INVESTIGADORES
SIERRA Maria belen
artículos
Título:
The aqueous catanionic system sodium undecenoate - dodecyltrimethylammonium bromide at low concentration
Autor/es:
MARÍA BELÉN SIERRA, MARCELA A. MORINI, PABLO C. SCHULZ
Revista:
COLLOID AND POLYMER SCIENCE
Editorial:
Springer Berlin / Heidelberg
Referencias:
Año: 2004 vol. 282 p. 633 - 641
ISSN:
0303-402X
Resumen:
Abstract The aqueous sodium undecenoate
(SUD) dodecyltrimethylammonium
bromide (DTAB)
catanionic system was studied at low
concentration. The system did not
precipitate, even at a 1:1 SUD:DTAB
proportion, but showed the
formation of a coacervate in a range
of surfactant mixture compositions.
Micelles have a preferential composition
of 0.37 mole fraction of SUD.
This behavior is attributed to the
presence of the double bond at the
distal extreme of the SUD molecule,
which can form hydrogen bonds
with water. Consequently, the
CH=CH2 group is situated at the
interface between the hydrocarbon
micelle core and water, reducing the
interfacial free energy. Structural
computations demonstrate that the
mentioned SUD proportion produces
complete coverage of the micelle
surface by the double bonds.The aqueous sodium undecenoate
(SUD) dodecyltrimethylammonium
bromide (DTAB)
catanionic system was studied at low
concentration. The system did not
precipitate, even at a 1:1 SUD:DTAB
proportion, but showed the
formation of a coacervate in a range
of surfactant mixture compositions.
Micelles have a preferential composition
of 0.37 mole fraction of SUD.
This behavior is attributed to the
presence of the double bond at the
distal extreme of the SUD molecule,
which can form hydrogen bonds
with water. Consequently, the
CH=CH2 group is situated at the
interface between the hydrocarbon
micelle core and water, reducing the
interfacial free energy. Structural
computations demonstrate that the
mentioned SUD proportion produces
complete coverage of the micelle
surface by the double bonds.2 group is situated at the
interface between the hydrocarbon
micelle core and water, reducing the
interfacial free energy. Structural
computations demonstrate that the
mentioned SUD proportion produces
complete coverage of the micelle
surface by the double bonds.
Keywords Sodium undecenoate ÆSodium undecenoate Æ
Dodecyltrimethylammonium
bromide Æ Catanionic surfactant ÆÆ Catanionic surfactant Æ
Critical micelle concentration ÆÆ
Coacervation