Kinetics of oxidation of vanillic acid by colloidal MnO2: correlation of micellar catalysis to the micellar properties of surfactants and mixed surfactants

The Catalytic Influence of Polymers and Surfactants on the Rate Constants of Reaction of Maltose with Cerium (IV) in Acidic Aqueous Medium

“…It was reported by Perrin [15] that the employing of the normal first-order integrated equation is expected to deviate from linearity way at the final stages of the chemical reaction owing to the increase of error in evaluating the values of the absorbance with time. Our group has previously investigated some redox reactions by employing the suitable nonlinear obeying to estimate the k obs values and other kinetic parameters [16,17]. Fortunately, the curvature of the plot of the absorbance and time was found to fit to the following nonlinear equation with regression coefficients r 2 ≥ 0.9995.…”

“…e k obs value was more than threefold that in the uncatalyzed reaction, followed by a sudden decrease in the k obs at higher [CTAB] as shown in Figure 8 (average standard deviation and error are 5.77 × 10 − 6 and 3.33 × 10 − 6 , respectively). is catalytic action may be due to an increase in the reaction solution viscosity in the presence of CTAB molecules or electrostatic repulsion between the positive head group of CTAB and one of the reactive cerium (IV) ions like Ce(SO 4 ) +2 [13,16]. In the same context, plotting of log (k obs − k w /k m − k obs ) against log [D] gives a straight line, and the value of n has been determined from Figure 5S to be 0.62, indicating a negative co-operatively.…”