Submicellar catalytic effect of cetyltrimethylammonium bromide in the oxidation of ethylenediaminetetraacetic acid by MnO4-.
The effects of cetyltrimethylammonium bromide (CTAB), sodiumdodecyl sulphate (SDS) and Triton X-100 (TX-100) on the oxidative degradation of ethylenediaminetetraacetic acid (EDTA) by MnO4(-) have been studied spectrophotometrically at 525 and 420 nm, respectively. It was found that cationic surfactant catalyse the reaction rate while anionic and non-ionic have no effect. The premicellar environment of CTAB strongly catalyses the reaction rate which may be due to the favorable electrostatic binding of both reactants (MnO4(-) and EDTA) with the positive head groups of the CTAB aggregates. The influence of different parameters such as [MnO4(-)], [EDTA], [H(+)] and [surfactants] were also considered. The reaction follows the first- and fractional-order kinetics with respect to [MnO4(-)] and [EDTA]. The proposed mechanism and the derived rate law are consistent with the observed kinetics.
Malik
Maqsood Ahmad
MA
Department of Chemistry, Jamia Millia Islamia Central University, Jamia Nagar, New Delhi 110025, India.
Khan
Zaheer
Z
D002384:Catalysis; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000494:pharmacology*; D004492:Edetic Acid / Q000378:metabolism*; D007700:Kinetics; D017895:Manganese Compounds / Q000494:pharmacology*; D008823:Micelles; D010084:Oxidation-Reduction / Q000187:drug effects; D010087:Oxides / Q000494:pharmacology*; D012967:Sodium Dodecyl Sulfate
D002593:Cetrimonium Compounds; D017895:Manganese Compounds; D008823:Micelles; D010087:Oxides; C048856:permanganic acid; D012967:Sodium Dodecyl Sulfate; D004492:Edetic Acid; D000077286:Cetrimonium