Kinetics of oxidation of aspirin by Ce(IV) in surfactant, polymer, and mixed surfactant-polymer media

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

“…e influence of PVP on the reaction rate has been presented by the catalytic profile in Figure 6, where the k obs have been plotted versus [polymer]. e impact of the existence of PVP on the rate of reactions is similar to that detected in our previous study [13]. But here, the rate increased linearly with [PVP].…”

“…Increasing the [SDS] is attached by a progressive increase in values of k obs , to reach a maximum, then drop slightly and end up with an almost steady plateaued curve (average standard deviation and error are 1.73 × 10 − 5 and 1.00 × 10 − 5 , respectively). e maximum k obs have emerged at 6.25 × 10 − 3 mol dm − 3 [SDS], which is slightly below the CMC of SDS (8.0 × 10 − 3 mol dm − 3 ) [13,25]. e higher value of k obs was more than double that in the uncatalyzed redox reaction.…”

“…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.…”

“…Whilst, Dahadha et al have employed PEG 4000, PVP, and mixed PEG4000-SDS systems as powerful catalysts in the redox reaction of aspirin under acidic reaction conditions. PEG 4000 and PVD, were found to increase the rate of the reaction and their kinetic catalytic data were successfully analyzed by the Benesi-Hildebrand model [13]. Also, our group studied and explained the catalytic influence of the mixed systems of polyethylene glycol 600, 1500, and 4000 with SDS on the reduction of Ce (IV) via o-Cresol, especially at the critical micelle concentration point of SDS [14].…”

Waugh Type Polyoxometalate Enneamolybdomangate(IV) as an Acid Catalyst for Hydrolysis and as an Oxidant for Aspirin: A Kinetic Study

“…Advanced oxidation [1] as well as electrochemical oxidation [2][3][4] have been proposed to degrade the unmetabolized aspirin in order to clean the biological effluents. Mechanism of reactions of aspirin with various oxidants in both alkaline [5][6][7][8][9] and acidic [10][11][12][13][14] medium have also been studied to understand the probable pathway of generation of the end products. Aspirin undergo hydrolysis [15,16] through uncatalyzed and acid as well as alkali catalyzed mechanism leading to the formation of salicylic acid.…”