NMR investigation of exchange dynamics and binding of phenol and phenolate in DODAC vesicular dispersions.
The interaction between phenol molecules, both in their undissociated and dissociated states, and cationic dioctadecyl dimethylammonium chloride (DODAC) vesicles were thoroughly investigated using NMR techniques. In particular, diffusion and relaxation measurements, combined with the two sites Kärger model, were used to evaluate the exchange dynamics and the binding of the aromatic molecules to the vesicles. The results reveal that, besides concentration and vesicle preparation method, pH conditions have the biggest impact on the phenol sorption behavior. Although the dissociated form of phenol formed at high pH is more hydrophilic, the results indicated that phenol-DODAC interactions were largely favored in basic conditions as a consequence of the strong electrostatic interaction between the phenolate anions and the cationic surfactant headgroup.
Particle and Interfacial Technology Group, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Gent, Belgium. Paolo.Sabatino@UGent.be
Paolo
P
Sabatino
Rudra Prosad
RP
Choudhury
Monika
M
Schönhoff
Paul
P
Van der Meeren
José C
JC
Martins
D002412:Cations / Q000737:chemistry; D004058:Diffusion; D006863:Hydrogen-Ion Concentration; D062385:Hydroxybenzoates / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D019800:Phenol / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013696:Temperature; D053835:Unilamellar Liposomes / Q000737:chemistry*
D002412:Cations; D062385:Hydroxybenzoates; D000644:Quaternary Ammonium Compounds; D053835:Unilamellar Liposomes; C015831:dimethyldioctadecylammonium; D019800:Phenol; C017616:phenolic acid