Abstract
In order to clarify effects of high electric charge on freezing of supercooled sodium acetate solution, 50 wt% solution was prepared as test specimen and two kinds of experiments were carried out using an electron-gun. In the first case, the electrode was dipped into the test specimen called the contact type. In the other case, the electrode was placed above the free surface of the test specimen called the non-contact type. Two types of test tubes were used as a container for the test specimen, namely, polypropylene and glass, and the degree of supercooling was varied from 10 to 30K. Voltage applied was varied from 45kV to 84kV. It was found that the supercooled sodium acetate solution solidified in a case of using polypropylene test tube whereas no solidification occurred in a case of glass test tube. The phenomenon was observed for both kinds of experiments, i.e. contact and non-contact types. The mechanism was discussed and suggested that ions are collected on the free surface of sodium acetate solution in a case of polypropylene test tube and discharged with sparks. The reason for the stable supercooling state was suggested that sodium acetate solution is ionized and sodium ion forms hydration. It causes to reduce the number of free water molecules to form hydration with sodium acetate. It is believed that solidification nuclei are generated by separating the ion hydration in aqueous solution, and it can be done by applying electric discharge with sparks. Therefore, with respect to coagulation control of sodium acetate aqueous solution in the low degree of supercooling, the high voltage applied is a very effective technique.
