Electrolyte content

What makes the latter items particularly important is the fact that the charge and electrolyte content of an unknown polymer may not be known hence it is important to design an osmotic pressure experiment correctly for such a system. It is often easier to add swamping amounts of electrolyte than to totally eliminate all traces of electrolyte. Under the former conditions a true molecular weight is obtained. Trouble arises only when the experimenter is indifferent toward indifferent electrolyte this sort of carelessness can be the source of much confusion. 

This energy maximum is calculated from the electric surface potential. An approximation of this surface potential is the zeta potential, which is experimentally deterrnined with commercial instmments. For o/w emulsions with low electrolyte content in the aqueous phase, a zeta potential of 40 mV is sufficient to bring the energy maximum to this level. 

Calculations of the relative height of the barrier with electrolyte content are interesting from a scientific point of view, but of limited value in... 

As a related matter it is easily understood that addition of salts at a certain concentration destabilizes an emulsion. It may be concluded that if an emulsion remains stable at electrolyte contents higher than those cited in the preceding paragraphs, the stabiUty is not the result of electric double-layer repulsion, which may be useful information to find the optimum manner for destabilization. 

Diethylenetriamine and aminoethylethanolamine derivatives of mixtures of fatty acids and ether carboxylic acids are described as textile softeners for laundry baths with high electrolyte content [42]. 

Fluids can be classified further according to their tonicity. Isotonic solutions (i.e., normal saline or 0.9% sodium chloride [NaCl]) have a tonicity equal to that of the ICF (approximately 310 mEq/L or 310 mmol/L) and do not shift the distribution of water between the ECF and the ICF. Because hypertonic solutions (i.e., hypertonic saline or 3% NaCl) have greater tonicity than the ICF (greater than 376 mEq/L or 376 mmol/L), they draw water from the ICF into the ECF. In contrast, hypotonic solutions (i.e., 0.45% NaCl) have less tonicity than the ICF (less than 250 mEq/L or 250 mmol/L) leading to an osmotic pressure gradient that pulls water from the ECF into the ICF. The tonicity, electrolyte content, and glucose content of selected fluids are shown in Table 24—3. 

Extensive, horizontal sandstone plateaus occur in tropical shield areas. Well-known examples are the Precambrian Roraima sandstone formations on the Guiana Shield and the Voltaian sandstone formations in Western Africa. Major occurrences of consolidated sands are found in Northern Africa, in Guyana and Surinam, eastern Peru, northeastern Brazil and in Liberia (western Africa). These sandstone formations have a history of tropical weathering in common they all have a deep weathering mantle of bleached, white sands that are very rich in quartz, poor in clay and excessively drained. Electrolyte contents differ by region In arid and semi-arid areas where evaporation exceeds precipitation, salts and carbonates may accumulate at or near the surface of the soil. 

Crust formation thus is attributed to the disaggregation of the uppermost soil layer, initiated by the mechanical impact of the rain drops, and the subsequent dispersion of the clay fraction facilitated by the high ESR of the soil and by the low electrolyte content of rain water (Shainberg, 1990). Upon drying, the dispersed clay is responsible for the formation of the hard crust and decreases in infiltration rate. 

Lower electrolyte content per calorie Hypertonic restriction, such as renal insufficiency. 

Protein content varies Low electrolyte content tions, but generally more expensive. 

Another example is the influence of the electrical resistance of PVC cable insulation. This is caused not by the organic pigment itself but by ethoxylated surfactants, which are added as auxiliaries in the manufacture of these pigments, especially azo pigments. Contrary to a repeatedly expressed view, a possible electrolyte content, which laked azo pigments for example can have, has no effect on the dielectric properties of PVC [34]. Some pigment manufacturers offer special product ranges with verified dielectric properties for this purpose. 

Figure 2.16 The pair potential calculated for rutile particles with a radius of 100 nm, background electrolyte concentration of 10 4moldm 3 and a -potential of —50 mV. Curve a was calculated for an isolated pair of particles and curve b corresponds to the potential for a pair ofparticles in a dispersion at a volume fraction of 0.45. Note how the increased electrolyte content due to the counterions introduced with the particles shorten the range of the repulsion enough for a small secondary minimum to be found at h 70 nm...

The remaining problem of the molecular mechanisms of this action was judged to be related to the conformation of the dicarboxylic acid at the interface. This conformation is usually determined directly with the use of a Langmuir trough (16-18). The disadvantage of such a method for the present problem lies with the restrictions of the environment of the molecule to be Investigated. The basic requirement is that the molecule must be virtually insoluble in the liquid substrate on which the monolayer is supported. For the dicarboxylic acid in question, this meant a pH value as low as 2 and also a high electrolyte content in the aqueous substrate. 

Acetazolamide is an aromatic sulfonamide used as a carbonic anhydrase inhibitor. It facilitates production of alkahne urine with an elevated biocarbonate, sodium, and potassium ion concentrations. By inhibiting carbonic anhydrase, the drug suppresses reabsorption of sodium ions in exchange for hydrogen ions, increases reflux of bicarbonate and sodium ions and reduces reflux of chloride ions. During this process, chloride ions are kept in the kidneys to cover of insufficiency of bicarbonate ions, and for keeping an ion balance. Electrolytic contents of fluid secreted by the kidneys in patients taking carbonic anhydrase inhibitors are characterized by elevated levels of sodium, potassium, and bicarbonate ions and a moderate increase in water level. Urine becomes basic, and the concentration of bicarbonate in the plasma is reduced. 

Hypertension is a syndrome characterized by elevated arterial blood pressure that depends on a number of factors. Some of the main factors that determine arterial blood pressure are parameters of heart rate, volume, viscosity, and electrolytic contents of circulating blood. 

CN098 Yartey, J., E. K. Harisson, L. A. Brakohiapa, and E. K. Nkrumah. Carbohydrate and electrolyte content of some home-available fluids used for oral rehydration in Ghana. J Trop Pediatr 1993 39(4) 234-237. 

An aqueous polybutyl methacrylate latex (average radius == 200 A) has a viscosity of 50,500 cP at 0 = 0.25 and a viscosity of 36.7 cP at the same rate of shear when 1.71 x 10-5 g NaCl is added per gram of polymer, t Assuming that these charged particles must be surrounded by a layer of dissolved ions in solution, what conclusions can you draw about the dependence of the thickness of this layer of ions on the electrolyte content of the continuous phase ... 

The general shape of the curves is roughly parabolic. The coordinates of the maximum in the electrocapillary curve depend on the electrolyte content of the system. Since 7 decreases on both sides of the electrocapillary maximum and since reductions in 7 are associated with adsorption, we conclude that adsorption increases as we move in either direction from the maximum that is, the electrocapillary maximum seems to be a point of minimum adsorption. 

The diffuse part of the double layer is of little concern to us at this point. Chapters 11 and 12 explore in detail various models and phenomena associated with the ion atmosphere. At present it is sufficient for us to note that the extension in space of the ion atmosphere may be considerable, decreasing as the electrolyte content of the solution increases. As micelles approach one another in solution, the diffuse parts of their respective double layers make the first contact. This is the origin of part of the nonideality of the micellar dispersion and is reflected in the second virial coefficient B as measured by osmometry or light scattering. It is through this connection that z can be evaluated from experimental B values. 

An issue of considerable practical importance is how the force of repulsion described by Equation (79) and its approximation Equation (82) varies with the electrolyte content of a solution. Since k varies with n 2, Equation (82) is of the form... 

A potential energy of repulsion may extend appreciable distances from surfaces, but its range is compressed (i.e., reduced) by increasing the electrolyte content of the system. 

The sensitivity of aqueous lyophobic colloids to electrolyte content is due to the dependence of interparticle repulsion on this concentration. 

We know from Chapter 11 that the potential drops gradually with distance from a charged surface, its range decreasing with increasing electrolyte content. Most of the expressions... 

The surface of shear is the location within the electrical double layer at which the various electrokinetic phenomena measure the potential. We saw in Chapter 11 how the double layer extends outward from a charged wall. The potential at any particular distance from the wall can, in principle, be expressed in terms of the potential at the wall and the electrolyte content of the solution. In terms of electrokinetic phenomena, the question is How far from the interface is the surface of shear situated and what implications does this have on the relation between measured zeta potential and the surface potential ... 

Throughout most of this chapter the emphasis has been on the evaluation of zeta potentials from electrokinetic measurements. This emphasis is entirely fitting in view of the important role played by the potential in the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory of colloidal stability. From a theoretical point of view, a fairly complete picture of the stability of dilute dispersions can be built up from a knowledge of potential, electrolyte content, Hamaker constants, and particle geometry, as we discuss in Chapter 13. From this perspective the fundamental importance of the f potential is evident. Below we present a brief list of some of the applications of electrokinetic measurements. 

First of all, we have to consider the electrolytic contents of the commercially available solutions which are compared in the following diagram (Fig. 6.10). 

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