Intrinsic viscosity definition

Solution It is apparent from the units of b] that solute concentration has been expressed in g/cm3. Dividing this concentration by the density of the unsolvated protein converts the concentration to dry volume fraction units. Since the concentration appears as a reciprocal in the definition of [17], we must multiply bl by p2 to obtain (lAA Mb/r/o) - 1]. For this protein the latter is given by (3.36)(1.34) = 4.50. If the particles were unsolvated, this quantity would equal 2.5 since the molecules are stated to be spherical. Hence the ratio 4.50/2.50 = 1.80 gives the volume expansion factor, which equals [1 + (mhb/m2)(p2/p )]. Therefore (m, tblm2) = 0.80(1.00/ 1.34) = 0.6O. The intrinsic viscosity reveals the solvation of these particles to be 0.60 g HaO per gram of protein. ... 

When v is expressed in terms of concentration, molecular weight and Avogadro s number [cf. eq. (3.43)], and the definition of the intrinsic viscosity is used [eq. (2.32)], one obtains for this quantity ... 

Calculation of the Endocellulase Activity from the Intrinsic Viscosity Values. The enzymic degradation of polymeric substrates can occur at different bonds in the same substrate molecule, and the enzymic activity has to be defined here as the initial number of moles of glyco-sidic bonds split per second (53). This definition corresponds to the definition of the katal, symbolyzed kat. This unit is defined as the catalytic amount of any catalyst (including any enzyme) that catalyzes a reaction rate of one mole per second in an assay system (54), and it is recommended by the International Union of Pure and Applied Chemistry (55) for the quantitative evaluation of catalytic activities. 

In Chap. 9 the following definition of the limiting viscosity number or intrinsic viscosity was given... 

Now, if all these different viscosity definitions are making you depressed, then this will make you suicidal. Along comes Krae-mer and defines the intrinsic viscosity a different way, as shown in Equation 12-46. 

Now, if you ve managed to keep track of all those viscosity definitions, you re a better man than I am Gunga Din (You have to be familiar with the romantic imperialism of the books and poems of Rudyard Kipling to get this allusion.) So, we have summarized them all in Table 12-3. There are two sets of names, the ones we have used, which almost everybody else also uses, and a set devised by IUPAC, which they hoped everybody would use, but almost nobody does. Just remember that what you measure is the relative viscosity and what you want to know is the intrinsic viscosity. 

The weight average expression follows directly from its definition, but obtaining the number average in terms of w. and M takes some manipulation, which we always leave as a homework problem. Also note that the intrinsic viscosity can be calculated from Equation 12-59 ... 

In Fig. 16 the heat-treated sampie(l) is obtained by heating poly-DSP crystals (a) up to 330°C at a scanning speed of 15°C/min. Then, the sample is cooled immediately to room temperature. The intrinsic viscosity of the original as-polymerized poly-DSP (2.1-2.9) is reduced (0.55-0.59) in sample (1). An X-ray pattern of sample (1) shows slight but definite differences when compared to that erf the original as-polymerized polymer and, in addition, the pattern agrees exactly with that ot the medium-sized polymer crystals (c), which are obtained by photopolymerization of DSP crystals upon irradiation with a xenon lamp for 50 min. DSC curves of sample (1) and polymer crystals (c) are also very similar to each other. From these results, it is concluded that the high... 

For the definition of intrinsic viscosity and related terms, see Table II. 

These figures have been compared with those obtained for rabbit acto-myosin and myosin (Hamoir, 1955). These last values differ notably from one author to another especially in the case of actomyosin, but they always remain lower than our determinations. The viscosity numbers determined by Kerekjarto (1952) for rabbit actomyosin and myosin at 15° C., which seem to be the most reliable, are, respectively, 0.32 and 0.17 ( 0.01). Both figures are definitely lower than our values carried out at higher temperature. In the case of actomyosin, this difference appears to be due to the structure of the solutions. Recent determinations (Hamoir, 1955) suggest that fish and rabbit actomyosins have approximately the same intrinsic viscosity at = 0. The axial ratio of these particles seems therefore not to differ notably. In view of this relationship, more accurate determinations are necessary in order to determine if the different viscosities observed in the presence of ATP are really due to a different shape of the particles. 

The intrinsic viscosity [77] is defined in Table 4.2 as a limit at zero concentration. Since the 77/770 ratios are obtained from Eq. (4.99) with measurements made at finite concentrations of the solution, it becomes necessary to extrapolate the data to zero concentration in order to satisfy this definition. There are a variety of ways to carry out this extrapolation. The variation in solution viscosity (77) with increasing concentration.(c) can be expressed as a power series in c. The equations usually used are the Huggins equation (Huggins, 1942) ... 

Here, the internal viscosity is defined as the contribution of the glassy-relaxation process to the zero-shear viscosity. This definition is different from the common understanding of the term used in literature/ although both have similar notions as to the existence of an effect of fast sub-Rouse-segmental motions on polymer viscoelasticity. In the literature the term internal viscosity generally refers to the effect that would lead to a plateau value of the intrinsic viscosity at high frequencies. 

Give the definitions and formulas for the relative viscosity, specific viscosity, reduced viscosity, inherent viscosity, and intrinsic viscosity. 

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