阅读说明：本技术 一种新型纳米原子级海水淡化薄膜及其制备方法与应用 (Novel nanometer atomic-level seawater desalination film and preparation method and application thereof ) 是由 宋维广 朱丽静 曾志翔 王刚 宋明海 于 2018-06-04 设计创作，主要内容包括：本发明公开了一种新型纳米原子级海水淡化薄膜及其制备方法与应用。所述的制备方法包括：提供基底,采用化学气相沉积法在所述基底表面生长纳米原子级的石墨烯薄膜；以及,使水溶性单体与非水溶性单体于石墨烯薄膜表面发生界面聚合反应,以填补石墨烯薄膜中的裂缝和缺陷,获得新型纳米原子级海水淡化薄膜。本方法通过气相沉积方法制备纳米原子级碳膜,并通过利用界面聚合技术,封闭填补石墨烯中的较大裂缝和缺陷,具有高的选择性和通量,可实现基于浓度梯度膜分离领域的直接应用,在海水淡化领域具有广阔的应用前景。(The invention discloses a novel nanometer atomic-level seawater desalination film and a preparation method and application thereof. The preparation method comprises the following steps: providing a substrate, and growing a nano atomic-scale graphene film on the surface of the substrate by adopting a chemical vapor deposition method; and enabling the water-soluble monomer and the water-insoluble monomer to generate an interfacial polymerization reaction on the surface of the graphene film so as to fill up cracks and defects in the graphene film and obtain the novel nano atomic-scale seawater desalination film. The method prepares the nanometer atomic-scale carbon film by a vapor deposition method, seals and fills large cracks and defects in graphene by utilizing an interfacial polymerization technology, has high selectivity and flux, can realize direct application in the field of membrane separation based on concentration gradient, and has wide application prospect in the field of seawater desalination.)

1. A preparation method of a novel nanometer atomic-scale seawater desalination film is characterized by comprising the following steps:

Providing a substrate, and growing a nano atomic-scale graphene film on the surface of the substrate by adopting a chemical vapor deposition method;

And enabling the water-soluble monomer and the water-insoluble monomer to generate an interfacial polymerization reaction on the surface of the graphene film so as to fill up cracks and defects in the graphene film and obtain the novel nano atomic-scale seawater desalination film.

2. The method according to claim 1, comprising: reacting a gas carbon source on the surface of the substrate for 0.5-3 h at 800-1300 ℃ under the action of reducing gas, and growing to form the graphene film; preferably, the thickness of the graphene film is 0.2-2 nm.

3. The method of claim 2, wherein: the gas carbon source comprises any one or the combination of more than two of methane, ethylene, acetylene, ethanol and poly-benzene ring; preferably, the concentration of the gas carbon source is 10-100 sccm; and/or, the reducing gas comprises hydrogen; preferably, the concentration of the reducing gas is 1-5 sccm; and/or, the substrate comprises a copper sheet; preferably, the thickness of the substrate is 5-40 μm.

4. The method of claim 1, further comprising: transferring the graphene film from a substrate to a polycarbonate substrate to obtain a graphene-polycarbonate film; preferably, the aperture of the polycarbonate substrate is 10-200 μm; preferably, the preparation method further comprises: placing the polycarbonate substrate in an ethanol solution containing didecylamine, stirring for 0.5-4 h, then cleaning, and drying; particularly preferably, the concentration of the didecylamine is 20-100 mmol/L.

5. The preparation method according to claim 4, characterized by specifically comprising: and placing the graphene-polycarbonate film in an electrolytic cell, respectively placing a water phase containing a water-soluble monomer and an oil phase containing a water-insoluble monomer at two ends of the electrolytic cell, and electrifying to enable the water-soluble monomer and the water-insoluble monomer to generate interfacial polymerization reaction on the surface of the graphene film.

6. The production method according to claim 1 or 5, characterized in that: the water-soluble monomer comprises any one or the combination of more than two of hexamethyl ethylenediamine, diethylenetriamine, triethylene tetramine and tetraethylene pentamine; and/or; the water-insoluble monomer comprises one or the combination of more than two of trimesoyl chloride, isophthaloyl dichloride and oxalyl dichloride.

7. The method of claim 6, wherein: the concentration of the water-soluble monomer in the water phase is 1-20 mg/ml; and/or the concentration of the water-insoluble monomer in the oil phase is 2-30 mg/ml; preferably, the solvent used in the oil phase comprises n-hexane.

8. The production method according to claim 1 or 5, characterized in that: the temperature of the interfacial polymerization reaction is 25-60 ℃, and the time is 0.2-3 h.

9. A novel nanoatomic scale desalination membrane made by the process of any one of claims 1-8; preferably, the novel nano atomic-scale seawater desalination film comprises: the structure comprises a polycarbonate substrate serving as a substrate and a graphene film combined with the polycarbonate substrate, wherein cracks and defects of the graphene film are filled by an interfacial polymerization reaction product of a water-soluble monomer and a water-insoluble monomer;

Preferably, the thickness of the novel nanometer atomic-level seawater desalination film is 0.2-2 nm;

preferably, when 2mol/L sodium chloride solution is used as an extraction solution, the water flux of the novel nano atomic-scale seawater desalination membrane is 9.2-14.1 L.m ^-2 h ^-1, and the sodium chloride rejection rate is 77-89%.

10. Use of the novel nano atomic-scale seawater desalination membrane of claim 9 in the field of seawater desalination.

Technical Field

The invention belongs to the technical field of membrane separation, and particularly relates to a novel nanometer atomic-scale seawater desalination membrane as well as a preparation method and application thereof.

Background

Of the total water in the world, ocean and salt lake water account for about 97%, and land water only accounts for 3%. In addition to the shortage of water resources, the discharge amount of industrial sewage is rapidly increased with the development of industrial technology, and the resulting harm has become a serious social crisis. In order to solve the increasingly serious crisis of fresh water, seawater desalination draws wide attention of society. The countermeasure aiming at the crisis of fresh water resources and the sustainable utilization of water resources mainly adopts the desalination measures of seawater and brackish water, and fresh water is needed for inexhaustible sea; a large amount of domestic sewage and industrial wastewater are treated and recycled, the regulation and control of natural circulation of water are enhanced, and the utilization rate of water resources is increased.

Sea water desalination, also known as sea water desalination, is a process of removing salt from sea water by a device and obtaining fresh water. Methods for desalinating seawater can be divided into distillation methods and membrane methods. The traditional distillation method for seawater desalination mainly comprises the following steps: multi-stage flash evaporation (MSF), low-temperature multi-effect (LT-MED) and vapor compression distillation (MVC). The first two technologies adopt steam as a steam source, and are mostly combined with a power plant to extract dead steam of a turbine to prepare distilled water. The vapor compression distillation technology is a heat pump evaporation technology which only uses electric energy. However, the distillation desalination technology has high energy consumption and cost, and the current common method is a membrane separation technology. The membrane method mainly refers to an osmosis technology, which utilizes a semipermeable membrane to allow water to permeate under pressure so as to intercept salt and impurities, and has the advantages of relatively high capacity and low price.

Carbon materials have become a focus of research in a number of current fields of science due to their special inductance, good mechanical properties and chemical aspects etc. The carbon film prepared by the carbon material has higher flux, better pollution resistance and better ion recognition function, so the carbon film is widely applied to the fields of ion separation and water treatment. However, the carbon film has poor selectivity and poor barrier property to sodium chloride, and sodium salt can quickly permeate the carbon film, so that the application of the sodium salt in seawater desalination is limited. Therefore, how to prepare a carbon membrane capable of effectively separating sodium ions remains a problem.

disclosure of Invention

The invention aims to provide a novel nanometer atomic-level seawater desalination film, and a preparation method and application thereof, so as to overcome the defect that the carbon material in the prior art has poor separation property on sodium ions.

In order to achieve the purpose, the technical scheme adopted by the invention comprises the following steps:

The embodiment of the invention provides a preparation method of a novel nanometer atomic-scale seawater desalination film, which comprises the following steps:

providing a substrate, and growing a nano atomic-scale graphene film on the surface of the substrate by adopting a chemical vapor deposition method;

And enabling the water-soluble monomer and the water-insoluble monomer to generate an interfacial polymerization reaction on the surface of the graphene film so as to fill up cracks and defects in the graphene film and obtain the novel nano atomic-scale seawater desalination film.

In some preferred embodiments of the present invention, the preparation method specifically comprises: and reacting a gas carbon source on the surface of the substrate for 0.5-3 h at 800-1300 ℃ under the action of reducing gas to grow and form the graphene film.

In some preferred embodiments of the present invention, the preparation method further comprises: and transferring the graphene film from the substrate to a polycarbonate substrate to obtain the graphene-polycarbonate film.

In some preferred embodiments of the present invention, the preparation method specifically comprises: and placing the graphene-polycarbonate film in an electrolytic cell, respectively placing a water phase containing a water-soluble monomer and an oil phase containing a water-insoluble monomer at two ends of the electrolytic cell, and electrifying to enable the water-soluble monomer and the water-insoluble monomer to generate interfacial polymerization reaction on the surface of the graphene film.

The embodiment of the invention also provides a novel nanometer atomic-scale seawater desalination film prepared by the method.

Preferably, the novel nano atomic-scale seawater desalination film comprises: the graphene film comprises a polycarbonate substrate serving as a substrate and a graphene film combined with the polycarbonate substrate, wherein cracks and defects of the graphene film are filled by an interfacial polymerization reaction product of a water-soluble monomer and a water-insoluble monomer.

The embodiment of the invention also provides application of the novel nanometer atomic-scale seawater desalination film in the field of seawater desalination.

compared with the prior art, the invention has the beneficial effects that:

(1) The preparation method of the novel nanometer atomic-level seawater desalination film provided by the invention utilizes the cracking of a gaseous carbon source at a high temperature to generate carbon atoms which are adsorbed on the surface of a copper sheet so as to form nuclei and grow and combine to obtain the graphene film;

(2) According to the invention, the graphene film is peeled off to the polycarbonate substrate by pressing, and the integrity of the film is improved by filling large cracks and defects in graphene through an interface polymerization method, so that a complete graphene permeable film is formed, and the film has high selectivity and flux and can improve the interception effect;

(3) The graphene film prepared by the invention has excellent selective mass transfer characteristics, can realize direct application in the field of membrane separation based on concentration gradient, and has wide application prospect in the field of seawater desalination.

Detailed Description

In view of the problem of poor separation of carbon materials from sodium ions in the prior art, the inventors of the present invention have made long-term research and extensive practice to provide a technical solution of the present invention, which is mainly to deposit a graphene film on a copper foil by a chemical vapor deposition method, then transfer the graphene film onto a polycarbonate substrate, and seal and fill large cracks and defects in graphene by an interfacial polymerization method to improve the integrity of the film, thereby improving the interception effect. The technical solution, its implementation and principles, etc. will be further explained as follows.

as one aspect of the technical scheme of the invention, the related preparation method of the novel nanometer atomic-scale seawater desalination film comprises the following steps:

Providing a substrate, and growing a nano atomic-scale graphene film on the surface of the substrate by adopting a chemical vapor deposition method;

And enabling the water-soluble monomer and the water-insoluble monomer to generate an interfacial polymerization reaction on the surface of the graphene film so as to fill up cracks and defects in the graphene film and obtain the novel nano atomic-scale seawater desalination film.

In some preferred embodiments of the present invention, the preparation method specifically comprises: and reacting a gas carbon source on the surface of the substrate for 0.5-3 h at 800-1300 ℃ under the action of reducing gas to grow the graphene film, wherein the thickness of the graphene film is 0.2-2 nm.

Further, the gaseous carbon source includes any one or a combination of two or more of methane, ethylene, acetylene, ethanol, and a poly-benzene ring, etc., but is not limited thereto.

Further, the concentration of the gaseous carbon source is 10-100 sccm.

Further, the reducing gas includes hydrogen.

Further, the concentration of the reducing gas is 1-5 sccm.

Further, the substrate includes a copper sheet, but is not limited thereto.

Further, the thickness of the substrate is 5-40 μm.

In some preferred embodiments of the present invention, the preparation method further comprises: and transferring the graphene film from a base to a Polycarbonate (PCTE) substrate to obtain a graphene-polycarbonate film (graphene-PCTE film).

Further, the pore diameter of the polycarbonate substrate is 10 to 200 μm.

Further, the preparation method further comprises the following steps: and (3) placing the polycarbonate substrate in an ethanol solution containing didecylamine, stirring for 0.5-4 h, cleaning and drying.

Particularly, the concentration of the didecylamine is 20-100 mmol/L.

In some preferred embodiments of the present invention, the preparation method specifically comprises: and placing the graphene-polycarbonate film in an electrolytic cell, respectively placing a water phase containing a water-soluble monomer and an oil phase containing a water-insoluble monomer at two ends of the electrolytic cell, and electrifying to enable the water-soluble monomer and the water-insoluble monomer to generate interfacial polymerization reaction on the surface of the graphene film.

Further, the water-soluble monomer includes any one or a combination of two or more of hexamethyl ethylenediamine, diethylenetriamine, triethylene tetramine, tetraethylene pentamine, and the like, but is not limited thereto.

Further, the water-insoluble monomer includes any one or a combination of two or more of trimesoyl chloride, isophthaloyl chloride, oxalyl chloride, and the like, but is not limited thereto.

Further, the concentration of the water-soluble monomer in the water phase is 1-20 mg/ml.

Further, the concentration of the water-insoluble monomer in the oil phase is 2-30 mg/ml.

Further, the solvent adopted by the oil phase comprises n-hexane solution.

In some preferred embodiments of the present invention, the interfacial polymerization reaction is carried out at a temperature of 25 to 60 ℃ for 0.2 to 3 hours.

Wherein, as a more specific embodiment, the preparation method may comprise the steps of:

Step 1) putting a copper sheet with the thickness of 5-40 micrometers into a quartz tube, introducing hydrogen into the quartz tube, heating to 1000 ℃, introducing a gas carbon source, reacting for 0.5-3 h, growing a graphene film on the surface of the copper sheet, and cooling the tube furnace to room temperature.

And 2) adopting Polycarbonate (PCTE) with a certain aperture as a substrate, placing the substrate in an ethanol solution containing didecylamine, stirring for 0.5-4 h, repeatedly washing for 5 times by using ethanol, and drying at room temperature. And (2) placing a copper foil on a Polycarbonate (PCTE) substrate, pressing a glass sheet on the copper foil, pressing the glass sheet for 1-5 min by using a finger, stripping the graphene from the copper foil onto the polycarbonate substrate, and taking down the copper foil to obtain the graphene-PCTE film.

And 3) clamping the graphene-PCTE film in the middle of an electrolytic cell, reacting for a period of time with a water phase containing a water-soluble monomer on one side and an oil phase containing a water-insoluble monomer on the other side, taking out the graphene-PCTE film, respectively cleaning for 3 times by using n-hexane and ethanol, and then air-drying to obtain the novel nano atomic-scale seawater desalination film.

As another aspect of the technical scheme of the invention, the invention also relates to a novel nanometer atomic-scale seawater desalination film prepared by the method.

Preferably, the novel nano atomic-scale seawater desalination film mainly comprises: the graphene film comprises a polycarbonate substrate serving as a substrate and a graphene film combined with the polycarbonate substrate, wherein cracks and defects of the graphene film are filled by an interfacial polymerization reaction product of a water-soluble monomer and a water-insoluble monomer.

Preferably, the thickness of the novel nanometer atomic-level seawater desalination film is 0.2-2 nm.

Preferably, when 2mol/L sodium chloride solution is used as an extraction solution, the water flux of the novel nano atomic-scale seawater desalination membrane is 9.2-14.1 L.m ^-2 h ^-1, and the sodium chloride rejection rate is 77-89%.

the embodiment of the invention also provides application of the novel nanometer atomic-scale seawater desalination film in the field of seawater desalination.

By the preparation process, the method prepares the nano atomic carbon film by a vapor deposition method, closes and fills large cracks and defects in graphene by utilizing an interfacial polymerization technology, has high selectivity and flux, can realize direct application based on the concentration gradient membrane separation field, and has wide application prospect in the seawater desalination field.

The technical solution of the present invention is explained in more detail below with reference to several preferred embodiments.