CN110449035A - A kind of water-oil separationg film and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of inorganic non-metallic materials, and in particular relates to an oil-water separation membrane and a preparation method thereof. The application provides a method for preparing an oil-water separation membrane, comprising the following steps: step 1, mixing ceramic powder, a solvent and an acid-base regulator to obtain a ceramic powder slurry; step 2, mixing the ceramic powder slurry Mixing and reacting the material with an organic acid to obtain a first reactant; step 3, mixing and emulsifying the first reactant, a surfactant and an organic solvent to obtain a second reactant; step 4, mixing the second reactant Sequentially carry out molding and drying treatment to obtain a ceramic membrane green body; step 5, sintering the ceramic membrane green body to obtain a porous ceramic membrane; step 6, setting a hydrophobic layer on the surface of the oil-water separation ceramic membrane to obtain an oil-water separation membrane. The invention provides a reusable and pollution-free oil-water separation membrane with high strength of micro-nano composite structure, micro/nano particles are not easy to wear and fall off.

Description

A kind of oil-water separation membrane and preparation method thereof

technical field

The invention belongs to the technical field of inorganic non-metallic materials, and in particular relates to an oil-water separation membrane and a preparation method thereof.

Background technique

In recent years, with my country's emphasis on environmental protection and yearning for a better home, people's awareness of environmental protection has generally increased, and corresponding environmental protection industry policies have been introduced one after another. Among them, the application requirements of oil-water separation are particularly urgent, such as the oil-water separation problem caused by the oil spill accident of ocean-going ships, the separation of oily/watery two-phase mixtures in organic chemistry laboratories, and the recovery and treatment of waste oil in the kitchen industry, etc. . Generally speaking, the current separation methods mainly include physical methods, biological methods, chemical methods, and electrochemical methods, among which physical separation methods include gravity separation, centrifugal separation, and filtration separation. These traditional oil-water separation technologies generally have the advantages of simple equipment, low single treatment cost, and simple operation methods, but on the other hand, these methods generally have disadvantages such as low separation efficiency, large floor space, and low oil recovery efficiency. , it is difficult to meet the increasingly stringent environmental protection requirements.

In recent years, advances in materials science have greatly promoted the technological development in the field of oil-water separation. For example, the new oil-water separation membrane material constructed by using the special wettability of the surface of the material has become one of the research hotspots in the field of surface interface materials, and has gradually become an important method for cleaning oil floating on the water surface and separating oil and water, which is expected to solve water pollution. Solving such issues will play a vital role. Generally speaking, oil-water separation using the special wettability of materials has the advantages of stable material properties, good separation effect and high separation efficiency compared with traditional separation methods.

Generally speaking, oil-water separation materials can be divided into two types according to material properties: 1) superhydrophobic-superoleophilic separation membrane, also known as "oil-removing" separation membrane; 2) superhydrophilic-superoleophobic separation Membrane, also known as "water removal type" separation membrane. Among them, the "oil removal type" separation membrane is widely used because of its strong oil-water selectivity and good separation effect, but its lipophilic nature makes this material have the following problems in the process of use: it is very easy to be polluted by oil. The final disposal or incineration and other treatment methods often cause secondary pollution to the environment. Therefore, it is extremely important to develop a superhydrophobic-superoleophilic separation membrane "oil-removing" oil-water separation membrane material that is environmentally friendly, reusable, and has a simple preparation process and is convenient for industrial production.

With the development of industry and the increasing urgency of ecological environment protection, the construction of ecological civilization has become a strategic task at the national level. The oil-water mixture discharged by industry is the number one killer of ecological damage to the ecological environment. Therefore, how to purify industrial wastewater and oil-water mixture has always been a hot research topic in academia and industry.

The technical shortcomings of the current "oil-removing (superhydrophobic-superoleophilic)" oil-water separation membrane mainly include:

1) The process flow is complex and the controllability of industrial production is not strong. For example, patent CN201810742339.7 adopts the complex process of electrospinning and layer-by-layer self-assembly to prepare oil-water separation membrane, which has many processes and complicated process; 2) the current process technology , such as coating, crystal growth, electrodeposition, etc., the prepared micro-nano composite structure is generally unstable, and the micro/nano particles are easy to wear and fall off; 3) polymers are used as the main material, which has a low degree of material reuse and is easy to pollute environmental issues.

To sum up, the oil-water separation membranes in the prior art have the technical defects that the micro-nano composite structure is generally unstable, the micro/nano particles are easy to wear and fall off, and the degree of repeated use is low, and the environment is easily polluted.

Contents of the invention

The first aspect of the present invention provides a micro-nano composite structure with high strength, micro/nano particles are not easy to wear and fall off, and can be reused and pollution-free for oil-water separation membrane.

The second aspect of the present invention provides a method for preparing an oil-water separation membrane capable of oil-water separation with simple preparation process and strong controllability in industrial production.

In view of this, the application provides a method for preparing an oil-water separation membrane, comprising the following steps:

Step 1, mixing ceramic powder, solvent and acid-base regulator to obtain ceramic powder slurry;

Step 2, mixing and reacting the ceramic powder slurry with an organic acid to obtain a first reactant;

Step 3, mixing and emulsifying the first reactant, surfactant and organic solvent to obtain a second reactant;

Step 4, forming and drying the second reactant in sequence to obtain a ceramic membrane green body;

Step 5, sintering the ceramic membrane blank to obtain a porous ceramic membrane;

Step 6, providing a hydrophobic layer on the surface of the oil-water separation ceramic membrane to obtain an oil-water separation membrane.

As preferably, in step 1, by adding an acid-base regulator, the pH value of the solvent is adjusted to increase the dissolution rate of the ceramic powder in the solvent. The pH of the solvent is lower than 7, which can improve the dissolution rate and dissolution rate of the ceramic powder in the solvent. properties, so that a small amount of solvent can be integrated into a large amount of ceramic powder under acidic conditions.

Preferably, the acid-base regulator is selected from strong acids such as hydrochloric acid, sulfuric acid, and nitric acid, or weak acids and strong bases such as sodium hydroxide. More preferably, the acid-base regulator is selected from hydrochloric acid and sodium hydroxide.

Preferably, in step 1, the pH range is 3.0-7.0.

More preferably, in step 1, the pH range is 4.3-6.0.

Preferably, in step 1, the pH is 5.3.

Preferably, in step 1, the ceramic powder is selected from one or more of alumina, zirconia, zirconia toughened alumina ceramics, boron nitride, silicon nitride and aluminum nitride; the solvent selected from deionized water or/and alcohol.

Preferably, in step 1, the solid phase content of the ceramic powder in the ceramic powder slurry is 5 vol%-80 vol%.

More preferably, in step 1, the solid phase content of the ceramic powder in the ceramic powder slurry is 30vol%-60vol%.

Preferably, in step 1, the mixing is ball milling, the ball milling time is 0.5-24 hours, and the ball milling speed is 200-600 r/min.

More preferably, in step 1, the ball milling time is 5-12 hours, and the ball milling speed is 250-350 r/min.

Wherein, the acid-base regulator is used to adjust the pH to form a chemical coordination reaction, and the ball milling is used to break up agglomerates to improve the dispersibility of the ceramic powder slurry.

As a preference, in step 2, the organic acid is selected from propionic acid or/and valeric acid; the amount of the organic acid added is: 0.01mmol-0.1mmol of the organic acid is added per gram of the ceramic powder; the The mixing time for the mixing reaction is 2-10 minutes.

Preferably, in step 2, the mixing reaction of the ceramic powder slurry and the organic acid is stirring and mixing, the stirring time is 0.05-0.5 h, and the stirring speed is 200-300 r/min.

It should be noted that the present application found that the ceramic powder slurry and organic acid were mixed and reacted, and the ceramic powder was modified so that the surface of the ceramic powder in the ceramic powder slurry was grafted with carboxyl functional groups, so as to realize the modification of the ceramic powder. The modified treatment of the body also facilitates the subsequent emulsification into the second reactant in the form of micro-droplets.

As preferably, in step 3, the surfactant is selected from one or more of polyvinyl alcohol, polyethylene glycol, sodium octadecyl sulfate and sodium stearate; the organic solvent is selected from n-octyl One or more of alkane, hexadecane and n-hexane.

As a preference, in step 3, the addition amount of the polyvinyl alcohol in the second reactant is: 0.1wt% to 10wt% of polyvinyl alcohol is added per gram of the solvent; the organic solvent is added in the The volume percentage in the second reactant is ≤95%, wherein the solvent is deionized water or/and alcohol.

It should be noted that the present application found that controlling the volume percentage of the polyvinyl alcohol in the second reactant through the holes can control the pore size of the porous structure of the oil-water separation membrane. Specifically, the polyvinyl alcohol in the The larger the proportion of the second reactant, the smaller the pore size of the oil-water separation membrane.

Preferably, in step 3, mixing the first reactant, the surfactant and the organic solvent includes stirring and mixing, and the stirring time is 0.05h˜0.5h.

It should be noted that please refer to Figure 11, Figure 11 is a three-dimensional simulation diagram of the oil-water separation membrane provided by the present application before sintering, and it is found that the emulsification and foaming treatment is carried out after mixing the first reactant, surfactant and organic solvent, The surfactant divides the organic solvent (such as one or more of n-octane, hexadecane and n-hexane) into countless small oil droplets, and the ceramic powder coats the small oil droplets to form self-assembly (ceramic powder coating organic solvent), the pores occupied by the organic solvent after the organic solvent volatilizes or/and evaporates form the pores of the oil-water separation membrane, that is to say, the first reactant is a ceramic powder with carboxyl functional groups on the surface, and the micro-droplet The coating function realizes the self-assembly function and forms micro-droplets of ceramic powder coated with organic solvents. After the organic solvent in the micro-droplets volatilizes, a regular three-dimensional network porous hollow structure is formed.

Specifically, under the action of surfactants and organic solvents, the ceramic powder with carboxyl functional groups on the surface is self-assembled in the ceramic powder slurry to form regularly arranged honeycomb micron-scale oil droplet groups, emulsifying The final ceramic slurry is molded and sintered.

Preferably, in step 4, the molding includes traditional mold molding, 3D printing molding, slip casting molding, gel casting molding, die casting molding or tape casting molding.

Among them, the use of 3D printing can realize the preparation of ceramic membranes with complex shapes.

Preferably, in step 4, the 3D printing is free direct writing 3D printing.

As a preference, in step 4, the drying is used to remove the solvent or liquid substance formed by the second reactant, such as oil droplets; do drying treatment for subsequent sintering; the drying is natural drying or oven drying; the natural drying The time is 72h.

Preferably, in step 5, the sintering temperature is 1000°C to 1700°C; the sintering temperature is below 800°C, the heating rate of the sintering is not more than 10°C/min, and the sintering temperature is above 800°C, The heating rate of the sintering does not exceed 5° C./min, and the temperature is kept at the highest temperature for two hours.

More preferably, in step 5, the sintering temperature is 1200°C to 1700°C; the sintering temperature is below 800°C, the heating rate of the sintering is not more than 10°C/min, and the sintering temperature is above 800°C , the heating rate of the sintering does not exceed 5°C/min, and the temperature is kept at the highest temperature for two hours.

As a preference, in step 6, the material of the hydrophobic layer is selected from the group consisting of polydimethylsiloxane, stearic acid, polytetrafluoroethylene, polysilazane and trimethoxyl (1H, 1H, 2H, 2H-10 One or more of heptafluorodecyl) silanes.

More preferably, in step 6, the material of the hydrophobic layer is selected from polydimethylsiloxane.

Preferably, the method for providing a hydrophobic layer on the surface of the oil-water separation ceramic membrane includes: vapor deposition, physical coating or immersion.

Wherein, a hydrophobic layer is arranged on the surface of the oil-water separation ceramic membrane, so that the oil-water separation ceramic membrane is a superhydrophobic-superoleophilic oil-water separation membrane that water cannot pass through and oil can pass through.

Wherein, the temperature of the vapor phase deposition is 200°C-300°C.

Preferably, the vapor deposition temperature is 235°C.

Wherein, the temperature of the physical coating and soaking is room temperature.

The second aspect of the present invention discloses an oil-water separation membrane, including the oil-water separation membrane prepared by the above-mentioned preparation method.

Specifically, this application provides a specific method for preparing an oil-water separation membrane, using deionized water as a solvent, alumina ceramic powder as a powder material, and a mixing ratio of 58vol% powder gradually added in an ultrasonic environment and a stirring environment, And gradually use HCl to adjust the pH, adjust the pH to be lower than 5.0, ball mill and mix, and the ball mill treatment time and rotating speed are set to 12h and 300r/min respectively; then, the suspension after ball milling is diluted to 46vol% slurry sample with deionized water, Use propionic acid as the organic acid molecule, and add propionic acid under vigorous stirring; then, add surfactant PVA and organic solvent n-octane, add PVA first under stirring, add n-octane after mixing, stir and foam 10min; Mold molding is used to realize the molding and preparation of ceramic biscuits, and natural drying is used as the drying condition for 72h; after demolding, sintering at 1550°C is carried out; after grinding the sample, PDMS is selected as the hydrophobic molecule, and the hydrophobic molecule is realized by vapor deposition method Uniform coating and plating on the surface and interior of the ceramic membrane.

As can be seen from the above technical solutions, the present application has the following advantages:

The application provides an oil-water separation membrane, the surface modification of the ceramic powder is grafted with carboxyl functional groups, which is conducive to the self-assembly of the modified ceramic powder in a specific environment, that is, the surfactant is combined with an organic solvent (such as n-octane , hexadecane and n-hexane) are divided into countless small oil droplets, ceramic powder coating small oil droplets to form self-assembly (ceramic powder coating organic solvent), organic solvent volatilization or/and evaporation Finally, the pores occupied by the organic solvent form the pores of the oil-water separation membrane. Therefore, after the emulsified final slurry is formed and sintered, a hydrophobic layer is placed on the surface to form a super-lipophilic-super-hydrophobic, high oil-water separation efficiency. , Lightweight, high strength, wear-resistant and compressive, and environmentally friendly, an oil-water separation membrane with a porous structure that can be reused many times. At the same time, the preparation method of the oil-water separation membrane of the present application is simple, and the pore size of the oil-water separation membrane can be controlled by controlling the amount of raw materials added, and its industrial production is highly controllable. Experiments have shown that the oil-water separation membrane of the present application has high oil-water separation efficiency and high compressive strength, which makes its structural strength high, and the surface micro-nano particles are not easy to wear and fall off; the oil-water separation membrane has a porous structure, specifically the rules of orderly arrangement The three-dimensional mesh porous hollow structure; and its three-dimensional structure is controllable, and any size ratio between the pore diameter and the through hole in the porous structure can be realized by adding the amount of raw materials; and the oil-water separation membrane can be reused without pollution.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the description of the embodiments or the prior art.

Fig. 1 is that the application provides the superhydrophobic contact angle characterization test figure of the oil-water separation membrane of embodiment 1;

Fig. 2 is the super-lipophilic contact angle characterization test diagram of the oil-water separation membrane provided in Example 1 provided by the application;

Fig. 3 is the physical diagram of the oil-water separation wettability of the oil-water separation membrane of Example 1 provided by the present application;

Fig. 4 is the product of comparative example 1 provided by the present application to carry out the physical figure of oil-water separation invasiveness;

Fig. 5 is the schematic diagram of the oil-water separation test of the oil-water separation membrane provided by the present application in Example 1, wherein, a is to drip oil droplet 1 and water droplet 2 on the oil-water separation membrane of Example 1 at the same time, and b is that oil droplet 1 passes through the implementation In the oil-water separation membrane of example 1, water droplet 2 does not pass through the oil-water separation membrane of embodiment 1, and c is that water droplet 2 stays on the surface of the oil-water separation membrane of embodiment 1 with water droplets;

Fig. 6 is the scanning electron micrograph of the oil-water separation membrane (PVA1wt%) of the embodiment of the present application enlarged 100 times;

Fig. 7 is the scanning electron micrograph of the oil-water separation membrane (PVA1wt%) of the embodiment of the present application enlarged 200 times;

Fig. 8 is the scanning electron micrograph of the oil-water separation membrane (PVA1wt%) of the embodiment of the present application enlarged 400 times;

Fig. 9 is a scanning electron microscope image enlarged 1200 times of the oil-water separation membrane (PVA1wt%) of the embodiment of the present application;

Fig. 10 is a scanning electron microscope image enlarged 10000 times of the oil-water separation membrane (PVA1wt%) of the embodiment of the present application;

Fig. 11 is a three-dimensional simulation diagram of the oil-water separation membrane provided by the present application before sintering.

Detailed ways

The invention provides an oil-water separation membrane and a preparation method thereof, which effectively solves the problem that the micro-nano composite structure is generally unstable, the micro/nano particles are easy to wear and fall off, and the low degree of repeated use and easy pollution of the oil-water separation membrane in the prior art Environmental technical deficiencies.

The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Among them, the raw materials used in the following examples are all commercially available or self-made; ceramic powder: α-Al ₂ O ₃ , purchased from Daming Alumina TM-DAR (particle size 0.2um; density 3.98g/ml; Japan Daming Chemical); Propionic acid: chemical formula is CH ₃ CH ₂ COOH, purity 99%, MW 74.08, Bailingwei Technology; polyvinyl alcohol: PVA, degree of alcoholysis 99.0-99.4mol%; viscosity: 12.0-16.0mPa.s; MW 44.05; Aladdin Reagent Company; n-octane: C ₈ H ₁₈ purity 96%, MW 114.23; Aladdin Reagent Company; polydimethylsiloxane: PDMS, 184 silicone rubber, American Dow Corning SYLGARD; polyethylene glycol: HO (CH ₂ CH ₂ O) _n H average Mn is 6000, Aladdin Reagent Company; Methyl blue: Molecular formula C ₃₇ H ₂₇ N ₃ Na ₂ O ₉ S ₃ , MW is 799.8 McLeans; Oil Red O: Oil RedO, Dimethylphenyl, molecular formula C ₂₆ H ₂₄ N ₄ O, MW 408.495, McLean.

SEM was performed using a scanning electron microscope SU 8220, Hitachi, Japan.

The contact angle measurement adopts XG-CAM contact angle measuring instrument, Contact Angle Meter Shanghai Xuanyi Chuangxi Industrial Equipment Co., Ltd.

The density adopts Archimedes drainage method, constant temperature heating platform, analytical balance, PTX-FA electronic analytical balance; USA.HZ&HUAZHI, USA Connecticut HZ Electronics Co., Ltd.

The sintering experiment adopts muffle furnace TSX1700 type, Sinoite (Beijing) Electric Furnace Co., Ltd.

The polishing experiment used MP-2B grinding and polishing machine, Laizhou Weiyi Experimental Instrument Manufacturing Co., Ltd.

Example 1

The embodiment of the present application provides an oil-water separation membrane, and its specific preparation steps are as follows:

1. Preparation of ceramic powder slurry

1. According to the addition amount in Table 1, under the action of stirring and ultrasound, gradually add α-Al ₂ O ₃ powder into the deionized water, adjust the pH with hydrochloric acid, and finally configure the oxidation with a solid content of 53.7vol% and a pH of 5.36. aluminum suspension. Among them, after emulsification and foaming, the deionized water is 16.2 vol%, and the α-Al ₂ O ₃ powder is 27.6 vol%.

2. According to the proportion of ball to material ratio of 1:1, add alumina ball milling balls, among which the ratio of Φ10mm ball milling balls and Φ5mm ball milling balls is 1:1. Mill overnight with a planetary ball mill (rotating speed 300r/min).

3. After ball milling, the balls are removed to obtain ceramic powder slurry.

2. Modification of ceramic powder slurry

1. Add deionized water to the ceramic powder slurry in step 1 to dilute to a solid content of 46vol%;

Add 0.04mmol of propionic acid per gram of alumina powder, and add dropwise under stirring. Stirring realizes the modification treatment of the ceramic powder and obtains the first reactant.

3. Emulsification and foaming treatment

1. The first reactant in step 2 is equally divided into 6 parts, and each part of the first reactant is added with polyvinyl alcohol, respectively marked as: PVA0wt%, PVA1wt%, PVA2wt%, PVA3wt%, PVA4wt% and PVA10wt%, that is PVA0wt% is that the addition amount of polyvinyl alcohol is 0, PVA1wt% is the polyvinyl alcohol that every gram of deionized water adds in the first reactant 0.01g, PVA2wt% is that every gram of deionized water adds 0.02g in the first reactant Polyvinyl alcohol, PVA3wt% is the polyvinyl alcohol that every gram of deionized water adds 0.03g in the first reactant, PVA4wt% is the polyvinyl alcohol that every gram of deionized water adds 0.04g in the first reactant, PVA10wt% is the first reactant 0.1 g of polyvinyl alcohol was added per gram of deionized water in a reactant; then 70 vol% n-octane was added according to the volume percentage for stirring and foaming, and the stirring time was 7 minutes. Direct n-octane is fully dissolved into the suspension and the emulsion. That is, the volume ratio of the first reactant to the volume of n-octane added is 3:7, and the second reactant of polyvinyl alcohol with different concentrations is obtained, respectively recorded as PVA0wt%, PVA1wt%, PVA2wt%, PVA3wt%, PVA4wt% % and PVA10wt%, wherein, as required, the pH value of the emulsion is adjusted to 4.4 with NaOH solution under the condition of stirring until the viscosity suitable for 3D printing.

4. Molding treatment

1. Take each of the second reactants in the previous step, and use 3D printing equipment to realize the molding and drying of the macro-ceramic green body, and dry it naturally at room temperature to obtain the ceramic film green body, which is respectively recorded as PVA0wt %, PVA1wt%, PVA2wt%, PVA3wt%, PVA4wt%, and PVA10wt%.

5. Sintering

1. Get every kind of ceramic membrane green body in the previous step and carry out sintering treatment to obtain porous ceramic membranes, which are respectively recorded as PVA0wt%, PVA1wt%, PVA2wt%, PVA3wt%, PVA4wt% and PVA10wt%; the sintering parameters are: sintering temperature 800 Below ℃, the temperature is raised at a rate of 10°C/min; when the temperature is 800-1550°C, the temperature is raised at a rate of 3.75°C/min, and when it reaches 1550°C, it is kept for 2 hours, and then the temperature is lowered. The temperature is lowered at a rate of min, and then cooled with the furnace.

6. Hydrophobic treatment of oil-water separation ceramic membrane

1. Get each kind of porous ceramic membrane in the previous step and polish it with a 200-mesh diamond grinding disc to make a filter ceramic membrane sample with a thickness of 0.8 mm. By vapor deposition at 235 ° C (take each filter ceramic membrane sample and place it in the culture In Dish 1, PDMS liquid glue was placed in Petri Dish 2, and the Petri Dish 1 and 2 were covered by inverting the beaker, and the mouth of the beaker was properly sealed with tin foil, and then the whole was placed in a muffle furnace and heated slowly to 235°C, and kept for 8 Hours, the PDMS in Petri dish 2 forms steam, evaporates and deposits a layer of PDMS molecular layer on the surface of the filter ceramic membrane sample, the vapor deposition parameter is to raise the temperature to 235°C at 7.8°C/min, and keep it at 235°C for 8 hours. Cool in the furnace afterwards), coat a layer of PDMS (polydimethylsiloxane) molecules on the sample surface, realize hydrophobic treatment, and obtain 6 kinds of oil-water separation membranes, which are respectively recorded as PVA0wt%, PVA1wt%, PVA2wt%, PVA3wt% , PVA4wt% and PVA10wt%.

Table 1

The average pore size, contact angle, oil-water separation efficiency and compressive strength of the prepared six oil-water separation membranes were measured, and the results are shown in Table 2.

Table 2

Average pore size (μm) Contact Angle (O) Oil-water separation efficiency (%) Compressive strength (MPa) PVA0% 137.5 147.64 99.87 unstable PVA1% 18.0 152.85 99.86 51.136 PVA2% 11.1 152.57 99.87 45.872 PVA3% 15.5 152.47 99.87 44.752 PVA4% 10.3 152.75 99.91 36.767 PVA10% 7.8 153.35 99.91 25.608

As can be seen from Table 2, when adding a polyvinyl alcohol aqueous solution with a concentration of 0wt%, the compressive strength of the oil-water separation membrane obtained is unstable, and the average pore size of the oil-water separation membrane is too large, the distribution of voids is uneven, and the contact angle of oil droplets is too high. Small. As the concentration of polyvinyl alcohol increases, the average pore size of the oil-water separation membrane becomes smaller and smaller. The compressive strength is relatively high, the water contact angle is 150° higher than the superhydrophobic boundary, and the oil-water separation efficiency reaches more than 99.8%.

The oil-water separation membrane (PVA1wt%) of the present embodiment is detected by scanning electron microscope, and the results are shown in Figures 6-9, and Fig. 6 is a 100-fold scanning electron microscope image of the oil-water separation membrane (PVA1wt%) of the embodiment of the present application, and Fig. 7 It is the scanning electron micrograph of the oil-water separation membrane (PVA1wt%) of the embodiment of the application enlarged 200 times, and Fig. 8 is the scanning electron microscope diagram of the oil-water separation membrane (PVA1wt%) of the embodiment of the application enlarged 400 times, and Fig. 9 is the implementation of the application Example of the oil-water separation membrane (PVA1wt%) magnified 1200 times the scanning electron microscope, Figure 10 is the application of the embodiment of the oil-water separation membrane (PVA1wt%) magnified 10000 times the scanning electron microscope, as can be seen from Figures 6-10, the application implementation The oil-water separation membrane (PVA1wt%) of the example has a regular three-dimensional mesh porous hollow structure arranged in an orderly manner. As can be seen in Figure 10, it can be seen under the scanning electron microscope at 10,000 times that the porous structure stacked by the self-assembly method of the present application , the crystal grains on the pore wall can be stacked into a solid pore shell with precise arrangement, so the macroscopic level has high-strength compressive performance, and it is a porous structure, so it has light weight and high strength performance.

Example 2

Determination of the superhydrophobic and superlipophilic properties of the oil-water separation membrane of Example 1 of the present application, please refer to Figure 1-2, Figure 1 is the superhydrophobic test diagram of the oil-water separation membrane of Example 1 provided by the application, and Figure 2 is the application The super-oleophilic test diagram of the oil-water separation membrane of Example 1 is provided. It can be seen from Figures 1-2 that the oil-water separation membrane of Example 1 of the present application has super-hydrophobic and super-oleophilic properties.

Comparative example 1

The comparative example of the present application provides a kind of comparative oil-water separation membrane, its specific preparation steps are as the type of preparation steps in Example 1, the difference is that the hydrophobic treatment in step 6 of Example 1 is not carried out, and the remaining steps are the same as in Example 1, and a pair of membranes is obtained. Product of scale 1.

Example 3

Please refer to Figure 5, Figure 5 is a schematic diagram of the oil-water separation test of the oil-water separation membrane of Example 1 provided by the present application, wherein Figure 5a is a simultaneous drop of oil droplets 1 and water droplets 2 on the oil-water separation membrane of Example 1, and Figure 5b Oil droplet 1 passes through the oil-water separation membrane of Example 1, and water droplet 2 does not pass through the oil-water separation membrane of Example 1. Figure 5c shows that water droplet 2 stays on the surface of the oil-water separation membrane of Example 1 in a droplet shape. According to the flow process of Figure 5, the product of Comparative Example 1 was also subjected to an oil-water separation test, and the physical results are shown in Figure 3 and Figure 4, and Figure 3 is the actual picture of the oil-water separation membrane provided in Example 1 by the present application after the oil-water separation test , Figure 4 is the physical picture of the product of Comparative Example 1 provided by the present application after the oil-water separation test. It can be seen from Figures 3-4 that Comparative Example 1 obtained without the hydrophobic treatment in Step 6 of Example 1 does not have the performance of oil-water separation.

The terms "first", "second", "third", "fourth", etc. (if any) in the description of the present application and the above drawings are used to distinguish similar objects and not necessarily to describe specific sequence or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein, for example, can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or device comprising a sequence of steps or elements is not necessarily limited to the expressly listed instead, may include other steps or elements not explicitly listed or inherent to the process, method, product or apparatus.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (10)

1. a preparation method of oil-water separation membrane, is characterized in that, comprises the following steps: Step 1, mixing ceramic powder, solvent and acid-base regulator to obtain ceramic powder slurry; Step 2, mixing and reacting the ceramic powder slurry with an organic acid to obtain a first reactant; Step 3, mixing and emulsifying the first reactant, surfactant and organic solvent to obtain a second reactant; Step 4, forming and drying the second reactant in sequence to obtain a ceramic membrane green body; Step 5, sintering the ceramic membrane blank to obtain a porous ceramic membrane; Step 6, providing a hydrophobic layer on the surface of the oil-water separation ceramic membrane to obtain an oil-water separation membrane. 2. The preparation method according to claim 1, wherein in step 1, the ceramic powder is selected from the group consisting of alumina, zirconia, zirconia toughened alumina ceramics, boron nitride, silicon nitride and nitrogen One or more in aluminum chloride; The solvent is selected from deionized water or/and alcohol. 3. The preparation method according to claim 1, characterized in that, in step 1, the solid content of the ceramic powder in the ceramic powder slurry is 5 vol%-80 vol%. 4. The preparation method according to claim 1, characterized in that, in step 2, the organic acid is selected from propionic acid or/and valeric acid; the addition amount of the organic acid is: per gram of the ceramic powder Add 0.01mmol-0.1mmol of the organic acid; the mixing time of the mixing reaction is 2-10 minutes. 5. preparation method according to claim 1, is characterized in that, in step 3, described tensio-active agent is selected from one in polyvinyl alcohol, polyethylene glycol, sodium octadecyl sulfate and sodium stearate one or more; the organic solvent is selected from one or more of n-octane, hexadecane and n-hexane. 6. The preparation method according to claim 5, characterized in that, in step 3, the amount of polyvinyl alcohol added to the second reactant is: 0.1wt% to 10wt% per gram of the solvent % of polyvinyl alcohol; the volume percentage of the organic solvent in the second reactant is ≤95%. 7. The preparation method according to claim 1, characterized in that in step 5, the sintering temperature is 1000°C to 1700°C; the sintering temperature is below 800°C, and the heating rate of the sintering is not more than 10 °C/min, the sintering temperature is above 800 °C, the heating rate of the sintering is not more than 5 °C/min, and the temperature is kept at the highest temperature for two hours. 8. The preparation method according to claim 1, wherein in step 6, the material of the hydrophobic layer is selected from polydimethylsiloxane, stearic acid, polytetrafluoroethylene, polysilazane and One or more of trimethoxy(1H,1H,2H,2H-heptadecafluorodecyl)silane. 9. The preparation method according to claim 1, characterized in that, the method of providing a hydrophobic layer on the surface of the oil-water separation ceramic membrane comprises: vapor deposition, physical coating or immersion. 10. An oil-water separation membrane, characterized in that it comprises the oil-water separation membrane prepared by the preparation method according to any one of claims 1-9.