Abstract

HERNANDEZ-ESCALONA, Margarita; GOMEZ-HERNANDEZ, Yanaisi  and  PENATE-VALLDEPERAS, Patricia. Aggregation process in aqueous dissolutions of TRITON x-100 and CTAB with alginates. Rev Cub Quim [online]. 2020, vol.32, n.1, pp. 88-103.  Epub Feb 26, 2020. ISSN 2224-5421.

The influence of aqueous dissolutions of sodium alginate and carboxymethylated derivatives on the absorption and micellar critical concentration (CAC and CMC*) of Triton X-100 and CTAB surfactants was studied by tensiometry (γ) and conductimetry (κ). An inflection at 0,1x10-4 mole/L in the curve of γ vs [Triton X-100] in the presence of solutions of 0,1, 0,5 and 1 g alginate/L was observed; suggesting weak polymer-surfactant interaction. The CMC* in the presence of alginate, decreases to 1.0x10-4 mole/L. CAC and CMC* of CTAB in the presence of alginate and the greatest substituted derived are similar by both methods, CAC tends to decrease with concentration, while CMC* increased with the concentration of polysaccharide and in a presence of a highest substitution degree, characteristic behavior of systems with opposite charges. These show three critical concentrations: CMC*, CAC and another originated by interactions attributed to the presence of non-cooperative associations about 0.045x10-3 mole/L.

Keywords : sodium alginate; carboxymethyl alginate; CTAB; Triton X-100; CMC.

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