The interactions of ι-carrageenan with cationic surfactants in aqueous solutions.
Soft Matter
; 10(23): 4126-36, 2014 Jun 21.
Article
em En
| MEDLINE
| ID: mdl-24752291
ABSTRACT
The interactions between the anionic polymer ι-carrageenan (IC) and the cationic surfactants 1-dodecyl-3-methylimidazolium bromide (C12mimBr), dodecyltrimethylammonium bromide (DTAB) and ethyl-α,ω-bis(dodecyldimethylammonium)dibromide (12-2-12) have been studied by fluorimetry and isothermal titration calorimetry. Our experimental results showed that at a low surfactant concentration, the monomers adsorbed on the IC chains through the electrostatic attraction, followed by the formation of induced micelles on the IC chains through the hydrophobic interaction until the IC chains are saturated by surfactant molecules; after that the added surfactant formed free micelles in the solution. A pseudo-phase-equilibrium thermodynamic model was proposed to explain the experimental results and to understand the mechanisms of the interactions in these three systems. Moreover, the salt effect on the interactions was investigated and found that it changed the critical concentrations but not the interaction mechanism.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Soft Matter
Ano de publicação:
2014
Tipo de documento:
Article