Swelling propensity

The substrate polymer beads used in this work are quite hard and do not swell and shrink when the solvent is changed. A measure of bead hardness is given by the swelling propensity value. This value is obtained by measuring the backpressure of a column with a tetrahydrofuran mobile phase and then with an aqueous phase. After correcting the eluent backpressure for viscosity, the swelling propensity, SP, is calculated by the following equation ... 

To be useful as a catalyst support, the gelular polymers must be swellable, the propensity of which can be controlled by the degree of cross-linking. Polymers can be tailor-made to swell in a particular solvent by appropriate selection of monomer and cross-linking agent. 

The degree of swelling of a random coil depends on the quality of the solvent. While 6 M GuCl or 8 M urea are moderately good solvents for randomly coiled proteins [2,3], water is certainly a rather bad one for denatured proteins, as demonstrated by the compact structure of the native state and suggested by their strong propensity to aggregate when unfolded in water, after heat denaturation for example. The problem is to know whether the size of denatured pro-... 

ITQ-2, a novel zeolitic structure prepared by swelling and delaminating a MWW precursor, has been studied by IR spectroscopy. The same precursor yields, when calcined, the zeolite MCM-22. Bronsted acidity has been measured as the propensity either to engage in H-bonds or to transfer the proton to unsaturated hydrocarbons. Comparison with MCM-22 shows that dealumination accompanies the process of delamination, but no appreciable change in residual Bronsted acidity takes place. Reaction of propene with Bronsted sites to branched oligomers occurs mainly on the external surface. Oligomers show no tendency to evolve to allylic cationic species, in contrast with MCM-22. 

The parameters characterizing the tendency of the compositions to biodegradation selected by their ability to absorb water (degree of swelling) and the mass loss by maintaining samples in soil. Water absorption is one of the indirect indicators of the propensity of the material to biodegradation, as the... 

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