Influence of colloid suspensions of humic acids upon the alkaline fading of carbocations

Abstract

The influence of humic substances (HSs) upon the alkaline hydrolysis of crystal violet (CV) and malachite green (MG) has been studied. Important inhibition of hydrolysis reaction has been reported. This inhibition has been explained in terms of association of reactants to the humic substances. Kinetic results have been modelized using the micellar pseudophase model.

Application of soluble bio-organic substances (SBO) as photocatalysts for wastewater treatment: Sensitizing effect and photo-Fenton-like process

“…It is worth to be mentioned that CV has been reported to form complexes with humic substances [25]. Formation of similar CV-SBO complexes deserve to be investigated too.…”

Influence of colloid suspensions of humic acids on the alkaline hydrolysis of N‐methyl‐N‐nitroso‐p‐toluene sulfonamide

“…5 presents the values of the binding constants of MNTS [28,37,[39][40][41] and CV [42,52] for different normal micelles as a function of the chain length of the surfactant. Taking into account these ratios, and assuming that the binding constant of CV [15] for OTACl and 45 times bigger than the ratio of SDS. This means that the hydrophobicity of the HS core is significantly bigger than the corresponding one of normal micelles.…”

“…Among properties of HSs possibly influencing their catalytic activity is their ability to form micelles [13]. There are few studies in which the catalytic activity of HSs has been compared [11,12,[14][15][16][17][18][19]. At the same time the study of the catalytic activity of HSs may be very important, considering their possible role in the fate in biogeochemical cycling of elements and high concentrations of HSs in natural environments.…”

“…At the same time the study of the catalytic activity of HSs may be very important, considering their possible role in the fate in biogeochemical cycling of elements and high concentrations of HSs in natural environments. The velocity of different reactions could be influenced by the presence of HSs [11,12,[14][15][16][17][18][19]. Reactions of interest would be related to hydroxyl ion attack, much studied to evaluate micellar catalysis [20,21].…”

Alkaline Fading of Triarylmethyl Carbocations in Self-Assembly Microheterogeneous Media

“…An inhibition of the reaction has been found, which was ascribed to the micellar nature of HSs in solution, whereas there is no quantitative explanation of the observed behaviour. Recently we have studied the influence of HS aggregates upon the alkaline fading of CV and MG [205]. In this case, the kinetic effect of the presence of HSs was modelled satisfactorily using the pseudophase model.…”