Swelling factor

Sephadex type Grade Dry bead diameter (/urn) Fractionation range peptides and proteins (g/mol) Fractionation range dextrans (g/mol) Swelling factor (ml/g dry Sephadex) Maximum operating pressure" (cm H,0) Permeability Ko Maximum linear velocity" (cm/hr) Swelling time (h) ... 

FIG. 13 Gel data contours of constant swelling factor from experimental data. Dashed line indicates the composition of an ideal gel. (Reprinted with permission from Ref. 313, Copyright 1971, Nature.)... 

It has been shown in Chapter XI that the force of retraction in a stretched network structure depends also on the degree of cross-linking. It is possible therefore to eliminate the structure parameter ve/Vo) by combining the elasticity and the swelling equations, and thus to arrive at a relationship between the equilibrium swelling ratio and the force of retraction at an extension a (not to be confused with the swelling factor as). In this manner we obtain from Eq. (XI-44) and Eq. (39)... 

The a used here corresponds to the isotropic swelling factor for the cross-linked gels treated in Chapter XIII. The subscript is dropped for simplicity. 

Swelling degree can be determined as swelling power or swelling factor. Starch suspensions (1%, w/w) are heated at certain temperatures for 30 minutes. The starch sample is centrifuged and the supernatants removed. The sediments are weighed to determine swelling power (Liu et al., 2003). 

We assume to be dose to the lower bound of the excluded volume regime, so that T >0.) To give an example, we consider the swelling factor... 

Fig. 1.5. The, swelling factor (Eq. (1.17)) as function of z (Eq, (1.16)). Points p o ly sty re ne- cyclohexane [MF81] [YFTY71]. Circles P-isobutvlc rio-iso amylisovalerate [MNE72]. Each set of data comprises several chain lengths. The theoretical crossover curve is also given. The precise definition of the variable used here, which later will be called i, is given in Sect. 13.3...

The crossover is traditionary described in terms of the swelling factor... 

Figure 16.5 Swelling factor of small and large granules of normal, waxy and high-amylose starches in the temperature range 50-95°C (a) small granules (b) large granules. (Adapted from reference 42 with permission)...

The broken line gives the hypothetical theta-solvent intrinsic viscosity, Me = KMand the gap between the solid and broken curves, therefore, represents the expansion or swelling factor a . The end effect is again seen in the deviation of the four lowest open circles from the line. It is interesting to note that if no measurements in dichloroacetic acid existed above a molecular weight of about 50,000 the viscosity exponent v would have to be chosen in the neighborhood of 0.5, even though it is clear from the complete body of data that the system is very far from the theta point ... 

Rudin combined Flory s theory of the dimension of polymer coils with Zimm s expression (Zimm, 1946) for the second virial coefficient in a dilute suspension of uniform spheres. He further assumed that the swelling factor (e) of the polymer coil (identical to a3 in Flory s formalism) reduces to 1 at a certain critical concentration cx, Ewhereas it tends to a value e0 (= [//] (/[//]w ) at infinite dilution. The functional relation between e and c, would therefore be... 

Calculate the for solutions in chlorobenzene of polystyrenes with molar weights of 2 x 105,5 x 105 and 106 g/mol the intrinsic viscosity, the critical concentration, the swelling factor, the hydrodynamic swollen volume, the second virial coefficient and the Flory-Huggins interaction parameter. 

For the effective coupling of amino acid residues to the polymer-bound peptide chain, the reaction should be carried out in solvents which swell the resin. Wieland et al. determined the swelling factors for a 2% cross-linked polystyrene-bound Boc-Phe resin in different solvents152>. The volumes of 1 g of this Boc-Phe resin after treatment for 50 hours in different solvents are given in Table 1. These values show that in the case of the polystyrene resin, swelling is minimum in very polar solvents (like methanol) or in very nonpolar solvents (like hexane) and is greatest in chlorinated solvents (like methylenechloride). 

SWELLING FACTORS OF L-PA IMPRINTED AND BLANK NON-IMPRINTED POLYMERS (BL) IN DIFFERENT SOLVENTS... 

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