Patent ID: 11925905
Assignee: BEIJING BAOSHENGTONG INTERNATIONAL ELECTRIC ENGINEERING TECHNOLOGY CO., LTD.
Field: Chemical engineering (Chemistry)
Classification: CPC B  Y | IPC B

Claim 11:
12. The method of preparing for a forward osmosis membrane of claim 11, wherein in the step (b), a mixing condition is to stir mixtures under a temperature of 30-50° C. for 12-48 hours to make the mixtures evenly mixed;
the defoaming method is to keep standing in air for 12-36 hours to achieve fully defoaming or through an assistance of a ultrasonic to defoam; the condition of standing in air is under an environment not be higher than 25° C. temperature and not be lower than 90% humidity, the standing time is from 30 seconds to 90 seconds to form the dense skin layer;
in the step (f), before soaking the membrane into the deionized water, heat treating the membrane into a water bath at 40-50° C. water for 5-20 minutes; the soaking time in the deionized water is 12-36 hours to remove the residuals of the organic solvents;
in the step (g), the concentration of the sodium metabisulfite solution is between 0.5-2% by volume.