Oxidation process at the surface of water

Abstract

Experiments on alkylcarboxylic acids were carded out to study the oxidative decomposition of surfactants at the water/air surface and to determine the oxidation conditions necessary for this. It has been found that at temperatures above ( T Jo + 20°C)—the experiments were carried out on myristic acid at 40°C—oxidation products such as dicarboxylic acids (e.g., maleic acid, succinic acid) are formed if 100 Å 2/molecule or a larger surface area is available to the alkylcarboxylic acid. If the oxidation of the alkylcarboxylic acid proceeds with a surface area of 30 Å 2/molecule or less being available, the presence of the dicarboxylic acids can no longer be detected—possibly because of a change in the alkyl chain arrangement. With such compacted films, oxidation takes place only at the methylene groups neighboring the carboxyl group. It is similar to the oxidation with H 2O 2 according to Dakin and it differs fundamentally from the oxidation with potassium permanganate. The oxidation products are shaved off the surface of the water in the Langmuir trough, concentrated and examined by chromatography (TLC and PC). The oxidation of the myristic acid on the water surface at 40°C takes place catalytically via an intermediate formation of hydration complexes. Its course shows a correlation with the alkylcarboxylic acid metabolism.