An investigation of kinetic and physicochemical properties of vesicular surfactants with oximate and hydroxamate ions: Hydrolytic reactions of organophosphorus pesticides

作者：Kandpal Neha; Dewangan Hitesh K; Nagwanshi Rekha; Ghosh Kallol K; Satnami Manmohan L

来源：Journal of Molecular Liquids, 2017, 243: 178-186.

DOI：10.1016/j.molliq.2017.08.015

• Vesicular surfactants
• Pesticides
• Kinetic parameters
• Oximate and hydroxamate ions

Rate constants have been determined spectrophotometrically for the reaction of paraoxon, parathion and fenitrothion (OP pesticides) with oximate (Ox(-)) and hydroxamate (HA(-)) ions in aqueous and cationic vesicular media at 300K. All reactions followed the pseudo-first-order kinetics. The surface properties i.e. the critical vesicle concentration (cvc), maximum surface access (Gamma(max)), surface pressure at the cvc (Pi(CVC)) and minimum surface area per molecule (A(min)) of vesicular surfactants dioctadecyldimethylammonium chloride (DODAC) and didodecyldimethylammonium bromide (DDAB) with Ox(-) and HA(-) ions have been evaluated by conductivity and surface tension measurements at 300 K. The standard Gibbs free energy of vesicle formation (Delta(0)(G)(V)), Standard Gibbs free energy of adsorption (Delta G(ad)(0)), and standard Gibbs free energy of vesicle formation per alkyl chain (Delta G(V)(0), (tail)) of cationic vesicular surfactants with Ox(-) and HA(-) ions have also been evaluated. SEM (Scanning Electron Microscope) and TEM (Transmission Electron Microscope) were used to investigate the morphological behavior and size of vesicular surfactants. We observed a well-defined contour of vesicular surfactants that are mostly spherical and globular shape. The effects of vesicular morphology and chemical reactivity have been discussed.

• 出版日期2017-10