Chemiluminescence For The Interface Mass Transfer Preliminary Study

Liquid/liquid interface is a physical interface formed by two liquids that can't be dissolved by each other, which is usually called oil-water interface. Due to the fact that it is very thin about several molecular diameters, the interface is hard to be determined exactly, so the features of the real interface is less likely to get with existing methods. By using chemical reactions at the interface with the relationship between the relative chemiluminescence intensity and interfacial features and concentration of substance at the interface, the thesis plans to employ a new method to probe interfacial properties by chemiluminescence, and also to explore the impact of surfactants and organic phase at interface.This thesis consists of two parts:literature review and research report. In literature review, liquid/liquid interface, interfacial mass transfer and research methods of interfacial mass transfer will be mentioned, and the research purpose and significance of this thesis will also be introduced. The research section contains two sections, as follows:1. Study on mass transfer at interface with a chemiluminescence analysis method H₂O₂ in aqueous is excessively more than TCPO in organic phase, and they react at the two-phase interface, producing chemiluminescence signals. Based on the relationship between the relative chemiluminescence intensity and the concentration of TCPO at the interface(I_CL= KC A), the concentration of TCPO can be got by the chemiluminescence curve. In addition, the effects of the TCPO concentration on mass transfer at interface are explored, and the results indicates that the relative chemiluminescence intensity is two times more when the concentration of TCPO is two times at the same time after sampling. According to the relationship between chemiluminescent signals and interfacial diffusion coefficient (I_CL= K(?)DA),showing that the increasing of substance concentration could change the properties of the interface, reduce the interfacial energy, and increase the mass transfer coefficient at the interface.2. Effect of surfactants on mass transfer at the interfaceThe type and concentration of surfactant affect the interfacial mass transfer of the substance. When different surfactant is added, interfacial properties is different, and mass transfer at the interface is different, too. When the concentration of surfactant is changed, the concentration of the substance at the interface could get a certain lowest point and then increase, but the lowest point is not the critical micelle concentration of surfactant. It can be concluded that the turning point is a point like the critical micelle concentration (CMC) when the concentration of surfactant at the interface gets saturation at first and then the surfactants form micelle which can change the interface properties and promote mass transfer. When the solvent of organic phase is changed, interfacial diffusion coefficient and mass transfer at the interface are changed, too.Main conclusions in this thesis include:For chemical reactions at the interface, the thesis establishes a new method to probe interfacial properties by chemiluminescence, with the relationship between the relative chemiluminescence intensity and interfacial feature and concentration of substance at the interface. Compared with the existing methods, this method reflects the mass transfer at or close to the real interface. Furthermore, the thesis explores the impact of substance concentration change, different surfactants and organic phase on interface.