A method for removing polyethylene glycol from water

Abstract

The application provides a method for removing polyethylene glycol in water, and specifically comprises the following steps: S1. adding a hydrogen peroxide solution to a solution containing polyethylene glycol, adding a sodium hydroxide solution after a reaction for a certain time, and adjusting the pH of the solution; S2. filtering the solution obtained in S1 by using a polyguanidine grafted two-component hollow electrospun fiber membrane to remove polyethylene glycol in water. In the application, the two-component hollow electrospun fiber membrane is prepared by taking carboxymethyl chitosan / berberine hydrochloride as a shell layer and a porous RGO membrane as a core layer; the berberine hydrochloride in the shell layer releases quaternary ammonium salt cations to adsorb carboxylate ions so as to realize the removal of polyethylene glycol; the PVP in the core layer is removed to construct a porous structure in the RGO fiber membrane, which is beneficial to the adsorption and mass transfer of the carboxylate ions; and the hollow fiber membrane has a high specific surface area, which provides more active sites for ion adsorption, thereby improving the adsorption efficiency.

Description

Technical Field

[0001] The present invention relates to the field of environmental protection, and in particular to a method for removing polyethylene glycol from water. Background Art

[0002] In recent years, with the growing demand for clean energy, the photovoltaic industry has experienced rapid growth. As a sustainable and clean energy source, solar energy is increasingly contributing to the global energy mix. The manufacture of photovoltaic cells is a key step in achieving efficient solar energy utilization, and silicon wafer cutting is a crucial step in the PV cell manufacturing process. Photovoltaic cutting fluid plays a vital role in the silicon wafer cutting process. It primarily cools and lubricates cutting tools, while also removing impurities such as silicon shavings generated during the cutting process, ensuring cutting accuracy and efficiency. Polyethylene glycol (PEG) is a common polymer widely used in photovoltaic cutting fluids due to its excellent water solubility, lubricity, and chemical stability. In cutting fluids, PEG helps improve cutting quality and efficiency and reduces wear on cutting tools. However, the presence of PEG in cutting fluids during post-use processing complicates their recovery and reuse. This is because PEG affects the recovery efficiency of other components in the cutting fluid, and direct discharge of PEG-containing cutting fluids can pollute the environment. Summary of the Invention

[0003] Technical problem to be solved: The purpose of the present invention is to provide a method for removing polyethylene glycol from water, which oxidizes the primary hydroxyl groups in polyethylene glycol into carboxyl groups, and ionizes the carboxyl groups into carboxylate ions by adjusting the pH of the solution, and finally removes the polyethylene glycol through the adsorption effect of a polyguanidine-grafted two-component hollow electrospun fiber membrane.

[0004] Technical solution:

[0005] A method for removing polyethylene glycol from water, comprising the following steps:

[0006] S1. Add hydrogen peroxide solution to the solution containing polyethylene glycol, add sodium hydroxide solution after a certain reaction time, and adjust the pH of the solution to 7-8;

[0007] S2. Filter the solution obtained in S1 using a polyguanidine-grafted two-component hollow electrospun fiber membrane to remove polyethylene glycol from the water;

[0008] In which, the polyguanidine-grafted two-component hollow electrospun fiber membrane in step S2 has carboxymethyl chitosan / berberine hydrochloride as the shell layer and a porous RGO membrane as the core layer. The core layer is formed by removing PVP to construct a porous structure in the RGO fiber membrane. The thickness of the polyguanidine-grafted two-component hollow electrospun fiber membrane is 15 to 25 μm and the porosity is 80 to 90%.

[0009] Preferably, the mass fraction of the solution containing polyethylene glycol in S1 is 5-15 wt %, the mass fraction of the hydrogen peroxide solution is 20-30 wt %, and the volume ratio of the solution containing polyethylene glycol to the hydrogen peroxide solution is 1:2-3.

[0010] Preferably, the preparation method of the polyguanidine grafted two-component hollow electrospun fiber membrane in S2 comprises the following steps:

[0011] S11. Dissolving carboxymethyl chitosan in acetic acid solution to obtain a solution A having a mass fraction of 8 to 15 wt %;

[0012] S12. Dissolving berberine hydrochloride in acetic acid / DMF solution to obtain a solution B having a mass fraction of 5 to 12 wt %;

[0013] S13. Mixing solution A and solution B to obtain an electrospinning shell solution;

[0014] S14. PVP was dissolved in water, and then RGO was added and ultrasonically dispersed to obtain an electrospinning core solution;

[0015] S15. Coaxially electrospinning the electrospinning shell solution and the electrospinning core solution in a volume ratio of 5 to 8:1 to obtain an electrospun fiber membrane;

[0016] S16. Performing a grafting reaction on the surface of the electrospun fiber membrane to obtain a polyguanidine-grafted two-component hollow electrospun fiber membrane.

[0017] Preferably, the volume ratio of solution A to solution B in S13 is 2 to 5:1.

[0018] Preferably, the mass ratio of PVP to RGO in S14 is 7 to 10:1, and the mass fraction of the obtained electrospinning core layer solution is 8 to 20 wt%.

[0019] Preferably, the voltage of the coaxial electrospinning in S15 is 16-24 kV, the receiving distance is 15-20 cm, the spinning speed of the core layer is 0.2-0.4 ml / h, and the spinning speed of the shell layer solution is 1-2 ml / h.

[0020] Preferably, the grafting reaction in S17 comprises the following steps:

[0021] S21. The polyguanidine is dissolved in water to obtain a solution having a mass fraction of 8 to 12 wt%;

[0022] S22. Soak the electrospun fiber membrane in PBS buffer, add the solution obtained in S21, and heat the reaction for a certain period of time to achieve grafting.

[0023] Preferably, the mass ratio of the electrospun fiber membrane to the PBS buffer in S22 is 1:20-30, and the pH of the PBS buffer is 7-8.

[0024] Preferably, the volume ratio of the PBS buffer in S22 to the solution obtained in S21 is 8 to 15:1.

[0025] Preferably, the temperature of the heating reaction in S22 is 30-50° C., and the time is 2-5 hours.

[0026] Beneficial effects: The present invention has the following advantages:

[0027] 1. In the present invention, hydrogen peroxide is used to oxidize the primary hydroxyl groups of polyethylene glycol into carboxyl groups. Subsequently, sodium hydroxide is added to ionize the carboxyl groups into carboxylate ions while removing unreacted hydrogen peroxide. Finally, the polyethylene glycol is removed through the multiple adsorption functions of the polyguanidine-grafted two-component hollow electrospun fiber membrane.

[0028] 2. The two-component hollow electrospun fiber membrane prepared in the present invention has carboxymethyl chitosan / berberine hydrochloride as the shell layer and a porous graphene membrane as the core layer. Berberine hydrochloride in the shell layer is a quaternary ammonium alkaloid that can release quaternary ammonium salt cations and adsorb carboxylate ions to achieve the removal of polyethylene glycol. By removing PVP from the core layer, a porous structure is constructed in the RGO fiber membrane, which is conducive to the adsorption and mass transfer of carboxylate ions. In addition, the electron density on the aromatic ring of RGO is low, forming an electron-deficient environment, thereby attracting negatively charged carboxylate ions, generating anion-π interactions, and achieving the removal of polyethylene glycol. The hollow fiber membrane has a high specific surface area, providing more active sites for ion adsorption. The internal cavity can provide a direct channel for ions, shortening the path for ions to diffuse from the solution to the interior of the material, thereby improving the adsorption efficiency.

[0029] 3. In the present invention, the carboxyl groups on the surface of carboxymethyl chitosan are used to undergo an amidation reaction with the amino groups contained in polyguanidine, and the polyguanidine is grafted onto the surface of the two-component hollow electrospun fiber membrane by forming an amide bond. The guanidine groups in the polyguanidine can combine with carboxylate ions through charge interaction, thereby achieving the removal of polyethylene glycol. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with examples, which are provided to explain the present invention and are not limited to the following examples:

[0031] Example 1

[0032] A method for removing polyethylene glycol from water, comprising the following steps:

[0033] S1. To a 5 wt % solution containing polyethylene glycol, a 20 wt % hydrogen peroxide solution was added, the volume ratio of the polyethylene glycol solution to the hydrogen peroxide solution was 1:2, and after reacting for 30 min, a 0.3 mol / L sodium hydroxide solution was added to adjust the pH of the solution to 7.5;

[0034] S2. Filter the solution obtained in S1 using a polyguanidine-grafted two-component hollow electrospun fiber membrane to remove polyethylene glycol from the water;

[0035] The polyguanidine-grafted two-component hollow electrospun fiber membrane in step S2 has carboxymethyl chitosan / berberine hydrochloride as a shell layer and a porous RGO membrane as a core layer. The core layer is formed by removing PVP to construct a porous structure in the RGO fiber membrane. The polyguanidine-grafted two-component hollow electrospun fiber membrane has a thickness of 15 μm and a porosity of 80%.

[0036] The preparation method of the polyguanidine grafted two-component hollow electrospun fiber membrane in S2 comprises the following steps:

[0037] S11. Dissolving carboxymethyl chitosan in acetic acid solution to obtain a solution A having a mass fraction of 8 wt %;

[0038] S12. Dissolving berberine hydrochloride in acetic acid / DMF solution to obtain a 5 wt % solution B;

[0039] S13. Solution A and solution B were mixed in a volume ratio of 2:1 to obtain an electrospinning shell solution;

[0040] S14. PVP was dissolved in water, and then RGO was added and ultrasonically dispersed. The mass ratio of PVP to RGO was 7:1, to obtain an electrospinning core layer solution with a mass fraction of 8 wt%;

[0041] S15. The electrospinning shell solution and the electrospinning core solution were coaxially electrospun at a volume ratio of 5:1. The coaxial electrospinning voltage was 16 kV, the receiving distance was 15 cm, the core layer spinning speed was 0.2 ml / h, and the shell layer solution spinning speed was 1 ml / h to obtain an electrospun fiber membrane;

[0042] S16. Performing a grafting reaction on the surface of the electrospun fiber membrane to obtain a polyguanidine-grafted two-component hollow electrospun fiber membrane.

[0043] Wherein, the grafting reaction in S17 comprises the following steps:

[0044] S21. The polyguanidine was dissolved in water to obtain a solution having a mass fraction of 8 wt%;

[0045] S22. Soak the electrospun fiber membrane in PBS buffer with a pH of 7, with a mass ratio of the electrospun fiber membrane to the PBS buffer of 1:20, and add the solution obtained in S21, with a volume ratio of PBS buffer to the solution obtained in S21 of 8:1. Heat to 30°C and react for 2 hours to achieve grafting.

[0046] Example 2

[0047] A method for removing polyethylene glycol from water, comprising the following steps:

[0048] S1. To a 5 wt % solution containing polyethylene glycol, a 20 wt % hydrogen peroxide solution was added, the volume ratio of the polyethylene glycol solution to the hydrogen peroxide solution was 1:2, and after reacting for 30 min, a 0.3 mol / L sodium hydroxide solution was added to adjust the pH of the solution to 7.5;

[0049] S2. Filter the solution obtained in S1 using a polyguanidine-grafted two-component hollow electrospun fiber membrane to remove polyethylene glycol from the water;

[0050] The polyguanidine-grafted two-component hollow electrospun fiber membrane in step S2 has carboxymethyl chitosan / berberine hydrochloride as a shell layer and a porous RGO membrane as a core layer. The core layer is formed by removing PVP to construct a porous structure in the RGO fiber membrane. The polyguanidine-grafted two-component hollow electrospun fiber membrane has a thickness of 15 μm and a porosity of 80%.

[0051] The preparation method of the polyguanidine grafted two-component hollow electrospun fiber membrane in S2 comprises the following steps:

[0052] S11. Dissolving carboxymethyl chitosan in acetic acid solution to obtain a solution A having a mass fraction of 8 wt %;

[0053] S12. Dissolving berberine hydrochloride in acetic acid / DMF solution to obtain a 5 wt % solution B;

[0054] S13. Solution A and solution B were mixed in a volume ratio of 3:1 to obtain an electrospinning shell solution;

[0055] S14. PVP was dissolved in water, and then RGO was added and ultrasonically dispersed. The mass ratio of PVP to RGO was 7:1, to obtain an electrospinning core layer solution with a mass fraction of 8 wt%;

[0056] S15. The electrospinning shell solution and the electrospinning core solution were coaxially electrospun at a volume ratio of 5:1. The coaxial electrospinning voltage was 16 kV, the receiving distance was 15 cm, the core layer spinning speed was 0.2 ml / h, and the shell layer solution spinning speed was 1 ml / h to obtain an electrospun fiber membrane;

[0057] S16. Performing a grafting reaction on the surface of the electrospun fiber membrane to obtain a polyguanidine-grafted two-component hollow electrospun fiber membrane.

[0058] Wherein, the grafting reaction in S17 comprises the following steps:

[0059] S21. The polyguanidine was dissolved in water to obtain a solution having a mass fraction of 8 wt%;

[0060] S22. Soak the electrospun fiber membrane in PBS buffer with a pH of 7, with a mass ratio of the electrospun fiber membrane to the PBS buffer of 1:20, and add the solution obtained in S21, with a volume ratio of PBS buffer to the solution obtained in S21 of 8:1. Heat to 30°C and react for 2 hours to achieve grafting.

[0061] Example 3

[0062] A method for removing polyethylene glycol from water, comprising the following steps:

[0063] S1. To a 5 wt % solution containing polyethylene glycol, a 20 wt % hydrogen peroxide solution was added, the volume ratio of the polyethylene glycol solution to the hydrogen peroxide solution was 1:2, and after reacting for 30 min, a 0.3 mol / L sodium hydroxide solution was added to adjust the pH of the solution to 7.5;

[0064] S2. Filter the solution obtained in S1 using a polyguanidine-grafted two-component hollow electrospun fiber membrane to remove polyethylene glycol from the water;

[0065] The polyguanidine-grafted two-component hollow electrospun fiber membrane in step S2 has carboxymethyl chitosan / berberine hydrochloride as a shell layer and a porous RGO membrane as a core layer. The core layer is formed by removing PVP to construct a porous structure in the RGO fiber membrane. The polyguanidine-grafted two-component hollow electrospun fiber membrane has a thickness of 15 μm and a porosity of 80%.

[0066] The preparation method of the polyguanidine grafted two-component hollow electrospun fiber membrane in S2 comprises the following steps:

[0067] S11. Dissolving carboxymethyl chitosan in acetic acid solution to obtain a solution A having a mass fraction of 8 wt %;

[0068] S12. Dissolving berberine hydrochloride in acetic acid / DMF solution to obtain a 5 wt % solution B;

[0069] S13. Solution A and solution B were mixed in a volume ratio of 4:1 to obtain an electrospinning shell solution;

[0070] S14. PVP was dissolved in water, and then RGO was added and ultrasonically dispersed. The mass ratio of PVP to RGO was 7:1, to obtain an electrospinning core layer solution with a mass fraction of 8 wt%;

[0071] S15. The electrospinning shell solution and the electrospinning core solution were coaxially electrospun at a volume ratio of 5:1. The coaxial electrospinning voltage was 16 kV, the receiving distance was 15 cm, the core layer spinning speed was 0.2 ml / h, and the shell layer solution spinning speed was 1 ml / h to obtain an electrospun fiber membrane;

[0072] S16. Performing a grafting reaction on the surface of the electrospun fiber membrane to obtain a polyguanidine-grafted two-component hollow electrospun fiber membrane.

[0073] Wherein, the grafting reaction in S17 comprises the following steps:

[0074] S21. The polyguanidine was dissolved in water to obtain a solution having a mass fraction of 8 wt%;

[0075] S22. Soak the electrospun fiber membrane in PBS buffer with a pH of 7, with a mass ratio of the electrospun fiber membrane to the PBS buffer of 1:20, and add the solution obtained in S21, with a volume ratio of PBS buffer to the solution obtained in S21 of 8:1. Heat to 30°C and react for 2 hours to achieve grafting.

[0076] Example 4

[0077] A method for removing polyethylene glycol from water, comprising the following steps:

[0078] S1. To a 10 wt % polyethylene glycol solution, a 25 wt % hydrogen peroxide solution was added, the volume ratio of the polyethylene glycol solution to the hydrogen peroxide solution was 1:2, and after reacting for 30 min, a 0.3 mol / L sodium hydroxide solution was added to adjust the pH of the solution to 8;

[0079] S2. Filter the solution obtained in S1 using a polyguanidine-grafted two-component hollow electrospun fiber membrane to remove polyethylene glycol from the water;

[0080] The polyguanidine-grafted two-component hollow electrospun fiber membrane in step S2 has carboxymethyl chitosan / berberine hydrochloride as the shell layer and a porous RGO membrane as the core layer. The core layer is formed by removing PVP to construct a porous structure in the RGO fiber membrane. The polyguanidine-grafted two-component hollow electrospun fiber membrane has a thickness of 18 μm and a porosity of 82%.

[0081] The preparation method of the polyguanidine grafted two-component hollow electrospun fiber membrane in S2 comprises the following steps:

[0082] S11. Carboxymethyl chitosan is dissolved in acetic acid solution to obtain solution A with a mass fraction of 10wt%;

[0083] S12. Berberine hydrochloride is dissolved in acetic acid / DMF solution to obtain solution B with a mass fraction of 8wt%;

[0084] S13. Solution A and solution B are mixed according to a volume ratio of 5:1 to obtain a static spinning shell solution;

[0085] S14. PVP is dissolved in water, followed by the addition of RGO and ultrasonic dispersion, the mass ratio of PVP to RGO being 9:1, to obtain a static spinning core solution with a mass fraction of 12wt%;

[0086] S15. The static spinning shell solution and the static spinning core solution are coaxially electrospun according to a volume ratio of 5:1, the voltage of the coaxial electrospinning being 20KV, the receiving distance being 18cm, the spinning speed of the core layer being 0.3ml / h, and the spinning speed of the shell solution being 2ml / h to obtain a static spinning fiber membrane;

[0087] S16. A grafting reaction is performed on the surface of the static spinning fiber membrane to obtain a polyguanidine grafted double-component hollow static spinning fiber membrane.

[0088] The grafting reaction in S17 comprises the following steps:

[0089] S21. Polyguanidine is dissolved in water to obtain a solution with a mass fraction of 10wt%;

[0090] S22. The static spinning fiber membrane is immersed in a PBS buffer solution with a pH of 7, the mass ratio of the static spinning fiber membrane to the PBS buffer solution being 1:25, and the solution obtained in S21 is added, the volume of the PBS buffer solution to the solution obtained in S21 being 12:1, and the solution is heated to 40℃ for 3h to realize grafting.

[0091] Example 5

[0092] A method for removing polyethylene glycol in water, the method comprising the following steps:

[0093] S1. A 30wt% hydrogen peroxide solution is added to a 15wt% polyethylene glycol-containing solution, the volume ratio of the polyethylene glycol-containing solution to the hydrogen peroxide solution being 1:2, and a 0.5mol / L sodium hydroxide solution is added after 80min of reaction to adjust the pH of the solution to 8;

[0094] S2. The solution obtained in S1 is filtered by using a polyguanidine grafted double-component hollow static spinning fiber membrane to remove polyethylene glycol in water;

[0095] The polyguanidine-grafted two-component hollow electrospun fiber membrane in step S2 has carboxymethyl chitosan / berberine hydrochloride as a shell layer and a porous RGO membrane as a core layer. The core layer is formed by removing PVP to construct a porous structure in the RGO fiber membrane. The polyguanidine-grafted two-component hollow electrospun fiber membrane has a thickness of 15 μm and a porosity of 88%.

[0096] The preparation method of the polyguanidine grafted two-component hollow electrospun fiber membrane in S2 comprises the following steps:

[0097] S11. Dissolving carboxymethyl chitosan in acetic acid solution to obtain a solution A having a mass fraction of 15 wt %;

[0098] S12. Dissolving berberine hydrochloride in acetic acid / DMF solution to obtain a solution B having a mass fraction of 8 wt %;

[0099] S13. Solution A and solution B were mixed in a volume ratio of 5:1 to obtain an electrospinning shell solution;

[0100] S14. PVP was dissolved in water, and then RGO was added and ultrasonically dispersed. The mass ratio of PVP to RGO was 9:1, to obtain an electrospinning core layer solution with a mass fraction of 12 wt%;

[0101] S15. The electrospinning shell solution and the electrospinning core solution were coaxially electrospun at a volume ratio of 8:1. The coaxial electrospinning voltage was 22 kV, the receiving distance was 18 cm, the core layer spinning speed was 0.3 ml / h, and the shell layer solution spinning speed was 2 ml / h to obtain an electrospun fiber membrane;

[0102] S16. Performing a grafting reaction on the surface of the electrospun fiber membrane to obtain a polyguanidine-grafted two-component hollow electrospun fiber membrane.

[0103] Wherein, the grafting reaction in S17 comprises the following steps:

[0104] S21. The polyguanidine was dissolved in water to obtain a solution having a mass fraction of 10 wt%;

[0105] S22. Soak the electrospun fiber membrane in PBS buffer with a pH of 7, with a mass ratio of the electrospun fiber membrane to the PBS buffer of 1:30, and add the solution obtained in S21, with a volume ratio of PBS buffer to the solution obtained in S21 of 15:1. Heat to 50°C and react for 3 hours to achieve grafting.

[0106] Example 6

[0107] A method for removing polyethylene glycol from water, comprising the following steps:

[0108] S1. To a 12 wt % polyethylene glycol solution, a 28 wt % hydrogen peroxide solution was added, the volume ratio of the polyethylene glycol solution to the hydrogen peroxide solution was 1:3, and after 80 min of reaction, a 0.4 mol / L sodium hydroxide solution was added to adjust the pH of the solution to 8;

[0109] S2. Filter the solution obtained in S1 using a polyguanidine-grafted two-component hollow electrospun fiber membrane to remove polyethylene glycol from the water;

[0110] The polyguanidine-grafted two-component hollow electrospun fiber membrane in step S2 has carboxymethyl chitosan / berberine hydrochloride as a shell layer and a porous RGO membrane as a core layer. The core layer is formed by removing PVP to construct a porous structure in the RGO fiber membrane. The polyguanidine-grafted two-component hollow electrospun fiber membrane has a thickness of 15 μm and a porosity of 90%.

[0111] The preparation method of the polyguanidine grafted two-component hollow electrospun fiber membrane in S2 comprises the following steps:

[0112] S11. Dissolving carboxymethyl chitosan in acetic acid solution to obtain a solution A having a mass fraction of 15 wt %;

[0113] S12. Dissolving berberine hydrochloride in acetic acid / DMF solution to obtain a solution B having a mass fraction of 8 wt %;

[0114] S13. Solution A and solution B were mixed in a volume ratio of 5:1 to obtain an electrospinning shell solution;

[0115] S14. PVP was dissolved in water, and then RGO was added and ultrasonically dispersed. The mass ratio of PVP to RGO was 9:1, to obtain an electrospinning core layer solution with a mass fraction of 12 wt%;

[0116] S15. The electrospinning shell solution and the electrospinning core solution were coaxially electrospun at a volume ratio of 8:1. The coaxial electrospinning voltage was 20 kV, the receiving distance was 15 cm, the core layer spinning speed was 0.3 ml / h, and the shell layer solution spinning speed was 1.5 ml / h to obtain an electrospun fiber membrane;

[0117] S16. Performing a grafting reaction on the surface of the electrospun fiber membrane to obtain a polyguanidine-grafted two-component hollow electrospun fiber membrane.

[0118] Wherein, the grafting reaction in S17 comprises the following steps:

[0119] S21. The polyguanidine was dissolved in water to obtain a solution having a mass fraction of 12 wt%;

[0120] S22. Soak the electrospun fiber membrane in PBS buffer with a pH of 8, with a mass ratio of the electrospun fiber membrane to the PBS buffer of 1:30, and add the solution obtained in S21, with a volume ratio of PBS buffer to the solution obtained in S21 of 14:1. Heat to 50°C and react for 4 hours to achieve grafting.

[0121] Example 7

[0122] A method for removing polyethylene glycol from water, comprising the following steps:

[0123] S1. To a 12 wt % polyethylene glycol solution, a 28 wt % hydrogen peroxide solution was added, the volume ratio of the polyethylene glycol solution to the hydrogen peroxide solution was 1:3, and after 80 min of reaction, a 0.4 mol / L sodium hydroxide solution was added to adjust the pH of the solution to 8;

[0124] S2. Filter the solution obtained in S1 using a polyguanidine-grafted two-component hollow electrospun fiber membrane to remove polyethylene glycol from the water;

[0125] The polyguanidine-grafted two-component hollow electrospun fiber membrane in step S2 has carboxymethyl chitosan / berberine hydrochloride as a shell layer and a porous RGO membrane as a core layer. The core layer is formed by removing PVP to construct a porous structure in the RGO fiber membrane. The polyguanidine-grafted two-component hollow electrospun fiber membrane has a thickness of 20 μm and a porosity of 82%.

[0126] The preparation method of the polyguanidine grafted two-component hollow electrospun fiber membrane in S2 comprises the following steps:

[0127] S11. Dissolving carboxymethyl chitosan in acetic acid solution to obtain a solution A having a mass fraction of 15 wt %;

[0128] S12. Dissolving berberine hydrochloride in acetic acid / DMF solution to obtain a solution B having a mass fraction of 8 wt %;

[0129] S13. Solution A and solution B were mixed in a volume ratio of 5:1 to obtain an electrospinning shell solution;

[0130] S14. PVP was dissolved in water, and then RGO was added and ultrasonically dispersed. The mass ratio of PVP to RGO was 9:1, to obtain an electrospinning core layer solution with a mass fraction of 12 wt%;

[0131] S15. The electrospinning shell solution and the electrospinning core solution were coaxially electrospun at a volume ratio of 8:1. The coaxial electrospinning voltage was 20 kV, the receiving distance was 15 cm, the core layer spinning speed was 0.3 ml / h, and the shell layer solution spinning speed was 1.5 ml / h to obtain an electrospun fiber membrane;

[0132] S16. Performing a grafting reaction on the surface of the electrospun fiber membrane to obtain a polyguanidine-grafted two-component hollow electrospun fiber membrane.

[0133] Wherein, the grafting reaction in S17 comprises the following steps:

[0134] S21. The polyguanidine was dissolved in water to obtain a solution having a mass fraction of 10 wt%;

[0135] S22. Soak the electrospun fiber membrane in PBS buffer with a pH of 8, with a mass ratio of the electrospun fiber membrane to the PBS buffer of 1:30, and add the solution obtained in S21, with a volume ratio of PBS buffer to the solution obtained in S21 of 14:1. Heat to 50°C and react for 4 hours to achieve grafting.

[0136] Example 8

[0137] A method for removing polyethylene glycol from water, comprising the following steps:

[0138] S1. To a 12 wt % polyethylene glycol solution, a 28 wt % hydrogen peroxide solution was added, the volume ratio of the polyethylene glycol solution to the hydrogen peroxide solution was 1:3, and after 80 min of reaction, a 0.4 mol / L sodium hydroxide solution was added to adjust the pH of the solution to 8;

[0139] S2. Filter the solution obtained in S1 using a polyguanidine-grafted two-component hollow electrospun fiber membrane to remove polyethylene glycol from the water;

[0140] The polyguanidine-grafted two-component hollow electrospun fiber membrane in step S2 has carboxymethyl chitosan / berberine hydrochloride as a shell layer and a porous RGO membrane as a core layer. The core layer is formed by removing PVP to construct a porous structure in the RGO fiber membrane. The polyguanidine-grafted two-component hollow electrospun fiber membrane has a thickness of 20 μm and a porosity of 82%.

[0141] The preparation method of the polyguanidine grafted two-component hollow electrospun fiber membrane in S2 comprises the following steps:

[0142] S11. Dissolving carboxymethyl chitosan in acetic acid solution to obtain a solution A having a mass fraction of 15 wt %;

[0143] S12. Dissolving berberine hydrochloride in acetic acid / DMF solution to obtain a solution B having a mass fraction of 8 wt %;

[0144] S13. Solution A and solution B were mixed in a volume ratio of 5:1 to obtain an electrospinning shell solution;

[0145] S14. PVP was dissolved in water, and then RGO was added and ultrasonically dispersed. The mass ratio of PVP to RGO was 9:1, to obtain an electrospinning core layer solution with a mass fraction of 12 wt%;

[0146] S15. The electrospinning shell solution and the electrospinning core solution were coaxially electrospun at a volume ratio of 8:1. The coaxial electrospinning voltage was 20 kV, the receiving distance was 15 cm, the core layer spinning speed was 0.3 ml / h, and the shell layer solution spinning speed was 1.5 ml / h to obtain an electrospun fiber membrane;

[0147] S16. Performing a grafting reaction on the surface of the electrospun fiber membrane to obtain a polyguanidine-grafted two-component hollow electrospun fiber membrane.

[0148] Wherein, the grafting reaction in S17 comprises the following steps:

[0149] S21. The polyguanidine was dissolved in water to obtain a solution having a mass fraction of 12 wt%;

[0150] S22. Soak the electrospun fiber membrane in PBS buffer with a pH of 8, with a mass ratio of the electrospun fiber membrane to the PBS buffer of 1:30, and add the solution obtained in S21, with a volume ratio of PBS buffer to the solution obtained in S21 of 14:1. Heat to 50°C and react for 4 hours to achieve grafting.

[0151] Comparative Example 1

[0152] A method for removing polyethylene glycol from water, comprising the following steps:

[0153] S1. To a 5 wt % solution containing polyethylene glycol, a 20 wt % hydrogen peroxide solution was added, the volume ratio of the polyethylene glycol solution to the hydrogen peroxide solution was 1:2, and after reacting for 30 min, a 0.3 mol / L sodium hydroxide solution was added to adjust the pH of the solution to 7.5;

[0154] S2. Filter the solution obtained in S1 using a polyguanidine-grafted two-component hollow electrospun fiber membrane to remove polyethylene glycol from the water;

[0155] The polyguanidine-grafted two-component hollow electrospun fiber membrane in step S2 has carboxymethyl chitosan / berberine hydrochloride as a shell layer and a porous RGO membrane as a core layer. The core layer is formed by removing PVP to construct a porous structure in the RGO fiber membrane. The polyguanidine-grafted two-component hollow electrospun fiber membrane has a thickness of 15 μm and a porosity of 80%.

[0156] The preparation method of the polyguanidine grafted two-component hollow electrospun fiber membrane in S2 comprises the following steps:

[0157] S11. Dissolving carboxymethyl chitosan in acetic acid solution to obtain a solution A having a mass fraction of 8 wt %;

[0158] S12. Dissolving berberine hydrochloride in acetic acid / DMF solution to obtain a 5 wt % solution B;

[0159] S13. Solution A and solution B were mixed in a volume ratio of 1:1 to obtain an electrospinning shell solution;

[0160] S14. PVP was dissolved in water, and then RGO was added and ultrasonically dispersed. The mass ratio of PVP to RGO was 7:1, to obtain an electrospinning core layer solution with a mass fraction of 8 wt%;

[0161] S15. The electrospinning shell solution and the electrospinning core solution were coaxially electrospun at a volume ratio of 5:1. The coaxial electrospinning voltage was 16 kV, the receiving distance was 15 cm, the core layer spinning speed was 0.2 ml / h, and the shell layer solution spinning speed was 1 ml / h to obtain an electrospun fiber membrane;

[0162] S16. Performing a grafting reaction on the surface of the electrospun fiber membrane to obtain a polyguanidine-grafted two-component hollow electrospun fiber membrane.

[0163] Wherein, the grafting reaction in S17 comprises the following steps:

[0164] S21. The polyguanidine was dissolved in water to obtain a solution having a mass fraction of 8 wt%;

[0165] S22. Soak the electrospun fiber membrane in PBS buffer with a pH of 7, with a mass ratio of the electrospun fiber membrane to the PBS buffer of 1:20, and add the solution obtained in S21, with a volume ratio of PBS buffer to the solution obtained in S21 of 8:1. Heat to 30°C and react for 2 hours to achieve grafting.

[0166] Comparative Example 2

[0167] A method for removing polyethylene glycol from water, comprising the following steps:

[0168] S1. To a 5 wt % solution containing polyethylene glycol, a 20 wt % hydrogen peroxide solution was added, the volume ratio of the polyethylene glycol solution to the hydrogen peroxide solution was 1:2, and after reacting for 30 min, a 0.3 mol / L sodium hydroxide solution was added to adjust the pH of the solution to 7.5;

[0169] S2. Filter the solution obtained in S1 using a polyguanidine-grafted two-component hollow electrospun fiber membrane to remove polyethylene glycol from the water;

[0170] The polyguanidyl grafted bi-component hollow electrospun fiber membrane in step S2 has a shell layer of carboxymethyl chitosan / berberine hydrochloride and a core layer of porous RGO membrane. The core layer is constructed by removing PVP to form a porous structure in the RGO fiber membrane. The thickness of the polyguanidyl grafted bi-component hollow electrospun fiber membrane is 15μm, and the porosity is 80%.

[0171] The preparation method of the polyguanidyl grafted bi-component hollow electrospun fiber membrane in S2 comprises the following steps:

[0172] S11. Carboxymethyl chitosan is dissolved in acetic acid solution to obtain solution A with a mass fraction of 8wt%.

[0173] S12. Berberine hydrochloride is dissolved in acetic acid / DMF solution to obtain solution B with a mass fraction of 5wt%.

[0174] S13. Solution A and solution B are mixed according to a volume ratio of 6:1 to obtain a shell layer electrospinning solution.

[0175] S14. PVP is dissolved in water, and then RGO is added and ultrasonically dispersed. The mass ratio of PVP to RGO is 7:1. An electrospinning core layer solution with a mass fraction of 8wt% is obtained.

[0176] S15. The shell layer electrospinning solution and the core layer electrospinning solution are coaxially electrospun according to a volume ratio of 5:1. The coaxial electrospinning voltage is 16KV, the receiving distance is 15cm, the spinning speed of the core layer is 0.2ml / h, and the spinning speed of the shell layer solution is 1ml / h to obtain an electrospun fiber membrane.

[0177] S16. A grafting reaction is carried out on the surface of the electrospun fiber membrane to obtain a polyguanidyl grafted bi-component hollow electrospun fiber membrane.

[0178] The grafting reaction in S17 comprises the following steps:

[0179] S21. Polyguanidine is dissolved in water to obtain a solution with a mass fraction of 8wt%.

[0180] S22. The electrospun fiber membrane is soaked in a PBS buffer solution with a pH of 7. The mass ratio of the electrospun fiber membrane to the PBS buffer solution is 1:20, and the solution obtained in S21 is added. The volume ratio of the PBS buffer solution to the solution obtained in S21 is 8:1. The solution is heated to 30℃ for 2h to realize grafting.

[0181] Table 1 Effect of volume ratio of solution A to solution B on polyethylene glycol removal rate

[0182] name Volume ratio of solution A to solution B Removal rate of polyethylene glycol / % Example 1 2:1 97.8 Example 2 3:1 96.3 Example 3 4:1 96.1 Comparative Example 1 1:1 82.7 Comparative Example 2 6:1 85.7

[0183] Comparative Example 3

[0184] A method for removing polyethylene glycol from water, comprising the following steps:

[0185] S1. To a 10 wt % polyethylene glycol solution, a 25 wt % hydrogen peroxide solution was added, the volume ratio of the polyethylene glycol solution to the hydrogen peroxide solution was 1:2, and after reacting for 30 min, a 0.3 mol / L sodium hydroxide solution was added to adjust the pH of the solution to 8;

[0186] S2. Filter the solution obtained in S1 using a polyguanidine-grafted two-component hollow electrospun fiber membrane to remove polyethylene glycol from the water;

[0187] The polyguanidine-grafted two-component hollow electrospun fiber membrane in step S2 has carboxymethyl chitosan / berberine hydrochloride as the shell layer and a porous RGO membrane as the core layer. The core layer is formed by removing PVP to construct a porous structure in the RGO fiber membrane. The polyguanidine-grafted two-component hollow electrospun fiber membrane has a thickness of 18 μm and a porosity of 82%.

[0188] The preparation method of the polyguanidine grafted two-component hollow electrospun fiber membrane in S2 comprises the following steps:

[0189] S11. Dissolving carboxymethyl chitosan in acetic acid solution to obtain a solution A having a mass fraction of 10 wt %;

[0190] S12. Dissolving berberine hydrochloride in acetic acid / DMF solution to obtain a solution B having a mass fraction of 8 wt %;

[0191] S13. Solution A and solution B were mixed in a volume ratio of 5:1 to obtain an electrospinning shell solution;

[0192] S14. PVP was dissolved in water, and then RGO was added and ultrasonically dispersed. The mass ratio of PVP to RGO was 9:1, to obtain an electrospinning core layer solution with a mass fraction of 12 wt%;

[0193] S15. The electrospinning shell solution and the electrospinning core solution were coaxially electrospun at a volume ratio of 5:1. The coaxial electrospinning voltage was 20 kV, the receiving distance was 18 cm, the core layer spinning speed was 0.3 ml / h, and the shell layer solution spinning speed was 2 ml / h to obtain a two-component electrospun fiber membrane;

[0194] S16. Soak the bicomponent electrospun fiber membrane obtained in S15 in water, and then dry it to obtain a bicomponent hollow electrospun fiber membrane.

[0195] Table 2 Effect of polyguanidine on the removal rate of polyethylene glycol

[0196] name Whether to graft polyguanidine Removal rate of polyethylene glycol / % Example 4 yes 96.8 Comparative Example 3 no 73.1

[0197] Comparative Example 4

[0198] A method for removing polyethylene glycol from water, comprising the following steps:

[0199] S1. To a 15 wt % polyethylene glycol solution, a 30 wt % hydrogen peroxide solution was added, the volume ratio of the polyethylene glycol solution to the hydrogen peroxide solution was 1:2, and after 80 min of reaction, a 0.5 mol / L sodium hydroxide solution was added to adjust the pH of the solution to 8;

[0200] S2. Filter the solution obtained in S1 using a polyguanidine-grafted two-component hollow electrospun fiber membrane to remove polyethylene glycol from the water;

[0201] The polyguanidine-grafted two-component hollow electrospun fiber membrane in step S2 has carboxymethyl chitosan / berberine hydrochloride as a shell layer and a porous RGO membrane as a core layer. The core layer is formed by removing PVP to construct a porous structure in the RGO fiber membrane. The polyguanidine-grafted two-component hollow electrospun fiber membrane has a thickness of 15 μm and a porosity of 88%.

[0202] The preparation method of the polyguanidine grafted two-component hollow electrospun fiber membrane in S2 comprises the following steps:

[0203] S11. Dissolving carboxymethyl chitosan in acetic acid solution to obtain a shell solution having a mass fraction of 15 wt %;

[0204] S14. PVP was dissolved in water, and then RGO was added and ultrasonically dispersed. The mass ratio of PVP to RGO was 9:1, to obtain an electrospinning core layer solution with a mass fraction of 12 wt%;

[0205] S15. The electrospinning shell solution and the electrospinning core solution were coaxially electrospun at a volume ratio of 8:1. The coaxial electrospinning voltage was 22 kV, the receiving distance was 18 cm, the core layer spinning speed was 0.3 ml / h, and the shell layer solution spinning speed was 2 ml / h to obtain an electrospun fiber membrane;

[0206] S16. Performing a grafting reaction on the surface of the electrospun fiber membrane to obtain a polyguanidine-grafted two-component hollow electrospun fiber membrane.

[0207] Wherein, the grafting reaction in S17 comprises the following steps:

[0208] S21. The polyguanidine was dissolved in water to obtain a solution having a mass fraction of 10 wt%;

[0209] S22. Soak the electrospun fiber membrane in PBS buffer with a pH of 7, with a mass ratio of the electrospun fiber membrane to the PBS buffer of 1:30, and add the solution obtained in S21, with a volume ratio of PBS buffer to the solution obtained in S21 of 15:1. Heat to 50°C and react for 3 hours to achieve grafting.

[0210] Table 3 Effect of berberine hydrochloride on the removal rate of polyethylene glycol

[0211] name Whether to add berberine hydrochloride Removal rate of polyethylene glycol / % Example 5 yes 95.8 Comparative Example 4 no 77.2

[0212] Comparative Example 5

[0213] A method for removing polyethylene glycol from water, comprising the following steps:

[0214] S1. To a 12 wt % polyethylene glycol solution, a 28 wt % hydrogen peroxide solution was added, the volume ratio of the polyethylene glycol solution to the hydrogen peroxide solution was 1:3, and after 80 min of reaction, a 0.4 mol / L sodium hydroxide solution was added to adjust the pH of the solution to 8;

[0215] S2. Filter the solution obtained in S1 using a polyguanidine-grafted two-component hollow electrospun fiber membrane to remove polyethylene glycol from the water;

[0216] The polyguanidine-grafted two-component hollow electrospun fiber membrane in step S2 has carboxymethyl chitosan / berberine hydrochloride as a shell layer and a porous RGO membrane as a core layer. The core layer is formed by removing PVP to construct a porous structure in the RGO fiber membrane. The polyguanidine-grafted two-component hollow electrospun fiber membrane has a thickness of 15 μm and a porosity of 90%.

[0217] The preparation method of the polyguanidine grafted two-component hollow electrospun fiber membrane in S2 comprises the following steps:

[0218] S11. Dissolving carboxymethyl chitosan in acetic acid solution to obtain a solution A having a mass fraction of 15 wt %;

[0219] S12. Dissolving berberine hydrochloride in acetic acid / DMF solution to obtain a solution B having a mass fraction of 8 wt %;

[0220] S13. Solution A and solution B were mixed in a volume ratio of 5:1 to obtain an electrospinning solution;

[0221] S14. The solution obtained in S13 was electrospun at a voltage of 20 kV, a receiving distance of 15 cm, and a spinning speed of 1.5 ml / h to obtain an electrospun fiber membrane;

[0222] S16. Performing a grafting reaction on the surface of the electrospun fiber membrane to obtain a polyguanidine-grafted electrospun fiber membrane.

[0223] Wherein, the grafting reaction in S16 comprises the following steps:

[0224] S21. The polyguanidine was dissolved in water to obtain a solution having a mass fraction of 12 wt%;

[0225] S22. Soak the electrospun fiber membrane in PBS buffer with a pH of 8, with a mass ratio of the electrospun fiber membrane to the PBS buffer of 1:30, and add the solution obtained in S21, with a volume ratio of PBS buffer to the solution obtained in S21 of 14:1. Heat to 50°C and react for 4 hours to achieve grafting.

[0226] Table 4 Effect of hollow structure on polyethylene glycol removal rate

[0227] name Is there a hollow structure? Removal rate of polyethylene glycol / % Example 6 yes 96.2 Comparative Example 5 no 72.9

[0228] Comparative Example 6

[0229] The difference between this comparative example and Example 7 is that the mass fraction of the polyguanidine solution is 4 wt %.

[0230] Comparative Example 7

[0231] The difference between this comparative example and Example 7 is that the mass fraction of the polyguanidine solution is 18 wt %.

[0232] Table 5 Effect of the mass fraction of polyguanidine on the removal rate of polyethylene glycol

[0233] name Mass fraction of polyguanidine / wt% Removal rate of polyethylene glycol / % Example 7 10 95.3 Example 8 12 96.8 Comparative Example 6 4 78.4 Comparative Example 7 18 70.5

[0234] Comparative Example 8

[0235] The difference between this comparative example and Example 8 is that berberine hydrochloride is not added to the shell layer but a quaternary ammonium salt is added.

[0236] Table 6 Effect of quaternary ammonium salt types on polyethylene glycol removal rate

[0237]

[0238]

[0239] Contrast 9

[0240] The difference between this comparative example and Example 7 is that the porosity of the polyguanidine-grafted two-component hollow electrospun fiber membrane is 70%.

[0241] Comparative Example 10

[0242] The difference between this comparative example and Example 7 is that the porosity of the polyguanidine-grafted two-component hollow electrospun fiber membrane is 93%.

[0243] Table 7 Effect of porosity on polyethylene glycol removal rate

[0244] name Porosity / % Removal rate of polyethylene glycol (%) Example 7 82 96.8 Comparative Example 9 70 90.7 Comparative Example 10 93 73.5

[0245] Performance Testing

[0246] The separation flux and the number of reusable times in each embodiment and comparative example are shown in Table 8.

[0247] Table 8 Separation flux and number of reusable times

[0248] name Separation flux / (L m -2 ·h -1 )]]> Reusable times Example 1 7662 10 Example 2 7537 8 Example 3 7806 10 Example 4 8023 9 Example 5 7654 8 Example 6 8139 8 Example 7 7912 9 Example 8 8120 10 Comparative Example 1 6654 9 Comparative Example 2 6920 8 Comparative Example 3 7036 4 Comparative Example 4 7133 5 Comparative Example 5 7159 6 Comparative Example 6 7281 7 Comparative Example 7 7338 5 Comparative Example 8 7680 6 Comparative Example 9 6342 8 Comparative Example 10 8477 7

[0249] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for removing polyethylene glycol from water, characterized in that: The method comprises the following steps: S1. Add hydrogen peroxide solution to the solution containing polyethylene glycol, add sodium hydroxide solution after a certain reaction time, and adjust the pH of the solution to 7.5~8.5; S2. Filter the solution obtained in S1 using a polyguanidine-grafted two-component hollow electrospun fiber membrane to remove polyethylene glycol from the water; The polyguanidine-grafted two-component hollow electrospun fiber membrane in step S2 has carboxymethyl chitosan / berberine hydrochloride as a shell layer and a porous graphene oxide membrane as a core layer. The core layer is formed by removing PVP to construct a porous structure in the graphene oxide fiber membrane. The polyguanidine-grafted two-component hollow electrospun fiber membrane has a thickness of 15 to 25 μm and a porosity of 80 to 90%. The method for preparing the polyguanidine-grafted two-component hollow electrospun fiber membrane in step S2 comprises the following steps: S11. Dissolving carboxymethyl chitosan in acetic acid solution to obtain a solution A having a mass fraction of 8 to 15 wt %; S12. Berberine hydrochloride was dissolved in acetic acid and DMF solution to obtain a mass fraction of 5 to 12 wt% solution B; S13. Mixing solution A and solution B to obtain an electrospinning shell solution; S14. PVP is dissolved in water, followed by addition of graphene oxide and ultrasonic dispersion to obtain an electrospinning core layer solution; S15. Coaxially electrospinning the electrospinning shell solution and the electrospinning core solution in a volume ratio of 5 to 8:1 to obtain an electrospun fiber membrane; S16. Performing a grafting reaction on the surface of the electrospun fiber membrane to obtain a polyguanidine-grafted two-component hollow electrospun fiber membrane.

2. The method for removing polyethylene glycol from water according to claim 1, wherein: The mass fraction of the polyethylene glycol solution in S1 is 5-15wt%, the mass fraction of the hydrogen peroxide solution is 20-30wt%, the volume ratio of the polyethylene glycol solution to the hydrogen peroxide solution is 1:2-3, the reaction time is 30-80min, and the concentration of the sodium hydroxide solution is 0.3-0.6mol / L.

3. The method for removing polyethylene glycol from water according to claim 1, wherein: The volume ratio of solution A to solution B in S13 is 2-5:

1.

4. The method for removing polyethylene glycol from water according to claim 1, wherein: The mass ratio of PVP to graphene oxide in S14 is 7-10:1, and the mass fraction of the obtained electrospinning core layer solution is 8-20 wt%.

5. The method for removing polyethylene glycol from water according to claim 1, wherein: The voltage of the coaxial electrospinning in the S15 is 16-24 kV, the receiving distance is 15-20 cm, the spinning speed of the core layer is 0.2-0.4 mL / h, and the spinning speed of the shell solution is 1-2 mL / h.

6. The method for removing polyethylene glycol from water according to claim 1, wherein: The grafting reaction in S16 comprises the following steps: S21. The polyguanidine was dissolved in water to obtain a solution having a mass fraction of 8 to 12 wt%; S22. Soak the electrospun fiber membrane in PBS buffer, add the solution obtained in S21, and heat the reaction for a certain period of time to achieve grafting.

7. The method for removing polyethylene glycol from water according to claim 6, wherein: The mass ratio of the electrospun fiber membrane to the PBS buffer in S22 is 1:20-30, and the pH of the PBS buffer is 7-8.

8. The method for removing polyethylene glycol from water according to claim 6, wherein: The volume ratio of the PBS buffer in S22 to the solution obtained in S21 is 8-15:

1.

9. The method for removing polyethylene glycol from water according to claim 6, wherein: The heating reaction in S22 is performed at a temperature of 30-50° C. for 2-5 hours.

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