Thermodynamic characterization of the interaction behavior of a hydrophobically modified polyelectrolyte and oppositely charged surfactants in aqueous solution: Effect of surfactant alkyl chain length

• Type: Article in International Scientific Journal
• Date: 2005

Authors

Bai, GY (Author) Other; Nichifor, M (Author) Other; Lopes, A (Author) FCUP; Bastos, M (Author) FCUP

Journal

Title: Journal of Physical Chemistry B

Vol. 109

Pages: 518-525

ISSN: 1520-6106

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 76 Citations

Scopus - 78 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-000-51E

DOI: 10.1021/jp046552b

Abstract (EN): We have used a precision isothermal titration microcalorimeter (ITC) to measure the enthalpy curves for the interaction of a hydrophobically modified polyelectrolyte (D40OCT30) with oppositely charged surfactants (SCnS) in aqueous solution. D40OCT30 is a newly synthesized polymer based on dextran having pendant N-(2-hydroxypropyl)-N,N-dimethyl-N-octylammonium chloride groups randomly distributed along the polymer backbone with degree of substitution of 28.1%. The employed anionic surfactants are sodium octyl sulfate (SC8S) and sodium tetradecyl sulfate (SC14S). Microcalorimetric results along with turbidity and kinematic viscosity measurements demonstrate systematically the thermodynamic characterization of the interaction of D40OCT30/SCnS. A three-dimensional diagram with the derived phase boundaries is drawn to describe the effect of the alkyl chain length of surfactant and of the ratio between surfactant and pendant groups on the interaction. A more complete picture of the interaction mechanism for D40OCT30/SCnS systems is proposed here.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8