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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

From Associative to Segregative Phase Separation: The Phase Behavior of Poly(acrylate)/Dodecyltrimethylammonium Complex Salts in the Presence of NaBr and NaCl

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Author(s):
Aquino Queiros, Marcos Vinicius [1] ; Loh, Watson [1]
Total Authors: 2
Affiliation:
[1] Univ Estadual Campinas, UNICAMP, Inst Chem, BR-13083970 Campinas, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Journal of Physical Chemistry B; v. 125, n. 11, p. 2968-2975, MAR 25 2021.
Web of Science Citations: 0
Abstract

We report here a systematic study on the phase behavior of dodecyltrimethylammonium-poly(acrylate) (C12TAPA) complex salts upon addition of simple salts (NaBr and NaCl). Complex salts of poly(acrylate) of two molar masses were employed (2000 and 450,000 g mol(-1)). Systems containing different surfactant mesophases were observed, whose structures were elucidated by small-angle X-ray scattering analyses. Overall, we observe a transition from associative to segregative phase separation intercalated with monophasic regions. In terms of surfactant association, a transition from micellar cubic phases to an isotropic micellar solution was observed, where these two phases occur in equilibrium with a dilute phase as a consequence of associative phase separation. However, as the salt concentration increases, segregative phase separation is observed, and scattering analyses of the surfactant-rich phase indicate the growth of micellar aggregates. These results are discussed in terms of the electrolyte effect screening the interactions between the oppositely charged surfactant and polymer and as a result of salting-out effects of the different electrolytes that prevail at higher concentrations. (AU)

FAPESP's process: 18/09099-3 - Phase behavior of electrostatic complexes in systems containing polymers and surfactants in the presence of inorganic salts
Grantee:Marcos Vinícius Aquino Queirós
Support Opportunities: Scholarships in Brazil - Doctorate
FAPESP's process: 15/25406-5 - Organizing matter: colloids formed by association of surfactants, polymers and nanoparticles
Grantee:Watson Loh
Support Opportunities: Research Projects - Thematic Grants