The Dielectric Property Measurement Of Electrolyte Solution Under Microwave Irradiation And The Influence Analysis Of Metal Impurities On Measurement Accuracy

The applications of microwave in chemistry almost extend to every aspect of the chemical research. The dielectric property showed in the interaction between microwave and chemical reactions becomes a key point for scientists, and the existence of metal impurities may influence the measurement accuracy in microwave measurement. In this paper, we studied the dielectric property of electrolyte solution under microwave action and analyzed the influence of metal impurities existing in the microwave measurement conditions on the measurement accuracy. It is helpful for understanding the microwave chemistry,studying the dielectric property of electrolyte solution and improving measurement accuracy.The main contents and innovation points of this thesis are as follows:Firstly, an experiment is designed in order to study the dielectric property of electrolyte solution under microwave action. In this paper, we measured the complex permittivity of three kinds of electrolyte solution, studying the dielectric property of electrolyte solution through the measure result. The measured results showed that the real part of the complex permittivity of the solution change very little under microwave action and the imaginary part was greatly influenced by the input power under microwave action with temperature which is constant, showing an ascending trend. Because microwave can heat the solution, we analyze the influence of temperature on the measure result. The analysis result showed that the factor of temperature can be excluded. Secondly, the existence of metal impurities will influence the measurement accuracy. In order to analyze the influence, we used FEM and capacitance model to compute the complex permittivity while the solution has metal impurity and compared it with the theoretical values without metal impurity. Because the shape of metal impurities is sphere,cube and cone, We analyze the influence of different shapes,different locations and different quantities of metal impurities on the measurement of complex permittivity of NaCl solution. The computation result showed, (1) the influence of different shape metal impurities in microwave measurement on measurement accuracy are very resemble; (2) metal impurities influence on the real part of the complex permittivity of the solution very little, and on the imaginary part very much; (3) the influence of metal impurities located the side face and the outer conductor face of the ended-port face influence on the measure result is very little; (4) metal impurities located the inner-conductor face and the dielectric surface of the ended-port of the measure probe influence on the measure result is very much. It is draw a conclusion that the influence of metal impurities on the measurement accuracy has mainly related with the location and the quantity of metal impurity.