is shaken with hexane. Solution 2, where the internal standard is omitted, is prepared in order to check that there are no excipients in the sample which would interfere with the peak due to the internal standard. 

The aqueous and organic layers are separated using a 500-mL separatory funnel. The organic layer is washed 3 times with 100 mL of deionized water. An emulsion commonly forms during this step, so saturated sodium chloride may be added to the mixture or used instead of water to aid in the separation of the layers. The organic layer is separated, filtered to remove precipitates, and evaporated to dryness under flowing nitrogen. The crude product is transferred to a 500-mL Erlenmeyer flask with 35 mL of chloroform. To this solution, 300 mL of pentane is added to precipitate the product. 

Sodium chloride was added to the hydrochloric acid solution and to the wash water to reduce emulsion formation. 

An emulsion may be obtained on further washing with water. A small amount of sodium chloride (2-3 g.) dissolved in the wash water assists in breaking such emulsions. 

In our experiments the monomer concentration was between about 150 and 200 grams per kg. of emulsion. Sodium dodecyl sulfate in a concentration of 5 to 15 grams per kg. of water was used as an emulsifier. The reaction temperature was generally 25 °C. Only with vinylidene chloride and chloroprene a reaction temperature of 5°C. was used because of the low boiling point of these monomers. Dose rate ranged between about 500 and 2000 rads per hour but was kept constant during each experiment. 

The most commonly used salts in vaccine formulations are sodium chloride, sodium phosphate, succinic acid, and sodium borate. The concentrations of the salts used in any given formulation are based on isotonicity, pH, and other stabilizers being used in the formulations. A typical range is from 5 to 20 mM salt concentration. These concentrations are also selected to reduce pain on injection and to accord rapid normalization with physiological fluid. Surfactants used in MF59 emulsion include Tween 80 and sorbitan trioleate. 

Peanut Seed. Ramanatham et al. (21) studied the influence of such variables as protein concentration, particle size, speed of mixing, pH, and presence of sodium chloride on emulsification properties of peanut flour (50% protein) and peanut protein isolate (90% protein). Emulsions were prepared by the blender... 

Data in Figure 6 show the effect of varying the pH and sodium chloride concentration on emulsion capacity of peanut protein isolate. Shifting the pH to levels above or below the isoelectric point improved emulsion capacity of peanut protein isolate in O.IM or 0.2M NaCl. Similar trends were noted when distilled water was used as the continuous phase (data not.shown). At the 0.5M NaCl concentration, however, little difference was noted in emulsion capacity at pH 3, 4, or 5 appreciable increases occurred when the pH was raised to 6 and above. At the highest salt concentration (1.OM NaCl), a gradual increase in emulsion capacity occurred when the pH was increased from 3 to 10. An overall suppression in emulsion capacity occurred as salt concentration increased except at pH 5 and 6. These emulsion-capacity curves closely resemble the protein-solubility curves of peanut protein shown in Figure 7... 

Agglomeration may be accomplished in several ways, such as by controlled adjustment of solids, by extensive shear of the emulsion, or by carefully controlled addition of electrolytes, such as water-soluble salts of inorganic acids, e.g., sodium chloride, potassium hypo-phosphite, potassium chloride, or sodium phosphate. Improved processes rely on the method of addition of the monomers in the distinct stages of polymerization (9). 

If emulsions are encountered, the addition of a few milliliters of saturated aqueous sodium chloride clears them readily. The combined ether extracts contain 4-5 g. of solid, neutral material. This product is mainly bibenzyl, b.p. 138-143°/7 mm., f.p. 40°. 

This simplification was used by Ottewill and Walker (7) in their study of the adsorption of a nonionic surfactant onto polystyrene latex in aqueous sodium chloride. In the case of carboxylated emulsion polymers, evidence from conductometric titrations suggests that the carboxyl groups are generally concentrated near the particle surface. The resultant model of an expanded particle is that of a hydrated acid-rich shell surrounding a compact polymer core. The hydrated shell may be viewed as a dilute polymer solution where the density is close to that of water, i.e., Pe= P0. With this assumption, Equation 1 reduces to the form ... 

The 6-T system consists of three separate bleaches, three separate toners, a sodium chloride solution, plus a gold-tone modifier. By mixing and matching the various bleaches and toners, and throwing in the chloride bath and/or the modifier, a large variety of tones can be achieved from purplish-brown to a bright sunlit sepia. This system works best with old-style soft emulsion papers. (Formulas Toners DuPont 6-TToning System)... 

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