Alkaline Hydrolysis of Methyl Decanoate in Surfactant-Based Systems

Abstract

Surfactant-modified reaction systems are one approach to perform organic reactions with water as the solvent involving hydrophobic reactants. Herein, the alkaline hydrolysis of the long-chain methyl decanoate in cationic and nonionic surfactant-modified systems is reported. The physicochemical behavior of the reaction mixture and the performance of the alkaline hydrolysis were systematically investigated. In water as the solvent, the reaction is slow, but at elevated temperatures, the alkaline hydrolysis of methyl decanoate is accelerated because the reaction product sodium decanoate acts as an ionic surfactant, leading to an increased solubility of methyl decanoate in the aqueous phase. The rate can be significantly increased by the addition of surfactants as solubilizers. In nonionic TX-100 solutions, the reaction rate can be increased by a factor of about 100 for a surfactant concentration of 5 wt %. If cationic surfactants are applied, the reaction rate can be further increased due to the electrostatic interaction between the hydroxide ions in solution and the charged head groups of the cationic micelles.

Hydrogenation of Itaconic Acid in Micellar Solutions: Catalyst Recycling with Cloud Point Extraction?

“…Although only NP8 as the nonionic surfactant will be appropriate for catalyst recycling via cloud point extraction, this study was to emphasize that surfactant selection is crucial for the catalytic reaction and that the reaction can be done with good performance in NP8 solutions. Parameters related to the surfactant itself, for example, surfactant structure, critical micelle concentration (CMC), solubilization capacity, size of the micelles, etc., may have an influence on the catalytic performance, which is already discussed in plenty of other investigations. − The impact of the NP8 concentration is shown in Figure . The applied surfactant concentrations are far from the CMC for NP8 to ensure high volume fractions of the catalyst-containing surfactant-rich phase, facilitating the catalyst recycling.…”

Interplay of Polarity and Confinement in Asymmetric Catalysis with Chiral Rh Diene Complexes in Microemulsions

“…However, the two types of reaction media differ on the one hand in the local concentration of the reactants and on the other hand in the environment in which the catalyst complex is located [14,15] . While in micellar reaction media the concentration of reactants is strongly limited by their solubility in the micellar core, the nanoscale solvent domains in microemulsions allow the reactant concentration to be adjusted over a wide concentration range.…”

“…However, the two types of reaction media differ on the one hand in the local concentration of the reactants and on the other hand in the environment in which the catalyst complex is located. [ 14 , 15 ] While in micellar reaction media the concentration of reactants is strongly limited by their solubility in the micellar core, the nanoscale solvent domains in microemulsions allow the reactant concentration to be adjusted over a wide concentration range. Assuming a slightly amphiphilic catalyst complex, the catalyst is localized in the surfactant film, where the hydrophobic part of the catalyst in the micellar system interacts only with the hydrophobic alkyl chains, while due to the penetration of solvent molecules into the surfactant film in microemulsions the catalyst environment and therewith the interaction is significantly different.…”

Kinetics of fluoride-catalysed synthesis of organosilica colloids in aqueous solutions of amphiphiles

“…However, for a hydrophobic substance to be effectively reacting "in water" without organic solvents, surfactants or amphiphiles are required to solubilize or concentrate the reactant in self-assembled micellar phases, where reaction takes place. [1][2][3] Indeed, the rate of chemical reactions can be markedly accelerated in such microreactors or nanoreactors. [4][5][6] In the past decade, aqueous micellar catalysis has been successfully applied for catalysing a wide range of organic reactions.…”