CN-122006493-A - Anti-wetting Janus film and preparation method and application thereof

Abstract

The invention provides an anti-wetting Janus membrane and a preparation method and application thereof, and relates to the technical field of membrane separation. The anti-wetting Janus membrane is prepared by floating a hydrophobic microporous membrane on the surface of a dopamine solution to perform first interfacial polymerization modification to obtain a polydopamine modified porous membrane, and immersing the polydopamine modified porous membrane in a trimesic chloride solution to perform second interfacial polymerization modification. The anti-wetting Janus membrane prepared by the invention comprises a hydrophobic porous substrate and a hydrophilic layer (polyamide layer) grafted on one side surface of the hydrophobic porous substrate, and has excellent anti-pollution wettability, and example results show that the pure water flux of the anti-wetting Janus membrane is improved to a certain extent relative to that of the original membrane; when the membrane distillation is used for treating wastewater containing the surfactant, the anti-wetting Janus membrane shows good anti-wetting performance, and the flux of the membrane is not obviously lost relative to that of the original membrane.

Inventors

• XING XING
• XIE YINGYING
• ZHANG ZHONGLIANG
• LI BINBIN
• LI LONG
• WANG JING
• KOU LIDONG
• HUANG ZUOHUA
• TIAN ZHENBANG

Assignees

• 河南省科学院化学研究所
• 河南省科学院化学研究所有限公司
• 河南省科学院

Dates

Publication Date

20260512

Application Date

20241111

Claims (10)

1. 1. A method of preparing an anti-wetting Janus film comprising the steps of: floating the hydrophobic microporous membrane on the surface of the dopamine solution to perform first interfacial polymerization modification to obtain a polydopamine modified porous membrane; And immersing the polydopamine modified porous membrane in a trimesic chloride solution for second interfacial polymerization modification to obtain the anti-wetting Janus membrane.
2. 2. The method according to claim 1, wherein the hydrophobic microporous membrane is a PVDF membrane having a pore size of 0.1 to 0.4 μm.
3. 3. The method according to claim 1, wherein the dopamine solution is prepared by mixing dopamine hydrochloride, water and ammonia water.
4. 4. The method according to claim 3, wherein the concentration of dopamine hydrochloride in the dopamine solution is 0.1-2 g/L.
5. 5. The method of claim 1, 3 or 4, wherein the first interfacial polymerization modification time is 1 to 24 hours.
6. 6. The preparation method of claim 1, wherein the trimesoyl chloride solution is prepared by mixing trimesoyl chloride and an organic solvent, and the mass fraction of trimesoyl chloride in the trimesoyl chloride solution is 1-10%.
7. 7. The preparation method according to claim 1 or 6, wherein the second interfacial polymerization modification time is 5s to 30min.
8. 8. The anti-wetting Janus membrane prepared by the preparation method of any one of claims 1-7, wherein the anti-wetting Janus membrane comprises a hydrophobic porous substrate and a hydrophilic layer grafted on one side surface of the hydrophobic porous substrate, and the hydrophilic layer is a polyamide layer.
9. 9. Use of the anti-wetting Janus membrane of claim 8 in a membrane distillation treatment of surfactant containing wastewater.
10. 10. The use according to claim 9, wherein the waste water further comprises salts.

Description

Anti-wetting Janus film and preparation method and application thereof Technical Field The invention relates to the technical field of membrane separation, in particular to an anti-wetting Janus membrane and a preparation method and application thereof. Background As a novel desalting technology, the Membrane Distillation (MD) has wide application prospect in the reduction and zero emission of high-salt wastewater. However, membrane materials such as PVDF membranes, which are common in practical applications, are prone to contamination by contaminants in water, especially in the presence of low surface energy contaminants (e.g., surfactants), which tend to wet the membrane surface, resulting in a loss of desalination capability of the membrane material. Disclosure of Invention In view of the above, the invention aims to provide an anti-wetting Janus film, and a preparation method and application thereof. The anti-wetting Janus membrane prepared by the invention has excellent anti-pollution wettability, and has good anti-wetting performance when the membrane is distilled to treat wastewater containing the surfactant, and the membrane flux is not obviously lost relative to the original membrane. In order to achieve the above object, the present invention provides the following technical solutions: the invention provides a preparation method of an anti-wetting Janus film, which comprises the following steps: floating the hydrophobic microporous membrane on the surface of the dopamine solution to perform first interfacial polymerization modification to obtain a polydopamine modified porous membrane; And immersing the polydopamine modified porous membrane in a trimesic chloride solution for second interfacial polymerization modification to obtain the anti-wetting Janus membrane. Preferably, the hydrophobic microporous membrane is a PVDF membrane, and the aperture of the PVDF membrane is 0.1-0.4 mu m. Preferably, the dopamine solution is formed by mixing dopamine hydrochloride, water and ammonia water. Preferably, the concentration of the dopamine hydrochloride in the dopamine solution is 0.1-2 g/L. Preferably, the time for the first interfacial polymerization modification is 1-24 hours. Preferably, the trimesic acid chloride solution is formed by mixing trimesic acid chloride and an organic solvent, and the mass fraction of the trimesic acid chloride in the trimesic acid chloride solution is 1-10%. Preferably, the second interfacial polymerization modification time is 5 s-30 min. The invention provides an anti-wetting Janus membrane prepared by the preparation method, which comprises a hydrophobic porous substrate and a hydrophilic layer grafted on one side surface of the hydrophobic porous substrate, wherein the hydrophilic layer is a polyamide layer. The invention provides application of the anti-wetting Janus membrane in membrane distillation treatment of wastewater containing a surfactant. Preferably, the wastewater further comprises salt. The invention provides a preparation method of an anti-wetting Janus membrane, which comprises the following steps of floating a hydrophobic microporous membrane on the surface of a dopamine solution for first interfacial polymerization modification to obtain a polydopamine modified porous membrane, and immersing the polydopamine modified porous membrane in a trimesic chloride solution for second interfacial polymerization modification to obtain the anti-wetting Janus membrane. According to the invention, a polydopamine layer is grafted on the surface of a hydrophobic microporous membrane to form a strong adhesion layer on the surface of the membrane, and then a compact polyamide hydrophilic surface layer is formed through interfacial polymerization of polydopamine and trimesoyl chloride. The anti-wetting Janus membrane prepared by the invention comprises a hydrophobic porous substrate and a hydrophilic layer (polyamide layer) grafted on one side surface of the hydrophobic porous substrate, wherein the surface hydrophilic layer is a compact hydrophilic film, organic molecules cannot pass through the compact layer to contact the hydrophobic porous membrane, so that wetting of organic pollutants, especially surfactant molecules, can be prevented, meanwhile, when the membrane is distilled to treat wastewater, water permeates through the hydrophilic layer to evaporate on the lower surface of the hydrophilic layer to form water vapor, and then the water vapor passes through the hydrophobic porous membrane to realize desalination and water purification, and compared with the unmodified hydrophobic porous membrane, the distance and resistance of water vapor transmission are not increased, so that the water flux is not obviously lost. The results of the examples show that the pure water flux of the anti-wetting Janus membrane prepared by the method is improved to a certain extent compared with that of the original membrane, and the anti-wetting Janus membrane shows good anti-wetti