Swelling processes

Monosized macroporous polystyrene-divinylbenzene particles have been prepared in a multistep swelling process, in which particles of different sizes... 

If the swelling process is carried out in the presence of a swelling agent, the Morton equation may be written as follows ... 

The final form of the Morton equation for the activated swelling process may be written by expressing the equilibrium swelling radius of the seed particles in terms of initial radius by using Eq. (10). 

Figure 4. Schematic description of the swelling process. The molecules of the swelling liquid start to penetrate inside the polymer framework from its surface (a) and to solvate the polymer chains. The polymer chain start to stretch out and to move away from one another the apparent volume of the polymer increases and the first nanopores are formed (b). Swelling stops when increasing elastic forces set up by the unfolding of the polymer chains counterbalance the forces which drive the molecules of the swelling agent into the polymer framework (c).

The rate of dissolution of PTF and BTF in nonpolar solvents is considerably higher than in tri-n-alkyltin fluorides. The former dissolve instantly while the latter dissolve only by a slow swelling process. This indicated that the presence of the trimethylsilyl group, at the end of the chain and somewhat away from... 

That is why logically to assume the possibility of specific interactions also during the swelling process, since the values of parameters of the coal solubility S2, which are determining accordingly to the Flory Renner s equation are differed. It depends on fact if the data for all solvents are taking into account in calculations or such calculations are performed with the exclusion of results for solvents able to be as acceptors of hydrogen bonds (amines, ketones). Different results have been obtained also under application of other methods for calculations, especially of the Van-Krevelen s method [14],... 

However, there are only two decisive parameters - the basicity which assists to swelling process and the is molar volume, which opposites to this process taking into account the needed energy and the negotiation of the cohesion forces have only insignificant influence and the exclusion of this parameter from the calculations practically does not worsen the equation... 

Scattering data over the extended range of q-space were also collected from Nafion samples containing a wide range of water contents = 0.05—0.84). While systematic shifts in the intensities and positions of the structure maxima (i.e., the crystalline and ionomer peaks) were observed and consistent with those found by others, the general shapes of the scattering profiles for all samples were quite similar. This observation supported the assumption that the swelling process simply involves a dilution of the... 

The relaxation or swelling process is assumed to be first order in the concentration difference which drives the relaxation and is expressed as... 

We suggest that the rapid process corresponds to hole-filling and/or adsorption onto surfaces, and that the slow process, which follows first-order behavior, corresponds to swelling of the coal extract. Extrapolation of the linear portion of the curves shown in Figures 10 and 11 to time zero should yield the total uptake of benzene attributed to swelling. The results of this analysis are summarized in Table IV, where the total benzene uptake, M , and the uptake attributed to the hole-filling/adsorption and the swelling processes, and M., are shown. 

When a polymer dissolves, the first step is often a slow swelling process called solvation, in which the polymer molecules swell by a factor S, which is related to CED. Linear and branched polymers dissolve in a second step, but network polymers remain in a swollen condition. In the dissolving process, external polymers are initially dissolved, exposing additional polymer chains to the solvent, eventually resulting in the entire polymer mass being dissolved. Thus, polymer solubility often takes considerably longer than the solubility of smaller molecules. 

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