A super-hydrophobic photothermal coating, preparation method and application thereof

Abstract

The present invention relates to a super-hydrophobic photothermal coating, a preparation method and application thereof, wherein the super-hydrophobic photothermal coating comprises a candle ash layer deposited on a substrate surface, a silicon dioxide layer coated on the candle ash layer, and a modified layer on the silicon dioxide layer modified by self-assembly of fluorinated silane. The super-hydrophobic photothermal coating in the present invention has anti-bacterial adhesion performance and photothermal sterilization performance, which can reduce the number of bacterial adhesions and can convert light energy into heat energy to kill adhered bacteria, and neither make bacteria resistant nor pollute the environment. In addition, the super-hydrophobic photothermal coating can kill all adhered bacteria with only low energy consumption on the basis of preventing a large number of bacterial adhesions; the preparation method of the super-hydrophobic photothermal coating in the present invention is simple, efficient, and has strong universality; the application of the super-hydrophobic photothermal coating in the present invention in photothermal sterilization can effectively reduce the energy consumption required for sterilization, and is economical and environmentally friendly.

Description

Technical Field

[0001] The invention relates to a super-hydrophobic photothermal coating, a preparation method and application thereof. Background Art

[0002] Bacteria adhere to the surface of materials and subsequently form biofilms, which can lead to infection of medical devices and failure of industrial equipment, posing a huge threat to human health and industrial production. In particular, the formation of biofilms on the surface of materials will enhance the drug resistance of bacteria, making it difficult to kill them by conventional means. Before the formation of biofilms on the surface of materials, giving the surface antibacterial function can effectively prevent bacterial infection.

[0003] Super-hydrophobic surfaces can form an air layer, thereby reducing the contact area between bacteria and the surface, effectively preventing bacterial adhesion. Although super-hydrophobic surfaces can prevent the adhesion of most bacteria, they cannot completely prevent bacterial adhesion. A small number of bacteria adhering to super-hydrophobic surfaces can still form biofilms under sufficient nutrition, which in turn causes great harm to human health and production and life. Super-hydrophobic surfaces with bactericidal functions are expected to overcome the above shortcomings and achieve a long-lasting anti-biofilm effect.

[0004] At present, the main preparation method of superhydrophobic bactericidal surfaces is to fix contact-type bactericides (such as quaternary ammonium salts, cationic polymers, etc.) or load release-type bactericides (such as metal ions, antibiotics and other drugs) on the superhydrophobic surface. The introduction of bactericidal components gives the superhydrophobic surface better antibacterial properties. This superhydrophobic surface with bactericidal function can prevent the adhesion of a large number of bacteria on the one hand, and kill bacteria adhered to the surface on the other hand. Even after the superhydrophobic surface loses its anti-adhesion function, it still has an antibacterial effect, which is more advantageous than the traditional superhydrophobic surface with a single function to prevent bacterial adhesion. However, the bactericidal mechanism of the contact bactericide itself is contradictory to the anti-bacterial adhesion function of the superhydrophobic surface; and the continuous release of the release-type bactericide may cause environmental pollution or cytotoxicity, leading to problems such as bacterial resistance. Therefore, the research on superhydrophobic coatings based on non-bactericides is of great significance. Summary of the invention

[0005] The purpose of the present invention is to provide a super-hydrophobic photothermal coating, which can not only prevent the adhesion of a large number of bacteria, but also has photothermal sterilization performance.

[0006] The second object of the present invention is to provide a method for preparing a super-hydrophobic photothermal coating, which is simple and has strong universality.

[0007] The third object of the present invention is to provide an application of a super-hydrophobic photothermal coating.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] A super-hydrophobic photothermal coating comprises a candle ash layer deposited on a substrate surface, a silicon dioxide layer coated on the candle ash layer, and a modified layer on the candle ash layer and / or the silicon dioxide layer modified by self-assembly of fluorine-containing silane.

[0010] Preferably, the super-hydrophobic photothermal coating comprises a candle ash layer deposited on the surface of a substrate, a silicon dioxide layer coated on the candle ash layer, and a modified layer on the silicon dioxide layer modified by self-assembly of fluorine-containing silane.

[0011] Preferably, the thickness of the superhydrophobic photothermal coating is 90-130 µm.

[0012] Further preferably, the thickness of the candle ash layer is 15-35 μm.

[0013] Further preferably, the total thickness of the silicon dioxide layer and the candle ash layer is 90-130 μm.

[0014] Further preferably, the modification layer is self-assembled and modified on the silicon dioxide layer by fluorine-containing silane, and the thickness of the modification layer is nanometer level.

[0015] Further preferably, the thickness of the final photothermal coating after modification with the fluorine-containing silane is 90-130 µm.

[0016] Preferably, the super hydrophobic photothermal coating increases in temperature under the irradiation of near-infrared light and is capable of killing bacteria adhered to the super hydrophobic photothermal coating.

[0017] Preferably, the contact angle of the superhydrophobic photothermal coating is greater than 150° and the rolling angle is less than 10°.

[0018] The second aspect of the present invention provides a method for preparing a super-hydrophobic photothermal coating, comprising the following steps: (1) placing a substrate in the flame of a burning candle, and depositing a candle ash layer on the surface of the substrate; (2) vapor-depositing silica on the candle ash layer to obtain a silica-coated candle ash coating; and (3) allowing fluorine-containing silane to self-assemble on the silica-coated candle ash coating to obtain the super-hydrophobic photothermal coating.

[0019] Preferably, after the step (2) is completed, the self-assembly of the fluorine-containing silane is directly carried out on the silica-coated candle ash coating.

[0020] Preferably, the vapor deposition comprises placing the substrate with the candle ash layer deposited thereon in a sealed container, adding tetraethyl orthosilicate and ammonia water into the container, and depositing the silicon dioxide on the candle ash layer at 40-80°C.

[0021] Further preferably, the tetraethyl orthosilicate and the ammonia water in the container are respectively arranged in different containing cavities, and the containing cavity has an open structure.

[0022] Preferably, the volume ratio of the tetraethyl orthosilicate to the ammonia water is 1:(1-1.5).

[0023] Further preferably, the volume ratio of the tetraethyl orthosilicate to the ammonia water is 1:1.

[0024] Preferably, the ratio of the volume of the tetraethyl orthosilicate to the area of ​​the substrate is 1 ml: (0.1-2.5) cm 2 .

[0025] Preferably, the deposition time is controlled to be 12 to 24 hours.

[0026] Preferably, the self-assembly comprises reacting the silica-coated candle ash coating in an organic solvent containing the fluorine-containing silane, wherein the fluorine-containing silane comprises one or more of 1H, 1H, 2H, 2H-perfluorodecyltrimethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyltrimethoxysilane, and 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane, and the organic solvent comprises one or more of anhydrous toluene and ethanol.

[0027] Further preferably, the volume ratio of the fluorine-containing silane to the organic solvent is (0.001-0.01):1.

[0028] More preferably, the volume ratio of the fluorine-containing silane to the organic solvent is (0.001-0.005):1.

[0029] Preferably, the reaction time is controlled to be 12 to 24 h.

[0030] Preferably, the reaction temperature is controlled at 25-35 °C.

[0031] Preferably, the substrate includes any one of a glass sheet, a silicon sheet, a gold sheet, and a stainless steel sheet.

[0032] Preferably, the substrate is placed at 1 / 2 to 4 / 5 of the flame of the candle from bottom to top, and the substrate is moved so that the candle ash layer is evenly deposited on the surface of the substrate.

[0033] The third aspect of the present invention provides an application of a superhydrophobic photothermal coating in photothermal sterilization.

[0034] Preferably, the super-hydrophobic photothermal coating includes the super-hydrophobic photothermal coating as described above or the super-hydrophobic photothermal coating prepared by the preparation method as described above.

[0035] Further preferably, the super hydrophobic photothermal coating kills bacteria under the irradiation of near-infrared light.

[0036] According to some preferred embodiments, the illumination intensity of the near-infrared light is 0.5-2 W / cm 2 .

[0037] More preferably, the irradiation time is controlled to be 2 to 10 min.

[0038] Preferably, the bacteria include Gram-negative bacteria and / or Gram-positive bacteria.

[0039] Further preferably, the Gram-negative bacteria include one or more of Pseudomonas aeruginosa, Escherichia coli, Proteus, Shigella dysenteriae, Klebsiella pneumoniae, Brucella, Haemophilus influenzae, Haemophilus parainfluenzae, Moraxella catarrhalis, Acinetobacter, Yersinia, Legionella pneumophila, Bordetella pertussis, Bordetella parapertussis, Shigella, Pasteurella, Vibrio cholerae, Bacillus parahaemolyticus, and Shigella-like Pyrromonas.

[0040] Further preferably, the Gram-positive bacteria include one or more of Staphylococcus, Streptococcus, Pneumococcus, Bacillus anthracis, Corynebacterium diphtheriae, and Corynebacterium tetani.

[0041] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0042] The super-hydrophobic photothermal coating of the present invention has anti-bacterial adhesion performance and photothermal sterilization performance, which can reduce the number of bacteria adhesion and can convert light energy into heat energy to kill bacteria adhered to the surface, without causing bacteria to develop drug resistance or polluting the environment. In addition, the super-hydrophobic photothermal coating can kill all bacteria adhered to the surface with only low energy consumption on the basis of preventing a large number of bacteria from adhering;

[0043] The preparation method of the super-hydrophobic photothermal coating of the present invention is simple, efficient and has strong universality;

[0044] The application of the super-hydrophobic photothermal coating in the present invention in photothermal sterilization can effectively reduce the energy consumption required for sterilization, which is economical and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 The contact angle variation diagram of different substrates before and after coating modification in Examples 1 to 4 of the present invention;

[0046] Figure 2This is a curve diagram of the surface temperature of the super-hydrophobic photothermal coating and the glass sheet obtained in Example 1 of the present invention changing with time under near-infrared light irradiation;

[0047] Figure 3 The following are photos of bacteria on the surface of a glass sheet and the coating of the super-hydrophobic photothermal coating prepared in Example 1, with and without near-infrared light irradiation;

[0048] Figure 4 It is a quantitative characterization of the number of bacteria adhering to the surface of the glass sheet and the super-hydrophobic photothermal coating prepared in Example 1 under the presence or absence of near-infrared light irradiation. DETAILED DESCRIPTION

[0049] Although traditional super-hydrophobic surfaces that rely on preventing bacterial adhesion can prevent a large number of bacteria from adhering, a small number of bacteria will still adhere to them, which will still lead to the formation of biofilms under sufficient nutrition. At present, some super-hydrophobic surfaces with bactericidal functions mainly rely on the effect of bactericides. However, the introduction of bactericides may cause problems such as increased bacterial resistance and environmental pollution.

[0050] Based on the deficiencies of the prior art, the applicant has obtained the solution of the present application after long-term experiments and extensive research. The solution is further elaborated below.

[0051] A super-hydrophobic photothermal coating comprises a candle ash layer deposited on the surface of a substrate, a silicon dioxide layer coated on the candle ash layer, and a modified layer modified on the candle ash layer and / or the silicon dioxide layer by self-assembly of fluorine-containing silane.

[0052] According to the present invention, the contact angle of the super-hydrophobic photothermal coating is greater than 150° and the rolling angle is less than 10°. The super-hydrophobic photothermal coating increases in temperature under the irradiation of near-infrared light and can kill bacteria adhering to the super-hydrophobic photothermal coating.

[0053] The super-hydrophobic photothermal coating of the present invention has anti-bacterial adhesion properties and photothermal sterilization properties. Compared with the surface of the substrate without the super-hydrophobic photothermal coating, the number of bacteria adhering to the surface can be reduced by more than 90%, and light energy can be converted into heat energy to kill bacteria adhering to the surface, which will neither make the bacteria resistant nor pollute the environment. Compared with materials that only rely on photothermal sterilization, it does not require high-power light and can kill all bacteria on the surface with lower energy consumption.

[0054] According to the present invention, the thickness of the super hydrophobic photothermal coating is 90-130 μm. Further, the thickness of the candle ash layer is 15-35 μm, the total thickness of the silicon dioxide layer and the candle ash layer is 90-130 μm, and the thickness of the final photothermal coating after modification with fluorinated silane is 90-130 μm.

[0055] The present invention also provides a method for preparing a super-hydrophobic photothermal coating, which comprises the following steps: (1) placing a substrate near the flame of a burning candle to deposit a candle ash layer on the surface of the substrate; (2) vapor-depositing silicon dioxide on the candle ash layer to obtain a silicon dioxide-coated candle ash coating; and (3) allowing fluorine-containing silane to self-assemble on the silicon dioxide-coated candle ash coating to obtain a super-hydrophobic photothermal coating.

[0056] The preparation method of the present invention is simple, efficient, and has strong universality, and can be prepared on various substrates. According to the present invention, the substrate includes but is not limited to any one of a glass sheet, a silicon sheet, a gold sheet, and a stainless steel sheet. Of course, in addition to sheet-like substrates, the preparation method of the present invention can also be prepared on mesh, filament, or other special-shaped structures.

[0057] According to the present invention, the substrate is placed at 1 / 2 to 4 / 5 of the candle flame from bottom to top, for example, at 1 / 2, 3 / 5, 2 / 3, 4 / 5, etc. The substrate is moved to uniformly deposit the candle ash layer on the substrate surface, the substrate surface including but not limited to the front and / or back of the substrate.

[0058] According to the present invention, the substrate is placed in a candle flame and burned, so that a candle ash layer is deposited on the surface of the substrate. The burning time is affected by the size of the substrate. The larger the substrate, the longer the burning time; the smaller the substrate, the shorter the burning time. According to some preferred embodiments, the ratio of the burning time to the substrate area is (20-150) s: 1 cm 2 , for example, it can be 20 s: 1 cm 2 , 30 s: 1 cm 2 , 50 s: 1 cm 2 , 70 s: 1 cm 2 , 90 s: 1 cm 2 , 110 s: 1 cm 2 , 130 s: 1 cm 2 , 150s: 1 cm 2 wait.

[0059] The vapor deposition comprises placing a substrate with a candle ash layer deposited thereon in a sealed container, adding tetraethyl orthosilicate and ammonia water into the container, and depositing silicon dioxide on the candle ash layer at 40-80°C. The temperature of the vapor deposition can be, for example, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, etc. The tetraethyl orthosilicate and ammonia water are respectively arranged in different containing cavities in the container, and the containing cavities have an open structure so that the tetraethyl orthosilicate and ammonia water can evaporate or volatilize to perform vapor deposition. According to some preferred embodiments, the side of the substrate having the candle ash layer faces upward.

[0060] According to the present invention, the volume ratio of tetraethyl orthosilicate to ammonia water is 1:(1-1.5), for example, it can be 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, etc.

[0061] According to the present invention, the ratio of the volume of ethyl orthosilicate to the area of ​​the substrate is 1 mL: (0.1-2.5) cm 2 , for example, it can be 1 mL: 0.1 cm 2 , 1 mL: 0.2 cm 2 , 1 mL: 0.3 cm 2 , 1 mL: 0.4 cm 2 , 1 mL: 0.5 cm 2 , 1 mL: 0.6 cm 2 , 1 mL: 0.7 cm 2 , 1 mL: 0.8 cm 2 , 1 mL: 0.9 cm 2 , 1 mL: 1 cm 2 , 1 mL: 1.1 cm 2 , 1 mL: 1.2 cm 2 , 1 mL: 1.3 cm 2 , 1 mL: 1.4 cm 2 , 1 mL: 1.5 cm 2 , 1 mL: 1.6 cm 2 , 1 mL: 1.7 cm 2 , 1 mL: 1.8 cm 2 , 1 mL: 1.9 cm 2 , 1 mL: 2.0 cm 2 , 1 mL: 2.1 cm 2 , 1 mL: 2.2 cm 2 , 1 mL: 2.3 cm 2 , 1 mL: 2.4 cm 2 , 1 mL: 2.5 cm 2 wait.

[0062] According to the present invention, the deposition time is controlled to be 10 to 15 h, for example, 10 h, 11 h, 12 h, 13 h, 14 h, 15 h, etc.

[0063] According to the present invention, after step (2) is completed, the silica-coated candle ash coating obtained in step (2) does not need to be treated, and the fluorine-containing silane can be directly self-assembled on the silica-coated candle ash coating.

[0064] The self-assembly comprises placing the candle ash coating coated with silicon dioxide in an organic solvent containing fluorine-containing silane for reaction, wherein the fluorine-containing silane comprises one or more of 1H, 1H, 2H, 2H-perfluorodecyl trimethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyl triethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyl trimethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyl triethoxysilane, and the organic solvent comprises one or more of anhydrous toluene and ethanol. The volume ratio of the fluorine-containing silane to the organic solvent is (0.001-0.01): 1. For example, it can be 0.001: 1, 0.002: 1, 0.003: 1, 0.004: 1, 0.005: 1, 0.006: 1, 0.007: 1, 0.008: 1, 0.009: 1, 0.01: 1, etc.

[0065] According to the present invention, the reaction time of self-assembly is 12 to 24 h, for example, it can be 12 h, 13 h, 14 h, 15 h, 16 h, 17 h, 18 h, 19 h, 20 h, 21 h, 22 h, 23 h, 24 h, etc.

[0066] According to the present invention, the reaction temperature of the self-assembly is 15-35°C, for example, 15°C, 20°C, 25°C, 30°C, 35°C, etc. In the present invention, the fluorine-containing silane is modified by self-assembly on the candle ash coating coated with silica, the operation steps are simple, the uniformity is good, no additional heating or cooling treatment is required, the reaction can be carried out at room temperature, energy consumption is saved, and it has good economic benefits.

[0067] The super-hydrophobic photothermal coating or the super-hydrophobic photothermal coating prepared by the above preparation method can kill bacteria under the irradiation of near-infrared light.

[0068] According to some preferred embodiments, the illumination intensity of the near-infrared light is 0.5-2 W / cm 2 , for example, it can be 0.5W / cm 2 , 1 W / cm 2 , 1.5 W / cm 2 , 2 W / cm 2 The irradiation time is 2 to 10 min, for example, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, etc.

[0069] Bacteria include gram-negative bacteria and / or gram-positive bacteria. Gram-negative bacteria include Pseudomonas aeruginosa, Escherichia coli, Proteus, Shigella dysenteriae, Klebsiella pneumoniae, Brucella, influenza (haemophilus) bacillus, parainfluenza (haemophilus) bacillus, catarrhalis (mora), acinetobacter, Yersinia, Legionella pneumophila, Bordetella pertussis, Bordetella parapertussis, Shigella, Pasteurella, Vibrio cholerae, Parahaemolyticus, Shigella-like Osmomonas one or more. Gram-positive bacteria include Staphylococcus, Streptococcus, Pneumococcus, Bacillus anthracis, Corynebacterium diphtheriae, and Clostridium tetani.

[0070] The present invention also provides a super-hydrophobic photothermal material, including a substrate and a super-hydrophobic photothermal coating deposited on the substrate. The substrate can be made of one or more of glass, silicon, gold, stainless steel, etc., and the super-hydrophobic photothermal coating is the super-hydrophobic photothermal coating as described above or the super-hydrophobic photothermal coating prepared by the preparation method as described above.

[0071] The present invention is further described below in conjunction with the examples. However, the present invention is not limited to the following examples. The implementation conditions used in the examples can be further adjusted according to the different requirements of specific use, and the implementation conditions not specified are conventional conditions in the industry. The technical features involved in each embodiment of the present invention can be combined with each other as long as they do not conflict with each other.

[0072] The boxes used in the following embodiments are of the same size and shape.

[0073] Example 1

[0074] (1) Place a 0.5 cm × 0.5 cm glass sheet in the outer flame of a candle (from bottom to top, the glass sheet is located at two-thirds of the entire flame height) and burn for 30 seconds. During the burning process, move the glass sheet back and forth to fully deposit the candle ash layer;

[0075] (2) Place the glass sheet with the candle ash layer deposited in a box, place two containers in the box, add 1 mL of tetraethyl orthosilicate (TEOS) and 1 mL of ammonia water to each container, and seal the box; place the box in a 60 °C oven for chemical vapor deposition for 12 h;

[0076] (3) Add 10 μL of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane to 5 mL of anhydrous toluene and sonicate for 20 s. Add the mixed solution to the reactor and transfer the sample after chemical vapor deposition to the reactor and react at room temperature for 12 h.

[0077] In this embodiment, the thickness of the candle ash layer obtained in step (1) is 30 ± 5 µm, the total thickness of the coating obtained in step (2) is 120 ± 10 µm, and the total thickness of the coating obtained in step (3) is 120 ± 10 µm.

[0078] The relationship between the surface temperature of the super hydrophobic photothermal coating prepared in this embodiment and time under near-infrared light irradiation is as follows: Figure 2 As shown, the irradiation intensity of near-infrared light is 2 W / cm 2 The unmodified glass sheet has no photothermal properties under near-infrared light irradiation, while the superhydrophobic photothermal coating has good photothermal properties.

[0079] Figure 3 It can be seen that without near-infrared light irradiation, a large number of colonies grew on the culture medium corresponding to the glass surface, and the number of colonies on the culture medium corresponding to the superhydrophobic photothermal coating was relatively small; 2 , irradiation time of 5 min), there were still a large number of colonies on the culture medium corresponding to the glass surface, but no colonies grew on the culture medium corresponding to the superhydrophobic photothermal coating.

[0080] Figure 4 It can be seen that in the absence of light, the superhydrophobic photothermal coating can use its special wettability to prevent the adhesion of most bacteria. Whether it is Gram-negative Pseudomonas aeruginosa or Gram-positive Staphylococcus aureus, the number of adhesions is reduced by more than 90% compared with the control glass surface. Under near-infrared light irradiation (irradiation intensity of 1.5 W / cm 2 , irradiation time of 5 min) had almost no effect on the adhesion of bacteria; while the superhydrophobic photothermal coating had no effect on the adhesion of bacteria under near-infrared light irradiation (irradiation intensity of 1.5 W / cm 2 , irradiation time of 5 min), almost all the bacteria on the surface were killed. This shows that the super-hydrophobic photothermal coating can prevent the adhesion of bacteria due to its special wettability; and under near-infrared light, the photothermal effect can kill bacteria adhering to the surface.

[0081] Example 2

[0082] (1) Place a 0.5 cm × 0.5 cm silicon wafer in the outer flame of a candle flame (from bottom to top, the glass wafer is located at two-thirds of the entire flame height) and burn for 30 seconds. During the burning process, move the silicon wafer back and forth to fully deposit the candle ash layer;

[0083] (2) Place the silicon wafer with the candle ash layer deposited in a box, place two containers in the box, add 1 mL of TEOS and 1 mL of ammonia water to each container, and seal the box; place the box in a 60 °C oven for chemical vapor deposition for 12 h;

[0084] (3) Add 10 μL of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane to 5 mL of anhydrous toluene and sonicate for 20 s. Add the mixed solution to the reactor and transfer the sample after chemical vapor deposition to the reactor and react at room temperature for 12 h.

[0085] In this embodiment, the thickness of the candle ash layer obtained in step (1) is 30 ± 5 µm, the total thickness of the coating obtained in step (2) is 120 ± 10 µm, and the total thickness of the coating obtained in step (3) is 120 ± 10 µm.

[0086] Example 3

[0087] (1) Place a 0.5 cm × 0.5 cm gold sheet in the outer flame of a candle (from bottom to top, the glass sheet is located at two-thirds of the entire flame height) and burn for 30 seconds. During the burning process, move the gold sheet back and forth to fully deposit the candle ash layer.

[0088] (2) Place the gold sheet with the candle ash layer deposited on it in a box, place two containers in the box, add 1 mL of TEOS and 1 mL of ammonia water to each container, and seal the box; place the box in a 60 °C oven for chemical vapor deposition for 12 h;

[0089] (3) Add 10 μL of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane to 5 mL of anhydrous toluene and sonicate for 20 s. Add the mixed solution to the reactor and transfer the sample after chemical vapor deposition to the reactor and react at room temperature for 12 h.

[0090] In this embodiment, the thickness of the candle ash layer obtained in step (1) is 30 ± 5 µm, the total thickness of the coating obtained in step (2) is 120 ± 10 µm, and the total thickness of the coating obtained in step (3) is 120 ± 10 µm.

[0091] Example 4

[0092] (1) Place a 0.5 cm × 0.5 cm stainless steel sheet in the outer flame of a candle (from bottom to top, the glass sheet is located at two-thirds of the entire flame height) and burn for 30 seconds. During the burning process, move the stainless steel sheet back and forth to fully deposit the candle ash layer;

[0093] (2) Place the stainless steel sheet with the candle ash layer deposited on it in a box, place two containers in the box, add 1 mL of TEOS and 1 mL of ammonia water to each container, and seal the box; place the box in a 60 °C oven for chemical vapor deposition for 12 h;

[0094] (3) Add 10 μL of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane to 5 mL of anhydrous toluene and sonicate for 20 s. Add the mixed solution to the reactor and transfer the sample after chemical vapor deposition to the reactor and react at room temperature for 12 h.

[0095] In this embodiment, the thickness of the candle ash layer obtained in step (1) is 30 ± 5 µm, the total thickness of the coating obtained in step (2) is 120 ± 10 µm, and the total thickness of the coating obtained in step (3) is 120 ± 10 µm.

[0096] Example 5

[0097] (1) Place a 1 cm × 1 cm glass sheet in the outer flame of a candle (from bottom to top, the glass sheet is located at two-thirds of the entire flame height) and burn for 60 s. During the burning process, move the glass sheet back and forth to fully deposit the candle ash layer;

[0098] (2) Place the glass sheet with the candle ash layer deposited in a box, place two containers in the box, add 3 mL of TEOS and 3 mL of ammonia water to each container, and seal the box; place the box in a 60 °C oven for chemical vapor deposition for 12 hours;

[0099] (3) Add 10 μL of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane to 5 mL of anhydrous toluene and sonicate for 20 seconds. Add the above mixed solution to the reactor, transfer the sample after chemical vapor deposition to the reactor, and react at room temperature for 12 hours.

[0100] In this embodiment, the thickness of the candle ash layer obtained in step (1) is 25 ± 5 µm, the total thickness of the coating obtained in step (2) is 110 ± 10 µm, and the total thickness of the coating obtained in step (3) is 110 ± 10 µm.

[0101] Example 6

[0102] (1) Place a 2 cm × 2 cm glass sheet in the outer flame of a candle (from bottom to top, the glass sheet is located at two-thirds of the entire flame height) and burn for 120 s. During the burning process, move the glass sheet back and forth to fully deposit the candle ash layer.

[0103] (2) Place the glass sheet with the candle ash layer deposited on it in a box, place two containers in the box, add 5 mL of TEOS and 5 mL of ammonia water to each container, and seal the box; place the box in a 60 °C oven for chemical vapor deposition for 24 hours;

[0104] (3) Add 10 μL of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane to 5 mL of anhydrous toluene and sonicate for 20 s. Add the mixed solution to the reactor and transfer the sample after chemical vapor deposition to the reactor and react at room temperature for 12 h.

[0105] In this embodiment, the thickness of the candle ash layer obtained in step (1) is 20 ± 5 µm, the total thickness of the coating obtained in step (2) is 100 ± 10 µm, and the total thickness of the coating obtained in step (3) is 100 ± 10 µm.

[0106] The above detailed description of the present invention is intended to enable persons familiar with the art to understand the contents of the present invention and implement them. It does not limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. Application of a super-hydrophobic photothermal coating in photothermal sterilization, characterized in that: The super-hydrophobic photothermal coating comprises a candle ash layer deposited on the surface of a substrate, a silicon dioxide layer coated on the candle ash layer, and a modified layer on the silicon dioxide layer modified by self-assembly of fluorine-containing silane. The super-hydrophobic photothermal coating has a thickness of 90-130 μm, the candle ash layer has a thickness of 15-35 μm, and the total thickness of the silicon dioxide layer and the candle ash layer is 90-130 μm. The application includes killing bacteria adhered to the super-hydrophobic photothermal coating under the irradiation of near-infrared light, wherein the illumination intensity of the near-infrared light is 0.5-2 W / cm 2 , irradiation time is 2~10 min, The preparation method of the super-hydrophobic photothermal coating comprises the following steps: (1) placing a substrate in the flame of a burning candle to deposit a layer of candle ash on the surface of the substrate; (2) vapor-depositing silicon dioxide on the candle ash layer to obtain a candle ash coating coated with silicon dioxide, wherein the vapor-depositing comprises placing the substrate on which the candle ash layer is deposited in a sealed container, adding ethyl orthosilicate and ammonia water into the container, and depositing the silicon dioxide on the candle ash layer at 40-80° C.; (3) After the step (2) is completed, the self-assembly of fluorinated silane is directly performed on the candle ash coating coated with silica, wherein the self-assembly comprises placing the candle ash coating coated with silica in an organic solvent containing the fluorinated silane for reaction, wherein the fluorinated silane comprises one or more of 1H, 1H, 2H, 2H-perfluorodecyltrimethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyltrimethoxysilane, and 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane, and the organic solvent comprises one or more of anhydrous toluene and ethanol, and the volume ratio of the fluorinated silane to the organic solvent is (0.001-0.01):

1.

2. The use of the super-hydrophobic photothermal coating in photothermal sterilization according to claim 1, characterized in that: The contact angle of the super hydrophobic photothermal coating is greater than 150° and the rolling angle is less than 10°; And / or, the substrate includes any one of a glass sheet, a silicon sheet, a gold sheet, and a stainless steel sheet.

3. The use of the super-hydrophobic photothermal coating in photothermal sterilization according to claim 1, characterized in that: The volume ratio of the tetraethyl orthosilicate to the ammonia water is 1: (1-1.5); And / or, the ratio of the volume of the tetraethyl orthosilicate to the area of ​​the substrate is 1 ml: (0.1-2.5) cm 2 ; And / or, the deposition time is controlled to be 12 to 24 hours.

4. The use of the super-hydrophobic photothermal coating in photothermal sterilization according to claim 1, characterized in that: The reaction time is controlled to be 12 to 24 hours; And / or, the reaction temperature is controlled to be 25-35°C.

5. The use of the super-hydrophobic photothermal coating in photothermal sterilization according to claim 1, characterized in that: From bottom to top, the substrate is placed at 1 / 2 to 4 / 5 of the flame of the candle, and the substrate is moved so that the candle ash layer is evenly deposited on the surface of the substrate.

6. The use of the super-hydrophobic photothermal coating in photothermal sterilization according to claim 1, characterized in that: The bacteria include Gram-negative bacteria and / or Gram-positive bacteria.

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