Organic silicon antibacterial material based on photocatalytic nanoparticles and preparation method thereof

Abstract

The invention discloses an organic silicon antibacterial material based on photocatalytic nanoparticles, the antibacterial material is a nitrogen-doped titanium dioxide-copper oxide / organic silicon composite system, and the antibacterial material comprises nitrogen-doped titanium dioxide nanoparticles, copper oxide nanoparticles and an organic silicon matrix; the nitrogen-doped titanium dioxide nanoparticles, the copper oxide nanoparticles and the organic silicon substrate form a heterojunction structure, and the heterojunction structure expands a light absorption edge from about 400 nanometers of traditional titanium dioxide to 500 nanometers. Compared with the prior art, the organic silicon antibacterial material based on the photocatalytic nanoparticles and the preparation method thereof have the advantages that the organic silicon antibacterial material is convenient to operate and use, ensures the antibacterial performance and is easy to popularize and operate.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of antibacterial materials, in particular to an organic silicon antibacterial material based on photocatalytic nanoparticles and a preparation method thereof. BACKGROUND

[0002] The market demand for antibacterial materials is showing explosive growth. However, the current widely used traditional antibacterial materials (such as chemical bactericides) have significant technical shortcomings: on the one hand, microorganisms are prone to drug resistance to chemical bactericides, resulting in attenuation of antibacterial effect with use time; on the other hand, some antibacterial materials have problems of heavy metal ion precipitation and organic matter migration polluting the environment, and lack of long-acting antibacterial performance, which seriously restricts their popularization and application in high-end medical, food contact, long-acting outdoor protection and other fields with strict requirements on environmental friendliness and safety.

[0003] Organic silicon materials are considered to be ideal substrates for preparing high-performance antibacterial coatings due to their excellent physical and chemical properties. However, when photocatalytic nanoparticles are compounded with an organic silicon substrate, the existing technology faces the bottleneck of poor dispersibility of nanoparticles in the organic silicon substrate and the dependence of traditional photocatalysts on ultraviolet light sources for excitation.

[0004] Therefore, it is of great significance to develop a new type of efficient organic silicon antibacterial material based on photocatalytic nanoparticles and a preparation method thereof to meet market demand and promote technological progress. SUMMARY

[0005] The technical problem to be solved by the application is to overcome the above technical defects and provide an organic silicon antibacterial material based on photocatalytic nanoparticles and a preparation method thereof, which are convenient to operate and use, ensure antibacterial performance and are easy to popularize and operate.

[0006] To solve the above technical problems, the technical solution provided by the application is as follows: an organic silicon antibacterial material based on photocatalytic nanoparticles, the antibacterial material being a "nitrogen-doped titanium dioxide-copper oxide / organic silicon" composite system, comprising nitrogen-doped titanium dioxide nanoparticles, copper oxide nanoparticles and an organic silicon substrate.

[0007] The nitrogen-doped titanium dioxide nanoparticles, copper oxide nanoparticles and organic silicon substrate form a heterojunction structure, and the heterojunction structure extends the light absorption edge from about 400 nanometers of traditional titanium dioxide to 500 nanometers.

[0008] Preferably, the antibacterial material has a killing rate of 99.9% or more for both Escherichia coli and Staphylococcus aureus within 2 hours.

[0009] Preferably, the nitrogen-doped titanium dioxide nanoparticles have a nitrogen doping amount of 0.5-5 at.%, and a particle size of 10-50 nm.

[0010] The particle size of the copper oxide nanoparticles is 5-30 nm.

[0011] Preferably, the mass ratio of the nitrogen-doped titanium dioxide nanoparticles to the copper oxide nanoparticles is 1:0.2-1:1.

[0012] Preferably, the silicone matrix is at least one of polydimethylsiloxane, methylvinylsiloxane or methylphenylsiloxane.

[0013] The dispersion uniformity of the nitrogen-doped titanium dioxide-copper oxide nanoparticles in the silicone matrix is ≥95%, and no obvious sedimentation is observed after long-term storage for 6 months.

[0014] Preferably, the surface of the nitrogen-doped titanium dioxide nanoparticles and the copper oxide nanoparticles is coated with a siloxane coating layer.

[0015] The siloxane coating layer is formed by the reaction of a silane coupling agent and a silicone prepolymer, and has a thickness of 5-20 nm.

[0016] Another aspect of the present application discloses a preparation method of an antibacterial material, comprising the following steps:

[0017] S1: raw material preparation: preparing nitrogen-doped titanium dioxide nanoparticles and copper oxide nanoparticles, and preparing a silicone matrix, a silane coupling agent and a silicone prepolymer;

[0018] S2: stirring the silane coupling agent and the nitrogen-doped titanium dioxide-copper oxide mixed nanoparticles at 50-80°C for 30-60 min, then adding the silicone prepolymer and continuing to react for 60-120 min to form a siloxane coating layer on the surface of the nanoparticles;

[0019] S3: adding the modified nanoparticles in S2 into the silicone matrix and dispersing by shearing stirring and ultrasonic;

[0020] S4: coating or molding the dispersed mixed system, and curing at 50-120°C for 1-4 h to obtain a silicone antibacterial material;

[0021] S5: testing the light absorption edge, the separation efficiency of photo-generated electron-hole pairs, the antibacterial performance, the stability and the biological safety of the molded material.

[0022] Preferably, high-shear double-planetary stirring and high-power ultrasonic are used in S3, and after stirring for 10-15 min, ultrasonic is applied for 5-10 min, and the cycle is repeated for 3-5 times until no obvious agglomerates of the nanoparticles are observed in the silicone matrix.

[0023] Preferably, the coating thickness in S4 is 5-50 μm, and the density of the molded product is 1.05-1.2 g / cm 3 .

[0024] Preferably, the light-generated electron-hole pair separation efficiency in S5 is characterized by a transient photocurrent test or a fluorescence spectrum test, the antibacterial performance is tested by a shake flask method or a film pasting method, and the biological safety is verified by a cytotoxicity test and a skin irritation test.

[0025] Compared with the prior art, the application has the advantages that in the application, the light absorption edge of the material is expanded to 500 nm, the light-generated electron-hole pair separation efficiency is increased by more than 40%, under visible light irradiation, the killing rate of Escherichia coli and Staphylococcus aureus is all greater than or equal to 99.9% within 2 hours, and the inactivation rate of adenovirus is greater than or equal to 4 logarithmic levels within 4 hours, without relying on an ultraviolet light source, the application is suitable for natural and indoor scenes, and the service life of the material is prolonged through a siloxane coating layer and a high-efficiency dispersion technology.

[0026] The raw materials used in the preparation process are easy to obtain, the steps are controllable, and the application can realize large-scale production, which helps to improve the domestication rate of high-end photocatalytic antibacterial organic silicon products and break through international technical barriers. DETAILED DESCRIPTION

[0027] The application will be further described in detail below.

[0028] As shown in the drawings, an organic silicon antibacterial material based on photocatalytic nanoparticles has the characteristics that the antibacterial material is a "nitrogen-doped titanium dioxide-copper oxide / organic silicon" composite system, which comprises nitrogen-doped titanium dioxide nanoparticles, copper oxide nanoparticles and an organic silicon matrix, the nitrogen-doped titanium dioxide nanoparticles, the copper oxide nanoparticles and the organic silicon matrix form a heterojunction structure, and the heterojunction structure expands the light absorption edge from about 400 nm of traditional titanium dioxide to 500 nm.

[0029] In use,

[0030] The application comprises the following steps:

[0031] S1: raw material preparation: prepare nitrogen-doped titanium dioxide nanoparticles and copper oxide nanoparticles, prepare an organic silicon matrix, a silane coupling agent and an organic silicon prepolymer;

[0032] S2: stir and react the silane coupling agent and the nitrogen-doped titanium dioxide-copper oxide mixed nanoparticles at 50-80 DEG C for 30-60 min, then add the organic silicon prepolymer and continue to react for 60-120 min to form a siloxane coating layer on the surface of the nanoparticles;

[0033] S3: shear stir and ultrasonically disperse the modified nanoparticles in S2 in the organic silicon matrix;

[0034] S4: coating or molding the dispersed mixture, curing at 50-120 DEG C for 1-4 h to obtain the silicone antibacterial material;

[0035] S5: testing the light absorption edge, the separation efficiency of photo-generated electron-hole pairs, the antibacterial property, the stability and the biological safety of the molded material.

[0036] In S3, high shear double planetary stirring and high power ultrasonic are used, after stirring for 10-15 min, ultrasonic is applied for 5-10 min, and the cycle is repeated for 3-5 times, until there is no obvious agglomeration of the nanoparticles in the silicone matrix, and in S4, the coating thickness is 5-50 mu m, and the density of the molded product is 1.05-1.2 g / cm 3 ;

[0037] In S5, the separation efficiency of photo-generated electron-hole pairs is characterized by transient photocurrent test or fluorescence spectrum test, the antibacterial property is tested by shake flask method or film pasting method, and the biological safety is verified by cytotoxicity test and skin irritation test.

[0038] In one of the embodiments,

[0039] The antibacterial material has a killing rate of 99.9% for E. coli and Staphylococcus aureus within 2 hours, the nitrogen-doped titanium dioxide nanoparticles have a nitrogen doping amount of 0.5-5 at.% and a particle size of 10-50 nm;

[0040] The copper oxide nanoparticles have a particle size of 5-30 nm.

[0041] The mass ratio of the nitrogen-doped titanium dioxide nanoparticles to the copper oxide nanoparticles is 1:0.2-1:1, and the silicone matrix is at least one of polydimethylsiloxane, methyl vinyl siloxane or methyl phenyl siloxane;

[0042] The dispersion uniformity of the nitrogen-doped titanium dioxide-copper oxide nanoparticles in the silicone matrix is 95%, and there is no obvious settlement after long-term storage for 6 months, the surface of the nitrogen-doped titanium dioxide nanoparticles and the copper oxide nanoparticles is coated with a siloxane coating layer, the siloxane coating layer is formed by the reaction of a silane coupling agent and a silicone prepolymer, and the thickness is 5-20 nm.

[0043] In the specific implementation of the present application,

[0044] The nitrogen-doped titanium dioxide nanoparticles are prepared by hydrolysis reaction of tetrabutyl titanate and urea at a mole ratio of 1:2 at 60 DEG C and calcination at 550 DEG C for 3 h, and have a nitrogen doping amount of 2 at.% and a particle size of 20 nm, the copper oxide nanoparticles are prepared by hydrothermal method and have a particle size of 15 nm, and the silicone matrix is polydimethylsiloxane.

[0045] The silane coupling agent is mixed with nitrogen-doped titanium dioxide-copper oxide at 70℃ and stirred for 45 min, then the organosilicon prepolymer is added and the reaction is continued for 90 min to form a siloxane coating layer. The modified nanoparticles are added to a polydimethylsiloxane matrix and subjected to high shear stirring at 2000 rpm for 12 min and ultrasonic treatment at 500 W for 8 min, with 4 cycles. Coating and molding (coating thickness 20 μm) is performed and the product is cured at 80℃ for 2 h.

[0046] The content not described in detail in the specification is the prior art known to those skilled in the art.

[0047] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the first feature is higher than the second feature in horizontal height. The first feature "under", "below" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or only means that the first feature is lower than the second feature in horizontal height

[0048] The above describes the present application and its embodiments, which are not restrictive, and the actual structure is not limited thereto. In general, if a person skilled in the art is inspired by it, without departing from the purpose of the present application, without creative design, similar structure and embodiments to the technical solution can be designed and belong to the protection scope of the present application.

Claims

1. An organosilicon antibacterial material based on photocatalytic nanoparticles, characterized in that: The antibacterial material is a "nitrogen-doped titanium dioxide-copper oxide / organosilicon" composite system, including nitrogen-doped titanium dioxide nanoparticles, copper oxide nanoparticles and an organosilicon matrix; The nitrogen-doped titanium dioxide nanoparticles, copper oxide nanoparticles, and organosilicon matrix form a heterojunction structure, which extends the light absorption edge from approximately 400 nanometers in traditional titanium dioxide to 500 nanometers.

2. The organosilicon antibacterial material based on photocatalytic nanoparticles according to claim 1, characterized in that: The antibacterial material has a kill rate of ≥99.9% against Escherichia coli and Staphylococcus aureus within 2 hours.

3. The organosilicon antibacterial material based on photocatalytic nanoparticles according to claim 1, characterized in that: The nitrogen doping amount of the nitrogen-doped titanium dioxide nanoparticles is 0.5–5 at.%, and the particle size is 10–50 nm. The copper oxide nanoparticles have a particle size of 5–30 nm.

4. The organosilicon antibacterial material based on photocatalytic nanoparticles according to claim 1, characterized in that: The mass ratio of nitrogen-doped titanium dioxide nanoparticles to copper oxide nanoparticles is 1:0.2 to 1:

1.

5. The organosilicon antibacterial material based on photocatalytic nanoparticles according to claim 1, characterized in that: The organosilicon matrix is ​​at least one of polydimethylsiloxane, methylvinylsiloxane, or methylphenylsiloxane; The nitrogen-doped titanium dioxide-copper oxide nanoparticles exhibit a dispersion uniformity of ≥95% in the organosilicon matrix and show no significant sedimentation after being left for 6 months.

6. The organosilicon antibacterial material based on photocatalytic nanoparticles according to claim 1, characterized in that: The nitrogen-doped titanium dioxide nanoparticles and copper oxide nanoparticles are coated with a siloxane coating layer. The siloxane coating layer is formed by the reaction of a silane coupling agent and an organosilicon prepolymer, and has a thickness of 5–20 nm.

7. A method for preparing an antibacterial material, applied to the organosilicon antibacterial material based on photocatalytic nanoparticles as described in any one of claims 1-6, characterized in that: Includes the following steps: S1: Raw material preparation: Prepare nitrogen-doped titanium dioxide nanoparticles and copper oxide nanoparticles, and prepare organosilicon matrix, silane coupling agent and organosilicon prepolymer; S2: The silane coupling agent and nitrogen-doped titanium dioxide-copper oxide mixed nanoparticles are stirred and reacted at 50-80℃ for 30-60 min, and then the organosilicon prepolymer is added and the reaction is continued for 60-120 min to form a siloxane coating layer on the surface of the nanoparticles. S3: The modified nanoparticles from S2 are added to the organosilicon matrix and dispersed by shear stirring and ultrasonication. S4: Coat or mold the dispersed mixture and cure it at 50-120℃ for 1-4 hours to obtain an organosilicon antibacterial material; S5: Test the light absorption edge, photogenerated electron-hole pair separation efficiency, antibacterial properties, stability and biosafety of the molded material.

8. The method for preparing an antibacterial material according to claim 1, characterized in that: In step S3, high-shear dual planetary stirring and high-power ultrasound are used. After stirring for 10 to 15 minutes, ultrasound is performed for 5 to 10 minutes, and the cycle is repeated 3 to 5 times until the nanoparticles do not show obvious agglomeration in the organosilicon matrix.

9. The method for preparing an antibacterial material according to claim 1, characterized in that: The coating thickness in step S4 is 5–50 μm, and the density of the molded product is 1.05–1.2 g / cm³. 3 .

10. The method for preparing an antibacterial material according to claim 1, characterized in that: The separation efficiency of photogenerated electron-hole pairs in S5 is characterized by transient photocurrent testing or fluorescence spectroscopy testing, the antibacterial performance is tested by shaking flask method or film application method, and the biosafety is verified by cytotoxicity test and skin irritation test.