Spectrofluorimetric determination of second critical micellar concentration of SDS and SDS/Brij 30 systems.
Potentially useful stead-state fluorimetric technique was used to determine the critical micellar concentrations (CMC(1) and CMC(2)) for two micellar media, one formed by SDS and the other by SDS/Brij 30. A comparative study based on conductimetric and surfacial tension measurements suggests that the CMC(1) estimated by the fluorimetric method is lower than the value estimated by these other techniques. Equivalent values were observed for SDS micelles without Brij 30 neutral co-surfactant. The use of acridine orange as fluorescent probe permitted to determine both CMC(1) and CMC(2). Based on it an explanation on aspects of micelle formation mechanism is presented, particularly based on a spherical and a rod like structures.
Romani
Ana Paula
AP
Departamento de Química-FFCLRP, Universidade de São Paulo, Ribeirão Preto, Brazil.
Machado
Antonio Eduardo da Hora
AE
Hioka
Noboru
N
Severino
Divinomar
D
Baptista
Mauricio S
MS
Codognoto
Lúcia
L
Rodrigues
Maira R
MR
de Oliveira
Hueder Paulo Moisés
HP
D000165:Acridine Orange; D005470:Fluorometry / Q000379:methods*; D008823:Micelles; D000077423:Polidocanol; D011092:Polyethylene Glycols / Q000737:chemistry*; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry
D008823:Micelles; D013501:Surface-Active Agents; D000077423:Polidocanol; D012967:Sodium Dodecyl Sulfate; D011092:Polyethylene Glycols; D000165:Acridine Orange