Viscosity of aqueous solutions

Concentration and Molecular Weight Effects. The viscosity of aqueous solutions of poly(ethylene oxide) depends on the concentration of the polymer solute, the molecular weight, the solution temperature, concentration of dissolved inorganic salts, and the shear rate. Viscosity increases with concentration and this dependence becomes more pronounced with increasing molecular weight. This combined effect is shown in Figure 3, in which solution viscosity is presented as a function of concentration for various molecular weight polymers. 

Liquid Aluminum Sulfate (Viscosity of aqueous solutions of liquid alum [Al2(S04)2 14.3 H2O] at different temperatures), go to the following web site http //WWW. ecoservices. us. rhodia. com/alum. asp. 

The analysis of the main properties of aqueous solutions of polyacrylamide and copolymers of acrylamide has been reviewed [4,5]. The main characteristics of aqueous solutions of polyacrylamide is viscosity. The viscosity of aqueous solutions increases with concentration and molecular weight of polyacrylamide and decreases with increasing temperature. The relationship between the intrinsic viscosity [q]) in cmVg and the molecular weight for polyacrylamide follows the Mark-Houwink equations ... 

The viscosities of aqueous solutions of PGA were determined with an Ubbelhode capillary viscometer at 298 K in the same concentration range as the density measurements. The temperature of the water bath was maintained to 0.05K. 

Meyer considers that the viscosity of aqueous solutions of hyaluronic acid, and the long, doubly refractive fibers obtained by spinning such solutions into a precipitant, are evidence of a long chain type of molecule. 

Papisov et al. (1974) performed calorimetric and potentiometric experiments to determine the thermodynamic parameters of the complex formation of PMAA and PAA with PEG. They investigated how temperature and the nature of the solvent affected the complex stability. They found that in aqueous media the enthalpy and entropy associated with the formation of the PMAA/PEG complex are positive while in an aqueous mixture of methanol both of the thermodynamic quantities become negative. The exact values are shown in Table II. The viscosities of aqueous solutions containing complexes of PMAA and PEG increase with decreasing temperature as a result of a breakdown of the complexes. 

Other physical phenomena that may be associated, at least partially, with complex formation are the effect of a salt on the viscosity of aqueous solutions of a sugar and the effect of carbohydrates on the electrical conductivity of aqueous solutions of electrolytes. Measurements have been made of the increase in viscosity of aqueous sucrose solutions caused by the presence of potassium acetate, potassium chloride, potassium oxalate, and the potassium and calcium salt of 5-oxo-2-pyrrolidinecarboxylic acid.81 Potassium acetate has a greater effect than potassium chloride, and calcium ion is more effective than potassium ion. Conductivities of 0.01-0.05 N aqueous solutions of potassium chloride, sodium chloride, potassium sulfate, sodium sulfate, sodium carbonate, potassium bicarbonate, potassium hydroxide, and sodium hydroxide, ammonium hydroxide, and calcium sulfate, in both the presence and absence of sucrose, have been determined by Selix.88 At a sucrose concentration of 15° Brix (15.9 g. of sucrose/100 ml. of solution), an increase of 1° Brix in sucrose causes a 4% decrease in conductivity. Landt and Bodea88 studied dilute aqueous solutions of potassium chloride, sodium chloride, barium chloride, and tetra-... 

G. Jones and M. Dole, The viscosity of aqueous solutions of strong electrolytes with spedal reference to barium chloride,... 

Temperature as well as salinity and other compositional variables have a profound influence on the viscosity of aqueous solutions and many aspects of life. As temperature declines and salinity increases, viscosity increases, diffusion rates decline, metabolic rates decline, motility of motile microorganisms and feeding rates decline, life spans may increase, and rates of evolution decline. All other things being equal, aqueous systems and planets allowing only cryogenic life will have less evolved life than chemical systems and planets that have permitted life to occur for substantial periods at higher temperatures. 

As to the viscosity of aqueous solutions of nonionic surfactants, in general, gel formation tendency is very important. Table V and Figure 5 show differences in viscosity of aqueous solutions and gel ranges for various nonionics. Gel ranges of SAE are remarkably narrow compared with those of PAE and NPE(Table V). 

Apparatus Use a Brookfield Model LV series viscometer, analog or digital, or equivalent type viscometer for the determination of viscosity of aqueous solutions of cellulose gum within the range of 25 to 10,000 centipoises at 25°. Rotational viscometers of this type have spindles for use in determining the viscosity of different viscosity types of cellulose gum. The spindles and speeds for determining viscosity within different ranges are tabulated below. 

In Figure 8, the reduced viscosity of aqueous solutions of the monomeric cationic surfactant is... 

Viscosity (dynamic) the viscosity of aqueous solutions depends on the molecular weight and the concentration. At concentrations less than 10%, the viscosity is less than lOmPas (25°C). 

Hydroxyethyl cellulose is also incompatible with certain fluorescent dyes or optical brighteners, and certain quaternary disinfectants which will increase the viscosity of aqueous solutions. 

Table V Viscosity of aqueous solutions of Klucel (Aqualon) at 25°C.

Increasing temperature causes the viscosity of aqueous solutions to decrease gradually until the viscosity drops suddenly at about 45°C owing to the limited solubility of hydroxypropyl cellulose. However, this process is reversible and on cooling the original viscosity is restored. 

The viscosity of aqueous solutions of povidone depends on their average molecular weight. This can therefore be calculated from the viscosity, giving the viscosity-average molecular weight (see Section 2.2.6). Fig. 7 shows the very considerable differences in viscosity between solutions of the different povidones in water, as a function of their concentration. A 20% aqueous solution of povidone K 12 shows hardly any visible difference to pure water, while a 20% solution of povidone K 90 in water gives high viscosities until 5000 mPa-s. 

Mazurkiewicz, J. and Nowotny-Rozanaksa, M., Viscosity of aqueous solutions of saccharides, Pol. J. Food Nutr. Sci., 7/2, 171, 1998. 

U.S. 4,256,611 (1981) Egan et al. (Sherex Chemical) Ethylene oxide adduct of partial glycerol esters of detergent-grade fatty acid and certain anionic surfactants Low eye and skin irritation adjust viscosity of aqueous solutions... 

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