Method of preparing flexible ceramic membrane by combining manganese oxide with layer-by-layer assembly technology

A method of preparing a flexible ceramic membrane by combining manganese oxide with layer-by-layer assembly technology, characterized in that, said method comprising the steps of:

• (a) Carrying out pretreatment of an organic membrane, which comprises the steps of:
• immersing an organic membrane in anhydrous ethanol, taking out the organic membrane, rinsing a surface of the organic membrane with deionized water and then immersing in deionized water to obtain a pretreated organic membrane
• (b) preparing a preformed solution, which comprises the steps of:
• adding potassium hydroxide and potassium permanganate to deionized water, and stirring to obtain a preformed solution;
• (c) introducing polar groups on the surface of the pretreated organic membrane, which comprises the steps of:
• placing the pretreated organic membrane in the preformed solution for a period of deposition time, then rinsing with deionized water to remove the preformed solution in excess to obtain an organic membrane with polar groups;
• (d) Preparing a polycationic coating solution, which comprises the steps of:
• adding polydimethyldiallyl ammonium chloride to deionized water and stirring evenly to obtain a polycationic coating solution;
• (e) Preparing coating solution A and coating solution B, which comprises the steps of:
• (e.1) adding potassium permanganate to deionized water, stirring evenly and carrying out reaction for a period of time to obtain potassium permanganate solution, which is the coating solution A;
• (e.2) adding manganese chloride to deionized water, stirring evenly and carrying out reaction for a period of time to obtain manganese chloride solution, which is the coating solution B;
• (f) Carrying out in-situ layer-by-layer assembly, which comprises the steps of:
• (f.1) immersing the organic membrane with polar groups in the polycation coating solution, after soaking for a period of time, rinsing the organic membrane with polar groups with deionized water to remove the polycation in excess on the surface of the organic membrane with polar groups;
• (f.2) immersing the organic membrane with polar groups in the coating solution A, carrying out reaction for a period of time while positioning on a shaking table, then taking out the organic membrane with polar groups from the coating solution A and immersing in the coating solution B, carrying out reaction for a period of time while positioning on the shaking table, thereby the coating solution A and the coating solution B are fully contact, then rinsing with deionized water to remove excess manganese oxide particles on the surface of the organic membrane with polar groups;
• (g) repeating step (f) 2-6 times to obtain a modified organic membrane;
• and
• (h) drying the modified organic membrane naturally and storing in deionized water, thereby a flexible ceramic membrane prepared by in-situ generation of manganese oxide combined with layer-by-layer assembly technology is obtained.