An experimental study is carried out to clarify the effect of the electric field on freezing initiation of supercooled water in a soft PVC (polyvinyl chloride) tube. It is selected for the reason that the hydrophobe of PVC is thought to maintain the supercooled state of water easily, in condition that the electric field is not applied. As water and silicone oil is filled in the tube, a triple-phase boundary is formed inside the tube. The electric field is applied from the outside of the tube by use of a pair of wire electrodes, which is set up in parallel to the axis of the tube. The experimental condition is -5℃ in temperature and 35kV DC in voltage. As a result, the PVC tube is, to some degree, effective to keep supercooled state of water steady. The electric field causes large amplitude oscillation of the triple-boundary in the tube. Application of the DC electric field is effective to initiate freezing of supercooled water, even if the water is filled in PVC tube of low wettability to water. Relative frequency of freezing initiation obtained is 1.0, and all samples began freezing within 10 seconds after the electric field had been applied.
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