Resumo

FERNANDEZ-D’ARLAS BIDEGAIN, Borja. Water matching Afinities model and interactions between polyelectrolites and ions in solution. Educ. quím [online]. 2022, vol.33, n.1, pp.29-40.  Epub 11-Nov-2022. ISSN 0187-893X.  https://doi.org/10.22201/fq.18708404e.2022.1.79063.

Here we discuss the phenomenology related to the interaction of macromolecules with ions in aqueous solution. We introduce the specific ion effects, also known as the lyotropic or Hofmeister series, which classify the ions according to their capability to coagulate or dissolve the proteins or other macromolecules. The phenomenology is explained as function of the Water Matching Affinities principle, introduced by Fajans for simple salts. Some implications will be discussed, and the phenomenology will be exemplified with the behavior of two surfactants: an anionic surfactant (sodium dodecyl sulphate) in the presence of different cations (Li+, Na+; K+, NH4 +) and a cationic polymeric surfactant (polydiallydimethylammonium chloride) in the presence of different anions (F-, Cl-, Br-, I-,CH3COO-).

Palavras-chave : Ions; Water; Proteins; Polymers; Lyotropic series; Hofmeister series.