Swelling degree, calculation

Fig. 2. Dependencies of the swelling degree of PAAm hydrogels on the concentration X (in mol L-1) of H+ (/), Ca2+ (2), and Na+ (3) in the solution. Dashed curve 3 is obtained by calculation. From Dubrovskii et al. [22]...

Various modifications of the Flory theory [4] are usually applied to describe the uncharged gels. Their crosslinking density can be simply calculated from the swelling degree using Eqs. (3.1) and (3.2) or analytical expressions for the Mc value (see, for example, Ref. [124]). 

These equations allow either to predict the swelling degree (w = l/(p) as a function of external conditions or to calculate the network parameters from the correlation between the theoretical and experimental dependencies w(q) or w(p) [22, 102], An example of such a correlation is given in Fig. 2 and 5. As can be seen, theoretical predictions are in good agreement with experimental data. However, when the outer solution contains multivalent cations, only a semi-quantitative agreement is attained. 

Table 1. Experimental [10] and calculated in accordance with the equation (10) values of swelling degree of the coal Illinois JVs 6... 

Significant factor as same as in a case of swelling degree is the solvents basicity. With the solvents basicity increasing, the process rate is also increased. The less essential is a role the solvents ability to electrophilic solvation although this factor increases the process rate but it exclusion from the consideration decreases R till 0,928. The value IgQ calculated in accordance with the equation (15) is represented in Table 3. 

Since swelling introduces an affine deformation of the network, the above calculation holds for any swelling degree and the distance d between first neighbor crosslinks can be written as ... 

The composites swelling degree (Q) was measured by immersing the composite samples in the pure component (water or camphene) at 50°C for 24 h. Then, the samples were taken out, wiped with tissue paper and weighted. For calculations was used Q = (m-mo)/mo, where m is the mass of the swollen sample and nto is its initial mass. 

Table 2 - Characteristics of the catalytic composites. Q , Qjamph - swelling degree for water and camphene, respectively De - camphene diffiisivity calculated from data collected in a two-...

The swelling degree q) of the crosslinked fibrous membrane was measured by immersing the membrane in pH buffers (pH 2 to 7) without or with lipase (5mg/ml) at 30 C for 24 hrs and calculated by the following equation. 

These parameters are related to one another and can be determined theoretically or through the use of a variety of experimental techniques. Usually they are calculated from typical macroscopic network properties, like swelling degree Q or Young s modulus E (for tensile or compression strain) or shear modulus G (for shearing strain), which can be determined by physical methods as will be shown in Sections 4.S.2-4.3.4. 

Fig. 64. Wiener component of birefringence in dependence on the degree of swelling g, calculated for the values of Hi indicated and for = 1.3333.

Comparison of Figures 1 and 2 shows that for swelling degrees greater than about ten, finite chain extensibility must be accounted for through non-Gaussian chain statistics. While such theoretical calculations have been proven to be qualitatively... 

RXM-y-20M at an irradiation dose 170 rad/s during 3-5 h (16). To remove the sol fraction, the gel samples were washed out by distilled water during 2 weeks. The swelling degree of amphoteric gels calculated by the... 

FIGURE 13.5 Measured ( ) and calculated ( ) oil swell of maleated polybutadienes with vaiydng degrees of... 

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