| 摘要 |
PURPOSE:To obtain a porous film suitable as a precise filter medium, by forming either one of positive and negative electrodes from a liquid containing ultrafine particles therein, placing a high polymer film therebetween and applying a high voltage across the positive and negative electrodes. CONSTITUTION:Either one of positive electrodes (6a) and (6b) or negative electrode 12 is formed from a liquid 3 containing ultrafine particles 2 therein and a high polymer film 13 is placed between the electrodes so as to be in contact with the above-mentioned liquid electrode. A high voltage is then applied across the positive and negative electrodes to form many small holes 16 in the high polymer film 13 and afford the aimed porous film. The electric conductivity of the above-mentioned fine particles 2 is preferably higher than that of the liquid. |
