Preparation of Ag+ / TiO2 antibacterial film on stainless steel substrate and application of Ag+ / TiO2 antibacterial film in tobacco flavoring essence

Abstract

The invention discloses preparation of an Ag < + > / TiO2 antibacterial film on a stainless steel substrate and application of the Ag < + > / TiO2 antibacterial film in tobacco flavoring essence. The preparation method of the stainless steel substrate comprises the following steps: pretreating the stainless steel substrate; dropwise adding a certain amount of tetrabutyl titanate and acetylacetone into ethanol, stirring, adding a certain amount of water and nitric acid into the solution, and continuously stirring to obtain transparent sol; taking a certain amount of silver nitrate, complexing in absolute ethyl alcohol by using citric acid, dripping into the sol, and stirring to obtain silver-doped TiO2 sol; and uniformly spraying the silver-doped titanium dioxide sol on the surface of the stainless steel by using a spray gun, air-drying, heating in a muffle furnace, preserving heat, and cooling to obtain the stainless steel substrate containing the Ag < + > / TiO2 antibacterial film. The stainless steel substrate containing the Ag < + > / TiO2 antibacterial film is applied to the tobacco charging essence for sterilization treatment and has the advantages of being simple in equipment, green, efficient and capable of being repeatedly used, the quality of the processed charging essence is not changed, and the quality stability is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of tobacco, and in particular to an Ag + Preparation of / TiO2 antibacterial film on stainless steel substrate and its application in tobacco flavoring. Background Art

[0002] Tobacco flavorings are commonly known as sugar materials. They mainly use water as a solvent system. Their main ingredients are invert sugar and natural extracts. They are prone to fermentation, mildew, bubbles and other deterioration phenomena, and have become a potential threat to the stability of cigarette products. Microbial contamination is the main cause of spoilage of flavorings. The sources of microbial contamination in flavorings are diverse. Air, water, processing machinery and equipment, and flavor raw materials may all be sources of contaminated microorganisms. Flavorings are heat-sensitive products. Excessive temperature will change the color and flavor of flavorings. Therefore, non-heating sterilization technology / low-temperature long-time cold sterilization technology is used to ensure product quality without changing the product flavor.

[0003] Since the mid-1970s, people have conducted a lot of research on the photocatalytic properties of titanium dioxide. Using titanium dioxide catalysts to eliminate and degrade pollutants has become a very active research direction in the field of environmental science. Studies have found that TiO2 photocatalytic materials have broad-spectrum antibacterial properties. Under light, they have a certain inhibitory and killing effect on various common pathogens. TiO2 generates photogenerated electrons (e - ) and photogenerated holes (h + ), photogenerated holes react with H2O or OH adsorbed on the catalyst surface - Reflects the production of highly oxidizing hydroxyl radicals OH, and photogenerated electrons react with oxygen molecules to generate superoxide ion radicals O2 - , further produces active oxygen species such as hydroxyl radicals OH and H2O2. These active oxygen species play a photocatalytic antibacterial role by oxidizing coenzyme A in bacteria, destroying the permeability of bacterial cell walls and the structure of DNA, and interrupting electron transmission. Silver ions have a strong bactericidal effect and can kill most common bacteria. In view of the strong bactericidal ability, good bactericidal durability, small dosage, sterility, and non-irritation of silver, various countries have researched and developed various types of silver antibacterial agents and antibacterial materials. Using TiO2 inorganic film as a silver ion carrier makes the antibacterial properties of the two complement each other, greatly improving the antibacterial efficacy.

[0004] Therefore, the present invention aims to provide an Ag + The invention discloses a method for preparing a TiO2 antibacterial film on a stainless steel substrate, and using the stainless steel substrate to sterilize the added flavor to extend the shelf life of the added flavor and ensure the product quality of the added flavor. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a Ag + / The preparation of TiO2 antibacterial film on stainless steel substrate and its application in tobacco flavors, and its application in tobacco flavors for sterilization has the characteristics of simple equipment, green and efficient, and can be repeatedly used. The quality of the flavors does not change after treatment, and the quality stability is improved.

[0006] The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0007] A kind of Ag + The method for preparing a TiO2 antibacterial film on a stainless steel substrate comprises the following steps:

[0008] (1) Pretreatment of stainless steel substrate: Place the stainless steel substrate in a pickling solution for 30 to 60 minutes to remove the oxide scale on the surface of the stainless steel. Then take out the pickled stainless steel parts and put them in deionized water for ultrasonic cleaning for 10 minutes. After cleaning, take out the stainless steel parts and dry them.

[0009] (2) Preparation of TiO2 sol:

[0010] 21) Take a certain amount of tetrabutyl titanate and acetylacetone and add them dropwise to ethanol. After stirring for 30 minutes, add a certain amount of water and nitric acid to the solution and continue stirring to obtain a transparent sol;

[0011] 22) Take a certain amount of silver nitrate, complex it with citric acid in anhydrous ethanol, and drop it into the above transparent sol, stir it thoroughly, and prepare silver-doped TiO2 sol;

[0012] (3) Ag + Preparation of antibacterial TiO2 film on stainless steel substrate: The silver-doped titanium dioxide sol was sprayed evenly on the treated stainless steel surface with a spray gun, and after natural air drying, it was placed in a muffle furnace and heated to 450℃~550℃ and kept warm for 1 hour, and then cooled with the furnace to obtain Ag-containing titanium dioxide sol. + / TiO2 antibacterial film on stainless steel substrate.

[0013] Preferably, in the above technical solution, in step (1), the pickling solution is an aqueous solution composed of components with the following concentrations: 200-300 mL / L of dilute sulfuric acid, 3-5 g / L of auxiliary acid citric acid, and 3-5 g / L of corrosion inhibitor sulfosalicylic acid.

[0014] Preferably, in the above technical solution, in step (2), the mass ratio of silver to TiO2 is 1:20 to 1:25.

[0015] Preferably, in the above technical solution, in step 21), the volume ratio of tetrabutyl orthotitanate, acetylacetone and ethanol is 1:1:(4-5); the volume ratio of nitric acid and water is 1:(10-15).

[0016] Preferably, in the above technical solution, in step 22), the molar ratio of silver nitrate to citric acid is (3-4):1.

[0017] Preferably, in the above technical solution, in step (3), the heating rate in the muffle furnace is 5 to 10° C. / min.

[0018] A kind of Ag + / TiO2 antibacterial film stainless steel substrate, the stainless steel substrate is prepared according to the above preparation method.

[0019] A kind of Ag + Application of a stainless steel substrate with a TiO2 antibacterial film in tobacco flavoring, wherein the stainless steel substrate is prepared according to the above preparation method.

[0020] Preferably, in the above technical solution, the application is to use the Ag-containing + The method comprises the following steps:

[0021] S1. Prepare additive flavors according to the product formula requirements of cigarette flavors and fragrances;

[0022] S2, pour the prepared flavoring into a stirring kettle and continue stirring for 30 minutes, wherein the stirring blade of the stirring kettle is made of Ag + / TiO2 antibacterial film made of stainless steel substrate;

[0023] S3. After the stirring is completed, open the discharge valve at the bottom of the stirring kettle, and pour the tobacco flavoring into the product packaging barrel through the filter box and seal it for storage.

[0024] Preferably, in the above technical solution, the stirring blades are straight blades, curved blades or folded blades.

[0025] The above technical solution of the present invention has the following beneficial effects:

[0026] The invention has the characteristics of simple equipment, green and efficient, and can be used repeatedly. + The stainless steel substrate with / TiO2 antibacterial film is applied to tobacco flavoring for sterilization treatment. After the treatment, the quality of the flavoring does not change, and the quality stability is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0028] Figure 1 This is a colony diagram of the product after sterilization according to an embodiment of the present application. DETAILED DESCRIPTION

[0029] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0030] Unless otherwise specified, the reagents used in this application are all commercially available or obtained through commercial channels, or can be prepared by referring to existing chemical methods.

[0031] Example 1

[0032] A kind of Ag + The method for preparing a TiO2 antibacterial film on a stainless steel substrate comprises the following steps:

[0033] (1) Pretreatment of stainless steel substrate:

[0034] The stainless steel substrate is placed in the pickling solution for 30 minutes to remove the oxide scale on the surface of the stainless steel. The pickled stainless steel parts are then taken out and ultrasonically cleaned in deionized water for 10 minutes. Finally, the cleaned stainless steel is taken out and dried. The pickling solution is an aqueous solution composed of the following concentrations: 200 mL / L dilute sulfuric acid, 3 g / L auxiliary acid citric acid, and 3 g / L corrosion inhibitor sulfosalicylic acid.

[0035] (2) Preparation of TiO2 sol:

[0036] Take a certain amount of tetrabutyl titanate and acetylacetone and drop them into ethanol, the volume ratio of tetrabutyl titanate, acetylacetone and ethanol is 1:1:4; after stirring for 30 minutes, add a certain amount of water and nitric acid into the solution, the volume ratio of nitric acid to water is 1:10; stir continuously to obtain a transparent sol; take a certain amount of silver nitrate, complex it with citric acid in anhydrous ethanol, the molar ratio of silver nitrate to citric acid is 3:1; drop it into the above transparent sol, stir it thoroughly, and obtain a silver-doped TiO2 sol. Converted into oxide, the mass ratio of silver to TiO2 is 1:20.

[0037] (3) Ag + Preparation of / TiO2 antibacterial film on stainless steel substrate:

[0038] The silver-doped titanium dioxide sol is sprayed evenly on the treated stainless steel surface with a spray gun. After the stainless steel sheet is naturally air-dried in a dry and dark place, it is placed in a muffle furnace and heated to 450°C at a rate of 5°C / min, and kept warm for one hour, and then cooled with the furnace to obtain the desired stainless steel substrate.

[0039] Sterilization treatment in tobacco flavorings:

[0040] Prepare the Red Flag Canal (Mango) flavoring according to the formula of cigarette flavors and fragrances, pour the prepared Red Flag Canal (Mango) flavoring into the mixing kettle and continue stirring for 30 minutes; the stirring blades in the mixing kettle are made of the prepared stainless steel substrate, and cut into specified shapes (such as straight leaves, curved leaves or folded leaves, of course, other shapes can be selected as needed, and this application is not limited to this); after the stirring is completed, open the discharge valve at the bottom of the mixing kettle, and pour the flavoring into the product packaging barrel through the filter box and seal it for storage. Take a sample and mark it as flavoring 1#.

[0041] Example 2

[0042] A kind of Ag + The method for preparing a TiO2 antibacterial film on a stainless steel substrate comprises the following steps:

[0043] (1) Pretreatment of stainless steel substrate:

[0044] The stainless steel substrate is placed in the pickling solution for 60 minutes to remove the oxide scale on the surface of the stainless steel. The pickled stainless steel parts are then taken out and ultrasonically cleaned in deionized water for 10 minutes. Finally, the cleaned stainless steel is taken out and dried. The pickling solution is an aqueous solution composed of the following concentrations: 300 mL / L of dilute sulfuric acid, 5 g / L of auxiliary acid citric acid, and 5 g / L of corrosion inhibitor sulfosalicylic acid.

[0045] (2) Preparation of TiO2 sol:

[0046] Take a certain amount of tetrabutyl titanate and acetylacetone and drop them into ethanol, the volume ratio of tetrabutyl titanate, acetylacetone and ethanol is 1:1:4.5; after stirring for 30 minutes, add a certain amount of water and nitric acid into the solution, the volume ratio of nitric acid to water is 1:10; stir continuously to obtain a transparent sol; take a certain amount of silver nitrate, complex it with citric acid in anhydrous ethanol, the molar ratio of silver nitrate to citric acid is 3.5:1; drop it into the above transparent sol, stir it thoroughly, and obtain a silver-doped TiO2 sol. Converted into oxide, the mass ratio of silver to TiO2 is 1:25.

[0047] (3) Ag + Preparation of TiO2 antibacterial film on stainless steel substrate:

[0048] The silver-doped titanium dioxide sol is sprayed evenly on the treated stainless steel surface with a spray gun. After the stainless steel sheet is naturally air-dried in a dry and dark place, it is placed in a muffle furnace and heated to 550°C at a rate of 10°C / min and kept warm for one hour, and then cooled with the furnace to obtain the desired stainless steel substrate.

[0049] Sterilization treatment in tobacco flavorings:

[0050] Prepare the Red Flag Canal (Mango) flavoring according to the formula of cigarette flavors and fragrances, pour the prepared Red Flag Canal (Mango) flavoring into the mixing kettle and continue stirring for 30 minutes; the stirring blades in the mixing kettle are made of the prepared stainless steel substrate, and cut into specified shapes (such as straight leaves, curved leaves or folded leaves, of course, other shapes can be selected as needed, and this application is not limited to this); after the stirring is completed, open the discharge valve at the bottom of the mixing kettle, and pour the flavoring into the product packaging barrel through the filter box and seal it for storage. Take a sample and mark it as flavoring 2#.

[0051] Example 3

[0052] A kind of Ag + The method for preparing a TiO2 antibacterial film on a stainless steel substrate comprises the following steps:

[0053] (1) Pretreatment of stainless steel substrate:

[0054] The stainless steel substrate is placed in the pickling solution for 40 minutes to remove the oxide scale on the surface of the stainless steel. The pickled stainless steel parts are then taken out and ultrasonically cleaned in deionized water for 10 minutes. Finally, the cleaned stainless steel is taken out and dried. The pickling solution is an aqueous solution composed of the following concentrations: 250 mL / L of dilute sulfuric acid, 4 g / L of auxiliary acid citric acid, and 4 g / L of corrosion inhibitor sulfosalicylic acid.

[0055] (2) Preparation of TiO2 sol:

[0056] Take a certain amount of tetrabutyl titanate and acetylacetone and drop them into ethanol, the volume ratio of tetrabutyl titanate, acetylacetone and ethanol is 1:1:4; after stirring for 30 minutes, add a certain amount of water and nitric acid into the solution, the volume ratio of nitric acid to water is 1:15; stir continuously to obtain a transparent sol; take a certain amount of silver nitrate, complex it with citric acid in anhydrous ethanol, the molar ratio of silver nitrate to citric acid is 4:1; drop it into the above transparent sol, stir it thoroughly, and obtain a silver-doped TiO2 sol. Converted into oxide, the mass ratio of silver to TiO2 is 1:25.

[0057] (3) Ag + Preparation of TiO2 antibacterial film on stainless steel substrate:

[0058] The silver-doped titanium dioxide sol is sprayed evenly on the treated stainless steel surface with a spray gun. After the stainless steel sheet is naturally air-dried in a dry and dark place, it is placed in a muffle furnace and heated to 550°C at a rate of 5°C / min, and kept warm for one hour, and then cooled with the furnace to obtain the desired stainless steel substrate.

[0059] Sterilization treatment in tobacco flavorings:

[0060] Prepare the Red Flag Canal (Mango) flavoring according to the formula of cigarette flavors and fragrances, pour the prepared Red Flag Canal (Mango) flavoring into the mixing kettle and continue stirring for 30 minutes; the stirring blades in the mixing kettle are made of the prepared stainless steel substrate, and cut into specified shapes (such as straight leaves, curved leaves or folded leaves, of course, other shapes can be selected as needed, and this application is not limited to this); after the stirring is completed, open the discharge valve at the bottom of the mixing kettle, and pour the flavoring into the product packaging barrel through the filter box and seal it for storage. Take a sample and mark it as flavoring 3#.

[0061] Of course, the added flavors of the present application may also adopt the flavor and fragrance formula of the heated cigarette formula commonly used in the art, and are not limited to the above products. The present application only uses this as an example for experimental description.

[0062] Refer to GB4789.2-2016 National Food Safety Standard Food Microbiology Test Total Colony Count Determination. Use NA medium to culture bacteria and dilute the sample to 1*10 -1 , take 100uL of each sample gradient to the plate, spread it evenly, and culture it at 37℃ for 72h.

[0063] The results are as follows Figure 1 As shown: Ag + After the antibacterial treatment with / TiO2 antibacterial film, the total number of colonies in flavors 1#, 2# and 3# decreased significantly, while the total number of colonies in the untreated flavors was higher. + / TiO2 antibacterial film can effectively eliminate bacteria in added flavors, extend the shelf life of added flavors, and ensure the stable quality of added flavors.

[0064] Although the present invention has been disclosed as above by the embodiments, it is not intended to limit the present invention. Any person skilled in the art may make various choices and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention is limited by the claims and their equivalents.

Claims

1. A kind of Ag + / The method for preparing TiO2 antibacterial film on a stainless steel substrate is characterized in that: The following steps are involved: (1) Pretreatment of stainless steel substrate: Place the stainless steel substrate in a pickling solution for 30 to 60 minutes to remove the oxide scale on the surface of the stainless steel. Then take out the pickled stainless steel parts and put them in deionized water for ultrasonic cleaning for 10 minutes. After cleaning, take out the stainless steel parts and dry them. (2) Preparation of TiO2 sol: 21) Take a certain amount of tetrabutyl titanate and acetylacetone and add them dropwise to ethanol. After stirring for 30 minutes, add a certain amount of water and nitric acid to the solution and continue stirring to obtain a transparent sol; 22) Take a certain amount of silver nitrate, complex it with citric acid in anhydrous ethanol, and drop it into the above transparent sol, stir it thoroughly, and prepare silver-doped TiO2 sol; (3) Ag + Preparation of antibacterial TiO2 film on stainless steel substrate: The silver-doped titanium dioxide sol was sprayed evenly on the treated stainless steel surface with a spray gun, and after natural air drying, it was placed in a muffle furnace and heated to 450℃~550℃ and kept warm for 1 hour, and then cooled with the furnace to obtain Ag-containing titanium dioxide sol. + / TiO2 antibacterial film on stainless steel substrate.

2. The Ag according to claim 1 + / The method for preparing TiO2 antibacterial film on a stainless steel substrate is characterized in that: In step (1), the pickling solution is an aqueous solution composed of the following components in concentration: 200-300 mL / L of dilute sulfuric acid, 3-5 g / L of auxiliary acid citric acid, and 3-5 g / L of corrosion inhibitor sulfosalicylic acid.

3. The Ag according to claim 1 + / The method for preparing TiO2 antibacterial film on a stainless steel substrate is characterized in that: In step (2), the mass ratio of silver to TiO2 is 1:20 to 1:

25.

4. The Ag according to claim 1 + / The method for preparing TiO2 antibacterial film on a stainless steel substrate is characterized in that: In step 21), the volume ratio of tetrabutyl orthotitanate, acetylacetone and ethanol is 1:1:(4-5); the volume ratio of nitric acid and water is 1:(10-15).

5. The Ag according to claim 1 + / The method for preparing TiO2 antibacterial film on a stainless steel substrate is characterized in that: In step 22), the molar ratio of silver nitrate to citric acid is (3-4):

1.

6. The Ag according to claim 1 + / The method for preparing TiO2 antibacterial film on a stainless steel substrate is characterized in that: In step (3), the temperature in the muffle furnace is increased at a rate of 5 to 10°C / min.

7. A kind of + / TiO2 antibacterial film stainless steel substrate, characterized in that, The stainless steel substrate is prepared according to any one of the preparation methods described in claims 1-6.

8. A kind of Ag-containing + Application of stainless steel substrate with / TiO2 antibacterial film in tobacco flavoring, characterized in that: The stainless steel substrate is prepared according to any one of the preparation methods described in claims 1-6.

9. The use according to claim 8, characterized in that: The application is to utilize the Ag-containing + The method comprises the following steps: S1. Prepare additive flavors according to the product formula requirements of cigarette flavors and fragrances; S2, pour the prepared flavoring into a stirring kettle and continue stirring for 30 minutes, wherein the stirring blade of the stirring kettle is made of Ag + / TiO2 antibacterial film made of stainless steel substrate; S3. After the stirring is completed, open the discharge valve at the bottom of the stirring kettle, and pour the tobacco flavoring into the product packaging barrel through the filter box and seal it for storage.

10. The use according to claim 8, characterized in that: The stirring blades are straight blades, curved blades or folded blades.

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