A surfactant-free microemulsion containing diethyl malonate, ethanol, and water: Microstructure, micropolarity and solubilizations

Publication date: 25 March 2020Source: Journal of Industrial and Engineering Chemistry, Volume 83Author(s): Miaomiao Song, Wenjiao Liu, Qian Wang, Jiao Wang, Jinling ChaiAbstractThe microstructure, micropolarity and solubilizations of a surfactant-free microemulsion (SFME) containing diethyl malonate (DEM), ethanol (EtOH), and water were investigated in details. The ternary phase diagram of the SFME was constructed, and the single-phase region of the diagram was divided into oil in water (O/W), bicontinuous (B.C.), and water in oil (W/O) subregions. The dynamic light scattering (DLS) results showed that there is an orderly microstructure in each subregion of the system. The UV–vis absorbance spectra of CoCl2 indicated the formation of complete W/O SFME droplets, when the water content is relatively large. With an increase in water content, the association between Cu2+ and water molecules increases, resulting in a red shift of the UV–vis absorbance spectra of CuCl2. The solubilization of K3Fe(CN)6 in the W/O SFME was investigated, and found that the SFME has better solubilization effect on inorganic salts. Riboflavin also has a strong solubilizing effect in the W/O SFME, and the absorbance conforms to Lambert–Beer’s law. When the water content is small, the absorbance deviates from Lambert–Beer’s law. This is in agreement with the results of the solubilization of CoCl2. A complete W/O SFME could be formed when the water mass fraction (ƒW) exceeds 0.10.Graphical ab...
Source: Journal of Industrial and Engineering Chemistry - Category: Chemistry Source Type: research