Solvent, role

COHEN STUART ET AT. Solvent Role in Polymer Adsorption... 

A solvent role can play a decisive role when a reaction chooses the ion-radical pathway. Thus, the solvent effect on thermodynamic contribution to activation free energy causes an increase in the... 

For each family of silica-aluminas several synthesis parameters can be identified and applied to control the textural properties of final products. For example the role of the type and the amount of gelling agent (8,9), the solvent role (10), the silica/alumina molar ratio (9) have been discussed for MSA and ERS-8 formation. 

Though ionic polymerization resembles free-radical polymerization in terms of initiation, propagation, transfer, and termination reactions, the kinetics of ionic polymerizations are significantly diflFerent from free-radical polymerizations. In sharp contrast to free-radical polymerizations, the initiation reactions in ionic polymerizations have very low activation energies, chain termination by mutual destruction of growing species is nonexistent, and solvent effects are much more pronounced, as the nature of solvent determines whether the chain centers are ion pairs, free ions, or both. No such solvent role is encountered in free-radical polymerization. The overall result of these features is to make the kinetics of ionic polymerization much more complex than the kinetics of free-radical polymerization. 

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