CN1759682A - Nano composite anti-bacterial agent and preparation method - Google Patents

Abstract

The invention provides a nanocomposite antibacterial agent, which includes nanometer zinc oxide and nanometer silver, part of nanometer zinc oxide and nanometer silver adhere to each other, and part of nanometer zinc oxide and nanometer silver exist independently as nanometer particles. The present invention also provides a preparation method of a nanocomposite antibacterial agent, comprising the steps of: taking a certain amount of zinc sulfate or zinc nitrate solution in a container and stirring continuously, and controlling the reaction temperature, adding dropwise ammonium bicarbonate solution; ammonium bicarbonate After the dropwise addition, stir for a period of time, then add dropwise silver nitrate and ammonium bicarbonate solution to continue stirring; then wash and centrifuge to separate the uniformly mixed nano-silver precursor and nano-zinc oxide precursor; dry the precursor under vacuum conditions; The dried precursor is sintered to obtain the nanocomposite antibacterial agent. In the nanocomposite antibacterial agent, the nano-silver attached to the surface of the nano-zinc oxide particle can promote the photocatalytic activity of the nano-zinc oxide, and the nano-zinc oxide attached to the surface of the nano-silver particle can improve the bactericidal performance of the nano-silver.

Description

Nanocomposite antibacterial agent and preparation method thereof

【Technical field】

The invention relates to an antibacterial agent and a preparation method thereof, in particular to a nanocomposite antibacterial agent and a preparation method thereof.

【Background technique】

In the 20th century, the progress of science and technology in various countries in the world has promoted the economic take-off, and the high-level development of scientific and technological civilization and material civilization has entered a new stage. However, during the rapid development of more than one hundred years, people have ignored the close relationship between environmental pollution and health. The ecological environment and microbial environment around the world have been seriously polluted, which has brought serious disasters to human health and life, made the living space of human beings increasingly narrow, and issued a serious warning to human survival. According to the statistics of WHO in 1998, the number of deaths caused by bacterial infection in the world exceeds more than 16 million people every year. Especially the SARS virus in 2003 and the raging bird flu in 2004 made people realize the importance of antibacterial products and gave birth to a large market for antibacterial products. Therefore, the research and development of various antibacterial agents has also become a research hotspot.

Antimicrobial agents can be divided into three categories: natural, organic and inorganic. Natural antibacterial agents are mainly natural plant extracts, and due to resource constraints, it is difficult to apply and promote them. Organic antibacterial agents have been used for more than 30 years. When selecting organic antibacterial agents, in addition to considering their safety (such as toxic and side effects, and some monomers even have carcinogenic effects), they also have poor heat resistance, easy decomposition and problems such as short service life. Compared with organic antibacterial agents, inorganic antibacterial agents, especially the nano-inorganic antibacterial agents developed in recent years, have the advantages of good broad-spectrum antibacterial properties, high safety, good heat resistance, long service life, no volatilization and toxic and side effects, etc. It has become one of the hot spots in the development of antibacterial agents.

Inorganic antibacterial agents mainly include two categories. One is to load metal ions with bactericidal properties such as: Ag ⁺ , Cu ⁺ , Zn ⁺ etc. on inorganic carriers. The carriers mainly include phosphate series, silicate and activated carbon, Glass etc., this type of antibacterial agent is researched more at present (as No. 3448530 of Japanese Patent; No. 3176054 of Japanese Patent; No. ZL01125125.5 of Chinese Patent; No. CN1286915A of Chinese Patent Publication etc.), and existing product sales in the market. However, the disadvantages of this type of antibacterial agent are that the carrier material has no antibacterial properties, the loading capacity of antibacterial metal ions is limited and cannot be controlled arbitrarily, the antibacterial active ingredients are few, and the antibacterial time is limited. And it only has antibacterial properties but no self-cleaning effect of degrading organic matter; the other type is photocatalytic antibacterial agents represented by TiO ₂ and ZnO, mainly nano-sized n-type semiconductor powders, which will be adsorbed on The OH- and H ₂ O molecules on the surface are oxidized into hydroxyl radicals (-OH) with strong oxidizing ability, etc., which can inhibit and kill microorganisms in the environment. In recent years, people have improved its photocatalytic activity and broadened the wavelength range of excitation light by loading various rare earths, Ag ⁺ , Cu ⁺ and doping N, F, etc. on TiO ₂ , and achieved good results (such as Chinese patent disclosure No. CN1559226A; Soga et al.J.Surf.Anal., 1999, 5 (2): P326; Chinese Patent No. ZL99126362.6; Chinese Patent No. ZL03117960.6; BeataKosowska, Sylwia Mozia, Antoni W.Morawski et al al. Solar Energy Materials & Solar Cells, 2005, 88: P269-280, etc.). However, this type of antibacterial agent must have the ability to sterilize, degrade organic matter and self-purify under the condition of light, especially ultraviolet light. Therefore, it will be a promising prospect to develop a kind of antibacterial agent that can be applied to various occasions with photocatalytic degradation of organic matter and self-purification ability no matter whether there is light or no light. Direction of development. Chinese Patent Publication No. CN1586202A obtains TiO ₂ and Ag ⁺ composite antibacterial agent by coating porous calcium hydroxyphosphate on the surface of nano-titanium dioxide and then loading silver ions, but the cost of the product is relatively high.

【Content of invention】

The technical problem to be solved by the present invention is to provide a nano-composite antibacterial agent, which has high antibacterial and bactericidal effects, can also degrade organic pollutants, deodorize and self-purify, and has low cost.

Another technical problem to be solved by the present invention is: provide a kind of preparation method of nano-composite antibacterial agent, the prepared nano-inorganic antibacterial agent has high antibacterial and bactericidal efficacy, and can also degrade organic pollutants, deodorize and self-purify, And the cost is lower.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical scheme: the present invention provides a nanocomposite antibacterial agent, which includes nano-zinc oxide and nano-silver, wherein, part of nano-zinc oxide and nano-silver are attached to each other, part of nano-zinc oxide, nano-silver Silver exists independently as nanoparticles.

The present invention also provides a kind of preparation method of nanocomposite antibacterial agent, it comprises the steps:

Take a certain amount and concentration of zinc sulfate or zinc nitrate solution in a container and keep stirring, and control the corresponding reaction temperature, drop a certain amount of ammonium bicarbonate solution;

After the ammonium bicarbonate has been added dropwise, stir for a while, then add a certain amount of silver nitrate and ammonium bicarbonate solution dropwise and continue to stir for a certain period of time;

Then wash with twice distilled water and/or absolute ethanol and centrifuge to separate the precursor of uniformly mixed nano-silver and the precursor of nano-zinc oxide;

drying the precursor under vacuum;

The dried precursor is sintered, heated to 380-600°C at a certain speed, and kept at this temperature for 2-5 hours. After the reaction is fully carried out, the nanocomposite antibacterial agent can be obtained by cooling with the furnace.

The beneficial effects of the present invention are: independently existing nano-Ag and ZnO particles can play bactericidal and photocatalytic effects respectively; Improve the bactericidal performance of nano-Ag, the nano-composite antibacterial agent has high antibacterial and bactericidal efficacy, and can also degrade organic pollutants, deodorize and self-purify, and the cost is low.

The present invention will be further described below in conjunction with accompanying drawing and specific embodiment:

【Description of drawings】

Fig. 1A is a transmission electron micrograph of the nanocomposite antibacterial agent obtained under the process conditions of the first embodiment.

FIG. 1B is another transmission electron micrograph of the nanocomposite antibacterial agent in FIG. 1A with different magnifications.

Fig. 2 is a graph showing the particle size distribution results of the nanocomposite antibacterial agent obtained under the process conditions of the first specific embodiment.

Fig. 3 is a diagram of the X-ray diffraction results of the nanocomposite antibacterial agent obtained under the process conditions of the first specific embodiment.

Fig. 4A is a transmission electron micrograph of the nanocomposite antibacterial agent obtained under the process conditions of the second specific embodiment.

FIG. 4B is another transmission electron micrograph of the nanocomposite antibacterial agent in FIG. 4A with different magnifications.

Fig. 5 is a graph showing the particle size distribution results of the nanocomposite antibacterial agent obtained under the process conditions of the second specific embodiment.

Fig. 6A is a transmission electron micrograph of the nanocomposite antibacterial agent obtained under the process conditions of the third specific embodiment.

FIG. 6B is another transmission electron micrograph of the nanocomposite antibacterial agent in FIG. 6A with different magnifications.

Fig. 7 is a graph showing the particle size distribution results of the nanocomposite antibacterial agent obtained under the process conditions of the third specific embodiment.

Fig. 8A is a transmission electron micrograph of the nanocomposite antibacterial agent obtained under the process conditions of the fourth specific embodiment.

FIG. 8B is another transmission electron micrograph of the nanocomposite antibacterial agent in FIG. 8A with different magnifications.

Fig. 9 is a graph showing the particle size distribution results of the nanocomposite antibacterial agent obtained under the process conditions of the fourth specific embodiment.

Fig. 10 is a graph showing the X-ray diffraction results of the nanocomposite antibacterial agent obtained under the process conditions of the fourth specific embodiment.

Fig. 11A is a transmission electron micrograph of the nanocomposite antibacterial agent obtained under the process conditions of the fifth specific embodiment.

FIG. 11B is another transmission electron micrograph of the nanocomposite antibacterial agent in FIG. 11A with different magnifications.

Fig. 12 is a graph showing the particle size distribution results of the nanocomposite antibacterial agent obtained under the process conditions of the fifth specific embodiment.

【Detailed ways】

The nanocomposite antibacterial agent of the invention is a series of nanocomposite antibacterial agents composed of ZnO and Ag nanoparticles in different proportions. In the antibacterial agent of the present invention, part of ZnO and Ag are attached to each other, and part is independently existing nanometer ZnO and Ag particles, so the antibacterial agent not only has antibacterial and bactericidal effects of nanometer Ag, ZnO and metal ions, but also has photocatalyst effect, Moreover, the two nanomaterials promote each other, so that they not only have high antibacterial properties, but also can degrade organic pollutants, deodorize, and self-purify, and are suitable for various products used under light and no light conditions. And by adjusting the ratio of ZnO and Ag nanoparticles in the antibacterial agent, it has different antibacterial and photocatalytic properties to meet the requirements of various occasions. In addition, the cost of the composite nano-antibacterial agent is lower than similar products such as TiO ₂ and Ag or nano-Ag antibacterial agent.

Chinese Patent Publication No. CN1341358A discloses an antibacterial agent composed of water-capacity amino acid silver, amino acid zinc and their decomposition products nano-silver and zinc oxide as main materials. The present invention is different from it in that: 1. The synthesis process method and principle are different. The present invention first obtains a uniformly mixed precursor through a simple inorganic chemical reaction, that is, reacts such as sulfuric acid or nitrate containing Ag and Zn with ammonium bicarbonate to generate Uniformly mixed Zn and Ag carbonate precursors; then thermally decomposed under conditions such as air, ammonia and vacuum to obtain ZnO and Ag composite nano-antibacterial agents. The whole preparation process, from raw materials to methods, belongs to the category of inorganic chemistry, without pollution and sewage. The method has simple process, wide sources of raw materials, low cost, simple equipment and is convenient for large-scale production. 2. The raw materials used are different. The present invention selects cheap conventional Zn sulfuric acid or nitrate, ammonium bicarbonate and silver nitrate as raw materials, which greatly reduces the cost. 3. The obtained products have different forms. The present invention first obtains a homogeneous mixture of precursors with a simple chemical reaction, and simultaneously generates ZnO and Ag nanoparticles with a particle size of 10 to 30 nm in the subsequent heating process. The obtained product is neither completely wrapped The covered type is not completely independent ZnO and Ag nanoparticles, but partly attached to each other, and partly exists independently in the form of nanoparticles. Such independently existing nano-Ag and ZnO particles can play a bactericidal effect, Ag attached to the surface of ZnO nanoparticles can promote its photocatalytic ability, and ZnO attached to the surface of Ag nanoparticles can improve its surface activity and promote its antibacterial property. In addition, ZnO can be doped with N and other elements by thermal decomposition in various atmospheres such as ammonia, thereby broadening the light wave range of ZnO photocatalysis. Therefore, the composite nano-antibacterial agent obtained by the present invention not only has high antibacterial and bactericidal effects, but also has photocatalytic effects, and the process and composition can be adjusted according to needs to achieve different performances, and there is no waste such as pollution and sewage. This series of antibacterial agents has a wide range of applications, safety, durability, high temperature resistance, no drug resistance and no secondary pollution.

The present invention also relates to a kind of preparation method of above-mentioned nanocomposite antibacterial agent, and concrete preparation method of the present invention is as follows:

(1) Preparation of precursor

First prepare a certain concentration of zinc sulfate or zinc nitrate, silver nitrate and ammonium bicarbonate aqueous solution as required. Take a certain amount of zinc sulfate or zinc nitrate solution with a concentration of 0.5-5mol/L and place it in a container, stir continuously at a temperature of 10-90°C, and add the same volume of 0.5～5mol/L ammonium bicarbonate solution, after the ammonium bicarbonate has been added dropwise, continue stirring for 0.5～3 hours, then add the same volume and concentration dropwise at the same time as Ag by mass ratio at a dripping speed of 2～15ml/s: ZnO=(1～50):(50～99) silver nitrate and ammonium bicarbonate, after the solution is added dropwise, continue to stir for 0.5～3 hours and then stop the reaction. Then wash with twice-distilled water and/or absolute ethanol and centrifuge to separate the precursor mixture, and then vacuum-dry until the precursor is prepared.

(2) Sintering of the precursor

Place the dried precursor sample in a vacuum controllable atmosphere furnace or a box-type resistance furnace, and raise the temperature at a certain speed to 380-600°C, and keep warm at this temperature for 2-5 hours, and after the reaction is fully carried out, cool with the furnace to obtain the zinc oxide/silver nanocomposite antibacterial agent.

The following will simply enumerate several specific implementation methods to describe in detail:

The first embodiment of the preparation method of the nanocomposite antibacterial agent of the present invention is as follows:

Take 200ml of zinc sulfate solution with a concentration of 1-2mol/L in a three-necked flask, stir continuously at a temperature of 20-50°C, and add 200ml of 1-2mol/L carbonic acid dropwise at a dropping speed of 3-8ml/s Hydrogen ammonia solution, after the addition of ammonium bicarbonate dropwise, continue to stir for 0.5 hours, then add dropwise at a rate of 2 to 6ml/s at the same time with a concentration of 0.1 to 1mol/ 100ml of silver nitrate and 0.1-1mol/L ammonium bicarbonate each. After the dropwise addition of the solution was completed, the stirring was continued for 0.5 to 1 hour, and then the reaction was stopped. The precipitate was then washed with double distilled water and absolute ethanol and centrifuged to separate the precursor, followed by vacuum drying. Place the dried precursor in a box-type resistance furnace, heat up to 430-460°C at a certain speed under the air, keep it at this temperature for 3-5 hours, and cool with the furnace to obtain zinc oxide/ Silver nanocomposite antibacterial agent. Figure 1A and Figure 1B are transmission electron micrographs of different magnifications of the zinc oxide/silver nanocomposite antibacterial agent obtained under the process conditions. Fig. 2 is the particle size distribution result of the zinc oxide/silver nanocomposite antimicrobial agent obtained under the process conditions. Fig. 3 is the X-ray diffraction result (XRD) of the zinc oxide/silver nanocomposite antimicrobial agent obtained under the process conditions. The minimum inhibitory concentration of the sample under no light conditions was 0.0075% (75PPm); 365nm ultraviolet light could degrade the methyl orange solution into a colorless solution.

The second embodiment of the preparation method of the nanocomposite antibacterial agent of the present invention is as follows:

Take 200ml of zinc sulfate solution with a concentration of 0.5-1.5mol/L in a three-necked flask, stir continuously at a temperature of 20-50°C, and add 200ml of 0.5-1.5mol/L dropwise at a dropping speed of 3-8ml/s. L ammonium bicarbonate solution, after the dropwise addition of ammonium bicarbonate, continue to stir for 1 hour, and then add it dropwise at a rate of 2-6ml/s at the same time. 100ml each of 1mol/L silver nitrate and 0.1-1mol/L ammonium bicarbonate. After the dropwise addition of the solution was completed, the stirring was continued for 0.5 to 1.5 hours, and then the reaction was stopped. The precipitate was then washed with double distilled water and/or absolute ethanol and centrifuged to separate the precursor, followed by vacuum drying. Place the dried precursor in a vacuum furnace, raise the temperature to 400-430°C at a certain speed under vacuum conditions, keep it at this temperature for 2-4 hours, and cool down with the furnace to obtain zinc oxide/silver Nanocomposite antibacterial agent. Figure 4A and Figure 4B are transmission electron micrographs of different magnifications of the zinc oxide/silver nanocomposite antibacterial agent obtained under the process conditions. Fig. 5 is the particle size distribution result of the zinc oxide/silver nanocomposite antimicrobial agent obtained under the process conditions. The minimum inhibitory concentration of the sample under no light conditions was 0.0175% (175PPm); 365nm ultraviolet light could degrade the methyl orange solution into a colorless solution.

The third embodiment of the preparation method of the nanocomposite antibacterial agent of the present invention is as follows:

Take 100ml of zinc sulfate solution with a concentration of 0.5-1.5mol/L in a three-necked flask, stir continuously at a temperature of 20-40°C, and add 100ml of 0.5-1.5mol/L dropwise at a dropping speed of 3-5ml/s. L ammonium bicarbonate solution, after the dropwise addition of ammonium bicarbonate, continue to stir for 1 to 1.5 hours, then simultaneously dropwise add silver nitrate and 0.05 to 0.1 mol/L silver nitrate and 0.05 to Each 50ml of 0.1mol/L ammonium bicarbonate is Ag:ZnO=5:95 by mass ratio. After the dropwise addition of the solution was completed, the stirring was continued for 0.5 to 1 hour, and then the reaction was stopped. The precipitate was then washed with double distilled water or absolute ethanol and centrifuged to separate the precursor, followed by vacuum drying. Place the dried precursor in a box-type resistance furnace, heat up to 440-500°C at a certain speed under the air, keep it at this temperature for 2-4 hours, and cool with the furnace to obtain zinc oxide/ Silver nanocomposite antibacterial agent. Figure 6A and Figure 6B are transmission electron micrographs of different magnifications of the zinc oxide/silver nanocomposite antibacterial agent obtained under the process conditions. Figure 7 is the particle size distribution result of the zinc oxide/silver nanocomposite antimicrobial agent obtained under the process conditions. The minimum inhibitory concentration of the sample was 0.0250% (250PPm) under the condition of no light; 365nm ultraviolet light could degrade the methyl orange solution into a colorless solution.

The fourth embodiment of the preparation method of the nanocomposite antibacterial agent of the present invention is as follows:

Take 200ml of zinc nitrate [Zn(NO ₃ ) ₂ ] solution with a concentration of 0.5-1.5mol/L in a three-necked flask, keep stirring at a temperature of 20-30°C, and drop it at a rate of 4-6ml/s. Add 200ml of 0.5 ~ 1.5mol/L ammonium bicarbonate solution, after the dropwise addition of ammonium bicarbonate, continue to stir for 0.5 ~ 1 hour, then add dropwise at a rate of 2 ~ 5ml/s to a concentration of 0.1 ~ 0.5mol Each 100ml of silver nitrate per L and 0.1～0.5mol/L ammonium bicarbonate is Ag:ZnO=10:90 by mass ratio. After the dropwise addition of the solution was completed, the stirring was continued for 0.5 to 1 hour, and then the reaction was stopped. The precipitate was then washed with double distilled water and absolute ethanol and centrifuged to separate the precursor, followed by vacuum drying. Place the dried precursor in a box-type resistance furnace, heat up to 450-500°C at a certain speed under the air, keep it at this temperature for 2-4 hours, and cool with the furnace to obtain zinc oxide/ Silver nanocomposite antibacterial agent. Figure 8A and Figure 8B are transmission electron micrographs of different magnifications of the zinc oxide/silver nanocomposite antibacterial agent obtained under the process conditions. Fig. 9 is the particle size distribution result of the zinc oxide/silver nanocomposite antimicrobial agent obtained under the process conditions. Figure 10 is the X-ray diffraction result (XRD) of the zinc oxide/silver nanocomposite antibacterial agent obtained under the process conditions. The minimum inhibitory concentration of the sample under no light conditions was 0.0175% (175PPm); 365nm ultraviolet light could degrade the methyl orange solution into a colorless solution.

The fifth embodiment of the preparation method of the nanocomposite antibacterial agent of the present invention is as follows:

Take 200ml of zinc nitrate [Zn(NO3)2] solution with a concentration of 0.5-1.5mol/L in a three-necked flask, stir continuously at a temperature of 20-30°C, and add dropwise at a rate of 4-6ml/s 200ml of 0.5~1.5mol/L ammonium bicarbonate solution, after the dropwise addition of ammonium bicarbonate, continue to stir for 0.5~1 hour, then add dropwise at a rate of 2~5ml/s at a concentration of 0.1~0.5mol/L Each 100ml of silver nitrate of L and 0.1～0.5mol/L ammonium bicarbonate is Ag:ZnO=10:90 by mass ratio. After the dropwise addition of the solution was completed, the stirring was continued for 0.5 to 1 hour, and then the reaction was stopped. The precipitate was then washed with double distilled water and absolute ethanol and centrifuged to separate the precursor, followed by vacuum drying. Place the dried precursor in a vacuum furnace, raise the temperature to 380-440°C at a certain speed under vacuum conditions, keep it at this temperature for 2-5 hours, and cool down with the furnace to obtain zinc oxide/silver Nanocomposite antibacterial agent. Figure 11A and Figure 11B are transmission electron micrographs of different magnifications of the zinc oxide/silver nanocomposite antibacterial agent obtained under the process conditions. Figure 12 is the particle size distribution result of the zinc oxide/silver nanocomposite antibacterial agent obtained under the process conditions. The minimum inhibitory concentration of the sample was 0.02% (200PPm) under the condition of no light; 365nm ultraviolet light could degrade the methyl orange solution into a colorless solution.

Claims (8)

1. composite nano germicide, it comprises nano zine oxide and Nano Silver, it is characterized in that: part nano zine oxide, Nano Silver adhere to mutually, and part nano zine oxide, Nano Silver independently exist with nano particle.

2. composite nano germicide as claimed in claim 1 is characterized in that: the nano zine oxide composition of wherein said composite nano germicide also is doped with nitrogen.

3. composite nano germicide as claimed in claim 1 or 2 is characterized in that: Nano Silver is 1～50 to 50～99 with the mass ratio of nano zine oxide.

4. the preparation method of a composite nano germicide, it comprises the steps:

Zinc sulphate or the zinc nitrate solution of getting a certain amount of and concentration constantly stir in a container, and control respective reaction temperature, drip a certain amount of ammonium bicarbonate solution;

After ammonium hydrogencarbonate dropwises, stir a period of time, drip a certain amount of silver nitrate and ammonium bicarbonate solution again and continue to stir certain hour;

Cleaning also with redistilled water and/or absolute ethyl alcohol afterwards, centrifugation goes out the presoma of mixed uniformly Nano Silver and the presoma of nano zine oxide;

Dry described presoma under the vacuum condition;

Dried presoma is carried out sintering, be warming up to 380～600 ℃, and under this temperature, be incubated 2～5 hours, by the time after sufficient reacting carries out,, can obtain composite nano germicide with the stove cooling with certain speed.

5. the preparation method of a kind of composite nano germicide as claimed in claim 4, it is characterized by: the synthesis temperature of presoma is: 10～90 ℃, the rate of addition 2～15ml/s of material solution.

6. the preparation method of a kind of composite nano germicide as claimed in claim 4 is characterized by: dried presoma is carried out sintering under air atmosphere.

7. the preparation method of a kind of composite nano germicide as claimed in claim 4 is characterized by: dried presoma is carried out sintering under the vacuum atmosphere condition.

8. the preparation method of a kind of composite nano germicide as claimed in claim 4 is characterized by: dried presoma is carried out sintering under the nitrogen containing atmosphere condition.

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