Modification of Cellulose Acetate Membranes with Unipolar Corona Discharge to Separate Oil–Water Emulsion

Abstract

The separation of oil–water emulsion with cellulose acetate membranes modified with a unipolar corona discharge at a voltage of 5–25 kV and time of 1–5 min was investigated. Decrease in the filter roughness after the impact of the corona discharge was determined using atomic-force microscopy. The results of X-ray diffraction analysis and of electrostatic field parameters’ measurements showed a decrease in crystallinity from 0.29 to 0.27 and the formation of positive charges on the surface of the sample, while the formation of a double electric layer according to dielectric spectrometry data was not detected. During the separation of the model oil–water emulsion, an increase in efficiency was revealed as 80 to 98% and the separation productivity from 15 to 35 dm³/(m² h) after treatment in the field of a unipolar corona discharge of cellulose acetate membranes, which is explained by a change in the supramolecular and chemical structure of the latter.