TY - JOUR
T1 - Reactivity of a lipophilic ingredient solubilized in anionic or cationic surfactant micelles
AU - Berton-Carabin, Claire C.
AU - Coupland, John N.
AU - Qian, Cheng
AU - McClements, D. Julian
AU - Elias, Ryan J.
N1 - Funding Information:
This work was supported by a grant by the USDA-AFRI program (award number 2009-65503-05960 , program code 93430).
PY - 2012/10/20
Y1 - 2012/10/20
N2 - The aim of this work was to investigate the location and reactivity of a lipophilic spin probe, 4-phenyl-2,2,5,5-tetramethyl-3-imidazoline-1-oxyl nitroxide (PTMIO) in anionic (sodium dodecyl sulfate, SDS) or cationic (dodecyl trimethylammonium bromide, DTAB) surfactant micelles. The analysis of electron paramagnetic resonance (EPR) spectra of PTMIO in micellar systems showed that probe molecules partitioned between two populations: a more mobile fraction in the aqueous phase and a less mobile fraction in the micelle. The fraction of PTMIO incorporated in surfactant micelles increased with surfactant concentration. The rate of the reduction of the nitroxide group of PTMIO by the negatively charged, water-soluble ascorbate decreased when the probe was solubilized in anionic SDS micelles and increased when it was solubilized in cationic DTAB micelles. Thus, both the surface charge as well as the solubilization capacity of the micelles controlled the reactivity of the lipophilic molecule.
AB - The aim of this work was to investigate the location and reactivity of a lipophilic spin probe, 4-phenyl-2,2,5,5-tetramethyl-3-imidazoline-1-oxyl nitroxide (PTMIO) in anionic (sodium dodecyl sulfate, SDS) or cationic (dodecyl trimethylammonium bromide, DTAB) surfactant micelles. The analysis of electron paramagnetic resonance (EPR) spectra of PTMIO in micellar systems showed that probe molecules partitioned between two populations: a more mobile fraction in the aqueous phase and a less mobile fraction in the micelle. The fraction of PTMIO incorporated in surfactant micelles increased with surfactant concentration. The rate of the reduction of the nitroxide group of PTMIO by the negatively charged, water-soluble ascorbate decreased when the probe was solubilized in anionic SDS micelles and increased when it was solubilized in cationic DTAB micelles. Thus, both the surface charge as well as the solubilization capacity of the micelles controlled the reactivity of the lipophilic molecule.
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U2 - 10.1016/j.colsurfa.2012.07.029
DO - 10.1016/j.colsurfa.2012.07.029
M3 - Article
AN - SCOPUS:84865866354
SN - 0927-7757
VL - 412
SP - 135
EP - 142
JO - Colloids and Surfaces A: Physicochemical and Engineering Aspects
JF - Colloids and Surfaces A: Physicochemical and Engineering Aspects
ER -