Osmotic properties

We shall be interested in determining the effect of electrolytes of low molecular weight on the osmotic properties of these polymer solutions. To further simplify the discussion, we shall not attempt to formulate the relationships of this section in general terms for electrolytes of different charge types-2 l, 2 2, 3 1, 3 2, and so on-but shall consider the added electrolyte to be of the 1 1 type. We also assume that these electrolytes have no effect on the state of charge of the polymer itself that is, for a polymer such as, say, poly (vinyl pyridine) in aqueous HCl or NaOH, the state of charge would depend on the pH through the water equilibrium and the reaction... 

Uses of lactose production by appHcation include baby and infant formulations (30%), human food (30%), pharmaceuticals (25%), and fermentation and animal feed (15%) (39). It is used as a diluent in tablets and capsules to correct the balance between carbohydrate and proteins in cow-milk-based breast milk replacers, and to increase osmotic property or viscosity without adding excessive sweetness. It has also been used as a carrier for flavorings. 

It is important to realise that whilst complete dissociation occurs with strong electrolytes in aqueous solution, this does not mean that the effective concentrations of the ions are identical with their molar concentrations in any solution of the electrolyte if this were the case the variation of the osmotic properties of the solution with dilution could not be accounted for. The variation of colligative, e.g. osmotic, properties with dilution is ascribed to changes in the activity of the ions these are dependent upon the electrical forces between the ions. Expressions for the variations of the activity or of related quantities, applicable to dilute solutions, have also been deduced by the Debye-Hiickel theory. Further consideration of the concept of activity follows in Section 2.5. 

Dextrans are particularly useful and are employed as a plasma substitute. A concentration of about 6% dextran (50,000-100,000 relative molecular weight) has equivalent viscosity and colloid-osmotic properties to blood plasma. Dextran can also be used as non-irritant absorbent wound dressings, an application also suited to alginate gels. 

Overton E. Osmotic properties of cells in the bearing on toxicology and pharmacology. Z Physik Chem 1897 22 189-209. 

Maltini, E., Torreggiani, D., Fomi, E., and Lattuada, R. 1990. Osmotic properties of fruit juice concentrates. In Engineering and Food Physical Properties and Process Control (W.L.E. Spiess and H. Schubert, eds), Vol. 1, pp. 567-573. Elsevier Science, London. 

Vandegriff KD, McCarthy M, Rohlfs RJ, et al. Colloid osmotic properties of modified hemoglobins chemically cross-linked versus polyethylene glycol surface-conjugated. Biophys Chem 1997 69 23. 

Mui BLS, Cullis PR, Evans EA, et al. Osmotic properties of large unilamellar vesicles prepared by extrusion. Biophys J 1993 64 443. 

To eliminate the threat of shock, replenishment of the circulation is essential. With moderate loss of blood, administration of a plasma volume expander may be sufficient Blood plasma consists basically of water, electrolytes, and plasma proteins. However, a plasma substitute need not contain plasma proteins. These can be suitably replaced with macromolecules ( colloids ) that like plasma proteins, (1) do not readily leave the circulation and are poorly filtrable in the renal glomerulus and (2) bind water along with its solutes due to their colloid osmotic properties. In this manner, they will maintain circulatory filling pressure for many hours. On the other hand, volume substitution is only transiently needed and therefore complete elimination of these colloids from the body is clearly desirable. 

McFarland, W.N. and Munz, F.W. (1958). A re-examination of the osmotic properties of the Pacific hagfish, Polistotrema stouti. Biological Bulletin, Marine Biological Laboratory, Woods Hole 114,348-356. 

A. 1948 - Hassler studies osmotic properties of cellophane membranes at UCLA... 

Real colligative properties are only found in ideal gases and ideal solutions. Examples are osmotic pressure, vapour pressure reduction, boiling-point elevation, freezing-point depression, in other words the osmotic properties. 

The functional and morphological heterogeneity of a lamellar system of chloroplasts indicates that pH values in different compartments (in granal and intergranal thylakoids) differ. This type of structure makes it difficult to measure local pH values at different sites. Therefore, mathematical models taking into account the spatial structure of chloroplasts provide a tool for studying the effect of diffusion restrictions on pH distributions over the thy lakoid on the rates of electron transport, proton transport, and ATP synthesis. The rate of ATP synthesis depends on the osmotic properties of a chloroplast-incubation medium and, therefore, on topological factors. 

This is used to express the concentration of solute relative to the mass of solvent, i.e. molkg . Molality is a temperature-independent means of expressing solute concentration, rarely used except when the osmotic properties of a solution are of interest (p. 49). 

C Calcium and iron supplementation are common causes of constipation. Polycarbophil, a bulk-forming laxative, exerts its therapeutic effect by increasing the mass and water content of stool and by speeding transit time in the colon. Cascara sagrada and sennosides are cathartics, which speed colonic transit time and alter water and electrolyte transport across the colonic mucosa. Sodium biphosphonate is a saline cathartic, which increases intestinal peristalsis by osmotic properties. Docusate sodium is a stool... 

Aluminium hydroxide acts primarily as a base, but it also ionises weakly as an acid pK = 12.2). The osmotic properties of sodium aluminate solutions are identical with those of NaOH both must have the same number of ions. Dissociations such as... 

Majors [13] has compiled the results of his perspectives survey of 14 leading separation scientists with an interest in CEC. As expected, there is a wide divergence in the opinions of these leaders with regard to current issues and future prospects for CEC. However, few underestimated the current technological difficulties of column manufacture, reproducibility of chromatographic and electro-osmotic properties of the packed capillary, and the short-term problems of competing with HPLC or CE, but the majority of scientists interviewed believe that like any new technique, these problems will be overcome and that CEC will become a routine method of analysis in time. 

Bratko, D., and Vlachy, V. An application of the modified Poisson-Boltzmann equation in studies of osmotic properties of micellar solutions. Colloid and Polymer Science, 1985, 263, No. 5, p. 417—419. 

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