Strong-hydrophobicity silver-loaded visible-light-response sterilization powder

Abstract

The invention discloses a strong hydrophobic silver-loaded visible light response sterilization powder. The preparation method comprises the following steps: 1) fully dispersing g-C3N4 nanosheets in deionized water under an ultrasonic condition to obtain a suspension, adding a silver nitrate aqueous solution into the suspension, adding methanol as a sacrificial agent, and irradiating and stirring by using a xenon lamp to obtain silver-loaded carbon nitride nanoparticles; 2) mixing vinyl-terminated polydimethylsiloxane and toluene, adding the silver-loaded carbon nitride nanoparticles, fully stirring under water bath heating, and then fully stirring by using full light irradiation in an air-isolated environment; 3) dispersing the carbon nitride nano-particles obtained in the step 2) in toluene for centrifugation, removing unloaded vinyl-terminated polydimethylsiloxane, dispersing the centrifuged carbon nitride nano-particles in ethanol, and drying the centrifuged carbon nitride nano-particles. The sterilization powder has good hydrophobicity, and has a broad-spectrum sterilization effect under visible light illumination.

Description

Technical Field

[0001] The present invention relates to a strongly hydrophobic, silver-loaded visible light-responsive bactericidal powder. Background Art

[0002] Blood adhesion and bacterial infection are two important causes of wound infection. When blood comes into contact with an external surface, due to the hemostatic mechanism that blood can induce blood coagulation and platelet activation, blood clots will form. However, this coagulation effect will inevitably lead to strong adhesion of blood to the matrix, making it easy for blood to adhere to the surface of the matrix. Therefore, blood is extremely likely to adhere to surfaces such as clothes and wound dressings, leading to wound infection and blood loss. Choon Hwai Yap et al. reported that by hydrophobically modifying the surface of wound dressings, controlling blood within the wound can, to a certain extent, solve the problem of blood adhesion. And according to the hydrodynamic effect, hydrophobic surfaces can effectively reduce the contact area between blood and the surface and reduce platelet adhesion. Therefore, it is highly desirable to develop a strongly hydrophobic wound dressing.

[0003] In addition to the coagulation effect, bacteria are also a major cause of wound infection. Bacteria first adhere to the wound surface and then proliferate to form a biofilm that is difficult to eliminate, thereby leading to intractable infections. For this reason, people choose to use antibiotics to inhibit bacterial infections. However, improper use of antibiotics will not only cause bacteria to develop drug resistance but also increase the occurrence of drug-induced diseases. Therefore, in order to prevent wound infections, a strongly hydrophobic wound dressing should also have effective bactericidal properties and prevent bacterial infections.

[0004] In previous studies, photocatalysts have been proven to be able to sterilize by generating reactive oxygen species (ROS) to oxidize phospholipid membranes, proteins, and nucleic acids, and have broad-spectrum properties. As a visible light photocatalyst, carbon nitride does not require high-voltage discharge light sources such as xenon lamps or mercury lamps and can operate under normal daylight illumination, but there is no report on modifying carbon nitride to make it have hydrophobicity, bactericidal properties, and biocompatibility at the same time. Summary of the Invention

[0005] In order to solve the problem that the existing wound dressings cannot simultaneously meet hydrophobicity, bactericidal properties, and biocompatibility, which easily lead to wound infections, the present invention provides a strongly hydrophobic, silver-loaded visible light-responsive bactericidal powder that can be used for wound dressings.

[0006] The strongly hydrophobic, silver-loaded visible light-responsive bactericidal powder of the present invention is prepared by the following steps: 1) g-C 3 N 4The nanosheets are fully dispersed in deionized water to obtain a suspension. An aqueous silver nitrate solution is added to the suspension, and then methanol is added as a sacrificial agent. After that, it is irradiated with a xenon lamp and stirred, and then filtered and dried to obtain silver-loaded carbon nitride nanoparticles; 2) Vinyl-terminated polydimethylsiloxane and toluene are mixed and then the silver-loaded carbon nitride nanoparticles obtained in step 1) are added. It is fully stirred under water bath heating. Then, under an air-free environment, it is irradiated with full light and fully stirred, and then filtered and dried to obtain vinyl-terminated polydimethylsiloxane-attached and silver-loaded carbon nitride nanoparticles; 3) The vinyl-terminated polydimethylsiloxane-attached and silver-loaded carbon nitride nanoparticles obtained in step 2) are dispersed in toluene and centrifuged to remove the unloaded vinyl-terminated polydimethylsiloxane. The centrifuged carbon nitride nanoparticles are dispersed in ethanol and dried to obtain the product.

[0007] In step 1), the mass ratio of g-C 3 N 4 nanosheets to deionized water is 1 - 100:1000, the concentration of the aqueous silver nitrate solution is 0.1 - 1 mol / L, and the volume ratio of deionized water, aqueous silver nitrate solution, and methanol is 10:1 - 1.5:1 - 3. The dispersion of g-C 3 N 4 nanosheets is ultrasonic dispersion, the ultrasonic frequency is 30 KHz, the ultrasonic dispersion time is 0.25 - 0.5 h, the xenon lamp uses a power of 300 W, and the irradiation time is 6 - 16 h.

[0008] In step 2), the mass ratio of vinyl-terminated polydimethylsiloxane, toluene, and silver-loaded carbon nitride nanoparticles is 10 - 30:2 - 10:1.

[0009] In step 2), the temperature of water bath heating is 30°C - 50°C, the stirring time under water bath heating is 8 - 16 h, the full light irradiation is carried out using a xenon lamp, the power is 300 W, and the stirring time under full light irradiation is 8 - 16 h.

[0010] In step 3), the centrifugation speed is 10000 r min -1 , the centrifugation is carried out six times. The first centrifugation time is 15 - 25 minutes, and the next five centrifugation times are 5 - 10 minutes. Drying is carried out using an oven, and the drying temperature is 60°C - 80°C. Since the higher the concentration of vinyl-terminated polydimethylsiloxane (PDMS), the higher the viscosity, the first time requires a longer time to remove most of the PDMS.

[0011] Beneficial effects: The carbon nitride nanoparticles loaded with silver nanoparticles and vinyl-terminated polydimethylsiloxane prepared by the method of the present invention can maintain good hydrophobicity, and at the same time have a broad-spectrum bactericidal effect under visible light irradiation. Its bactericidal performance is far stronger than that of ordinary carbon nitride, and it can be used as an important component of products such as wound dressings and antibacterial coatings. In terms of photocatalysts: Most of the existing photocatalysts on the market that can carry out sterilization are made of titanium dioxide (TiO 2 ), and titanium dioxide can only utilize ultraviolet light, and ultraviolet light only accounts for less than 5% of the solar spectrum. Therefore, carbon nitride that uses visible light for catalysis has a higher energy utilization efficiency; secondly, ultraviolet light also has certain harms to humans, animals and plants, while the corresponding visible light catalysis of carbon nitride does not have such harms and is safer; finally, the light passing through the glass indoors and the diffusely reflected light will filter out the ultraviolet part. Therefore, using carbon nitride as a photocatalyst greatly broadens the application scenarios. In terms of the impact on the human body: Both PDMS and silver are biocompatible materials and have a wide range of applications in the medical field; carbon nitride is environmentally friendly and has a stable structure; silver has also long been widely used as an antibacterial material in the medical field; this ensures its safety when applied to wound dressings and antibacterial coatings. Description of the Drawings

[0012] Figure 1 It is an observation diagram of the bactericidal powder of the present invention under a transmission electron microscope; among them, (a) is the overall morphology of the powder particles under the transmission electron microscope; (b) is the distribution and content of different elements on the surface of the powder particles under the transmission electron microscope; (c)-(f) are the content and distribution positions of different elements on the surface of the powder particles respectively.

[0013] Figure 2 It is a hydrophobic property diagram; among them, (a) is the hydrophobic property diagram of ordinary carbon nitride without hydrophobic modification; (b) is the hydrophobic property diagram of the bactericidal powder of the present invention; Figure 3 It is a bactericidal performance diagram; among them, (a) is the bactericidal performance diagram of ordinary carbon nitride; (b) is the bactericidal performance diagram of the bactericidal powder of the present invention. Detailed Embodiments

[0014] Now, the present invention will be further described in detail through embodiments with reference to the drawings, but the present invention is not limited to the embodiments. Embodiment

[0015] The present invention is a strongly hydrophobic, silver-loaded visible light-responsive bactericidal powder, which is prepared by the following steps: 1) First, add 0.3 g of g-C 3 N 4In 100 mL of deionized water and nanosheets, ultrasonic dispersion was carried out for 0.5 h at a frequency of 30 KHz using an ultrasonic device (XM-400UVF, Xiaomei Ultrasonic Instrument (Kunshan) Co., Ltd.) to obtain a suspension. Subsequently, 15 mL of an aqueous silver nitrate solution with a concentration of 0.5 mol / L was added to the above suspension, then 10 mL of methanol was added as a sacrificial agent. Then, it was irradiated with a 300 W xenon lamp and stirred for 12 h. After centrifugal filtration using a centrifuge (Xiangyi H1850), it was dried in an oven at 60 °C for 12 h to obtain silver-loaded carbon nitride nanoparticles.

[0016] 2) After mixing 12 g of vinyl-terminated polydimethylsiloxane (PDMS) (DMS-V41-100GM, Gelest Inc.) and 4 mL of toluene, 0.5 g of the silver-loaded carbon nitride nanoparticles prepared in step 1) was added, and the mixture was stirred for 12 h under heating in a 40 °C water bath. Then, in an air-insulated environment, the mixture was irradiated with a 300 W xenon lamp for full-light irradiation and stirred for 12 h. After centrifugal filtration using a centrifuge (Xiangyi H1850), it was dried in an oven at 60 °C for 12 h to obtain vinyl-terminated polydimethylsiloxane-attached and silver-loaded carbon nitride nanoparticles.

[0017] 3) After dispersing the vinyl-terminated polydimethylsiloxane-attached and silver-loaded carbon nitride nanoparticles prepared in step 2) in toluene, centrifugation was carried out. First, centrifugation was carried out at a speed of 10000 r min -1 for 20 minutes to remove the unloaded vinyl-terminated polydimethylsiloxane, then it was mixed with toluene again and centrifuged at a speed of 10000 r min -1 for 10 minutes. This was repeated five times to maximize the removal of the unloaded vinyl-terminated polydimethylsiloxane. Finally, the centrifuged carbon nitride nanoparticles were dispersed in ethanol and baked in an oven at 60 °C for 12 h to obtain a strongly hydrophobic, silver-loaded visible-light-responsive bactericidal powder. Example

[0018] In Example 1, “15 mL of an aqueous silver nitrate solution with a concentration of 0.5 mol / L was added to the above suspension” was changed to “15 mL of an aqueous silver nitrate solution with a concentration of 0.1 mol / L was added to the above suspension”. Except for this, in the same manner as in Example 1, a strongly hydrophobic, silver-loaded visible-light-responsive bactericidal powder was obtained. Example

[0019] In Example 1, “add 15 mL of an aqueous silver nitrate solution with a concentration of 0.5 mol / L to the above suspension” was changed to “add 15 mL of an aqueous silver nitrate solution with a concentration of 1 mol / L to the above suspension”. Except for this, in the same manner as in Example 1, a strongly hydrophobic, silver-loaded visible-light-responsive bactericidal powder was obtained.

[0020] Performance Test Characterize the microstructure and elemental composition of the strongly hydrophobic, silver-loaded visible-light-responsive bactericidal powder of Example 1. Place the strongly hydrophobic, silver-loaded visible-light-responsive bactericidal powder under a transmission electron microscope (electron microscope Talos F200S; energy spectrum SUPER X) for observation, as Figure 1 shown in (a)- Figure 1 (f). Among them, (a) is the overall morphology of the powder particles under the transmission electron microscope; (b) is the distribution and content of C, N, O, Si, and Ag elements on the surface of the powder particles under the transmission electron microscope; (c) is the content and distribution position of Si element on the surface of the powder particles; (d) is the content and distribution position of N element on the surface of the powder particles; (e) is the content and distribution position of C element on the surface of the powder particles; (f) is the content and distribution position of Ag element on the surface of the powder particles. It was found from the figure that elements such as silicon and silver appear on the particle surface, and carbon nitride itself does not contain these two elements. Therefore, this successfully verified the successful loading of vinyl-terminated polydimethylsiloxane containing silicon element and silver nanoparticles.

[0021] Test the hydrophobic property of the strongly hydrophobic, silver-loaded visible-light-responsive bactericidal powder of Example 1. Place unmodified ordinary carbon nitride and the strongly hydrophobic, silver-loaded visible-light-responsive bactericidal powder of the present invention (wherein the carbon nitride is hydrophobically modified) in water and irradiate with a laser pointer. It was found that the unmodified carbon nitride sank in water, as shown in Figure (2a), while the strongly hydrophobic, silver-loaded visible-light-responsive bactericidal powder of the present invention could easily float in water due to its hydrophobic property and the relatively small mass of the nanoparticles themselves, as shown in Figure (2b).

[0022] Test the bactericidal property of the strongly hydrophobic, silver-loaded visible-light-responsive bactericidal powder of Example 1. Place ordinary carbon nitride and the strongly hydrophobic, silver-loaded visible-light-responsive bactericidal powder of the present invention in 10 -7 CFU of Escherichia coli bacterial solution. After irradiating with a 300W xenon lamp for 3 h, place the bacterial solution in a petri dish for cultivation, and repeat the experiment three times for each. It was found that the antibacterial ability of ordinary carbon nitride under light (as shown in Figure (3a)) was much lower than that of the strongly hydrophobic, silver-loaded visible-light-responsive bactericidal powder of the present invention (as shown in Figure (3b)).

[0023] For the technologies not specifically mentioned above, reference is made to the prior art.

[0024] Based on the above-mentioned ideal embodiments of the present invention as inspiration, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification.

Claims

1. A highly hydrophobic, silver-loaded visible light-responsive bactericidal powder, characterized in that: Prepared by the following steps: 1) Fully dispersing g-C3N4 nanosheets in deionized water to obtain a suspension, adding a silver nitrate aqueous solution to the suspension, and then adding methanol as a sacrificial agent, and then irradiating with a xenon lamp and stirring, filtering and drying to obtain silver-loaded carbon nitride nanoparticles; 2) vinyl-terminated polydimethylsiloxane and toluene are mixed and then added to the silver-loaded carbon nitride nanoparticles obtained in step 1), and the mixture is fully stirred under water bath heating, and then the mixture is fully irradiated with full light and fully stirred in an air-tight environment, and then filtered and dried to obtain vinyl-terminated polydimethylsiloxane and silver-loaded carbon nitride nanoparticles; 3) The vinyl-terminated polydimethylsiloxane and silver-loaded carbon nitride nanoparticles obtained in step 2) are dispersed in toluene and centrifuged to remove unloaded vinyl-terminated polydimethylsiloxane. The carbon nitride nanoparticles after centrifugation are dispersed in ethanol and dried.

2. The highly hydrophobic, silver-loaded visible light-responsive bactericidal powder according to claim 1, characterized in that: In step 1), the mass ratio of g-C3N4 nanosheets to deionized water is 1-100:1000, the concentration of the silver nitrate aqueous solution is 0.1-1 mol / L, the volume ratio of deionized water, silver nitrate aqueous solution, and methanol is 10:1-1.5:1-3, the dispersion of the g-C3N4 nanosheets is ultrasonic dispersion, the ultrasonic frequency is 30 KHz, the ultrasonic dispersion time is 0.25-0.5 h, the xenon lamp uses a power of 300 W, and the irradiation time is 6-16 h.

3. The highly hydrophobic, silver-loaded visible light-responsive bactericidal powder according to claim 1, characterized in that: In step 2), the mass ratio of vinyl-terminated polydimethylsiloxane, toluene, and silver-loaded carbon nitride nanoparticles is 10-30:2-10:

1.

4. The highly hydrophobic, silver-loaded visible light-responsive bactericidal powder according to claim 1, characterized in that: In step 2), the water bath heating temperature is 30°C-50°C, the stirring time under water bath heating is 8-16 hours, the full light irradiation is performed using a xenon lamp with a power of 300W, and the stirring time under full light irradiation is 8-16 hours.

5. The highly hydrophobic, silver-loaded visible light-responsive bactericidal powder according to claim 1, characterized in that: In step 3), the centrifugal speed is 10000 r min -1 The centrifugation is carried out six times, the first centrifugation time is 15-25 minutes, and the next five centrifugation times are 5-10 minutes. The drying is carried out in an oven at a drying temperature of 60℃-80℃.

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