阅读说明：本技术 一种二维高分子刷功能隔膜及其制备方法和应用 (Two-dimensional polymer brush functional diaphragm and preparation method and application thereof ) 是由 吴丁财 刘倩彤 刘如亮 郑冰娜 于 2021-06-25 设计创作，主要内容包括：本发明涉及高性能隔膜的制备技术和锂电池领域,公开了一种二维高分子刷功能隔膜的制备方法及其制备方法和应用,所述的二维高分子刷功能隔膜是通过表面接枝技术在氧化石墨烯上接枝功能高分子,通过抽滤或者加热挥发制成薄膜,充当锂电池中的隔膜部分。所述的二维高分子刷功能隔膜是以二维片状氧化石墨烯为骨架,接枝功能分子刷构筑新型的功能隔膜,厚度仅有10μm,不仅可以明显提高材料的吸液率,同时有效提高锂离子的移动速度,还有效改善锂电池的枝晶问题。本发明通过在氧化石墨烯表面接枝功能高分子,堆积的二维高分子刷之间的空隙为电解液扩散提供了快速途径,提高锂离子的离子电导率,具有优异的电化学性能,在锂电池领域具有广泛的应用前景。(The invention relates to the field of preparation technology of high-performance diaphragms and lithium batteries, and discloses a preparation method of a two-dimensional polymer brush functional diaphragm, and a preparation method and application thereof. The two-dimensional polymer brush functional diaphragm is a novel functional diaphragm constructed by a two-dimensional sheet graphene oxide serving as a framework and a grafting functional molecular brush, the thickness of the novel functional diaphragm is only 10 micrometers, the liquid absorption rate of a material can be obviously improved, the moving speed of lithium ions is effectively improved, and the problem of dendritic crystals of a lithium battery is effectively solved. According to the invention, functional polymers are grafted on the surface of graphene oxide, and gaps among the two-dimensional polymer brushes stacked provide a rapid way for electrolyte diffusion, so that the ionic conductivity of lithium ions is improved, and the graphene oxide brush has excellent electrochemical performance and wide application prospects in the field of lithium batteries.)

1. A preparation method of a two-dimensional polymer brush functional diaphragm is characterized by comprising the following steps:

(1) introducing inert gas into an aqueous solution containing graphene oxide to remove oxygen, then adding a high-molecular monomer and an initiator, uniformly mixing, and reacting under the protection of the inert gas at the reaction temperature of 60-90 ℃ for 24-72 h; the high molecular monomer is lithium sulfonate;

(2) adding a solvent I into the reaction product obtained in the step (1), centrifuging and washing with water for several times, dispersing the centrifuged product in a LiOH solution, stirring for 6-24h, centrifuging again and washing the centrifuged product with water to be neutral;

(3) and (3) dispersing the reaction product obtained in the step (2) in a solvent II, and performing suction filtration or heating volatilization to form a film to obtain the two-dimensional polymer brush functional diaphragm.

2. The preparation method according to claim 1, wherein the mass ratio of the high molecular monomer to the graphene oxide in the step (1) is 20-60: 1; the molar ratio of the high molecular monomer to the initiator is 25-100: 1.

3. the preparation method according to claim 2, wherein the mass ratio of the polymer monomer to the graphene oxide in the step (1) is 30 ± 5: 1; the molar ratio of the high molecular monomer to the initiator is 58 +/-5: 1.

4. the preparation method of claim 1, 2 or 3, wherein the initiator is one or more of potassium persulfate, ammonium persulfate and azodiisobutylamine hydrochloride; the high molecular monomer is styrene sulfonate or sodium p-styrene sulfonate.

5. The preparation method according to claim 4, wherein the solvent I is hydrochloric acid solution, and the solvent II is one or more of water, ethanol and N, N-dimethylformamide.

6. The preparation method according to claim 5, wherein the reaction temperature in the step (1) is 75 + 5 ℃ and the reaction time is 48 + 6 h.

7. The method according to claim 5, wherein the inert gas is introduced in the step (1) for 10 to 30 min; the concentration of the LiOH solution in the step (2) is 20 +/-10 mg/mL.

8. A two-dimensional polymer brush functional separator prepared by the method of any one of claims 1 to 7.

9. The use of the two-dimensional polymer brush functional separator according to claim 8 in a lithium metal battery, wherein the separator and an electrolyte are directly assembled into the lithium metal battery in a glove box.

10. The use according to claim 9, wherein the electrolyte is a lithium ion electrolyte or a lithium sulphur electrolyte.

Technical Field

The invention relates to the field of preparation technology of high-performance diaphragms and lithium batteries. The invention relates to a two-dimensional polymer brush functional diaphragm and a preparation method thereof.

Background

Lithium metal batteries consist of three key components: a lithium negative electrode, a positive electrode, and a separator (including an electrolyte). However, the safety of lithium metal batteries in liquid electrolytes has seriously hindered their commercialization: (1) the lithium metal undergoes corrosion reaction, and the volume is infinitely expanded and unstable, so that the battery is short-circuited and even exploded; (2) the "dead lithium" created during lithium dendrite growth also shortens battery life. In recent years, a great deal of research has been conducted on these problems of lithium metal negative electrodes, wherein separator modification is considered to be a simple and effective way to inhibit lithium dendrite growth. Although the separator is not necessarily an active component in the battery, it plays a key role in the ion transport process, affecting the rate performance, life and safety of the battery. Therefore, designing a separator that can promote uniform transport of lithium ions in the electrolyte is of great scientific significance for realizing a high-performance lithium metal battery without dendrites.

The current commercial lithium battery separator in the market is mainly a microporous polyolefin separator mainly made of Polyethylene (PE) and polypropylene (PP). The diaphragm has the advantages of good mechanical property, good chemical stability, low cost and the like, and is widely applied to lithium battery diaphragms. But due to the lyophobic surface and low surface energy, the wettability of the polyolefin material diaphragm on the electrolyte is poor, and the cycle life of the battery is influenced. Meanwhile, the glass transition temperature is low, the thermal stability is poor, and the diaphragm can be seriously thermally shrunk when the temperature is too high, so that the diaphragm is not suitable for being used in a high-temperature environment, and the traditional polyolefin diaphragm can not meet the use requirements of the current 3C products (computers, communication and consumer electronics products) and power batteries.

In response to the development demand of lithium battery technology, researchers have developed various novel lithium battery separator materials based on the conventional polyolefin separator. The current strategy for improving the membrane is mainly to graft or coat a functional layer on the surface, thereby improving the performance of the membrane. The additional coating layer inevitably increases the thickness of the separator and the absorption of the electrolyte, thereby increasing the weight and internal resistance of the battery, and reducing the energy density of the lithium metal battery. Although this strategy can achieve excellent thermal stability or specific wetting properties, properties such as lightness and flexibility cannot be achieved. Therefore, in order to meet the increasing demand for batteries having high energy density and high safety, it is a great challenge to develop a novel separator having ultra-thinness and high ionic conductivity.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a two-dimensional high-molecular brush functional diaphragm, a preparation method thereof and application thereof in a lithium battery. Polystyrene sulfonate is grafted on the surface of Graphene Oxide (GO) through simple free radical polymerization and ion exchange reaction. The graphene oxide can form a layer of soft and compact film, and due to the existence of gaps among the two-dimensional polymer brushes, the migration capacity of lithium ions is improved, and the lithium ions are uniformly deposited on the surface of the electrode, so that the uniform deposition of the lithium ions on the surface of the electrode is promoted. Therefore, the two-dimensional polymer brush functional diaphragm is expected to improve the problems of interface compatibility, interface impedance and thermal stability in the diaphragm, so that the diaphragm keeps good ion transmission regulation capacity, and the two-dimensional polymer brush functional diaphragm has important significance for improving the power density of a battery and reducing the polarization of the battery.

In order to achieve the purpose, the technical scheme adopted by the application is as follows:

in a first aspect, the invention provides a molecular brush material with functional groups grafted on graphene oxide, wherein the material is prepared by grafting functional polymers on a graphene oxide nanosheet through a surface grafting technology, and then performing suction filtration or heating volatilization to prepare a macroscopic membrane which is cut into a size of a diaphragm and is used for a lithium battery.

Preferably, the present invention provides one or both of graphene oxide having a lateral dimension of 3-5 μm and a thickness of about 1nm and graphene oxide having a lateral dimension of 20-30 μm and a thickness of about 1 nm.

Preferably, the present invention provides one or both of free radical polymerization and surface initiated-atom transfer radical polymerization (SI-ATRP).

In a second aspect, the invention provides a preparation method of a two-dimensional polymer brush functional diaphragm, which comprises the following steps:

(1) introducing inert gas into an aqueous solution containing graphene oxide to remove oxygen, then adding a high-molecular monomer and an initiator, uniformly mixing, and reacting under the protection of the inert gas at the reaction temperature of 60-90 ℃ for 24-72 h; the high molecular monomer is lithium sulfonate;

(2) adding a solvent I into the reaction product obtained in the step (1), centrifuging and washing with water for several times, dispersing the centrifuged product in a LiOH solution, stirring for 6-24h, centrifuging again and washing the centrifuged product with water to be neutral;

(3) and (3) dispersing the reaction product obtained in the step (2) in a solvent II, and performing suction filtration or heating volatilization to form a film to obtain the two-dimensional polymer brush functional diaphragm.

Preferably, the mass ratio of the polymer monomer to the graphene oxide in the step (1) is 20-60: 1; the molar ratio of the high molecular monomer to the initiator is 25-100: 1; the weight ratio of the high molecular monomer to the solvent I is 1: 50-150.

Preferably, the mass ratio of the polymer monomer to the graphene oxide in the step (1) is 30 ± 5: 1; the molar ratio of the high molecular monomer to the initiator is 58 +/-5: 1.

preferably, the initiator is one or more of potassium persulfate, ammonium persulfate and azodiisobutylamine hydrochloride; the high molecular monomer is styrene sulfonate or sodium p-styrene sulfonate.

Preferably, the solvent I is hydrochloric acid solution (with the concentration of 3mol/L), and the solvent II is one or more of water, ethanol and N, N-dimethylformamide.

Preferably, the reaction temperature in the step (1) is 75 +/-5 ℃, and the reaction time is 48 +/-6 h.

Preferably, the time for introducing the inert gas in the step (1) is 10-30 min; the concentration of the LiOH solution in the step (2) is 20 +/-10 mg/mL.

In a third aspect, the invention provides an application of the two-dimensional polymer brush functional diaphragm prepared by the method in lithium metal batteries, and the diaphragm and electrolyte are directly assembled into the lithium metal batteries in a glove box. The electrolyte is lithium ion electrolyte (1.0M LiPF)₆in EC/DEC (1:1, v/v)) or lithium sulfur electrolyte (1.0M LiTFSI in DME/DOL (1:1, v/v) with1 wt% LiNO₃)。

Preferably, the inert gas in step (1) comprises one or two of nitrogen and argon.

The principle of the invention is as follows: firstly, grafting a functional polymer on cellulose by using a common free radical polymerization reaction, then preparing a macroscopic material from the graphene oxide @ functional polymer molecular brush by using a suction filtration film forming mode or a natural volatilization film forming mode, and the like, and then using the macroscopic material for a lithium metal battery. The graphene oxide is used as a two-dimensional sheet material, and a guarantee is provided for constructing a two-dimensional hybrid macro-membrane, namely the two-dimensional polymer brush functional membrane takes the two-dimensional sheet graphene oxide as a framework, and a grafted functional molecular brush constructs a novel functional membrane, so that the liquid absorption rate of the material can be obviously improved, and the moving speed of lithium ions can be effectively improved. In addition, the graphene oxide has excellent mechanical property and thermodynamic stability, and can inhibit the growth of lithium dendrites to a certain extent in the charge-discharge cycle process, so that the service life of the battery is prolonged, and the safety of the battery is improved. Meanwhile, the introduction of the lithium sulfonate can obviously improve the ion migration number and the lithium ion conductivity.

Compared with the prior art, the invention has the following beneficial effects:

(1) functional polymers are grafted on the surface of the graphene oxide, and gaps among the accumulated two-dimensional polymer brushes provide a rapid way for electrolyte diffusion, so that the ionic conductivity of lithium ions is improved. Meanwhile, the thickness of the diaphragm is very thin and is only 10 mu m. Compared with a common PP or PE diaphragm, the lithium ion transmission path is greatly reduced.

(2) Lithium sulfonate is introduced through a functional polymer chain, and the single-ion conductor polymer electrolyte can obviously improve the transference number of lithium ions, reduce polarization and inhibit the growth of lithium dendrites by fixing anions on a polymer main chain. Meanwhile, the lithium-rich functional groups homogenize the flux of lithium ions on the surface of the electrode, thereby promoting the uniform deposition of lithium and prolonging the cycle life of the lithium battery.

(3) The graphene oxide is used as a matrix material, so that the mechanical property of the material can be improved, and good thermodynamic stability is kept.

Drawings

Fig. 1 (a) and (B) are scanning electron micrographs before and after a film is formed on the polymer brush material with a two-dimensional sheet structure provided in example 1 of the present invention, and (C) is a scanning electron micrograph of a first polymer brush material with a two-dimensional sheet structure provided in example 1 of the present invention; (D) a first polymer brush material with a two-dimensional sheet structure provided in embodiment 1 of the present invention is a real photograph.

Fig. 2 is a digital photograph of a polymer brush material with a two-dimensional sheet structure and a polypropylene separator (PP) which are respectively heat-treated at 25, 80, 120, 160 and 200 ℃ for 1 hour according to example 1 of the present invention.

Fig. 3 is a resistance test curve of a polymer brush material having a two-dimensional sheet structure according to example 1 of the present invention and a polypropylene separator.

Fig. 4 is a linear sweep voltammogram of a polymer brush material having a two-dimensional sheet structure and a polypropylene membrane provided in example 1 of the present invention.

Fig. 5(a) shows a polymer brush material with a two-dimensional sheet structure, a polypropylene membrane, Graphene Oxide (GO), and a mechanical mixture of graphene oxide and a polymer (GO) provided in embodiment 1 of the present invention&PSSLi) Assembly into a Li | Li symmetrical Battery at 5mA cm^-2，1mAh cm^-2Cycling performance under conditions; (B) the cycle performance of the LFP | Li half-cell assembled by the polymer brush material i with the two-dimensional sheet structure and the polypropylene diaphragm provided in embodiment 1 of the present invention is shown.

Detailed Description

The present invention will now be described in further detail, with reference to the following brief description of the embodiments and the accompanying drawings, which are required for a description of the prior art.

Example 1

The embodiment of the invention provides a preparation method of a two-dimensional polymer brush functional diaphragm and application of the diaphragm in preparation of a lithium metal battery, which comprises the following steps:

(1) dispersing 100mg of graphene oxide in 40ml of aqueous solution, performing ultrasonic treatment for 30min, introducing nitrogen for 10-30min, adding 3g of sodium p-styrenesulfonate and 57mg of ammonium persulfate, uniformly stirring, mixing under the protection of nitrogen, heating to 75 ℃, reacting for 48h, and performing centrifugal washing for several times by using deionized water after the reaction is finished to obtain an intermediate product I;

(2) adding the intermediate product I prepared in the step (1) into 200mL of hydrochloric acid solution with the concentration of 3mol/L, stirring for 4h, centrifuging, washing for several times by using deionized water until the solution is weakly acidic, dispersing the centrifuged product into 150mL of LiOH solution with the concentration of 20mg/mL, stirring for 24h, centrifuging again, and washing the centrifuged product for several times by using water until the solution is neutral to obtain an intermediate product II;

(3) and (3) dispersing the intermediate product II prepared in the step (2) in water, and heating and volatilizing the intermediate product II on a polytetrafluoroethylene plate at 30 ℃ to form a film, so as to obtain the high polymer brush material I with a two-dimensional sheet structure.

(4) Cutting the first material into the size of a diaphragm, taking 30 mu L of electrolyte, and assembling the first material into a lithium metal battery in a glove box.

Example 2

The embodiment of the invention provides a preparation method of a two-dimensional polymer brush functional diaphragm and application of the diaphragm in preparation of a lithium metal battery, which comprises the following steps:

(1) dispersing 100mg of graphene oxide in 40mL of aqueous solution, performing ultrasonic treatment for 30min, introducing nitrogen for 10-30min, adding 3g of sodium p-styrenesulfonate and 57mg of ammonium persulfate, uniformly stirring, mixing under the protection of nitrogen, heating to 75 ℃, reacting for 24h, and performing centrifugal washing for several times by using deionized water after the reaction is finished to obtain an intermediate product I;

(2) adding the intermediate product I prepared in the step (1) into 200mL of hydrochloric acid solution with the concentration of 3mol/L, stirring for 4h, centrifuging, washing for several times by using deionized water until the solution is weakly acidic, dispersing the centrifuged product into 150mL of LiOH solution with the concentration of 20mg/mL, stirring for 24h, centrifuging again, and washing the centrifuged product for several times by using water until the solution is neutral to obtain an intermediate product II;

(3) and (3) dispersing the intermediate product II prepared in the step (2) in water, and heating and volatilizing the intermediate product II on a polytetrafluoroethylene plate at 30 ℃ to form a film, so as to obtain a high polymer brush material II with a two-dimensional sheet structure.

(4) Cutting the first material into the size of a diaphragm, taking 30 mu L of electrolyte, and assembling the first material into a lithium metal battery in a glove box.

Example 3

The embodiment of the invention provides a preparation method of a two-dimensional polymer brush functional diaphragm and application of the diaphragm in preparation of a lithium metal battery, which comprises the following steps:

(1) dispersing 100mg of graphene oxide in 40mL of aqueous solution, performing ultrasonic treatment for 30min, introducing nitrogen for 10-30min, adding 3g of sodium p-styrenesulfonate and 57mg of ammonium persulfate, uniformly stirring, mixing under the protection of nitrogen, heating to 75 ℃, reacting for 36h, and performing centrifugal washing for several times by using deionized water after the reaction is finished to obtain an intermediate product I;

(2) adding the intermediate product I prepared in the step (1) into 200mL of hydrochloric acid solution with the concentration of 3mol/L, stirring for 4h, centrifuging, washing for several times by using deionized water until the solution is weakly acidic, dispersing the centrifuged product into 150mL of LiOH solution with the concentration of 20mg/mL, stirring for 24h, centrifuging again, and washing the centrifuged product for several times by using water until the solution is neutral to obtain an intermediate product II;

(3) and (3) dispersing the intermediate product II prepared in the step (2) in water, and heating and volatilizing the intermediate product II on a polytetrafluoroethylene plate at 30 ℃ to form a film, so as to obtain a high polymer brush material III with a two-dimensional sheet structure.

(4) Cutting the first material into the size of a diaphragm, taking 30 mu L of electrolyte, and assembling the first material into a lithium metal battery in a glove box.

Example 4

The embodiment of the invention provides a preparation method of a two-dimensional polymer brush functional diaphragm and application of the diaphragm in preparation of a lithium metal battery, which comprises the following steps:

(1) dispersing 100mg of graphene oxide in 40mL of aqueous solution, performing ultrasonic treatment for 30min, introducing nitrogen for 10-30min, adding 3g of sodium p-styrenesulfonate and 57mg of ammonium persulfate, uniformly stirring, mixing under the protection of nitrogen, heating to 75 ℃, reacting for 72h, and performing centrifugal washing for several times by using deionized water after the reaction is finished to obtain an intermediate product I;

(2) adding the intermediate product I prepared in the step (1) into 200mL of hydrochloric acid solution with the concentration of 3mol/L, stirring for 4h, centrifuging, washing for several times by using deionized water until the solution is weakly acidic, dispersing the centrifuged product into 150mL of LiOH solution with the concentration of 20mg/mL, stirring for 24h, centrifuging again, and washing the centrifuged product for several times by using water until the solution is neutral to obtain an intermediate product II;

(3) and (3) dispersing the intermediate product II prepared in the step (2) in water, and heating and volatilizing the intermediate product II on a polytetrafluoroethylene plate at 30 ℃ to form a film, so as to obtain a high polymer brush material III with a two-dimensional sheet structure.

(4) Cutting the first material into the size of a diaphragm, taking 30 mu L of electrolyte, and assembling the first material into a lithium metal battery in a glove box.

TABLE 1 Polymer content in Polymer Brush Membrane having a two-dimensional lamellar Structure

The results show that: the reaction time in the step (1) has a certain influence on the polymer brush content of the product. The content of polymeric brush in the product can be increased with the increase of the reaction time. However, if the reaction time is too long, side reactions may occur to reduce the graft amount of the polymer brush.

Example 5

The embodiment of the invention provides a preparation method of a two-dimensional polymer brush functional diaphragm and application of the diaphragm in preparation of a lithium metal battery, which comprises the following steps:

(1) dispersing 100mg of graphene oxide in 40mL of aqueous solution, performing ultrasonic treatment for 30min, introducing nitrogen for 10-30min, adding 3g of sodium p-styrenesulfonate and 57mg of ammonium persulfate, uniformly stirring, mixing under the protection of nitrogen, heating to 65 ℃, reacting for 48h, and performing centrifugal washing for several times by using deionized water after the reaction is finished to obtain an intermediate product I;

(2) adding the intermediate product I prepared in the step (1) into 200mL of hydrochloric acid solution with the concentration of 3mol/L, stirring for 4h, centrifuging, washing for several times by using deionized water until the solution is weakly acidic, dispersing the centrifuged product into 150mL of LiOH solution with the concentration of 20mg/mL, stirring for 24h, centrifuging again, and washing the centrifuged product for several times by using water until the solution is neutral to obtain an intermediate product II;

(3) and (3) dispersing the intermediate product II prepared in the step (2) in water, and heating and volatilizing the intermediate product II on a polytetrafluoroethylene plate at 30 ℃ to form a film, so as to obtain the polymer brush material IV with a two-dimensional sheet structure.

(4) Cutting the first material into the size of a diaphragm, taking 30 mu L of electrolyte, and assembling the first material into a lithium metal battery in a glove box.

Example 6

The embodiment of the invention provides a preparation method of a two-dimensional polymer brush functional diaphragm and application of the diaphragm in preparation of a lithium metal battery, which comprises the following steps:

(1) dispersing 100mg of graphene oxide in 40mL of aqueous solution, performing ultrasonic treatment for 30min, introducing nitrogen for 10-30min, adding 3g of sodium p-styrenesulfonate and 57mg of ammonium persulfate, uniformly stirring, mixing under the protection of nitrogen, heating to 85 ℃, reacting for 48h, and performing centrifugal washing for several times by using deionized water after the reaction is finished to obtain an intermediate product I;

(2) adding the intermediate product I prepared in the step (1) into 200mL of hydrochloric acid solution with the concentration of 3mol/L, stirring for 4h, centrifuging, washing for several times by using deionized water until the solution is weakly acidic, dispersing the centrifuged product into 150mL of LiOH solution with the concentration of 20mg/mL, stirring for 24h, centrifuging again, and washing the centrifuged product for several times by using water until the solution is neutral to obtain an intermediate product II;

(3) and (3) dispersing the intermediate product II prepared in the step (2) in water, and heating and volatilizing the intermediate product II on a polytetrafluoroethylene plate at 30 ℃ to form a film, so as to obtain the polymer brush material V with the two-dimensional sheet structure.

(4) Cutting the first material into the size of a diaphragm, taking 30 mu L of electrolyte, and assembling the first material into a lithium metal battery in a glove box.

Example 7

The embodiment of the invention provides a preparation method of a two-dimensional polymer brush functional diaphragm and application of the diaphragm in preparation of a lithium metal battery, which comprises the following steps:

(1) dispersing 50mg of graphene oxide in 40mL of aqueous solution, performing ultrasonic treatment for 30min, introducing nitrogen for 10-30min, adding 3g of sodium p-styrenesulfonate and 57mg of ammonium persulfate, uniformly stirring, mixing under the protection of nitrogen, heating to 75 ℃, reacting for 48h, and performing centrifugal washing for several times by using deionized water after the reaction is finished to obtain an intermediate product I;

(2) adding the intermediate product I prepared in the step (1) into 200mL of hydrochloric acid solution with the concentration of 3mol/L, stirring for 4h, centrifuging, washing for several times by using deionized water until the solution is weakly acidic, dispersing the centrifuged product into 150mL of LiOH solution with the concentration of 20mg/mL, stirring for 24h, centrifuging again, and washing the centrifuged product for several times by using water until the solution is neutral to obtain an intermediate product II;

(3) and (3) dispersing the intermediate product II prepared in the step (2) in water, and heating and volatilizing the intermediate product II on a polytetrafluoroethylene plate at 30 ℃ to form a film, so as to obtain the high polymer brush material VI with the two-dimensional sheet structure.

(4) Cutting the first material into the size of a diaphragm, taking 30 mu L of electrolyte, and assembling the first material into a lithium metal battery in a glove box.

TABLE 2 Polymer content in Polymer Brush Membrane having a two-dimensional lamellar Structure

The results show that: the reaction temperature and the feeding ratio in the step (1) have certain influence on the polymer brush content of the product. The content of polymeric brush in the product can be increased with the increase of the reaction temperature. However, as the temperature increases, side reactions occur to reduce the grafting amount of the polymeric brush. The feed ratio is reduced, which is beneficial to improving the content of the polymer brush.

Finally, it should be noted that: the above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention in any way. It will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof, and it is intended that the present invention encompass such changes and modifications.