Composite silicon nano antibacterial material as well as preparation method and application thereof

Abstract

The invention discloses a composite silicon nano antibacterial material as well as a preparation method and application thereof, the antibacterial material takes SiO2 with a pore structure as a carrier, and metal oxide and chitin are loaded in pores of the carrier; metal ions in the metal oxide are selected from at least two of iron ions, calcium ions, zinc ions, manganese ions and copper ions. According to the composite silicon nano antibacterial material, multiple metal ions are compounded, and compared with a single metal silicon oxide composite nano antibacterial material, the bimetal silicon oxide composite nano antibacterial material has better antibacterial performance; and after the chitosan is loaded, the antibacterial capability of the nano material is obviously higher than that of an iron-calcium composite silicon nano material.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparation of antibacterial materials, and particularly relates to a composite silicon nano antibacterial material, a preparation method thereof and an application thereof. Background Art

[0002] As the most frequently used tool by people at present, mobile phones play a huge role in daily life. However, from a biological perspective, like clothes and tableware, bacteria need to be cleaned regularly after long-term use. However, the frequency of cleaning clothes is much higher than that of cleaning mobile phones. Mobile phones will accumulate bacteria and pathogens every day through contact with our bodies. Therefore, although we wash our hands before eating, when eating or drinking tea while watching the mobile phone, bacteria will be inadvertently brought into the mouth. In hospitals, when doctors take care of patients with infectious diseases (such as real-time monitoring of diabetes and asthma, vaccination and control of epidemics during travel, etc.), while greatly improving the work efficiency of medical staff, mobile phones, as a place for bacterial colonization, have the potential to be contaminated by pathogenic bacteria. Some microbiologists believe that the heat generated by mobile phones due to frequent contact creates an ideal breeding ground for microorganisms commonly found on human skin. Especially in key departments such as operating rooms, intensive care units (ICUs), and neonatal wards, the possibility of mobile phones causing hospital infections, especially multi-drug resistant bacterial infections, cannot be ignored. Extended to daily life, nearly 1 / 8 of deaths are related to infections caused by bacterial antimicrobial resistance. The situation of mobile phones carrying bacteria cannot be ignored.

[0003] People have gradually started to pay attention to disinfection, anti-mildew and antibacterial in daily life. It is not uncommon for a mobile phone to have two or more kinds of bacteria. Most of the microorganisms are normal flora on human skin or in the oral cavity, but there are also pathogenic bacteria or conditional pathogenic bacteria. Among them, the most isolated Gram-positive bacteria are Staphylococcus, and the Gram-negative bacteria are Acinetobacter. The survey results show that the isolation rates of various bacteria are: Staphylococcus aureus 54%, Micrococcus 21%, Corynebacterium-like 8%, Enterococcus 4%, Pseudomonas, Citrobacter and Bacillus 3%, Acinetobacter, Enterobacter and Streptococcus viridans 2%.

[0004] At present, the research on antibacterial mobile phone case materials has not been expanded, and some antibacterial materials on the market have not been effectively popularized, and related research is almost zero. Summary of the Invention

[0005] To address the above technical problems, the present invention provides a composite silicon nanometer antibacterial material. The antibacterial material uses SiO2 with a pore structure as a carrier, and both metal oxide and chitin are loaded within the pores of the carrier; the metal ions in the metal oxide are selected from at least two of iron ions, calcium ions, zinc ions, manganese ions, and copper ions, preferably iron ions and calcium ions.

[0006] According to an embodiment of the present invention, the SiO2 has a mesoporous morphology, with a particle size of 50 - 200 nm; its pore diameter is 5 - 20 nm.

[0007] According to an embodiment of the present invention, the loading amount of the metal oxide on the carrier is 2 - 30 wt%.

[0008] According to an embodiment of the present invention, the metal oxide is iron oxide and calcium oxide, and the iron oxide and calcium oxide are co - loaded on the carrier. Among them, the loading content of the iron oxide is 3 - 18 wt%, such as 15 - 17 wt%, and the loading content of the calcium oxide is 9 - 14 wt%.

[0009] According to an embodiment of the present invention, the loading amount of the chitin is 9 - 15 wt%.

[0010] According to an embodiment of the present invention, the composite silicon nanometer antibacterial material is spherical.

[0011] The present invention also provides a preparation method of the composite silicon nanometer antibacterial material. The method is as follows:

[0012] (1) Mix a precursor containing metal ions, a reducing agent, and silica with a pore structure, and use a hydrothermal method to prepare an intermediate;

[0013] (2) Mix chitin and the above - mentioned intermediate in an organic solvent to obtain the composite silicon nanometer antibacterial material.

[0014] According to an embodiment of the present invention, in step (1), the precursor containing metal ions is selected from at least two of ferric chloride, calcium chloride, zinc chloride, manganese chloride, and copper chloride, preferably ferric chloride and calcium chloride.

[0015] According to an embodiment of the present invention, in step (1), the reducing agent is selected from one of hexamine, sodium carbonate, ammonia water, and formaldehyde, preferably hexamine.

[0016] According to an embodiment of the present invention, in step (1), the mass ratio of the precursor containing metal ions to the silica is 1 - 10:1.

[0017] According to an embodiment of the present invention, in step (1), the mass ratio of the reducing agent to the silica is 1 - 20:1.

[0018] According to an embodiment of the present invention, in step (1), the temperature of mixing is 50 - 100 °C; the time of mixing is 1 - 48 h.

[0019] According to an embodiment of the present invention, step (1) is specifically: ultrasonically mixing a metal ion-containing precursor, a reducing agent, and silica with a pore structure, stirring for half an hour at 90 °C, adding a reducing agent and continuing to mix, and preparing the intermediate by a hydrothermal method.

[0020] According to an embodiment of the present invention, step (1) further includes a post-treatment step of washing and centrifuging the prepared product, etc.

[0021] According to an embodiment of the present invention, in step (2), the mass ratio of chitin to the intermediate is 1:1 - 20, preferably 1:2 - 10.

[0022] According to an embodiment of the present invention, in step (2), the temperature of mixing is 15 - 40 °C; the time of mixing is 1 - 48 h.

[0023] According to an embodiment of the present invention, in step (2), the organic solvent is selected from at least one of dimethyl sulfoxide, ethanol, methanol, etc.

[0024] According to an embodiment of the present invention, in step (2), the content of the organic solvent is not particularly limited as long as it can partially dissolve or completely dissolve each raw material.

[0025] According to an embodiment of the present invention, step (2) further includes a post-treatment step of washing and centrifuging the prepared product, etc.

[0026] The present invention also provides the application of the above composite silicon nanometer antibacterial material as an antibacterial material, for example, as an antibacterial auxiliary for antibacterial resin, and preferably, it is used in antibacterial mobile phone case materials.

[0027] The present invention also provides a composite antibacterial resin, and its raw materials include:

[0028] 100 parts of bis(hexacyclic carbonate);

[0029] 10 - 60 parts of triolamine; and,

[0030] 1 - 10 parts of the above composite silicon nanometer antibacterial material.

[0031] According to an embodiment of the present invention, the raw materials of the composite antibacterial resin include 20 - 50 parts of triolamine, such as 20 parts, 25 parts, 30 parts, 33 parts, 40 parts, 45 parts or 50 parts.

[0032] According to an embodiment of the present invention, the composite antibacterial resin raw material includes 2 to 6 parts of the above-mentioned composite silicon nano antibacterial material, such as 2 parts, 3 parts, 4 parts, 5 parts or 6 parts.

[0033] The above-mentioned composite antibacterial resin of the present invention can be used as a raw material for mobile phone case materials.

[0034] The present invention also provides a preparation method of the above-mentioned composite antibacterial resin, and the method is as follows:

[0035] Mix bis(hexacyclic carbonate), trihydric alcoholamine and the composite silicon nano antibacterial material, dry after hot pressing to obtain the composite antibacterial resin.

[0036] According to an embodiment of the present invention, the hot pressing pressure is 1-5 MPa, preferably 2-4 MPa.

[0037] According to an embodiment of the present invention, the hot pressing temperature is 110-180 °C, preferably 120-150 °C; the hot pressing time is 2-10 min, preferably 4-6 min.

[0038] According to an embodiment of the present invention, the drying temperature is 80-130 °C, preferably 90-110 °C; the drying time is 1-6 h, preferably 1-3 h.

[0039] According to an embodiment of the present invention, after the mixing of bis(hexacyclic carbonate), trihydric alcoholamine and the composite silicon nano antibacterial material, it can also be shaped.

[0040] According to an embodiment of the present invention, the preparation method of bis(hexacyclic carbonate) is: mix bis(trimethylol) propane and diphenyl carbonate and react to prepare bis(hexacyclic carbonate).

[0041] According to an embodiment of the present invention, in the preparation of bis(hexacyclic carbonate), the molar ratio of bis(trimethylol) propane to diphenyl carbonate is 1:2-20, preferably 1:8-15.

[0042] According to an embodiment of the present invention, in the preparation of bis(hexacyclic carbonate), the reaction temperature is 120-170 °C, preferably 130-150 °C; the reaction time is 16-60 h, preferably 28-50 h.

[0043] According to an embodiment of the present invention, in the preparation of bis(hexacyclic carbonate), the method further includes a post-treatment step, such as filtering, washing, collecting the product, recrystallizing and drying the prepared product.

[0044] The present invention also provides the application of the above-mentioned composite antibacterial resin in the preparation of daily antibacterial articles. For example, the daily antibacterial articles can be mobile phone cases.

[0045] Advantages of the present invention:

[0046] 1. In the composite silicon nanometer antibacterial material of the present invention, Fe and Ca ions have a broad antibacterial spectrum, and the incidence of antibacterial drug resistance is very low. At the same time, chitin has a good bacteriostatic effect, and the three work together to kill bacteria.

[0047] 2. The Fe element and Ca element of the present invention are common antibacterial metal materials, which can generate ROS to damage the bacterial cell wall and cause bacteria to lyse and die. Ca ions have the characteristics of Fenton-like, enter into the bacteria cells, cause the cell wall of bacteria to break, and the cell fluid to flow out, resulting in the death of bacteria. The chitin of the present invention has an inhibitory effect on many fungi due to its unique structure. The present invention uses a hydrothermal reduction method to prepare the composite silicon nanometer antibacterial material in one step, and uses this as the raw material to prepare the material for mobile phone cases. Compared with the antibacterial materials in the prior art, the present invention has a better resistance effect against bacteria.

[0048] 3. The composite silicon nanometer antibacterial material of the present invention is prepared by compounding a variety of metal oxides. After loading chitin, it has high antibacterial performance against drug-resistant Gram-negative bacteria (Escherichia coli) and drug-resistant Gram-positive bacteria (Staphylococcus aureus). Especially, the performance effect on cocci is the best.

[0049] 4. The composite silicon nanometer antibacterial material of the present invention is prepared by compounding a variety of metal ions. The double-metal oxide silicon composite nanometer antibacterial material has better antibacterial performance than the single-metal oxide silicon composite nanometer antibacterial material; at the same time, it has a drug-loading performance, and its antibacterial ability after loading chitin is significantly higher than that of the iron-calcium composite silicon nanometer material.

[0050] 5. The preparation process of the composite antibacterial resin of the present invention is simple. The material is synthesized by a one-step method. Through solvent dispersion and heat curing treatment, a composite antibacterial resin with antibacterial effect is obtained. It has good toughness, is not easy to crack, has a smooth surface, is not easy to stain with foreign objects, has less bacterial attachment, and has an antibacterial effect. After degradation, it is pollution-free, green and environmentally friendly.

[0051] 6. The composite antibacterial resin of the present invention can change its shape and color, and the process is simple, which is suitable for mass production. Description of the Drawings

[0052] Figure 1 : Figures A - B are the transmission electron microscope photos and enlarged transmission electron microscope photos of the iron-calcium composite silicon nanometer material Fe-Ca prepared in Example 1;

[0053] Figures C - D are the transmission electron microscope photos and enlarged transmission electron microscope photos of the composite silicon nanometer antibacterial material Fe-Ca@C prepared in Example 1;

[0054] Figure E is the elemental distribution map of the composite silicon nanometer antibacterial material Fe-Ca@C in Example 1 under a high-resolution transmission microscope;

[0055] Figure 2 : Figure A is the infrared spectrogram of the composite silicon nanometer antibacterial material Fe-Ca@C and chitin in Example 1;

[0056] Figure B is the scanning electron micrograph of the composite silicon nanometer antibacterial material Ca@C in Comparative Example 1;

[0057] Figures C-D are the low-magnification scanning electron micrograph and high-magnification scanning electron micrograph of the mobile phone case material (Resin-Fe-Ca@C) in Example 2.

[0058] Figure 3 : Figure A is the electron photograph of the products of Resin in Comparative Example 2, Resin-Fe-Ca in Comparative Example 3, and Resin-Fe-Ca@C in Example 2;

[0059] Figure B is the thermal conductivity and mechanical property diagram of the products of Resin in Comparative Example 2, Resin-Fe-Ca in Comparative Example 3, and Resin-Fe-Ca@C in Example 2.

[0060] Figure 4 : Figures A and C are respectively the photographs after incubation for 24 h when different concentrations of Fe-Ca@C in Application Example 1 are added to the R-E.coli and R-S.aureus bacterial suspensions.

[0061] Figure 4 B and D are respectively the absorbance values after incubation of different concentrations of Fe-Ca@C with the two bacteria for different times.

[0062] Figure E is the single colony count diagram after incubation of Fe-Ca@C in Example 1 and Ca@C in Comparative Example 1 with Escherichia coli for different times in Application Example 1.

[0063] Figure 5 : Figures A-D are respectively the scanning electron micrographs of drug-resistant Escherichia coli and drug-resistant Staphylococcus aureus sampled from the surfaces of Normal bacteria, Resin in Comparative Example 2, Resin-Fe-Ca in Comparative Example 3, and Resin-Fe-Ca@C in Example 2 in Application Example 2. Detailed implementation manners

[0064] The technical solutions of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only for illustrative explanation of the present invention and should not be construed as limiting the protection scope of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0065] Unless otherwise specified, the raw materials and reagents used in the following examples are all commercially available products or can be prepared by known methods.

[0066] Example 1

[0067] 1.1 Preparation of composite silicon nanomaterials

[0068] First, silica was prepared by the two-phase method. This method is easy to operate, and the pore channels and sizes of the silica spheres are controllable. In the present invention, mesoporous silica with a pore diameter of 5 - 10 nm and a particle size of 120 nm was prepared. Take more than 50 mg of the prepared mesoporous silica and place it in a 100 mL single-necked flask. After adding 60 mL of aqueous solution, ultrasonicate for 10 minutes to obtain a silicon solution, which is milky white. Place the above silicon solution on an oil bath at 300 rpm and 90 °C, stir well for 30 minutes, and then add 30 mg of ferric chloride and 70 mg of calcium chloride as precursors. After stirring well for 30 minutes, the precursors are all dissolved, and then add 100 mg of hexamine as a reducing agent, and keep stirring for 24 hours. Finally, centrifuge the sample (3500 rpm, 10 minutes) to collect it, and wash it three times by centrifugation with aqueous solution to obtain iron-calcium composite silicon nanomaterials (Fe-Ca); among them, the loading content of the iron oxide is 16.2%, and the loading content of the calcium oxide is 8.3%.

[0069] 1.2 Preparation of chitin-loaded iron-calcium composite silicon nanomaterials with antibacterial properties

[0070] Add 100 mg of the above-prepared iron-calcium composite silicon nanomaterials Fe-Ca to 15 ml of dimethyl sulfoxide, and ultrasonicate for 10 minutes to disperse it fully. Then, at room temperature, add 20 mg of chitin powder under continuous stirring at 300 rpm. After continuously stirring at room temperature for 24 hours, centrifuge the sample at 3500 rpm for 10 minutes to collect it, and wash it three times by centrifugation with aqueous solution to obtain chitin-loaded iron-calcium composite silicon nanomaterials with antibacterial properties (Fe-Ca@C), where the loading amount of the chitin is 12.5%.

[0071] Take 200 μg of Fe-Ca and Fe-Ca@C of Example 1 and dissolve them in 500 μL of ultrapure water respectively, ultrasonicate for 10 minutes to disperse, suck 10 μl of the mixed solution and drop it on a copper grid, and dry it in an oven at 60 °C. Use a transmission electron microscope and a scanning transmission electron microscope, with a voltage of 100 kV, to observe the morphology, size, and dispersion of the prepared Fe-Ca and Fe-Ca@C of Example 1, and select a pollution-free and clear field of view to take pictures and save.

[0072] Figure 1A-B are the transmission electron microscope (TEM) images and magnified TEM images of the prepared iron-calcium composite silicon nanomaterial Fe-Ca. It can be seen that Fe-Ca is mainly loaded in the pores of silica. The size of this composite silicon nanomaterial is 130 nm, and mesopores (5-10 nm) can be seen in the silica.

[0073] Figure 1 C-D are the TEM images and magnified TEM images of the iron-calcium composite silicon nanomaterial loaded with chitin Fe-Ca@C in Example 1. It can be seen that the mesoporous channels almost disappear, proving the successful loading of chitin.

[0074] Take 200 μg of Fe-Ca@C from Example 1 and dissolve it in 500 μL of ultrapure water. Disperse it by ultrasonic treatment for 10 minutes. Pipette 10 μl of the mixed solution and drop it on the ultra-thin carbon film, and dry it in an oven at 60 °C. Use a high-resolution transmission electron microscope with a voltage of 200 kV to take pictures and analyze the morphology, size, dispersibility, sample and composition of Fe-Ca@C in Example 1. The results are as Figure 1 E, where, Figure 1 Ei is the scanning transmission electron microscope image of Fe-Ca@C in Example 1, Figure 1 Eii-V are the elemental distribution maps of elements Si, O, Fe and Ca respectively;

[0075] Figure 1 Evi is the superposition map of the four elements; From Figure 1 the TEM images of Eii-Ev, it can be seen that the main elements of Fe-Ca@C are Si ( Figure 1 Eii), O ( Figure 1 Eiii), Fe ( Figure 1 Eiv) and Ca ( Figure 1 Ev).

[0076] Take 20 mg of Fe-Ca@C from Example 1 and chitin respectively and press them in a tablet press. Measure the Fourier transform infrared absorption spectra of the two samples by an infrared spectrometer. The test results are as Figure 2 A shows that, from Figure 2 A, it can be seen that the characteristic peaks of chitin can all be found in Fe-Ca@C of Example 1, proving the successful loading of chitin in Example 1.

[0077] Comparative Example 1

[0078] The difference between Comparative Example 1 and Example 1 is that: in the preparation process of the composite silicon nanomaterial, ferric chloride precursor was not added, and the content of ferric chloride in Example 1 was replaced with calcium chloride in equal proportion, and the prepared calcium composite silicon material was loaded with chitin, that is, the composite silicon nanomaterial was marked as Ca@C.

[0079] Dissolve 200 μg of Ca@C in 500 μL of ultrapure water, disperse it by ultrasonic treatment for 10 minutes, aspirate 10 μL of the mixture and drop it onto a copper mesh, and dry it in an oven at 60 °C. Use a scanning transmission electron microscope with a voltage of 100 kV to observe the morphology, size, and dispersibility of Ca@C, and select a pollution-free and clear field of view for photographing and saving. The results are as Figure 2 shown in Figure B. Comparative Example 1 is spherical with a size of 130 nm, similar to Example 1.

[0080] Example 2

[0081] a. Preparation of bis(hexacyclic carbonate) monomer

[0082] At room temperature, add bis(trimethylol)propane (10 g, 39.9 mmol) and diphenyl carbonate (84.75 g, 400 mmol) to a 500 mL two-necked flask, then slowly heat up to 140 °C and stir and react for 48 h. After the reaction is completed, wait for the flask to cool to room temperature, add ether and stir thoroughly for extraction, filter by suction, and collect the solid crude product. The obtained crude product is further recrystallized three times with anhydrous tetrahydrofuran, collect the white crystals, and vacuum dry for 12 h to obtain the bis(hexacyclic carbonate) monomer.

[0083] b. Preparation of composite antibacterial mobile phone case material (or composite antibacterial resin)

[0084] The raw material composition of the composite antibacterial mobile phone case material is as follows:

[0085] 100 parts of bis(hexacyclic carbonate)

[0086] 33 parts of triethanolamine

[0087] 2.6 - 3 parts of Fe-Ca@C in the above Example 1

[0088] 1) Add bis(hexacyclic carbonate) (1 g, 3.3 mmol) and triethanolamine (0.33 g, 2.2 mmol) to an agate mortar, and then add Fe-Ca@C in Example 1 (0.22 g) and mix evenly. After sufficient grinding, the mixture is in a putty state and can be shaped into small cubes. After the small cubes are placed at room temperature for 12 h, manually press them into sheets, and then put them into a hot press and hot press at 150 °C and 4 MPa for 5 min to obtain a composite material sheet with a soft texture and arbitrary bendability. Subsequently, put the obtained sheet into an oven and react at 105 °C for 1 - 3 h to obtain the composite antibacterial mobile phone case material (Resin-Fe-Ca@C).

[0089] The composite antibacterial mobile phone case material of Example 2 with a size of 2 mm × 2 mm × 2 mm was pasted on the conductive adhesive. After sputtering gold for 10 minutes, a scanning transmission electron microscope was used at a voltage of 80 kV to observe the morphology, size, and dispersibility of the mobile phone case material of Example 2, and a pollution-free and clear field of view was selected for taking pictures and saving. Figure 2 C-D are the low-magnification scanning electron microscope image and high-magnification scanning electron microscope image of the mobile phone case material (Resin-Fe-Ca@C) in Example 2. Figure 2 The results of C-D show that Fe-Ca@C of Example 1 was well dispersed in the polymer resin, proving the successful preparation of the antibacterial mobile phone case material.

[0090] Comparative Example 2

[0091] The difference between Comparative Example 2 and Example 2 is that Fe-Ca@C was not added, and its content was replaced with bis(hexacyclic carbonate) and triethanolamine in equal proportions, and the prepared antibacterial resin was labeled as Resin.

[0092] Comparative Example 3

[0093] The difference between Comparative Example 3 and Example 2 is that Fe-Ca@C in Example 2 was replaced with an equal amount of Fe-Ca (i.e., Fe-Ca in Example 1), and the prepared antibacterial resin was labeled as Resin-Fe-Ca.

[0094] The contents of each raw material in Comparative Example 2, Comparative Example 3, and Example 2 are shown in the following table.

[0095] Table 1. Contents of each raw material in Comparative Examples 1-2

[0096]

[0097]

[0098] Photographs were taken of the products of Resin in Comparative Example 2, Resin-Fe-Ca in Comparative Example 3, and Resin-Fe-Ca@C in Example 2, and tensile strength and thermal conductivity tests were carried out.

[0099] Tensile strength: Tested in accordance with GB / T 2567—2008, and the test temperature was (23 ± 2)°C. Three specimens were selected for testing in each group, and the arithmetic mean of the obtained results was taken.

[0100] Thermal conductivity performance: The thermal conductivity of the nanomaterial was tested using a Hot Disk thermal conductivity meter (TPS2500S, Hot Disk Company, Sweden). Three groups of comparisons were made for the same component at a temperature of 23°C, and the average value was taken.

[0101] Figure 3A is the electron micrograph of Comparative Example 2 Resin, Comparative Example 3 Resin-Fe-Ca, and Example 2 Resin-Fe-Ca@C products. It can be seen from Figure 3 A that their shapes are controllable.

[0102] Thermal conductivity and tensile strength are as Figure 3 shown in B. There are no significant differences in the thermal conductivity and tensile strength of Comparative Example 2 Resin, Comparative Example 3 Resin-Fe-Ca, and Example 2 Resin-Fe-Ca@C, proving that adding a certain amount of nano-antibacterial additive, namely Fe-Ca@C in Example 1, to the antibacterial resin will not affect the mechanical properties of the resin.

[0103] Application Example 1

[0104] The powder of Example 1 Fe-Ca@C and Comparative Example 1 Ca@C were sterilized by high-temperature and high-pressure (121 °C, 0.5 h) for subsequent use.

[0105] The cryopreservation solution containing drug-resistant Staphylococcus aureus (R-S.aureus) and drug-resistant Escherichia coli (R-E.coli) was stored in a -80 °C refrigerator.

[0106] First, use a 10 μL sterile pipette tip to aspirate 10 μL of the cryopreserved bacterial solution and scrape it onto the surface of the LB solid medium (composition: 10 g / L tryptone, 5 g / L yeast extract, 10 g / L sodium chloride, and 15 g / L agar powder). Then, place the plate in an incubator (37 °C, 5% CO2) and let it stand for 12 h for cultivation. Next, use a 10 μL sterile pipette tip to pick a single colony and add it to 50 mL of LB liquid medium (composition: 0 g / L tryptone, 5 g / L yeast extract, 10 g / L sodium chloride, and 15 g / L agar powder). Vigorously pipette and shake well, and place the bacterial sample suspension on a shaker and shake (37 °C, 300 rpm / min) overnight.

[0107] Take 100 μL of the above bacterial suspension and then add it dropwise into a 96-well plate. Then, use a microplate reader to measure the absorbance of the suspension at 600 nm, and determine the concentration of the original stock solution by querying the linear relationship between the bacterial solution and the absorbance. Then, dilute the bacterial suspension with physiological saline and measure the absorbance. The final concentration of the obtained bacteria is 1×10 7 CFU / mL for standby.

[0108] After the above Fe-Ca@C sample is cooled to 30-50 °C at room temperature, 5 mL of the two kinds of bacterial suspensions prepared above is taken, and then Fe-Ca@C powder with different masses is added to make the final concentrations 0 μg / mL, 100 μg / mL, 150 μg / mL, 200 μg / mL, 250 μg / mL and 300 μg / mL. Then the suspension is placed in a shaker and shaken thoroughly (37 °C, 300 rpm / min) for different times (0 h, 2 h, 4 h, 8 h, 12 h, 24 h). After that, the 24-h incubation group is photographed. Then, after all the samples are allowed to stand for 2 h, 100 μL of the supernatant is aspirated and added to a 96-well plate, and the absorbance value of the suspension at 600 nm is measured with an enzyme-linked immunosorbent assay (ELISA) reader.

[0109] Figure 4 A and C are respectively the photos after different concentrations of Fe-Ca@C in Application Example 1 are added to the R-E.coli and R-S.aureus bacterial suspensions and incubated for 24 h. From Figure 4 A and C, it can be seen that the precipitated dead bacteria increase with the increase of the concentration. At the same time, the antibacterial efficiency of Fe-Ca@C against R-S.aureus is higher than that against R-E.coli.

[0110] Figure 4 B and D are respectively the absorbance values after different concentrations of Fe-Ca@C are incubated with the two kinds of bacteria for different times. From Figure 4 the results of B and D, it can be seen that the antibacterial efficiency of Fe-Ca@C is concentration-dependent. At the same time, the antibacterial efficiency of Fe-Ca@C against R-S.aureus is higher. This is because the curvature of cocci is higher than that of bacilli, and the antibacterial material has a higher adhesion to bacteria with a larger curvature, so the killing effect is greater.

[0111] The Fe-Ca@C in Example 1 and the Ca@C sample in Comparative Example 1 are cooled to 30-50 °C at room temperature. 5 mL of the R-S.aureus bacterial suspension prepared above is taken, and then the same mass of Fe-Ca@C and Ca@C is added respectively to make the final concentration 300 μg / mL. The suspension is placed in a shaker and shaken thoroughly (37 °C, 300 rpm / min) for different incubation times (2 h, 4 h, 8 h, 12 h and 24 h respectively). 100 μL of the above R-S.aureus bacterial suspension is taken on the surface of an LB solid medium, and the suspension is spread evenly with a bacterial glass spreader. Finally, the plate is placed in an incubator (37 °C, 5% CO2) and incubated for 24 h and photographed.

[0112] Figure 4 E is the result of the pour plate after Fe-Ca@C and Ca@C are incubated with R-S.aureus for different times. From the number of colonies, we can see that because the Fenton reaction efficiency of Fe is much higher than that of Ca, the antibacterial effect of the antibacterial material in Example 1 is much higher than that in Comparative Example 1.

[0113] Application Example 2

[0114] A cryopreservation solution containing drug-resistant Staphylococcus aureus (R-S.aureus) and drug-resistant Escherichia coli (R-E.coli) was stored in a -80 °C refrigerator. First, 10 μL of the cryopreserved bacterial solution was aspirated using a 10 μL sterile pipette tip and smeared on the surface of an LB solid medium (composition: 10 g / L tryptone, 5 g / L yeast extract, 10 g / L sodium chloride, and 15 g / L agar powder). Then, the plate was placed in an incubator (37 °C, 5% CO2) and left to stand for 12 h for cultivation. Next, a single colony was picked using a 10 μL sterile pipette tip and added to 50 mL of LB liquid medium (composition: 0 g / L tryptone, 5 g / L yeast extract, 10 g / L sodium chloride, and 15 g / L agar powder). The mixture was thoroughly pipetted and shaken evenly, and the bacterial sample suspension was placed in a shaker and shaken (37 °C, 300 rpm / min) overnight.

[0115] 100 μL of the above bacterial suspension was taken and then added dropwise into a 96-well plate. Then, the absorbance of the suspension at 600 nm was measured using a microplate reader, and the concentration of the original stock solution was determined by querying the linear relationship between the bacterial solution and the absorbance. Then, the bacterial suspension was diluted with physiological saline, the absorbance was measured, and the final concentration of the bacteria obtained was ~1×10 7 CFU / mL for standby.

[0116] The above 100 μL of R-E.coli and R-S.aureus bacterial suspensions were respectively spread on the surfaces of Comparative Example 2 Resin, Comparative Example 3 Resin-Fe-Ca, and Example 2 Resin-Fe-Ca@C. After 24 h, the surfaces of the antibacterial resins were rinsed with 100 μL of physiological saline to obtain three groups of bacterial suspensions (in triplicate). A 100 μL bacterial suspension left to stand for 24 h was set as a control group (i.e., Figure 5Normal (in triplicate). After centrifuging to obtain bacterial pellets, the final bacteria were resuspended in physiological saline, centrifuged at 3000 - 5000 rpm for 1 - 5 min three times, and finally bacterial pellets were obtained. 1 mL of 2.5% paraformaldehyde was added to all the above samples, and then the samples were placed in a refrigerator at 4°C for 30 min. Then all the samples were centrifuged at 3000 - 5000 rpm for 1 - 5 min. After obtaining the bacterial pellets, the final pellet products were resuspended by pipetting with 30% ethanol - aqueous solution, incubated for another 5 min, and then centrifuged at 3000 - 5000 rpm for 1 - 5 min to obtain preliminarily dehydrated bacterial samples. Then the bacteria were resuspended in 40%, 50%, 60%, 70%, 80%, 90%, and 100% ethanol - aqueous solutions for step - by - step dehydration. Finally, the bacteria resuspended in absolute ethanol were smeared on silicon wafers, sputter - coated with gold, and observed for the morphology of all bacteria under a field - emission scanning electron microscope (LEO1530VP, Germany) at a voltage of 80 kV.

[0117] As Figure 5 Shown in B - D are the scanning electron micrographs of the killing effect of Resin of Comparative Example 2, Resin - Fe - Ca of Comparative Example 3, and Resin - Fe - Ca@C of Example 2 on R - E.coli and R - S.aureus in Application Example 2; it can be seen that compared with the normal group ( Figure 5 Normal in the figure (bacterial suspension stock solution)) ( Figure 5 A), only partial deformation of bacteria occurred in the treatment group of Comparative Example 2 (i.e., Figure 5 B), proving that the antibacterial efficiency of the antibacterial resin is limited; Figure 5 D (i.e., Example 2) had significantly higher antibacterial performance than Figure 5 C (Comparative Example 3). After 24 h of incubation, overall deformation, rupture, and degradation occurred in both types of bacteria. The above results indicate that the antibacterial mobile phone case material of the present invention has high antibacterial performance.

[0118] Above, the embodiments of the present invention have been described by way of example. However, the protection scope of the present invention is not limited to the above - mentioned embodiments. Any modifications, equivalent substitutions, improvements, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A composite silicon nanometer antibacterial material, characterized in that, The antibacterial material uses SiO2 with a pore structure as a carrier, and both the metal oxide and chitin are loaded in the pores of the carrier; the metal ions in the metal oxide are selected from at least two of iron ions, calcium ions, zinc ions, manganese ions, and copper ions.

2. The composite silicon nanometer antibacterial material according to claim 1, wherein The metal ions are selected from iron ions and calcium ions; Preferably, the SiO2 has a mesoporous morphology, with a particle size of 50 - 200 nm; and a pore diameter of 5 - 20 nm; Preferably, the loading amount of the metal oxide on the carrier is 2 - 30 wt%.

3. The composite silicon nanometer antibacterial material according to claim 1 or 2, characterized in that, The metal oxide is iron oxide and calcium oxide, and the iron oxide and calcium oxide are co - loaded on the carrier, wherein the loading content of the iron oxide is 3 - 18 wt%, and the loading content of the calcium oxide is 9 - 14 wt%; Preferably, the loading amount of the chitin is 9 - 15 wt%. Preferably, the composite silicon - based nano antibacterial material is spherical.

4. The preparation method of the composite silicon nanometer antibacterial material according to any one of claims 1 to 3, characterized in that, The method is as follows: (1) Mix a precursor containing metal ions, a reducing agent, and silica with a pore structure, and prepare an intermediate by a hydrothermal method; (2) Mix chitin and the above - mentioned intermediate in an organic solvent to obtain the composite silicon - based nano antibacterial material.

5. The method according to claim 4, wherein In step (1), the precursor containing metal ions is selected from at least two of ferric chloride, calcium chloride, zinc chloride, manganese chloride, and copper chloride. Preferably, in step (1), the reducing agent is selected from one of hexamine, sodium carbonate, ammonia water, and formaldehyde. Preferably, in step (1), the mass ratio of the precursor containing metal ions to the silica is 1 - 10:

1. Preferably, in step (1), the mass ratio of the reducing agent to the silica is 1 - 20:

1. Preferably, in step (1), the mixing temperature is 50 - 100 °C; and the mixing time is 1 - 48 h.

6. The method according to claim 4, characterized in that, In step (2), the mass ratio of the chitin to the intermediate is 1:1 - 20. Preferably, in step (2), the organic solvent is selected from at least one of dimethyl sulfoxide, ethanol, and methanol.

7. The application of the composite silicon - based nano antibacterial material according to any one of claims 1 - 3 as an antibacterial material, for example, as an antibacterial aid for antibacterial resin, preferably, for use in antibacterial mobile phone case materials.

8. A composite antibacterial resin, characterized in that, Its raw materials include: 100 parts of bis(hexacyclic carbonate); 10 - 60 parts of triolamine; and, 1 - 10 parts of the composite silicon - based nano antibacterial material according to any one of claims 1 - 3.

9. The preparation method of the composite antibacterial resin according to claim 8, characterized in that, The method is as follows: Mix bis(hexacyclic carbonate), triolamine, and the composite silicon - based nano antibacterial material according to any one of claims 1 - 3, hot - press and then dry to obtain the composite antibacterial resin. Preferably, the hot - press pressure is 1 - 5 MPa, preferably 2 - 4 MPa. Preferably, the hot - press temperature is 110 - 180 °C; and the hot - press time is 2 - 10 min. Preferably, the drying temperature is 80 - 130 °C; and the drying time is 1 - 6 h. Preferably, the preparation method of the bis(hexacyclic carbonate) is: mix bis(trimethylolpropane) and diphenyl carbonate and react to prepare the bis(hexacyclic carbonate).

10. Use of the composite antibacterial resin according to claim 8 in the preparation of daily antibacterial articles, for example, the daily antibacterial articles are mobile phone cases.

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