阅读说明：本技术 多肽修饰氧化石墨烯改性复合抗菌正渗透膜及其制备方法 (Polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane and preparation method thereof ) 是由 宋维广 朱丽静 曾志翔 王刚 宋明海 于 2018-06-04 设计创作，主要内容包括：本发明公开了一种多肽修饰氧化石墨烯改性复合抗菌正渗透膜及其制备方法。所述的制备方法包括：将包含有溶剂的水溶液和硅烷偶联剂混合后逆光水解,之后加入氧化石墨烯反应,获得炔基化氧化石墨烯；通过点击化学技术在炔基化氧化石墨烯表面修饰抗菌多肽,实现碳杂原子与多肽连接,获得多肽修饰氧化石墨烯；使多肽修饰氧化石墨烯、高分子聚合物和溶剂混合均匀,之后采用液相转化法涂膜,获得多肽修饰氧化石墨烯改性复合抗菌正渗透膜。本发明通过多肽修饰氧化石墨烯,有效的提升石墨烯的抗菌性能,所制备的正渗透膜具有长效抗菌能力,具有无污染,无需再生等特点,渗透效率高,运行稳定,具有广阔的应用前景。(The invention discloses a polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane and a preparation method thereof. The preparation method comprises the following steps: mixing an aqueous solution containing a solvent and a silane coupling agent, carrying out reverse light hydrolysis, and then adding graphene oxide for reaction to obtain alkynyl graphene oxide; modifying antibacterial polypeptide on the surface of the alkynylated graphene oxide by a click chemistry technology to connect carbon heteroatom with the polypeptide to obtain polypeptide-modified graphene oxide; the polypeptide modified graphene oxide, the high molecular polymer and the solvent are uniformly mixed, and then a liquid phase conversion method is adopted for coating to obtain the polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane. According to the invention, the graphene oxide is modified by the polypeptide, so that the antibacterial performance of the graphene is effectively improved, and the prepared forward osmosis membrane has long-acting antibacterial capability, has the characteristics of no pollution, no need of regeneration and the like, is high in permeation efficiency, stable in operation and has wide application prospect.)

1. A preparation method of a polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane is characterized by comprising the following steps:

(1) Mixing an aqueous solution containing a solvent and a silane coupling agent, carrying out reverse light hydrolysis, and then adding graphene oxide for reaction to obtain alkynyl graphene oxide;

(2) Modifying polypeptide on the surface of the alkynylated graphene oxide by a click chemistry technology to obtain polypeptide modified graphene oxide;

(3) The polypeptide modified graphene oxide, the high molecular polymer and the solvent are uniformly mixed, and then a liquid phase conversion method is adopted for coating to obtain the polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane.

2. The method according to claim 1, wherein the step (1) specifically comprises: uniformly mixing an aqueous solution containing a solvent and a silane coupling agent, carrying out backlight hydrolysis for 0.5-5 h at 10-40 ℃, then adding graphene oxide for ultrasonic dispersion for 0.5-2 h, and reacting the obtained reaction solution for 5-20 h at 20-60 ℃ to obtain the alkynyl graphene oxide.

3. the method of claim 2, wherein: the content of the solvent in the aqueous solution in the step (1) is 80-98 wt%; and/or, the preparation method comprises the following steps: adjusting the pH value of the aqueous solution to 3-6 by adopting an acidic substance; preferably, the acidic substance includes any one or a combination of two or more of acetic acid, hydrochloric acid, nitric acid and sulfuric acid.

4. The method of claim 2, wherein: the silane coupling agent in the step (1) comprises any one or the combination of more than two of vinyl triethoxysilane, vinyl trimethoxysilane, vinyl tri (beta-methoxyethoxy) silane and aminopropyl triethoxysilane; and/or the molar ratio of the silane coupling agent to the graphene oxide is 1: 5-1: 20;

And/or the graphene oxide is prepared by adopting a Hummer method.

5. the preparation method according to claim 1, wherein the step (2) specifically comprises the step of carrying out a light-shielding reaction for 2-10 hours at 10-40 ℃ in a protective atmosphere in a mixed reaction system containing alkynyl graphene oxide, CuSO ₄, tris (3-hydroxypropyl triazolylmethyl) amine, PEG-polypeptide, sodium ascorbate and a solvent to obtain the polypeptide-modified graphene oxide.

6. the preparation method according to claim 5, wherein in the step (2), the mass-to-volume ratio of the alkynylated graphene oxide to the solvent is 3-15 g: 100ml, preferably, the molar volume ratio of the CuSO ₄, the PEG-polypeptide, the tris (3-hydroxypropyl triazolylmethyl) amine, the sodium ascorbate to the solvent is (0.2-2 μmol): 2-10 μmol): 0.5-5 μmol: (0.2-2 mmol): 100ml, preferably, the polypeptide-PEG comprises any one or a combination of more than two of cyclopolypeptide-polyethylene glycol-azide, cyclopolypeptide-polyethylene glycol-polyethyleneimine, cyclopolypeptide-polyethylene glycol-amine dendrimer, cyclopolypeptide-polyethylene glycol-distearoylphosphatidylethanolamine and cyclopolypeptide-polyethylene glycol-hydroxyl, and/or the protective atmosphere comprises nitrogen.

7. the method of claim 1, wherein: the mass ratio of the polypeptide modified graphene oxide to the high molecular polymer in the step (3) is 1: 5-1: 20; and/or the high molecular polymer comprises any one or the combination of more than two of polyvinylidene fluoride, polyether sulfone, polysulfone, cellulose acetate and polycaprolactone.

8. The method of claim 1, wherein: the solvent comprises any one or the combination of more than two of methanol, ethanol and propanol.

9. A polypeptide-modified graphene oxide-modified composite antibacterial forward osmosis membrane prepared by the method of any one of claims 1 to 8;

Preferably, the thickness of the polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane is 0.2-2 nm;

Preferably, when 2mol/L sodium chloride solution is used as an extraction solution, the pure water flux is 16.7-32.6 L.m ^-2 h ^-1, and the sterilization rate of the composite antibacterial forward osmosis membrane on escherichia coli and staphylococcus aureus is 80-90%.

10. the use of the polypeptide-modified graphene oxide-modified composite antibacterial forward osmosis membrane according to claim 9 in the fields of seawater desalination, drinking water treatment or wastewater treatment.

Technical Field

the invention relates to a forward osmosis membrane, in particular to a polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane and a preparation method thereof, and belongs to the technical field of forward osmosis membrane application.

Background

Forward osmosis refers to the process by which water flows from the higher water chemical potential side region through the permselective membrane to the lower water chemical potential side region. Two solutions with different osmotic pressures are respectively placed on two sides of the membrane with selective permeability, one is raw material liquid with lower osmotic pressure, the other is driving solution with higher osmotic pressure, and forward osmosis uses osmotic pressure difference of the solutions on two sides of the membrane as driving force, so that water can spontaneously permeate the membrane with selective permeability from one side of the raw material liquid to one side of the driving liquid. Compared with other pressure-driven membrane separation processes such as microfiltration, ultrafiltration and reverse osmosis, the technology has a plurality of unique advantages in process essence, such as low-pressure or even non-pressure operation, lower energy consumption, almost complete interception of a plurality of pollutants, good separation effect, low membrane pollution characteristic, simple membrane process and equipment and the like. Has good application prospect in many fields, especially in seawater desalination, drinking water treatment and waste water treatment.

however, the raw material liquid of the forward osmosis membrane is usually natural water, such as seawater, river water, wastewater and the like, and the water contains a large amount of microorganisms, and during the use process, the microorganisms can gather and propagate on the membrane surface to influence the flux of the forward osmosis membrane, so that the use of the forward osmosis membrane is limited to a certain extent.

Graphene Oxide (GO) is obtained by oxidizing graphite under acidic conditions and peeling graphite sheets, contains a large number of oxidizing groups such as hydroxyl, carboxyl and epoxy groups on the surface and the edges of the sheets, has a certain antibacterial property, and is often used in the field of water treatment. However, the antimicrobial properties of GO are affected by many factors, such as the number of layers, surface functional groups, material size, dispersion concentration, and interactions with bacteria. This makes the antibacterial effect of GO unstable, limiting its practical application.

Disclosure of Invention

The invention aims to provide a polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane and a preparation method thereof, so as to overcome the defects in the prior art.

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

The embodiment of the invention provides a preparation method of a polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane, which comprises the following steps:

(1) Mixing an aqueous solution containing a solvent and a silane coupling agent, carrying out reverse light hydrolysis, and then adding graphene oxide for reaction to obtain alkynyl graphene oxide;

(2) Modifying polypeptide on the surface of the alkynylated graphene oxide by a click chemistry technology to obtain polypeptide modified graphene oxide;

(3) The polypeptide modified graphene oxide, the high molecular polymer and the solvent are uniformly mixed, and then a liquid phase conversion method is adopted for coating to obtain the polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane.

in some preferred embodiments of the present invention, step (1) specifically comprises: uniformly mixing an aqueous solution containing a solvent and a silane coupling agent, carrying out backlight hydrolysis for 0.5-5 h at 10-40 ℃, then adding graphene oxide for ultrasonic dispersion for 0.5-2 h, and reacting the obtained reaction solution for 5-20 h at 20-60 ℃ to obtain the alkynyl graphene oxide.

In some preferred embodiments of the invention, the step (2) specifically comprises the step of carrying out a light-shielding reaction for 2-10 hours at 10-40 ℃ in a protective atmosphere in a mixed reaction system containing alkynyl graphene oxide, CuSO ₄, tris (3-hydroxypropyl triazolylmethyl) amine, PEG-polypeptide, sodium ascorbate and a solvent to obtain the polypeptide-modified graphene oxide.

Further, the mass ratio of the polypeptide modified graphene oxide to the high molecular polymer is 1: 5-1: 20.

Further, the high molecular polymer comprises one or more of polyvinylidene fluoride, polyether sulfone, polysulfone, cellulose acetate and polycaprolactone.

The embodiment of the invention also provides the polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane prepared by the method.

the embodiment of the invention also provides application of the polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane in the fields of seawater desalination, drinking water treatment or wastewater treatment.

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

1) The polypeptide in the polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane provided by the invention can prevent bacteria from proliferating on the surface of a biological material, so that the possibility of drug resistance of the bacteria is reduced to the minimum, the polypeptide is relatively stable in an antibacterial process, the antibacterial performance of the graphene is effectively improved, and the antibacterial capability of the surface of the membrane can be effectively improved by applying the polypeptide in the forward osmosis membrane;

2) According to the invention, polypeptide modification is carried out on graphene oxide through a click reaction, so that the operation is simple and convenient, the efficiency is high, and the problem that the polypeptide is inactivated by a traditional grafting method can be solved;

3) The polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane provided by the invention has a long-acting antibacterial functional group, has long-acting antibacterial capability, can prevent biological breeding, thoroughly stops bacterial propagation, has the characteristics of no pollution, no need of regeneration and the like, improves the permeation efficiency, the operation stability and the service life in the application process, reduces the maintenance cost, and has a wide application prospect.

Detailed Description

In view of the problem of poor separation of carbon materials from sodium ions in the prior art, the inventors of the present invention have made long-term research and extensive practice to provide a technical scheme of the present invention, which mainly modifies antibacterial polypeptides on the surface of alkynylated graphene oxide by a click chemistry technique to connect carbon heteroatoms with polypeptides, and prepares a forward osmosis membrane by using the polypeptide-modified graphene oxide as a modifier through a phase conversion method to obtain a polypeptide-modified graphene oxide-modified composite antibacterial forward osmosis membrane. The technical solution, its implementation and principles, etc. will be further explained as follows.

As one aspect of the technical scheme of the invention, the preparation method of the polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane comprises the following steps:

(1) Mixing an aqueous solution containing a solvent and a silane coupling agent, carrying out reverse light hydrolysis, and then adding graphene oxide for reaction to obtain alkynyl graphene oxide;

(2) Modifying polypeptide on the surface of the alkynylated graphene oxide by a click chemistry technology to obtain polypeptide modified graphene oxide;

(3) The polypeptide modified graphene oxide, the high molecular polymer and the solvent are uniformly mixed, and then a liquid phase conversion method is adopted for coating to obtain the polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane.

In some preferred embodiments of the present invention, step (1) specifically comprises: uniformly mixing an aqueous solution containing a solvent and a silane coupling agent, carrying out backlight hydrolysis for 0.5-5 h at 10-40 ℃, then adding graphene oxide for ultrasonic dispersion for 0.5-2 h, and reacting the obtained reaction solution for 5-20 h at 20-60 ℃ to obtain the alkynyl graphene oxide.

Further, the content of the solvent in the aqueous solution in the step (1) is 80-98 wt%.

Further, the preparation method comprises the following steps: and adjusting the pH value of the aqueous solution to 3-6 by adopting an acidic substance.

further, the acidic substance includes any one or a combination of two or more of acetic acid, hydrochloric acid, nitric acid, sulfuric acid, and the like, but is not limited thereto.

Further, the silane coupling agent in the step (1) includes any one or a combination of two or more of vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (β -methoxyethoxy) silane, aminopropyltriethoxysilane, and the like, but is not limited thereto.

Further, the molar ratio of the silane coupling agent to the graphene oxide is 1: 5-1: 20.

Further, the amount of the silane coupling agent is 0.05 to 0.5 mmol.

further, the graphene oxide is prepared by adopting a Hummer method.

In some preferred embodiments of the invention, the step (2) specifically comprises the step of carrying out a light-shielding reaction for 2-10 hours at 10-40 ℃ in a protective atmosphere in a mixed reaction system containing alkynyl graphene oxide, CuSO ₄, tris (3-hydroxypropyl triazolylmethyl) amine, PEG-polypeptide, sodium ascorbate (AA) and a solvent to obtain the polypeptide-modified graphene oxide.

According to the invention, polypeptide modification is carried out on graphene oxide through a click reaction, the operation is simple and convenient, the efficiency is high, and the problem that the polypeptide is inactivated by a traditional grafting method can be solved.

Further, in the step (2), the mass-to-volume ratio of the alkynylated graphene oxide to the solvent is 3-15 g: 100ml, and the molar volume ratio of the CuSO ₄, the PEG-polypeptide, the tris (3-hydroxypropyl triazolylmethyl) amine, the sodium ascorbate to the solvent is (0.2-2 μmol): 2-10 μmol (0.5-5 μmol): 0.2-2 mmol): 100 ml.

Furthermore, in 100ml of the solvent in the step (2), the mass of the alkynylated graphene oxide is 3-15 g, the amount of CuSO ₄ is 0.2-2 mu mol, the amount of PEG-polypeptide is 2-10 mu mol, the amount of tris (3-hydroxypropyl triazolyl methyl) amine is 0.5-5 mu mol, and the amount of AA is 0.2-2 mmol.

Further, the polypeptide-PEG in the step (2) includes any one or a combination of two or more of cyclic polypeptide-polyethylene glycol-azide (RGD-PEG-N3), cyclic polypeptide-polyethylene glycol-polyethyleneimine (RGD-PEG-PEI), cyclic polypeptide-polyethylene glycol-amine dendrimer (RGD-PEG-PAMAM), cyclic polypeptide-polyethylene glycol-distearoylphosphatidylethanolamine (RGD-PEG-DSPE), and cyclic polypeptide-polyethylene glycol-hydroxyl (RGD-PEG-COOH), but is not limited thereto. The polypeptide can prevent bacteria from proliferating on the surface of the biological material, so that the possibility of drug resistance of the bacteria is reduced to the minimum, the polypeptide is relatively stable in the antibacterial process, and the antibacterial capability of the surface of the membrane can be effectively improved by applying the polypeptide to the forward osmosis membrane.

further, the protective atmosphere includes a nitrogen atmosphere, but is not limited thereto.

In some preferred embodiments of the present invention, the mass ratio of the polypeptide-modified graphene oxide to the high molecular polymer is 1: 5-1: 20.

Further, the high molecular polymer includes any one or a combination of two or more of polyvinylidene fluoride (PVDF), polyether sulfone (PES), Polysulfone (PS), Cellulose Acetate (CA), Polycaprolactone (PLA), and the like, but is not limited thereto.

Further, the solvent includes methanol, ethanol, propanol, or the like, but is not limited thereto.

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

Step 1) preparing 100ml of ethanol aqueous solution with a certain pH value, adding a silane coupling agent, carrying out backlight hydrolysis for 0.5-5 h, adding GO prepared by a Hummer method into silane coupling agent hydrolysate, and carrying out ultrasonic dispersion for 0.5-2 h. And then placing the prepared reaction solution on a shaking table to react for 5-20 h at room temperature. And after the reaction is finished, adding ethanol, and carrying out centrifugal cleaning for 5-10 times to obtain the alkynylated graphene oxide.

And 2) ultrasonically dispersing the prepared alkynylated graphene oxide in a three-necked bottle filled with 100ml of ethanol, then sequentially adding CuSO4, tris (3-hydroxypropyl triazolylmethyl) amine, PEG-polypeptide and sodium ascorbate (AA), vacuumizing, reacting for 2-10 hours in a dark place under the protection of nitrogen, then centrifugally cleaning the reacted solution for 5-10 times by using ethanol, and then drying in vacuum to obtain polypeptide modified graphene oxide powder.

And 3) adding the polypeptide modified graphene oxide and a high molecular polymer into a solvent according to a certain proportion, stirring to uniformly mix the mixture, vacuumizing, and coating by adopting a liquid phase conversion method to obtain the polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane.

As another aspect of the technical scheme of the invention, the invention also relates to the polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane prepared by the method.

preferably, the thickness of the polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane is 0.2-2 nm.

Preferably, when 2mol/L sodium chloride solution is used as an extraction solution, the pure water flux is 16.7-32.6 L.m ^-2 h ^-1, and the sterilization rate of the composite antibacterial forward osmosis membrane on escherichia coli and staphylococcus aureus is 80-90%.

the embodiment of the invention also provides application of the polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane in the fields of seawater desalination, drinking water treatment or wastewater treatment.

By the preparation process, the polypeptide modified graphene oxide modified composite antibacterial forward osmosis membrane has a long-acting antibacterial functional group, has long-acting antibacterial capacity, can prevent biological breeding, thoroughly stops bacterial propagation, has the characteristics of no pollution, no need of regeneration and the like, improves the permeation efficiency, the operation stability and the service life in the application process, reduces the maintenance cost, and has a wide application prospect.

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