Effects Investigation Of Pulsed Electric Field On KCl Solution Activity

Thermodynamics of electrolyte solutions is an important part of solution theory. It is widely used in many industrial and natural processes. As an important parameter of thermodynamics of electrolyte solutions, activity coefficient mainly reflects the relationship between ions and solvent molecules at different temperature or in different concentration. It is a macroscopical parameter of thermodynamics reflected microcosmic property of solution. In the mean time, activity of electrolyte solutions is also an important investigation parameter in chemical thermodynamic aspect and it is valuable in many fields such as bioengineering, ocean chemistry, environment protection and hydrometallurgy. Therefore, it is very important to investigate activity coefficient and its thermodynamic balance.At first, the basic theory of electrolyte solutions was introduced in this article, then the relative calculation model of conductivity and freezing point with activity and activity coefficient was set up on the basis of some mature theoretic model. The calculation model is likely to become the theoretic basic for the following study.Effects of pulsed electric field on activity of KCl solution were measured with two different methods including conductivity and freezing point depression. It was concluded that both conductivity and freezing point can be changed by pulsed electric field. These changes were relative with solution concentration, pulsed time and parameters such as voltage and frequency. It was showed that the lower concentration, longer pulsed time, larger pulsed voltage, the stronger effects of pulsed electric field on activity of KCl solution.The changes of macro-property such as activity and activity coefficient, which are determined by microcosmic structure, and stand for solution micro-structure. It was thought that the activity and activity coefficient were changed because of the change of ion structure and the increase of effective ion concentration during pulsed electric field. At thesame time, the conductivity was improved as the result of increase in effective ion concentration. The pulsed electric field speed up the growth of coagulate nucleus, consequently increased the freezing point of solutions.