Silver-series nano deodorizing and antibacterial sol and preparation method thereof

Abstract

The invention discloses silver-series nano deodorizing and antibacterial sol and a preparation method thereof. The sol particles comprise nano-particles formed by coupling crystalline nano-silver and crystalline nano-titanium dioxide, titanium dioxide is mixed crystal nano-particles formed by coupling rutile and anatase, the crystalline nano-silver is coupled with rutile titanium dioxide nano-particles, the primary particle size of the rutile titanium dioxide is 8-90 nm, the secondary particle size of the crystalline nano-silver is 8-90 nm, and the secondary particle size of the crystalline nano-titanium dioxide is 8-90 nm. The primary particle size range of the anatase type titanium dioxide is 20%-70% of the primary particle size of the rutile type titanium dioxide; the primary particle size range of the crystalline silver is 10%-80% of the primary particle size of the rutile type titanium dioxide. According to the invention, the nano-particles with coupled crystalline nano-silver and crystalline nano-titanium dioxide and the sol of the nano-particles are prepared by adopting a photoreduction method of ultraviolet irradiation, and the sol can be applied to the fields of antibiosis, antivirus, deodorization and peculiar smell elimination of textiles, household articles, building materials, organic cultivation of vegetables, fruits and tea leaves and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of colloid chemistry, and particularly relates to a silver-based nano deodorant and antibacterial sol and a preparation method thereof. Background Art

[0002] A sol is a dispersion system in which the diameter of colloidal particles is 1 - 100 nm, and is classified into aerosol, liquid sol, and solid sol according to the dispersion medium. A sol generally refers to a liquid sol, which is a nano- or micron-sized organic or inorganic particle formed by hydrolysis and polymerization. These particles repel each other due to the charge they carry, and thus can exist in a suspended state in the solvent, that is, a sol is formed.

[0003] When a silver salt (silver nitrate or silver sulfate) solution is irradiated with ultraviolet light, silver ions undergo a photoreduction reaction to generate silver nanoparticles, which have antibacterial and antiviral properties. However, since the silver nanoparticles generated by the photoreduction reaction are usually amorphous, their chemical affinity for odor molecules such as ammonia and hydrogen sulfide is low, and the adsorption ability is poor. Therefore, the ability to deodorize and eliminate odors is weak.

[0004] Titanium dioxide nanopowder has the ability to photocatalytically decompose odor molecules such as ammonia and hydrogen sulfide under ultraviolet light irradiation, and also has antibacterial and antiviral abilities under ultraviolet light irradiation. If crystalline silver nanoparticles can be prepared on the surface of titanium dioxide nanoparticles, the crystalline silver nanoparticles and titanium dioxide nanoparticles are coupled with each other. In the absence of ultraviolet light (at night or in places where there is no irradiation), the crystalline silver nanoparticles not only have antibacterial and antiviral properties, but also have a strong chemical affinity for odor molecules such as ammonia and hydrogen sulfide, and can adsorb ammonia, hydrogen sulfide and other odor molecules significantly, producing a good deodorizing effect; under ultraviolet light irradiation, the ammonia and hydrogen sulfide molecules adsorbed on the surface of the crystalline silver nanoparticles are decomposed by active groups such as hydroxyl radicals generated by titanium dioxide under ultraviolet light irradiation, so that the ammonia and hydrogen sulfide adsorbed on the surface of the crystalline silver nanoparticles are decomposed and desorbed, making the crystalline silver nanoparticles regain the ability to adsorb ammonia, hydrogen sulfide and other odor molecules. For example, underwear loaded with nanoparticles coupled with crystalline silver nanoparticles and titanium dioxide nanoparticles can not only have antibacterial and antiviral properties. When worn on people, even if there is no ultraviolet light irradiation, it can deodorize through the chemical adsorption of crystalline silver nanoparticles and ammonia and hydrogen sulfide molecules. When the underwear is washed and dried, under ultraviolet light irradiation, ammonia and hydrogen sulfide molecules are decomposed, and the underwear regains the ability to adsorb ammonia, hydrogen sulfide and other odor molecules, that is, it regains the deodorizing ability. The physical mixing of silver nanopowder and titanium dioxide nanopowder, or the physical mixing of silver nanoparticle solution and titanium dioxide nanoparticle solution cannot achieve the above effects because there is no coupling between silver nanoparticles and titanium dioxide nanoparticles. The coupling between silver nanoparticles and titanium dioxide nanoparticles means that silver nanoparticles are generated on the surface of titanium dioxide nanoparticles. Therefore, how to prepare nanoparticles coupled with crystalline silver nanoparticles and crystalline titanium dioxide nanoparticles is a technical problem. Summary of the Invention

[0005] The object of the present invention is to overcome the deficiencies of the prior art, and provides a silver-based nano deodorant and antibacterial sol and a preparation method thereof, solving the problems in the above-mentioned background technology.

[0006] One of the technical solutions adopted by the present invention to solve its technical problems is: providing a silver-based nano deodorant and antibacterial sol, including nanoparticles in which crystalline nano silver and crystalline nano titanium dioxide are coupled; wherein the titanium dioxide is a mixed crystal type nanoparticle coupled by rutile type and anatase type, and the crystalline nano silver is coupled with rutile type titanium dioxide nanoparticles.

[0007] In a preferred embodiment of the present invention, the primary particle size of the rutile type titanium dioxide is 8 nm to 90 nm, and the primary particle sizes of the anatase type titanium dioxide and the crystalline nano silver are smaller than the primary particle size of the rutile type titanium dioxide.

[0008] In a preferred embodiment of the present invention, the size range of the primary particle size of the anatase type titanium dioxide is 20% to 70% of the primary particle size of the rutile type titanium dioxide, and the size range of the primary particle size of the crystalline nano silver is 10% to 80% of the primary particle size of the rutile type titanium dioxide.

[0009] In a preferred embodiment of the present invention, it is composed of nanoparticles in which crystalline nano silver and crystalline nano titanium dioxide are coupled and a dispersion medium, and the dispersion medium includes water.

[0010] The ability of silver nanoparticles to adsorb odor molecules such as ammonia and hydrogen sulfide is mainly related to the surface chemical affinity in addition to the specific surface area of the nanoparticles. For example, the silver ions generated by the loss of electrons on the surface of silver nanoparticles, because one silver ion forms a silver ammonia complex ion [Ag(NH 3 ) 2 + , there is a tendency for silver nanoparticles to chemically adsorb ammonia molecules on the surface; on the other hand, the ability of silver ions generated by the loss of electrons on the surface of silver nanoparticles is related to its own work function. The theoretical work function value depends on the crystal arrangement. The more closely and orderly the arrangement, the more negative the work function value. That is, the work function of crystalline silver nanoparticles is lower than that of amorphous silver nanoparticles. Therefore, compared with amorphous silver nanoparticles, crystalline silver nanoparticles are more likely to lose electrons on the surface to form silver ions. The surface chemical affinity of crystalline silver nanoparticles with odor molecules such as ammonia and hydrogen sulfide is high, and the ability of crystalline silver nanoparticles to chemically adsorb odor molecules such as ammonia and hydrogen sulfide on the surface is high, and the deodorization ability is high.

[0011] ​Odor can be removed by adsorbing odor molecules such as ammonia and hydrogen sulfide. However, after adsorption saturation, the odor removal ability by adsorption will decrease. Only with the ability of desorption, that is, the cycle of adsorption-saturation-desorption-re-adsorption, can the odor removal effect be maintained. In the present invention, a photocatalytic desorption mechanism is designed at the molecular level by coupling crystalline silver nanoparticles with rutile titanium dioxide nanoparticles. The coupling of amorphous silver nanoparticles and titanium dioxide nanoparticles can improve the separation of photogenerated electrons and photogenerated electron holes of titanium dioxide to a certain extent by absorbing the photogenerated electrons of titanium dioxide, thereby improving the photocatalytic decomposition ability of titanium dioxide to a certain extent. In the present invention, the primary particle size of rutile titanium dioxide is 8 nm to 90 nm, and the primary particle size of anatase titanium dioxide is smaller than that of rutile titanium dioxide, and the primary particle size of anatase titanium dioxide is between 20% and 70% of the primary particle size of rutile titanium dioxide; crystalline silver nanoparticles are coupled with rutile titanium dioxide nanoparticles, and the primary particle size of crystalline silver is smaller than that of rutile titanium dioxide, and the primary particle size of crystalline silver is between 10% and 80% of the primary particle size of rutile titanium dioxide. At this time, the photocatalytic decomposition ability of the nanoparticles formed by coupling crystalline silver nanoparticles and crystalline titanium dioxide nanoparticles is greatly improved compared with that of the coupling of amorphous silver nanoparticles and crystalline titanium dioxide nanoparticles. Odor molecules such as ammonia and hydrogen sulfide chemisorbed on the surface of crystalline silver nanoparticles are photocatalytically decomposed by rutile titanium dioxide nanoparticles coupled with crystalline silver nanoparticles and anatase nanoparticles coupled with rutile titanium dioxide nanoparticles, so that the odor molecules such as ammonia and hydrogen sulfide on the surface of crystalline silver nanoparticles are desorbed, and the surface of crystalline silver nanoparticles restores the ability to adsorb odor molecules such as ammonia and hydrogen sulfide. For such a structure, its photocatalytic decomposition ability is greatly improved. One of the reasons is that the energy level of the crystalline metal nanoparticles is at a more negative position than that of the amorphous state. Therefore, the Schottky barrier formed by the crystalline metal and the carrier has a lower energy level than that formed by the amorphous metal, which is more conducive to absorbing electrons and more conducive to the separation of photogenerated electrons and photogenerated electron holes of titanium dioxide.Second, both pure rutile-type or pure anatase-type titanium dioxide nanoparticles have photocatalytic decomposition ability. Compared with pure anatase-type titanium dioxide, the photocatalytic decomposition ability of pure rutile-type titanium dioxide is lower. However, the photocatalytic ability of titanium dioxide coupled with rutile-type and anatase-type is higher. After coupling, photo-generated electrons can transfer from the conduction band of anatase-type titanium dioxide with a higher energy level to the conduction band of rutile-type titanium dioxide with a lower energy level, improving the separation of photo-generated electrons and photo-generated electron holes, thereby enhancing the photocatalytic decomposition ability. For titanium dioxide nanoparticles coupled with rutile-type and anatase-type, the primary particle size of rutile-type titanium dioxide is 8 nm to 90 nm, and the primary particle size of anatase-type titanium dioxide is between 20% and 70% of the primary particle size of rutile-type titanium dioxide, and the photocatalytic decomposition ability is the best. When the primary particle size of rutile-type titanium dioxide nanoparticles is less than 8 nm, the particle size is too small and the crystal structure is incomplete, resulting in a decrease in photocatalytic decomposition ability. On the contrary, when the primary particle size is greater than 90 nm, the particle size is too large and the specific surface area is small, resulting in a decrease in photocatalytic decomposition ability. When the primary particle size of anatase-type titanium dioxide is less than 20% of the primary particle size of rutile-type titanium dioxide, the coupling between rutile-type titanium dioxide and anatase-type titanium dioxide is incomplete, resulting in a decrease in photocatalytic decomposition ability. During the process of preparing nanoparticles and their sols coupled with crystalline silver nanoparticles and crystalline titanium dioxide by photoreduction under ultraviolet light irradiation, amorphous silver nanoparticles are formed on the surface of anatase-type titanium dioxide. When the primary particle size of anatase-type titanium dioxide is greater than 70% of the primary particle size of rutile-type titanium dioxide, the proportion of amorphous silver nanoparticles increases, and the proportion of crystalline silver nanoparticles formed on the surface of rutile-type titanium dioxide decreases, resulting in a decrease in photocatalytic ability. Third, the photocatalytic decomposition ability of rutile-type titanium dioxide nanoparticles stems from the oxidation ability of photo-generated electron holes. Photo-generated electron holes oxidize the water molecules on the surface to generate hydroxyl radicals with strong oxidation ability. Hydroxyl radicals can drift to the surface of crystalline silver nanoparticles coupled with rutile-type titanium dioxide nanoparticles and oxidize and decompose odor molecules such as ammonia and hydrogen sulfide adsorbed on the surface of crystalline silver nanoparticles. However, the activity of hydroxyl radicals is very high and the drifting distance is limited. Therefore, the primary particle size of rutile-type titanium dioxide is 8 nm to 90 nm, crystalline silver nanoparticles are coupled with rutile-type titanium dioxide nanoparticles, the primary particle size of crystalline silver is smaller than the primary particle size of rutile-type titanium dioxide, and the primary particle size of crystalline silver is between 10% and 80% of the primary particle size of rutile-type titanium dioxide, and the efficiency of oxidizing and decomposing odor molecules such as ammonia and hydrogen sulfide adsorbed on the surface of crystalline silver nanoparticles by hydroxyl radicals is the best.

[0012] The second technical solution adopted by the present invention to solve its technical problems is: providing a preparation method of a silver-based nano deodorant and antibacterial sol. A mixed aqueous solution of titanium dioxide and silver nitrate is prepared according to a molar ratio of titanium dioxide: silver nitrate of 1: 0.04 to 0.08, wherein the concentration of titanium dioxide in the mixed aqueous solution is 0.005 to 0.05 mol / L; with a UVA ultraviolet intensity of 0.6 to 2.0 mW / cm 2 Irradiate for 6 to 20 h, and perform photoreduction reaction while irradiating and stirring to obtain nanoparticles and their sol in which crystalline nano silver and crystalline nano titanium dioxide are coupled.

[0013] In a preferred embodiment of the present invention, the nano titanium dioxide is a mixed crystal nano particle in which rutile type and anatase type are coupled.

[0014] In a preferred embodiment of the present invention, the preparation steps of the nano titanium dioxide include: ① Using 5 nm to 40 nm anatase type titanium dioxide as the raw material, heat-treat for 1 h under a pressure of 350 °C and 0.01 kPa to 1 kPa; ② Continue heat-treating for 6 to 20 h at 350 °C to 550 °C in an air atmosphere to obtain a mixed crystal nano particle in which rutile type and anatase type are coupled. Control the transformation degree of anatase type titanium dioxide to rutile type titanium dioxide to be 15 to 55%.

[0015] Rutile type is the stable crystal form of titanium dioxide. Through heat treatment, anatase type has a tendency to transform into rutile type. The first step is the nucleation process of anatase type titanium dioxide transforming into rutile type titanium dioxide. It is to form partially deoxidized anatase titanium dioxide (TiO 2-x , the subscript 2-x indicates oxygen deficiency and the lattice contains defects) in a vacuum environment. The anatase type titanium dioxide nanoparticles with defects in the lattice have many defects and high energy, reducing the activation energy required to overcome the nucleation process of transforming from anatase type to rutile type. Therefore, the nucleation of rutile type titanium dioxide can be promoted at a lower temperature.

[0016] The second step is the growth process of the transformation of anatase titanium dioxide into rutile titanium dioxide. Due to the sufficient nucleation process in the first step, the growth process in the second step does not require a temperature higher than 550 °C. When the temperature is higher than 550 °C or the heat treatment time is longer than 20 h, the growth time of the rutile titanium dioxide nanoparticles grown is too long, and the primary particle size will be greater than 90 nm. At the same time, the anatase titanium dioxide nanoparticles will also grow during the heat treatment process. When the temperature is higher than 550 °C or the heat treatment time is longer than 20 h, the primary particle size of the anatase nanoparticles exceeds 70% of the primary particle size of the rutile type. When the heat treatment time is less than 6 hours, the growth time of the rutile titanium dioxide nanoparticles is insufficient, and the primary particle size cannot reach 8 nm. The heat treatment in the second step requires an air atmosphere because heat treatment in air can repair the oxygen-deficient defects in the titanium dioxide lattice generated in the first step, promote the formation of rutile titanium dioxide nanoparticles with a complete lattice, enhance their chemical affinity with odor molecules such as ammonia and hydrogen sulfide, thereby promoting chemical adsorption and improving the deodorization effect.

[0017] Subsequently, in the third step, nanocomposites of crystalline silver nanoparticles and crystalline titanium dioxide nanoparticles are prepared by photoreduction method. In this step, rutile titanium dioxide nanoparticles are irradiated with UVA, absorbing UVA ultraviolet light to generate photoexcited electrons. The photoexcited electrons photoreduce the silver ions adsorbed on the surface of rutile titanium dioxide nanoparticles. Based on the crystal plane matching between rutile titanium dioxide crystal and crystalline silver, the silver nanoparticles photoreduced on the surface of rutile titanium dioxide nanoparticles are crystalline, and the crystalline silver nanoparticles are coupled with rutile titanium dioxide nanoparticles. Although anatase titanium dioxide nanoparticles also absorb UVA ultraviolet light to generate photoexcited electrons and photoreduce the silver ions adsorbed on the surface, due to the mismatch between the crystal plane of anatase titanium dioxide crystal and that of Ag, the silver nanoparticles photoreduced on the surface of anatase titanium dioxide nanoparticles are amorphous. For 1 mol of titanium dioxide, the proportion of silver nitrate is less than 0.04 mol. If the silver nitrate is too dilute, the primary particle size of crystalline silver cannot reach 10% of the primary particle size of rutile titanium dioxide. If the proportion of silver nitrate is greater than 0.08 mol, the silver nitrate is too concentrated, and the primary particle size of crystalline silver exceeds 80% of the primary particle size of rutile titanium dioxide. When the concentration of titanium dioxide in the mixed aqueous solution is less than 0.005 mol / L, the concentration of titanium dioxide nanoparticles is too dilute, and the absorption of UVA ultraviolet light is insufficient, so that the primary particle size of crystalline silver cannot reach 10% of the primary particle size of rutile titanium dioxide. When the concentration of titanium dioxide in the mixed aqueous solution is greater than 0.05 mol / L, the concentration of titanium dioxide is too concentrated. Although stirring is carried out during irradiation, the photoreduction reaction in the solution is still uneven, and it is easy to have the situation that the primary particle size of crystalline silver cannot reach 10% of the primary particle size of rutile titanium dioxide or exceeds 80% of the primary particle size of rutile titanium dioxide. The intensity of UVA ultraviolet light refers to the intensity of UVA ultraviolet light irradiated on the solution surface. When it is less than 0.6 mW / cm 2 ², the UVA ultraviolet light is too weak, and the primary particle size of crystalline silver cannot reach 10% of the primary particle size of rutile titanium dioxide. When the intensity of UVA ultraviolet light is greater than 2.0 mW / cm 2 ², the UVA ultraviolet light is too strong, and the primary particle size of crystalline silver exceeds 80% of the primary particle size of rutile titanium dioxide. For the UVA ultraviolet photoreduction time, when it is less than 6 h, the photoreduction reaction time is too short, and the primary particle size of crystalline silver cannot reach 10% of the primary particle size of rutile titanium dioxide. When it exceeds 20 h, the photoreduction reaction time is too long, and the primary particle size of crystalline silver exceeds 80% of the primary particle size of rutile titanium dioxide. For the photoreduction reaction, stirring is carried out during irradiation to make the reaction uniform. When not stirring or stirring insufficiently, it is easy to have the situation that the primary particle size of crystalline silver cannot reach 10% of the primary particle size of rutile titanium dioxide or exceeds 80% of the primary particle size of rutile titanium dioxide.

[0018] The solution obtained in the ③rd step is the nanoparticle sol of coupled crystalline silver nanoparticles and crystalline titanium dioxide nanoparticles. By ordinary filtration and drying, the nanoparticles of coupled crystalline silver nanoparticles and crystalline titanium dioxide nanoparticles can be obtained.

[0019] Compared with the background technology, this technical solution has the following advantages:

[0020] 1. This invention uses a mixed titanium dioxide nanoparticle of anatase type and rutile type. By coupling crystalline silver nanoparticles with rutile type titanium dioxide nanoparticles, a photocatalytic desorption mechanism is designed at the molecular level, greatly improving the adsorption-desorption performance, ensuring the desorption of odor molecules such as ammonia and hydrogen sulfide on the surface of crystalline silver nanoparticles, and restoring the ability of the surface of crystalline silver nanoparticles to adsorb odor molecules such as ammonia and hydrogen sulfide.

[0021] 2. This invention first prepares a mixed crystalline type nanoparticle of coupled rutile type and anatase type by the transformation of anatase type titanium dioxide to rutile type titanium dioxide under specific conditions, and then prepares the sol by a photoreduction method using ultraviolet light irradiation, solving the technical problem of coupling crystalline silver nanoparticles and crystalline titanium dioxide nanoparticles.

[0022] 3. The silver-based nano deodorant and antibacterial sol of this invention can be used directly, or organic additives, organic coupling agents or inorganic additives can be added to make the sol stable without precipitation for a long time, or the nanoparticles in the sol can be coupled with plant fibers and applied to antibacterial, antiviral, deodorizing and odor eliminating in the fields of textiles, household products, building materials, and organic cultivation of fruits, vegetables and tea. Description of the Drawings

[0023] Figure 1 It is the transmission electron microscope (TEM) photograph of the powder in Example 1. Detailed Embodiment

[0024] The following describes the present invention in detail with reference to examples and comparative examples.

[0025] The primary particle size of the nanoparticles refers to the primary particle size of the nanoparticles, which is calculated by using the data of the full width at half maximum of the XRD main peak of each crystal through the X-ray diffraction (XRD) pattern and the Scherrer formula. The mixed crystalline type titanium dioxide nanoparticles of coupled rutile type and anatase type do not refer to the physical mixture between pure rutile type titanium dioxide nanoparticles and pure anatase type titanium dioxide nanoparticles. Similarly, the coupling of crystalline silver nanoparticles and rutile type titanium dioxide nanoparticles does not refer to the physical mixture between crystalline silver nanoparticles and rutile type titanium dioxide nanoparticles. Physical mixing cannot achieve tight binding, and coupling refers to the tight binding that forms a grain boundary between the two.

[0026] Example 1

[0027] The preparation method of the silver-based nano deodorant and antibacterial sol in this embodiment is as follows:

[0028] ① Using 1 mol of anatase titanium dioxide with a primary particle size of 7 nm as the raw material, heat-treat it at 350 °C under a vacuum environment of 0.1 kPa for 1 h;

[0029] ② Continuously heat-treat it at 450 °C in an air atmosphere for 12 h to obtain mixed crystal form titanium dioxide nanoparticles with rutile type and anatase type coupled.

[0030] ③ Take 0.03 mol of mixed crystal form titanium dioxide nanoparticles with rutile type and anatase type coupled and 1 L of water, and prepare a mixed aqueous solution of titanium dioxide and silver nitrate according to the ratio of 1 mol of titanium dioxide and 0.06 mol of silver nitrate. The concentration of titanium dioxide in the mixed aqueous solution is 0.03 mol / L. Irradiate it with a UVA ultraviolet intensity of 1.0 mW / cm 2 for 12 h, and carry out a photoreduction reaction while irradiating and stirring to obtain a nanoparticle sol with crystalline nano silver and crystalline nano titanium dioxide coupled. Take a part of this sol, filter it with filter paper, and dry it at 60 °C for 2 h to obtain a powder of nanoparticles with crystalline nano silver and crystalline nano titanium dioxide coupled.

[0031] Characterization method is as follows: Determine that there is crystalline silver, rutile type titanium dioxide, and anatase type titanium dioxide in the obtained powder through the X-ray diffraction (XRD) pattern. Respectively use the half-width data of the XRD main peaks of the single crystal silver (2θ = 38.1°, corresponding to the (111) crystal plane of the Ag crystal), the XRD main peak of the rutile type titanium dioxide crystal form (2θ = 27.4°, corresponding to the (110) crystal plane of the rutile titanium dioxide crystal), and the XRD main peak of the anatase type titanium dioxide crystal form (2θ = 25.3°, corresponding to the (101) crystal plane of the anatase type titanium dioxide crystal), and calculate through the Scherrer formula to obtain the primary particle sizes of crystalline silver, rutile type titanium dioxide, and anatase type titanium dioxide. The data is shown in Table 1.

[0032] The obtained powder is observed for crystal grains through a transmission electron microscope (TEM) and X-ray energy spectrum (EDS). It is observed that crystalline nano silver is coupled with rutile type titanium dioxide nanoparticles, and the crystal grains of crystalline silver are smaller than those of rutile type titanium dioxide; amorphous nano silver is coupled with anatase type titanium dioxide nanoparticles; rutile type titanium dioxide nanoparticles are coupled with anatase type titanium dioxide nanoparticles, and the crystal grains of anatase type titanium dioxide nanoparticles are smaller than those of rutile type titanium dioxide nanoparticles. Figure 1 is a representative TEM photo of the obtained powder, indicating that crystalline nano silver is coupled with rutile type titanium dioxide nanoparticles, and the crystal grains of crystalline silver are smaller than those of rutile type titanium dioxide.

[0033] Taking the application of bedding textiles as an example, the deodorization and bactericidal effects of the high-efficiency silver-based nano deodorant and antibacterial sol of this embodiment are illustrated. Using an ordinary bedsheet as the textile before treatment, an impregnating and rolling equipment is adopted, and it is processed through the impregnating and rolling process in the obtained sol, which is called the textile after treatment. The nano-particles of this embodiment are loaded on the textile after treatment through impregnating and rolling. Taking ammonia as the representative of the odor component, the deodorization rate of ammonia component is tested according to GB / T 33610.2-2017 Determination of deodorization performance of textiles - Part 2: Detecting tube method. This test is carried out in an environment without ultraviolet light indoors. The deodorization rate of ammonia is achieved by the adsorption of ammonia molecules, rather than by the photocatalytic decomposition of ammonia molecules. The textile before treatment has no deodorization ability, and the deodorization rate of ammonia is less than 10%. For the textile after treatment, if the deodorization rate of ammonia reaches more than 50%, it indicates that the textile has good deodorization ability. Test of desorption ability: The textile after treatment is placed in an ammonia atmosphere for 24 h to reach adsorption saturation, and then dried in the sun for 6 h, and desorption treatment is carried out through the photocatalytic decomposition reaction, which is called the textile after desorption. For the textile after desorption, the deodorization rate of ammonia component is tested again according to GB / T 33610.2-2017 Determination of deodorization performance of textiles - Part 2: Detecting tube method. The higher the deodorization rate of ammonia, the higher the photocatalytic decomposition rate through drying in the sun and the stronger the desorption ability, so that the textile can restore its deodorization ability. When the deodorization rate of ammonia of the textile after desorption reaches more than 50%, it indicates that the textile has good desorption ability and can desorb and then adsorb and deodorize. The antibacterial test is as follows: Taking Staphylococcus aureus as the representative, the antibacterial rate is tested according to GB / T 201510-2008 Test method for antibacterial properties of nano-inorganic materials. If the antibacterial rate of the textile before treatment is lower than 30%, it indicates that it has no antibacterial ability. For the textile after treatment, when the antibacterial rate is greater than 70%, it is considered to have good antibacterial ability. The deodorization rate data of ammonia of the textile after treatment and the textile after desorption are shown in Table 1. The antibacterial rate data of the textile after treatment are shown in Table 1.

[0034] Example 2

[0035] Using anatase titanium dioxide with a primary particle size of 18 nm as the raw material, and the others are the same as in Example 1.

[0036] It is determined by the X-ray diffraction (XRD) pattern that there are crystalline silver, rutile titanium dioxide, and anatase titanium dioxide in the obtained powder.

[0037] The primary particle size data of crystalline silver nano-particles, rutile titanium dioxide nano-particles, and anatase titanium dioxide nano-particles are shown in Table 1. The deodorization rate data of ammonia of the textile after treatment and the textile after desorption are shown in Table 1. The antibacterial rate data of the textile after treatment are shown in Table 1.

[0038] Example 3

[0039] Using anatase titanium dioxide with a primary particle size of 35 nm as the raw material, the others are the same as in Example 1.

[0040] The presence of crystalline silver, rutile titanium dioxide, and anatase titanium dioxide in the obtained powder was determined by X-ray diffraction (XRD) patterns.

[0041] The primary particle size data of crystalline silver nanoparticles, rutile titanium dioxide nanoparticles, and anatase titanium dioxide nanoparticles are shown in Table 1. The ammonia deodorization rate data of the treated textiles and the desorbed textiles are shown in Table 1. The antibacterial rate data of the treated textiles are shown in Table 1.

[0042] Example 4

[0043] Change the time of the preparation condition in Example 1, "continue heat treatment at 450 °C for 12 h in an air atmosphere", to "6 h", and the others are the same as in Example 1.

[0044] The presence of crystalline silver, rutile titanium dioxide, and anatase titanium dioxide in the obtained powder was determined by X-ray diffraction (XRD) patterns.

[0045] The primary particle size data of crystalline silver nanoparticles, rutile titanium dioxide nanoparticles, and anatase titanium dioxide nanoparticles are shown in Table 1. The ammonia deodorization rate data of the treated textiles and the desorbed textiles are shown in Table 1. The antibacterial rate data of the treated textiles are shown in Table 1.

[0046] Example 5

[0047] Change the time of the preparation condition in Example 1, "continue heat treatment at 450 °C for 12 h in an air atmosphere", to "20 h", and the others are the same as in Example 1.

[0048] The presence of crystalline silver, rutile titanium dioxide, and anatase titanium dioxide in the obtained powder was determined by X-ray diffraction (XRD) patterns.

[0049] The primary particle size data of crystalline silver nanoparticles, rutile titanium dioxide nanoparticles, and anatase titanium dioxide nanoparticles are shown in Table 1. The ammonia deodorization rate data of the treated textiles and the desorbed textiles are shown in Table 1. The antibacterial rate data of the treated textiles are shown in Table 1.

[0050] Example 6

[0051] In the preparation condition of Example 1, "prepare a mixed aqueous solution of titanium dioxide and silver nitrate according to the molar ratio of 1 mol of titanium dioxide and 0.06 mol of silver nitrate", change "0.06 mol of silver nitrate" to "0.04 mol"; "UVA ultraviolet intensity 1.0 mW / cm 2Change "irradiate for 12 h" to "UVA ultraviolet intensity of 0.6 mW / cm 2 Irradiate for 6 h", and the others are the same as in Example 1.

[0052] Example 7

[0053] In the preparation conditions of Example 1, change "prepare a mixed aqueous solution of titanium dioxide and silver nitrate in a molar ratio of 1 mol of titanium dioxide to 0.06 mol of silver nitrate" to "0.08 mol"; "UVA ultraviolet intensity of 1.0 mW / cm 2 Change "irradiate for 12 h" to "UVA ultraviolet intensity of 2.0 mW / cm 2 Irradiate for 20 h", and the others are the same as in Example 1.

[0054] Comparative Example 1

[0055] The preparation method of the silver-based nanosol in the comparative example is as follows:

[0056] Using anatase titanium dioxide with a primary particle size of 7 nm as the raw material, take 0.03 mol of the titanium dioxide nanoparticles and 1 L of water, and prepare a mixed aqueous solution of titanium dioxide and silver nitrate in a molar ratio of 1 mol of titanium dioxide to 0.06 mol of silver nitrate. The concentration of titanium dioxide in the mixed aqueous solution is 0.03 mol / L, with a UVA ultraviolet intensity of 1.0 mW / cm 2 Irradiate for 12 h, and stir while irradiating to carry out a photoreduction reaction to obtain a nanoparticle sol in which amorphous silver nanoparticles are coupled with crystalline titanium dioxide nanoparticles. Take a part of this sol, filter it with filter paper and dry it at 60 °C to obtain a powder of nanoparticles in which crystalline silver nanoparticles are coupled with crystalline titanium dioxide nanoparticles.

[0057] It is determined by the X-ray diffraction (XRD) pattern that there is no crystalline silver and no rutile-type titanium dioxide in the obtained powder, and there is anatase-type titanium dioxide. The obtained powder is observed for crystal grains by transmission electron microscopy (TEM) and X-ray energy spectrum (EDS), and it is confirmed that there is no crystalline silver and no rutile-type titanium dioxide in the obtained powder, and there are anatase-type titanium dioxide and amorphous silver nanoparticles. Since there are no crystalline silver nanoparticles and no rutile-type titanium dioxide nanoparticles in the powder obtained in Comparative Example 1, the obtained powder is a coupling of amorphous silver nanoparticles and anatase-type titanium dioxide nanoparticles. It can be considered that the primary particle sizes of crystalline silver nanoparticles and rutile-type titanium dioxide nanoparticles are 0. Amorphous silver nanoparticles have no XRD peaks, and the primary particle size cannot be calculated by XRD. The primary particle size data of anatase-type titanium dioxide nanoparticles are shown in Table 1. The ammonia deodorization rate data of the treated textiles and the textiles after desorption are shown in Table 1. The antibacterial rate data of the treated textiles are shown in Table 1.

[0058] Comparative Example 2

[0059] Change the preparation condition of Example 1 “450 °C in an air atmosphere” to “800 °C in an air atmosphere”, and the others are the same as those in Example 1.

[0060] It is determined by the X-ray diffraction (XRD) pattern that there is crystalline silver and rutile titanium dioxide in the obtained powder, but there is no anatase titanium dioxide. The primary particle size of the anatase titanium dioxide nanoparticles is 0 nm.

[0061] The primary particle size data of the crystalline silver nanoparticles, rutile titanium dioxide nanoparticles, and anatase titanium dioxide nanoparticles are shown in Table 1. The ammonia deodorization rate data of the treated textile and the desorbed textile are shown in Table 1. The antibacterial rate data of the treated textile are shown in Table 1.

[0062] Comparative Example 3

[0063] Using anatase titanium dioxide with a primary particle size of 2 nm as the raw material, and the others are the same as those in Example 1.

[0064] It is determined by the X-ray diffraction (XRD) pattern that there is crystalline silver, rutile titanium dioxide, and anatase titanium dioxide in the obtained powder.

[0065] The primary particle size data of the crystalline silver nanoparticles, rutile titanium dioxide nanoparticles, and anatase titanium dioxide nanoparticles are shown in Table 1. The ammonia deodorization rate data of the treated textile and the desorbed textile are shown in Table 1. The antibacterial rate data of the treated textile are shown in Table 1.

[0066] Comparative Example 4

[0067] Using anatase titanium dioxide with a primary particle size of 45 nm as the raw material, and the others are the same as those in Example 1.

[0068] It is determined by the X-ray diffraction (XRD) pattern that there is crystalline silver, rutile titanium dioxide, and anatase titanium dioxide in the obtained powder.

[0069] The primary particle size data of the crystalline silver nanoparticles, rutile titanium dioxide nanoparticles, and anatase titanium dioxide nanoparticles are shown in Table 1. The ammonia deodorization rate data of the treated textile and the desorbed textile are shown in Table 1. The antibacterial rate data of the treated textile are shown in Table 1.

[0070] Comparative Example 5

[0071] Change the time of the preparation condition of Example 1 “continue heat treatment at 450 °C for 12 h in an air atmosphere” to “5 h”, and the others are the same as those in Example 1.

[0072] The presence of crystalline silver, rutile titanium dioxide, and anatase titanium dioxide in the obtained powder was determined by X-ray diffraction (XRD) patterns.

[0073] The primary particle size data of crystalline silver nanoparticles, rutile titanium dioxide nanoparticles, and anatase titanium dioxide nanoparticles are shown in Table 1. The ammonia deodorization rate data of the treated textiles and the textiles after desorption are shown in Table 1. The antibacterial rate data of the treated textiles are shown in Table 1.

[0074] Comparative Example 6

[0075] The preparation condition of Example 1 "continue heat treatment at 450 °C for 12 h in an air atmosphere" was changed to "22 h", and the others were the same as those in Example 1.

[0076] The presence of crystalline silver, rutile titanium dioxide, and anatase titanium dioxide in the obtained powder was determined by X-ray diffraction (XRD) patterns.

[0077] The primary particle size data of crystalline silver nanoparticles, rutile titanium dioxide nanoparticles, and anatase titanium dioxide nanoparticles are shown in Table 1. The ammonia deodorization rate data of the treated textiles and the textiles after desorption are shown in Table 1. The antibacterial rate data of the treated textiles are shown in Table 1.

[0078] Comparative Example 7

[0079] In the preparation condition of Example 1 "prepare a mixed aqueous solution of titanium dioxide and silver nitrate according to the molar ratio of 1 mol of titanium dioxide and 0.06 mol of silver nitrate", "0.06 mol of silver nitrate" was changed to "0.03 mol"; "UVA ultraviolet intensity 1.0 mW / cm 2 Irradiate for 12 h" was changed to "UVA ultraviolet intensity 0.4 mW / cm 2 Irradiate for 5 h", and the others were the same as those in Example 1.

[0080] Comparative Example 8

[0081] In the preparation condition of Example 1 "prepare a mixed aqueous solution of titanium dioxide and silver nitrate according to the molar ratio of 1 mol of titanium dioxide and 0.06 mol of silver nitrate", "0.06 mol of silver nitrate" was changed to "0.10 mol"; "UVA ultraviolet intensity 1.0 mW / cm 2 Irradiate for 12 h" was changed to "UVA ultraviolet intensity 2.5 mW / cm 2 Irradiate for 25 h", and the others were the same as those in Example 1.

[0082] Table 1 Test results of the primary particle size and sol properties of each nanoparticle

[0083]

[0084]

[0085] Note: ○ indicates good; × indicates bad.

[0086] As can be seen from the above table, the nanoparticles and their sols formed by coupling crystalline nano-silver and crystalline nano-titanium dioxide prepared in Examples 1 to 7 are characterized in that the titanium dioxide is a mixed crystalline form of rutile type and anatase type coupled nanoparticles, wherein the primary particle size of rutile type titanium dioxide is 8 nm to 90 nm, and the primary particle size of anatase type titanium dioxide is smaller than that of rutile type titanium dioxide, and the primary particle size of anatase type titanium dioxide is between 20% and 70% of the primary particle size of rutile type titanium dioxide; crystalline nano-silver is coupled with rutile type titanium dioxide nanoparticles, and the primary particle size of crystalline silver is smaller than that of rutile type titanium dioxide, and the primary particle size of crystalline silver is between 10% and 80% of the primary particle size of rutile type titanium dioxide. The ammonia deodorization rate of the treated textile, the ammonia deodorization rate of the desorbed textile, and the antibacterial rate of the treated textile are all good, demonstrating the effectiveness of the high-efficiency deodorant silver-based nano-deodorant and antibacterial sol of the present invention.

[0087] Comparative Examples 1 and 2 do not have mixed crystalline form nanoparticles of rutile type and anatase type coupled titanium dioxide. In Comparative Examples 3 and 4, the primary particle size of rutile type titanium dioxide does not meet the requirement of 8 nm to 90 nm. In Comparative Examples 5 and 6, the primary particle size of anatase type titanium dioxide does not meet the proportion requirement. In Comparative Examples 7 and 8, the primary particle size of crystalline silver nanoparticles does not meet the proportion requirement. Although the antibacterial rates of the textiles treated in Comparative Examples 1 to 8 are all good, and the ammonia deodorization rates of the textiles treated in some of the comparative examples are good, the ammonia deodorization rates of the desorbed textiles are all bad. Comparative Examples 1 to 8 do not show the situation where all three indicators (the ammonia deodorization rate of the treated textile, the ammonia deodorization rate of the desorbed textile, and the antibacterial rate of the treated textile) are good.

[0088] In summary, the present invention provides a high-efficiency silver-based nano-deodorant and antibacterial sol, which significantly improves the deodorization performance compared with the usual silver-loaded titanium dioxide. It can be widely applied to the fields of antibacterial and antiviral, deodorization and odor elimination of textiles, household items, building materials, and organic cultivation of fruits, vegetables, and tea leaves.

[0089] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A silver-based nano-deodorant and antibacterial sol, characterized in that: It comprises nanoparticles coupled with crystalline nanosilver and crystalline nanotitanium dioxide; wherein the titanium dioxide is a mixed crystal nanoparticle coupled with rutile type and anatase type, and the crystalline nanosilver is coupled with the rutile type titanium dioxide nanoparticles.

2. The silver nano-deodorant and antibacterial sol according to claim 1, characterized in that: The primary particle size of the rutile titanium dioxide is 8nm to 90nm, and the primary particle size of the anatase titanium dioxide and the primary particle size of the crystalline nano silver are smaller than the primary particle size of the rutile titanium dioxide.

3. The silver-based nano-deodorant and antibacterial sol according to claim 1, characterized in that: The primary particle size of the anatase titanium dioxide is 20% to 70% of the primary particle size of the rutile titanium dioxide, and the primary particle size of the crystalline nano silver is 10% to 80% of the primary particle size of the rutile titanium dioxide.

4. The silver-based nano-deodorant and antibacterial sol according to claim 1, characterized in that: The invention is composed of nanoparticles of crystalline nanosilver and crystalline nanotitanium dioxide coupled with each other and a dispersion medium, wherein the dispersion medium includes water.

5. A method for preparing a silver nano-deodorant and antibacterial sol, characterized in that: A mixed aqueous solution of titanium dioxide and silver nitrate is prepared according to a molar ratio of titanium dioxide to silver nitrate of 1:0.04-0.08, wherein the concentration of titanium dioxide in the mixed aqueous solution is 0.005-0.05 mol / L; and the UVA intensity is 0.6-2.0 mW / cm 2 The irradiation is performed for 6 to 20 hours, and the photoreduction reaction is carried out while stirring, so as to obtain nanoparticles and sol of crystalline nanosilver coupled with crystalline nanotitanium dioxide.

6. The method for preparing a silver-based nano-deodorant and antibacterial sol according to claim 5, characterized in that: Nano-titanium dioxide is a mixed crystal nanoparticle of rutile and anatase types coupled.

7. The method for preparing a silver-based nano-deodorant and antibacterial sol according to claim 6, characterized in that: The preparation steps of nano titanium dioxide include: using 5nm-40nm anatase titanium dioxide as a raw material, heat treating it at 350°C and a pressure of 0.01kPa-1kPa for 1 hour; continuing the heat treatment at 350°C-550°C in an air atmosphere for 6-20 hours to obtain mixed crystal nanoparticles of rutile and anatase coupled phases.

8. The method for preparing a silver-based nano-deodorant and antibacterial sol according to claim 7, characterized in that: The degree of transformation of anatase titanium dioxide to rutile titanium dioxide is controlled to be 15-55%.

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