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

Hassan, Mohammed; Dahadha, Adnan A.; Al-Dhoun, Mohammad; Batineh, Yazan; Mfarej, Tamara

doi:10.1007/s11144-021-02030-8

Cited by 4 publications

(2 citation statements)

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“…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.…”

Section: Kinetic Measurementsmentioning

confidence: 99%

“…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.…”

Section: Effect Of Ctabmentioning

confidence: 99%

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

Dahadha

Hassan

Mfarej

et al. 2022

Journal of Chemistry

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Kinetics of the reaction of maltose with cerium ammonium sulfate were analyzed spectrophotometrically by observing the decrease of the absorbance of cerium (IV) at 385 nm in the presence and absence of polyethylene glycols (600, 1500, and 4000) and polyvinylpyrrolidone (PVP), in addition to anionic micelles of sodium dodecyl sulfate (SDS), cationic micelles of cetyltrimethylammonium bromide (CTAB) and non-ionic micelles of Tween 20 surfactants. Generally, there is little literature about using the polymers (PEGs and PVP) as catalysts in the oxidation-reduction reactions. Therefore, the major target of this work was to investigate the influence of the nature of polymers and surfactants on the oxidation rates of maltose by cerium (IV) in acidic aqueous media, as well as employing the Piszkiewicz model to explain the catalytic effect. The kinetic runs were derived by adaptation of the pseudo first-order reaction conditions with respect to the cerium (IV). The reaction was found to be first-order with respect to the oxidant and fractional-order to maltose and H2SO4. The reaction rates were enhanced in the presence of polymer and micellar catalysis. Indeed, the surfactants were found to work perfectly close to their critical micelle concentrations (CMC). Electrostatic interaction and H-bonding appear to play an influential role in binding maltose molecules to polymer/surfactant micelles, while oxidant ions remain at the periphery of the Stern layer within the micelle.

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Section: Kinetic Measurementsmentioning

confidence: 99%

Section: Effect Of Ctabmentioning

confidence: 99%