Long-acting deodorant and preparation method thereof

Abstract

The invention relates to the field of industrial waste gas treatment, and particularly discloses a long-acting deodorant and a preparation method thereof.The deodorant is prepared from cyclodextrin / plant essential oil mother liquor, and the cyclodextrin / plant essential oil mother liquor is prepared from, by mass, 5-10% of cyclodextrin, 8-15% of hydrogen peroxide solution, 15-25% of acetic acid solution, 8-15% of lemon essential oil, 0.1-1% of stabilizer, 1-3% of emulsifier and the balance water. 3-8% of a thickening agent and the balance of water; the invention further discloses a preparation method of the odor treatment agent. The odor treatment agent has the advantage of achieving efficient and long-acting treatment on various odor molecules.

Description

Technical Field

[0001] The present application relates to the field of industrial waste gas treatment and environmental protection, and more specifically, to a long-acting deodorant and a preparation method thereof. Background Art

[0002] With the rapid development of industrialization, the odor pollution problem in industrial sites such as tanneries has become increasingly serious, causing significant impacts on the surrounding environment and human health. The odorous gases produced during the production process of tanneries are complex in composition, mainly including hydrogen sulfide (H2S), 2 S), ammonia (NH 3 ), amine compounds and volatile organic compounds (VOCs). These odor molecules come from processes such as dehairing, softening, tanning and wastewater treatment. More specifically, hydrogen sulfide is produced in the dehairing and softening processes and has a typical rotten egg smell. Ammonia and amine compounds are produced by the use of amino chemicals in the tanning process and have a pungent smell. Volatile organic compounds such as methyl mercaptan, propionic acid, isobutyric acid, etc. come from the fat decomposition of raw materials and the fermentation of wastewater. The odor molecules formed in the above process are highly volatile and diffuse quickly. In addition, hydrogen sulfide and amine compounds are difficult to remove, which not only pollutes the environment, but may also cause respiratory diseases and other health problems.

[0003] At present, the technologies for the above-mentioned odor treatment mainly include chemical deodorants, plant extract deodorants and adsorption material deodorization technology. However, the commonly used chemical deodorants, such as the industrial waste gas deodorants based on sodium hypochlorite, mainly remove gases such as hydrogen sulfide through oxidation reactions, but the above deodorants have the following problems: 1) sodium hypochlorite is prone to secondary pollution such as chloride residues; 2) the removal efficiency of ammonia and amine compounds is low; 3) long-term use leads to equipment corrosion.

[0004] Plant extract deodorants, such as tea tree essential oil-based plant deodorants, mainly rely on the volatilization of essential oils to cover up odors. However, the above mechanism of action only covers up odors and cannot eliminate odor molecules from the source. The treatment effect on high-concentration odor sources is limited and the sustainability is poor. The adsorption material commonly used in adsorption material deodorization technology is activated carbon. Although activated carbon has a high adsorption capacity for hydrogen sulfide, its adsorption capacity will decay over time, and the adsorption effect on amine compounds and volatile organic compounds is weak.

[0005] In view of the shortcomings of current deodorization technology, there is an urgent need to develop an efficient and long-lasting deodorizer to meet the odor control needs of industrial sites such as tanneries. Summary of the invention

[0006] In order to achieve efficient and long-term treatment of various odor molecules, the present application provides a long-acting deodorant and a preparation method thereof.

[0007] In the first aspect, the present application provides a long-lasting deodorant, which adopts the following technical solution: A long-acting deodorant, comprising a cyclodextrin / plant essential oil mother liquor, wherein the cyclodextrin / plant essential oil mother liquor comprises the following raw materials in percentage by weight: Cyclodextrin 5-10%, hydrogen peroxide solution 8-15%, acetic acid solution 15-25%, lemon essential oil 8-15%, stabilizer 0.1-1%, emulsifier 1-3%, thickener 3-8%, and the balance is water.

[0008] By adopting the above technical scheme, the deodorant in the present application uses cyclodextrin / plant essential oil mother liquor as raw material, the cyclodextrin in the mother liquor has the ability to capture hydrogen sulfide and fatty acid odor molecules, and can capture and complex with odor molecules such as hydrogen sulfide and ammonia, hydrogen peroxide can oxidize sulfide and amine compounds and convert them into odorless products, while acetic acid can neutralize ammonia and amine molecules to generate stable salts, and monoterpene compounds in essential oils such as citral further fix the captured objects through hydrogen bonds and hydrophobic effects to prevent secondary release.

[0009] Finally, the cyclodextrin in the mother liquor of the present application captures hydrogen sulfide and fatty acid VOCs through inclusion complexation, significantly reducing their volatility, and combines with hydrogen peroxide and acetic acid to achieve oxidation and neutralization of odor molecules, converting the odor molecules into odorless salts or stable compounds, achieving structural reforming, and finally fixing the odor source through the action of essential oils. The molecular capture effect of cyclodextrin provides a physically closed environment for the oxidation and reforming of odor molecules, while the fixation effect of essential oils further stabilizes the oxidation products. Finally, the above-mentioned mother liquor is used in the present application to realize the closed-loop path of "molecular capture-reformation-deodorization", comprehensively solving the diffusion, transformation and fixation problems of odor molecules, and realizing comprehensive treatment of odor, and it is more efficient and long-lasting.

[0010] Optionally, the stabilizer is gallic acid, the emulsifier is Tween, and the thickener is glycerol.

[0011] By adopting the above technical scheme, gallic acid as a stabilizer can achieve an antioxidant effect on plant essential oils, Tween as an emulsifier plays a stabilizing role in the preparation of mother liquid plant essential oil emulsions to prevent stratification, and glycerol as a thickener can improve the adhesion and durability of the deodorant in this application after spraying.

[0012] Optionally, the cyclodextrin / plant essential oil mother solution is prepared by the following method: 1) Mix 1 / 4-1 / 3 of water with cyclodextrin to prepare a cyclodextrin solution; 2) Add hydrogen peroxide solution to the remaining amount of water, then add acetic acid solution, and stir to obtain a liquid mixture; 3) Mixing lemon essential oil with thickener and emulsifier and then shearing and homogenizing to obtain oil phase emulsion; 4) The prepared cyclodextrin solution, liquid mixture, oil phase emulsion and stabilizer are mixed and homogenized by ultrasonication to prepare a cyclodextrin / plant essential oil mother solution.

[0013] By adopting the above technical scheme, cyclodextrin is first fully dissolved and the cyclodextrin solution with appropriate concentration is mixed with other ingredients later, and then a uniformly dispersed hydrogen peroxide solution and acetic acid solution are obtained. The uniformly dispersed system can quickly react with hydrogen sulfide, ammonia, amine compounds and some volatile organic compounds for oxidation when in contact with odor. The uniform distribution of acetic acid can better react with ammonia and alkaline amine compounds for neutralization, effectively removing odor. When preparing the oil phase emulsion, shear homogenization is performed after mixing to disperse the lemon essential oil into tiny oil droplets, increase the contact area between the lemon essential oil and the odor, and the particle size of the lemon essential oil droplets is less than 1 μm by shear homogenization, which helps to improve the emulsification stability and improve the odor removal efficiency. At the same time, thickeners and emulsifiers are added to stabilize the oil phase emulsion system.

[0014] Emulsifiers make the oil phase and the water phase mix evenly to form a stable emulsion system. In the deodorization process, it helps the lemon essential oil to be more evenly dispersed in the mother liquor, and then it can be deodorized through the spray system, and it can more effectively contact and react with the odor molecules. At the same time, the emulsifier can reduce the oil-water interfacial tension, so that the oil droplets are more stable in the water phase, prolong the volatilization time of the lemon essential oil, and continue to play a deodorizing role; the thickener increases the viscosity of the mother liquor. On the one hand, it makes the emulsion system more stable and prevents the separation of the oil phase and the water phase. On the other hand, the thickened mother liquor can form a relatively stable protective film on the surface of the object when it comes into contact with the odor, slowing down the volatilization rate of the effective ingredients in the mother liquor and prolonging the deodorization time.

[0015] Finally, after the raw materials are mixed, ultrasonic homogenization is performed to further refine the particle or droplet size of each component, so that cyclodextrin, hydrogen peroxide, acetic acid, lemon essential oil and other components are more evenly mixed at the molecular level. When the evenly mixed mother liquor is sprayed and contacts the odor, the various components can work synergistically. At the same time, ultrasonic homogenization helps the stabilizer to play a better role, stabilizes the mother liquor system, and ensures that the mother liquor maintains good deodorizing performance for a long time.

[0016] Moreover, the components in the mother solution prepared in the present application can synergize and enhance the effect. Cyclodextrin has a unique ring structure and hydrophobic cavity, which can encapsulate the odor molecules inside by physical inclusion. In this process, the acidic and oxidative environment created by acetic acid and hydrogen peroxide helps to change the polarity and chemical activity of some odor molecules, making them easier to be included by cyclodextrin. For example, for some volatile organic compounds with weak polarity, polar groups are introduced into the molecular structure under the oxidation of hydrogen peroxide, thereby increasing the interaction with cyclodextrin and improving the saturation efficiency of cyclodextrin. At the same time, the saturation effect of cyclodextrin can also protect active ingredients such as hydrogen peroxide and acetic acid, slow down their decomposition rate, prolong their action time in the system, and improve the timeliness of deodorization. In addition, some components in lemon essential oil, such as limonene, can undergo synergistic oxidation reactions with hydrogen peroxide. The strong oxidizing property of hydrogen peroxide can activate the active components in lemon essential oil, enabling them to react with more types of odor molecules. For example, some volatile organic compounds that are difficult to be oxidized alone can undergo oxidation, addition and other reactions under the joint action of hydrogen peroxide and lemon essential oil, converting them into substances with less odor, thereby enhancing the deodorizing performance. In addition, hydrogen peroxide can oxidize hydrogen sulfide with a foul odor into elemental sulfur precipitation, and at the same time oxidize ammonia, amine compounds and some volatile organic compounds, changing their chemical structure and reducing the odor intensity. Acetic acid is acidic and can react with ammonia and alkaline amine compounds to produce odorless salt substances. During the process, for some nitrogen-containing odor compounds, hydrogen peroxide first partially oxidizes them to enhance their alkalinity, making it easier to react with acetic acid to neutralize, thereby improving the odor removal effect.

[0017] Optionally, during the preparation of the cyclodextrin / plant essential oil mother solution, the shear rate in step 3) is 4000±200rpm, and the shear homogenization treatment is performed for 10-15min; In step 4), the ultrasonic homogenization time is 5-10 min, and the ultrasonic frequency is 20±2 kHz.

[0018] By adopting the above technical scheme, in step 3), the shear rate and time are controlled so that the particle size range of the essential oil emulsion droplets is 120-200nm, which has a better odor removal effect; and in step 4), ultrasonic homogenization is used to make the particle size range of the microparticles in the mother liquor reach 100-150nm. By combining high-speed shear homogenization with ultrasonic homogenization, the particle size of the essential oil emulsion reaches the nanometer level, which significantly improves the stability and uniformity of the emulsion and has a better odor removal effect.

[0019] Optionally, the long-acting deodorant further comprises molecularly imprinted particles, wherein the molecularly imprinted particles comprise hydrogen sulfide MIP particles and ammonia MIP particles in a mass ratio of 1:(0.8-1.2), and the content of the molecularly imprinted particles in the long-acting deodorant is 1-3wt%.

[0020] By adopting the above technical solution, molecular imprinting polymers targeting hydrogen sulfide and ammonia are added to target the main odor molecules, and template molecules are used to form specific recognition sites with high selectivity and long-term capture capabilities, which can further improve the odor removal effect.

[0021] Optionally, the hydrogen sulfide MIP particles are prepared by the following method: Methacrylic acid, ethylene glycol dimethacrylate and initiator are dissolved in dimethylformamide and stirred evenly to obtain a monomer solution. Then, a sodium sulfide aqueous solution is added and stirred at room temperature for 20-40 minutes. The solution is treated at a constant temperature of 55-70°C in a water bath for 10-13 hours to form a polymer. The sodium sulfide is then washed with water to remove the sodium sulfide to obtain sodium sulfide MIP particles.

[0022] Optionally, the ammonia MIP particles are prepared by the following method: Methacrylic acid, ethylene glycol dimethacrylate and initiator were dissolved in acetonitrile, and then ammonium chloride solution was added and stirred evenly, and then reacted under ultraviolet light reaction conditions for 5-7h, and then washed with ethanol and water alternately to remove the ammonium chloride to obtain ammonia MINP particles.

[0023] By adopting the above technical scheme, in the preparation process of the above molecular imprinted particles, sodium sulfide aqueous solution and ammonium chloride solution are used as template molecules, methacrylic acid is used as a functional monomer, and ethylene glycol dimethacrylate is used as a cross-linking agent. Under the action of an initiator, the functional monomer and the cross-linking agent undergo a polymerization reaction to form a three-dimensional network polymer structure. During the process, the template molecules and the cross-linking agent are arranged and polymerized in a specific manner to form specific recognition sites in the polymer network that match the shape, size and functional group distribution of the template molecules. After the polymerization is completed, the template molecules are removed by washing, and holes complementary to the template molecules are left in the polymer particles, which have specific selective recognition capabilities.

[0024] In the present application, when sodium sulfide is used as a template molecule to prepare a molecular imprinted polymer, due to the sulfur ions ionized by sodium sulfide in an aqueous solution, the internal holes of the polymer are shaped according to the sulfur ions and the ionic environment related thereto, and the sulfur atom in the hydrogen sulfide molecular structure carries a lone pair of electrons, and its electron cloud distribution and spatial configuration have certain similarities with the sulfur ions, and hydrogen sulfide will also produce a certain degree of ionization in the solution, so that the hydrogen sulfide molecules can fit well into the holes formed with sodium sulfide as a template; and the chemical environment around the holes of the molecular imprinted polymer prepared with sodium sulfide as a template, such as some functional groups, will have specific chemical interactions with the hydrogen sulfide molecules, such as the electron cloud interaction of the sulfur atom, etc., which can promote the specific binding of the hydrogen sulfide molecules to the molecular imprinted polymer.

[0025] Similarly, when ammonium chloride is used as the template molecule, the hole formed in the polymer matches the shape, size and charge distribution of the ammonium ion. Ammonia has a pair of lone pairs of electrons that can react with H + Combined to form ammonium ions, from the perspective of electron cloud distribution density and spatial structure, ammonia and ammonium ions have a certain relationship, which allows ammonia molecules to interact with specific sites in the hole, such as hydrogen bonds, to achieve specific adsorption of ammonia; the chemical groups around the hole of the molecular imprinted polymer formed with ammonium chloride as a template can interact with ammonia through hydrogen bonds, thereby achieving specific adsorption of ammonia.

[0026] Optionally, during the preparation of hydrogen sulfide MIP particles, each raw material is added according to the following mass percentages: 15-25% sodium sulfide aqueous solution, 5-10% methacrylic acid, 10-20% ethylene glycol dimethacrylate, 0.5-1.5% initiator and the balance dimethylformamide, the concentration of the sodium sulfide aqueous solution is 5-8wt%.

[0027] Optionally, during the preparation of ammonia MIP particles, each raw material is added according to the following mass percentages: 20-30% ammonium chloride solution, 8-15% methacrylic acid, 15-25% ethylene glycol dimethacrylate, 0.5-1.5% initiator, and the balance is acetonitrile, and the concentration of the ammonium chloride solution is 5-10wt%.

[0028] In a second aspect, the present application provides a method for preparing a long-acting deodorant, using the following technical solution: A method for preparing a long-acting deodorant comprises the following steps: The cyclodextrin / plant essential oil mother solution and the molecular imprinted particles are mixed in proportion and then ultrasonically homogenized and dispersed to prepare a long-acting deodorant.

[0029] By adopting the above technical solution, the mother liquid and the molecularly imprinted particles are mixed and homogenized to form a highly stable composite liquid deodorant, which has excellent stability and no stratification after storage for three months. Moreover, it is prepared in the form of a liquid deodorant and used in a spraying manner, which can quickly diffuse in the air or on the surface of an object, quickly contact and act with odor molecules, thereby quickly achieving a deodorizing effect.

[0030] In summary, this application has the following beneficial effects: 1. In the present application, cyclodextrin captures hydrogen sulfide and fatty acid VOCs through inclusion complexation, significantly reducing their volatility, and combines with hydrogen peroxide and acetic acid to achieve oxidation and neutralization of odor molecules, converting the odor molecules into odorless salts or stable compounds, achieving structural reformation, and finally fixing the odor source through the action of essential oils. The molecular capture of cyclodextrin provides a physically closed environment for the oxidation and reformation of odor molecules, while the fixation of essential oils further stabilizes the oxidation products. Finally, the mother liquor is used in the present application to achieve the closed-loop path of "molecular capture-reformation-deodorization", comprehensively solving the diffusion, conversion and fixation problems of odor molecules, and achieving comprehensive treatment of odor, which is more efficient and long-lasting. 2. In the present application, cyclodextrin can encapsulate ingredients such as lemon essential oil to form a sustained-release system, so that active ingredients such as lemon essential oil can be slowly released and their action time can be prolonged. At the same time, the presence of the thickener makes the mother solution form a certain viscosity, which helps to adhere the molecular imprinted polymer and other effective ingredients to the surface of the object or keep them from being easily lost, so that the whole system can continue to play a deodorizing role for a long time, achieving long-term deodorization; 3. The present application also adds molecular imprinting polymers for hydrogen sulfide and ammonia, using template molecules to form specific recognition sites, which have high selectivity and long-term capture capabilities, and can further improve the odor removal effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is the Fourier infrared spectrum of cyclodextrin after it is combined with odor molecules; Figure 2 This is the NMR spectrum of cyclodextrin combined with odor molecules; Figure 3 It is a liquid chromatography-mass spectrometry (LC-MS) spectrum after the deodorant in Example 1 of the present application is combined with the odor molecules. DETAILED DESCRIPTION

[0032] The present application is further described in detail below in conjunction with the examples. It is particularly noted that if no specific conditions are specified in the following examples, the experiments are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources.

[0033] The lemon essential oil in the following examples is selected from the lemon essential oil of Jiangxi Hengcheng Natural Spice Oil Co., Ltd.

[0034] The following preparation example is an example of the preparation of hydrogen sulfide MIP particles: Preparation Example 1 A method for preparing hydrogen sulfide MIP particles comprises the following steps: Preparation of materials: Using a 6wt% sodium sulfide aqueous solution as a template molecule to simulate a hydrogen sulfide environment, using methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a crosslinker, azobisisobutyronitrile as an initiator, and dimethylformamide as a solvent, prepare the raw materials according to the following mass ratios: 20% sodium sulfide aqueous solution, 8% methacrylic acid, 15% ethylene glycol dimethacrylate, 1% initiator and the balance dimethylformamide; Preparation of sulfide MIP particles: dissolve methacrylic acid, ethylene glycol dimethacrylate and initiator in dimethylformamide, stir evenly to obtain a monomer solution, then add sodium sulfide aqueous solution, stir at room temperature for 30 minutes, and treat at a constant temperature of 60°C in a water bath for 12 hours to form a polymer, then wash the polymer with water to remove sodium sulfide to obtain sodium sulfide MIP particles.

[0035] Preparation Example 2 A method for preparing hydrogen sulfide MIP particles comprises the following steps: Preparation of materials: Using 8wt% sodium sulfide aqueous solution as a template molecule to simulate the hydrogen sulfide environment, using methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a crosslinker, azobisisobutyronitrile as an initiator, and dimethylformamide as a solvent, prepare the raw materials according to the following mass ratios: 15% sodium sulfide aqueous solution, 5% methacrylic acid, 10% ethylene glycol dimethacrylate, 0.5% initiator and the balance dimethylformamide; Preparation of sulfide MIP particles: dissolve methacrylic acid, ethylene glycol dimethacrylate and initiator in dimethylformamide, stir evenly to obtain a monomer solution, then add sodium sulfide aqueous solution, stir at room temperature for 20 minutes, and treat at a constant temperature of 55°C in a water bath for 13 hours to form a polymer, and then wash the polymer with water to remove sodium sulfide to obtain sodium sulfide MIP particles.

[0036] Preparation Example 3 A method for preparing hydrogen sulfide MIP particles comprises the following steps: Preparation of materials: Using a 5wt% sodium sulfide aqueous solution as a template molecule to simulate a hydrogen sulfide environment, using methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a crosslinker, azobisisobutyronitrile as an initiator, and dimethylformamide as a solvent, prepare the raw materials according to the following mass ratios: 25% sodium sulfide aqueous solution, 10% methacrylic acid, 20% ethylene glycol dimethacrylate, 1.5% initiator and the balance dimethylformamide; Preparation of sulfide MIP particles: dissolve methacrylic acid, ethylene glycol dimethacrylate and initiator in dimethylformamide, stir evenly to obtain a monomer solution, then add sodium sulfide aqueous solution, stir at room temperature for 40 minutes, and treat at a constant temperature of 70°C in a water bath for 10 hours to form a polymer, then wash the polymer with water to remove sodium sulfide to obtain sodium sulfide MIP particles.

[0037] Preparation Example 4 A method for preparing ammonia MIP particles comprises the following steps: Preparation of materials: Using 8wt% ammonium chloride solution as a template molecule to simulate an ammonia environment, using methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a crosslinker, azobisisobutyronitrile as an initiator, and acetonitrile as a solvent, prepare the raw materials according to the following mass ratios: 25% ammonium chloride solution, 10% methacrylic acid, 20% ethylene glycol dimethacrylate, 1% initiator, and the balance acetonitrile; methacrylic acid, ethylene glycol dimethacrylate, and initiator are dissolved in acetonitrile, and then the ammonium chloride solution is added and stirred evenly, and then placed in an ultraviolet light reactor (wavelength of 365nm) to react for 6 hours, and then washed alternately with ethanol and water to remove the ammonium chloride to obtain ammonia MINP particles.

[0038] Preparation Example 5 A method for preparing ammonia MIP particles comprises the following steps: Preparation of materials: Using 10wt% ammonium chloride solution as a template molecule to simulate an ammonia environment, using methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a crosslinker, azobisisobutyronitrile as an initiator, and acetonitrile as a solvent, prepare the raw materials according to the following mass ratios: 20% ammonium chloride solution, 8% methacrylic acid, 15% ethylene glycol dimethacrylate, 0.5% initiator, and the balance acetonitrile; methacrylic acid, ethylene glycol dimethacrylate, and initiator are dissolved in acetonitrile, and then the ammonium chloride solution is added and stirred evenly, and then placed in an ultraviolet light reactor (wavelength of 365nm) to react for 5 hours, and then washed alternately with ethanol and water to remove the ammonium chloride to obtain ammonia MINP particles.

[0039] Preparation Example 6 A method for preparing ammonia MIP particles comprises the following steps: Preparation of materials: Using 5wt% ammonium chloride solution as a template molecule to simulate an ammonia environment, using methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a crosslinker, azobisisobutyronitrile as an initiator, and acetonitrile as a solvent, prepare the raw materials according to the following mass ratios: 30% ammonium chloride solution, 15% methacrylic acid, 25% ethylene glycol dimethacrylate, 1.5% initiator, and the balance acetonitrile; Methacrylic acid, ethylene glycol dimethacrylate and initiator were dissolved in acetonitrile, and then ammonium chloride solution was added and stirred evenly. Then, the mixture was placed in an ultraviolet light reactor (wavelength of 365 nm) to react for 7 h, and then the ammonium chloride was removed by alternate washing with ethanol and water to obtain ammonia MINP particles.

[0040] Example 1 The long-acting deodorant in this embodiment contains cyclodextrin / plant essential oil mother liquor, and the cyclodextrin / plant essential oil mother liquor includes the following raw materials in percentage by weight: β-cyclodextrin 8%, 30% hydrogen peroxide solution 10%, 5% acetic acid solution 20%, lemon essential oil 10%, stabilizer 0.2%, emulsifier 2%, thickener 5%, the balance is water, the stabilizer is gallic acid, the emulsifier is Tween 80, and the thickener is glycerol; The preparation method of the long-acting deodorant in this embodiment includes the preparation of cyclodextrin / plant essential oil mother solution, which specifically includes the following steps: 1) Heat 1 / 3 of the water to 40°C, then add β-cyclodextrin, and stir at a constant temperature of 800rpm for 15 minutes to obtain a transparent cyclodextrin solution without precipitation; 2) Slowly add hydrogen peroxide solution to the remaining water while stirring, then add acetic acid solution, and stir at 500 rpm to obtain a liquid mixture; 3) Mix the lemon essential oil with the thickener and emulsifier, and then use a high-speed shear homogenizer to shear and homogenize for 10 minutes to obtain an oil phase emulsion at a shear rate of 4000 rpm; 4) The prepared cyclodextrin solution, liquid mixture, oil phase emulsion and stabilizer were mixed and homogenized using an ultrasonic homogenizer for 8 min at an ultrasonic frequency of 20 kHz and an ultrasonic power of 500 W to obtain a cyclodextrin / plant essential oil mother solution.

[0041] Example 2 The long-acting deodorant in this embodiment contains cyclodextrin / plant essential oil mother liquor, and the cyclodextrin / plant essential oil mother liquor includes the following raw materials in percentage by weight: β-cyclodextrin 5%, 30% hydrogen peroxide solution 8%, 5% acetic acid solution 15%, lemon essential oil 8%, stabilizer 0.1%, emulsifier 1%, thickener 3%, the balance is water, the stabilizer is gallic acid, the emulsifier is Tween 80, and the thickener is glycerol; The preparation of cyclodextrin / plant essential oil mother solution comprises the following steps: 1) Heat 1 / 4 of the water to 38°C, then add β-cyclodextrin, and stir at a constant temperature of 800rpm for 15 minutes to obtain a transparent cyclodextrin solution without precipitation; 2) Slowly add hydrogen peroxide solution to the remaining water while stirring, then add acetic acid solution, and stir at 500 rpm to obtain a liquid mixture; 3) Mix the lemon essential oil with the thickener and emulsifier, and then use a high-speed shear homogenizer to shear and homogenize for 10-15 minutes to obtain an oil phase emulsion at a shear rate of 3800 rpm; 4) The prepared cyclodextrin solution, liquid mixture, oil phase emulsion and stabilizer were mixed and homogenized with an ultrasonic homogenizer for 5 min at an ultrasonic frequency of 20 kHz and an ultrasonic power of 400 W to obtain a cyclodextrin / plant essential oil mother solution.

[0042] Example 3 The long-acting deodorant in this embodiment contains cyclodextrin / plant essential oil mother liquor, and the cyclodextrin / plant essential oil mother liquor includes the following raw materials in percentage by weight: β-cyclodextrin 10%, 30% hydrogen peroxide solution 15%, 5% acetic acid solution 25%, lemon essential oil 15%, stabilizer 1%, emulsifier 3%, thickener 8%, the balance is water, the stabilizer is gallic acid, the emulsifier is Tween 80, and the thickener is glycerol; The preparation method of the long-acting deodorant in this embodiment includes the preparation of cyclodextrin / plant essential oil mother solution, which specifically includes the following steps: 1) Heat 1 / 3 of the water to 42°C, then add β-cyclodextrin, and stir at a constant temperature of 800rpm for 10 minutes to obtain a transparent cyclodextrin solution without precipitation; 2) Slowly add hydrogen peroxide solution to the remaining water while stirring, then add acetic acid solution, and stir at 500 rpm to obtain a liquid mixture; 3) Mix the lemon essential oil with the thickener and emulsifier, and then use a high-speed shear homogenizer to shear and homogenize for 15 minutes to obtain an oil phase emulsion at a shear rate of 4200 rpm; 4) The prepared cyclodextrin solution, liquid mixture, oil phase emulsion and stabilizer were mixed and homogenized using an ultrasonic homogenizer for 10 min at an ultrasonic frequency of 22 kHz and an ultrasonic power of 600 W to obtain a cyclodextrin / plant essential oil mother solution.

[0043] Example 4 A long-acting deodorant, which is different from that in Example 1 in that the long-acting deodorant in this example further comprises molecular imprinted particles, and the molecular imprinted particles comprise hydrogen sulfide MIP particles and ammonia MIP particles in a mass ratio of 1:1, and the content of molecular imprinted particles in the long-acting deodorant is 1.5wt%.

[0044] The long-acting deodorant in this embodiment comprises the following steps: S1. Prepare cyclodextrin / plant essential oil mother solution according to the method in Example 1; S2, mixing the hydrogen sulfide MIP particles prepared in Preparation Example 1 and the ammonia MIP particles prepared in Preparation Example 4 in a mass ratio of 1:1 to prepare molecularly imprinted particles, and then adding the cyclodextrin / plant essential oil mother solution prepared in step S1 to prepare a mixed solution, so that the content of the molecularly imprinted particles in the mixed solution is 1.5wt%; S3. Then, the mixed liquid obtained in step S2 is homogenized by ultrasonic homogenizer, the ultrasonic frequency is 20 kHz, and the ultrasonic homogenization time is 5 min, to obtain a composite liquid long-acting deodorant.

[0045] Example 5 A long-acting deodorant, which is different from that in Example 1 in that the long-acting deodorant in this example further comprises molecular imprinted particles, and the molecular imprinted particles comprise hydrogen sulfide MIP particles and ammonia MIP particles in a mass ratio of 1:0.8, and the content of molecular imprinted particles in the long-acting deodorant is 1 wt%.

[0046] The long-acting deodorant in this embodiment comprises the following steps: S1. Prepare cyclodextrin / plant essential oil mother solution according to the method in Example 1; S2, mixing the hydrogen sulfide MIP particles prepared in Preparation Example 1 and the ammonia MIP particles prepared in Preparation Example 4 in a mass ratio of 1:0.8 to prepare molecularly imprinted particles, and then adding the cyclodextrin / plant essential oil mother solution prepared in step S1 to prepare a mixed solution, so that the content of the molecularly imprinted particles in the mixed solution is 1wt%; S3. Then, the mixed liquid obtained in step S2 is homogenized by ultrasonic homogenizer, the ultrasonic frequency is 20 kHz, and the ultrasonic homogenization time is 5 min, to obtain a composite liquid long-acting deodorant.

[0047] Example 6 A long-acting deodorant, which is different from that in Example 1 in that the long-acting deodorant in this example further comprises molecular imprinted particles, and the molecular imprinted particles comprise hydrogen sulfide MIP particles and ammonia MIP particles in a mass ratio of 1:1.2, and the content of molecular imprinted particles in the long-acting deodorant is 3wt%.

[0048] The long-acting deodorant in this embodiment comprises the following steps: S1. Prepare cyclodextrin / plant essential oil mother solution according to the method in Example 1; S2, the hydrogen sulfide MIP particles prepared in Preparation Example 1 and the ammonia MIP particles prepared in Preparation Example 4 were mixed in a mass ratio of 1:1.2 to prepare molecularly imprinted particles, and then the cyclodextrin / plant essential oil mother solution prepared in step S1 was added to prepare a mixed solution, so that the content of the molecularly imprinted particles in the mixed solution was 3wt%; S3. Then, the mixed liquid obtained in step S2 is homogenized by ultrasonic homogenizer, the ultrasonic frequency is 20 kHz, and the ultrasonic homogenization time is 10 min, to obtain a composite liquid long-acting deodorant.

[0049] Comparative Example 1 A method for preparing a long-acting deodorant is carried out according to the method in Example 1, except that no hydrogen peroxide solution is added to the raw materials.

[0050] Comparative Example 2 A method for preparing a long-acting deodorant is carried out according to the method in Example 1, except that an equal amount of lemon essential oil is replaced by clove essential oil.

[0051] Comparative Example 3 A method for preparing a long-acting deodorant is carried out according to the method in Example 1, except that an equal amount of lemon essential oil is replaced by lemon extract (purchased from Lianfeng Biotechnology Co., Ltd.).

[0052] Comparative Example 4 A method for preparing a long-acting deodorant is carried out according to the method in Example 1, except that an equal amount of lemon essential oil is replaced by green tea essential oil.

[0053] Comparative Example 5 The invention discloses a long-lasting deodorant, which uses a sodium hypochlorite solution with a chlorine content of 12%.

[0054] Application 1 A long-lasting deodorant is applied to atomization spraying in a tannery, specifically in areas with high odor concentration and fast odor diffusion such as unhairing rooms, wastewater pools and meat workshops in tannery, using atomization spraying technology for deodorization, and the specific application method is: dilute the prepared long-lasting deodorant according to a volume ratio of 1:500, that is, take 2mL of liquid deodorant and add 1L of water to mix and prepare a spray liquid, use an ultrasonic atomizer, the nozzle particle size is 20μm, and the flow rate is controlled to 2L / h. In the unhairing room, the surface of the wastewater pool and the tanning workshop, the nozzles are arranged at intervals of 5m, the continuous spraying time is 30min, and the spraying is carried out twice a day.

[0055] Performance Testing The deodorants prepared in the examples and comparative examples were applied in the above-mentioned application mode, and then the hydrogen sulfide removal rate, ammonia removal rate, VOCs removal rate (%), odor intensity reduction rate and long-term effectiveness were tested. The specific method is as follows: Hydrogen sulfide removal rate: The hydrogen sulfide concentration in the air before spraying and 20 minutes after spraying was detected by a portable gas detector, in ppm; Ammonia removal rate: Use an ammonia detector to measure the change in ammonia concentration; VOCs removal rate: Use a photoionization detector to measure the VOCs concentration before and after spraying, and calculate the removal rate; Odor intensity reduction rate: According to GB / T 14675-1993 olfactory evaluation standard, a five-person olfactory panel will score (scoring range 0-5, 0 for no odor, 5 for extremely strong odor), and the odor intensity reduction rate will be calculated based on the scoring standard; Long-term effect: Record the change of odor concentration within 6 hours after spraying, and calculate the residual concentration after 6 hours to evaluate the long-term effect.

[0056] The statistical results are shown in Table 1 below.

[0057] Table 1: Table 1 continued: Referring to the test results in Table 1 above, the deodorant provided in the examples of the present application can efficiently capture and oxidize hydrogen sulfide, can neutralize ammonia to generate stable products, and lemon essential oil and cyclodextrin synergistically capture fatty acids, and ultimately have a high removal rate for hydrogen sulfide, ammonia and VOCs, excellent comprehensive treatment effect, low probability of secondary release, and significantly enhanced sustainability. Combined with the test results of Example 1 and Example 4, it can be seen that on the basis of further improving its removal rate, its long-term effectiveness is significantly improved.

[0058] Combined with the test results in Example 1 and Comparative Example 1, when no hydrogen peroxide solution was added in Comparative Example 1, the removal rate of hydrogen sulfide and the removal rate of ammonia were significantly reduced. Hydrogen peroxide can play an oxidative role to reduce its content, and after oxidation, it can be better removed in coordination with other components. Combined with the test results in Comparative Examples 2 and 4, it can be seen that when lemon essential oil is replaced with clove essential oil or green tea essential oil, the long-term effect is further improved. Combined with the test results in Comparative Example 3, when lemon extract is added in Comparative Example 3, its long-term effect is The odor intensity reduction rate is also reduced. Lemon essential oil is extracted from the fresh peel of lemon by cold pressing method. The main components include limonene and other fat-soluble compounds. Lemon essential oil is rich in monoterpenoid compounds such as limonene and citral. The captured objects are further fixed by hydrogen bonds and hydrophobic effects to prevent secondary release. Lemon extract is usually juice squeezed from lemon pulp. The main components are citric acid and vitamin C and other water-soluble components. The main components are citric acid and vitamin C, which cannot play the synergistic fixation and deodorization effect of lemon essential oil and cyclodextrin. Finally, combined with the test results of Example 1 and Comparative Example 5, it can be seen that the deodorant in this application is better than the commonly used sodium hypochlorite deodorant.

[0059] In addition, the above-mentioned process was explored and combined with Figure 1 This is the Fourier infrared spectrum of cyclodextrin after combining with odor molecules. It can be seen that when cyclodextrin forms a complex with odor molecules, the chemical bond environment will change, resulting in a change in the position or intensity of the characteristic absorption peak. The focus is on analyzing the changes in the groups of odor molecules (such as the SH bond of hydrogen sulfide and the C=O bond of fatty acids), specifically: Single odor molecule (hydrogen sulfide): The absorption peak of the SH bond at 2600-2550cm-1 is obvious. Complex of cyclodextrin and hydrogen sulfide: The intensity of the SH characteristic peak is weakened or disappeared, indicating that hydrogen sulfide is included in the hydrophobic cavity of cyclodextrin, limiting its free vibration. Single fatty acid (isobutyric acid): The C=O stretching vibration peak is significant at 1700-1725cm-1. Complex of cyclodextrin and fatty acid: The C=O characteristic peak is displaced or weakened, indicating that the carbonyl group is involved in the intermolecular force (such as hydrogen bond).

[0060] Recombination Figure 2 The nuclear magnetic resonance (NMR) spectrum of cyclodextrin after combining with odor molecules. When cyclodextrin forms inclusion complex with odor molecules, the chemical shift (δ value) of protons in the cyclodextrin cavity will change. Some hydrogen atom signals of odor molecules such as fatty acids will also shift due to changes in the electronic environment. Changes in hydrogen signal of cyclodextrin: The chemical shift of hydrogen in the cyclodextrin cavity (H-3 and H-5) moves to the high field (smaller δ value), indicating that the odor molecules have entered the cavity. Changes in odor molecule signal: The methyl group of isobutyric acid (-CH 3) and the hydrogen signals near the carbonyl group shifted, indicating that it formed an intermolecular interaction with cyclodextrin.

[0061] Finally, combine Figure 3 This is the liquid chromatography-mass spectrometry (LC-MS) spectrum after the odor agent and the odor molecule are combined in Example 1 of the present application. LC-MS is used to detect whether the odor molecules (such as hydrogen sulfide and isobutyric acid) are converted into stable products such as sulfate and acetate. It can be seen that the original molecular peak (H 2 S) disappeared, and a new characteristic peak of sulfate ion (mass-to-charge ratio m / z=97) was added. After treatment with isobutyric acid: the C=O stretching vibration peak disappeared, and the characteristic peak of isobutyl acetate appeared, indicating that the fatty acid was converted.

[0062] In addition, the mechanism of action of acetic acid in the deodorant is analyzed: in Example 1, ammonia gas is introduced into the deodorant, and the conductivity value (μS / cm) of the solution is measured in real time using a conductivity meter. Table 2 below shows the characteristic conductivity value of the deodorant after absorbing ammonia gas.

[0063] Table 2: It can be seen that the initial conductivity value is about 150-200μS / cm, which is mainly provided by a small amount of ionized acetic acid; the intermediate conductivity value gradually increases to 400-600μS / cm, ammonium acetate is gradually generated, and the ion concentration in the solution increases; the final conductivity value is stable at 800-1000μS / cm, acetic acid is completely consumed, and only the complete electrolysis product of ammonium acetate is in the system. In the middle stage of the reaction, the conductivity value rises rapidly (200μS / cm to 800μS / cm), indicating that ammonium acetate is generated in large quantities, which is direct evidence of the reaction between ammonia and acetic acid; when the conductivity value tends to be stable (800-1000μS / cm), it means that acetic acid is completely consumed and the reaction reaches equilibrium.

[0064] The liquid deodorant prepared in this application can be applied not only by atomization spraying, but also by conventional spraying. The following application method 2 is a conventional spraying application, which is aimed at the odor generated by the decomposition and fermentation of scum in the wastewater pool. The high-pressure spraying method is used to directly cover the surface of the wastewater pool to reduce the spread of odor. The specific application method is: the deodorant prepared in Example 1 is diluted according to a volume ratio of 1:500 to prepare a spray liquid, that is, 2 ml of the deodorant is added to 1L of water and mixed, and a high-pressure spraying system is used, the nozzle diameter is 1.5mm, the injection pressure is controlled to be 1.5MPa, and the spraying flow rate is 4L / min. The spraying equipment is arranged along the edge of the wastewater pool, and a nozzle is arranged every 3m to cover the surface of the wastewater pool; when spraying, the distance between the nozzle and the wastewater surface is kept at 1.5m, and the spraying time is 20 minutes to ensure that the liquid is evenly distributed.

[0065] The hydrogen sulfide removal rate, ammonia removal rate, VOCs removal rate and odor intensity reduction rate after the above conventional spraying were tested, and the test results are shown in Table 3 below.

[0066] Table 3: Hydrogen sulfide removal rate / % Ammonia removal rate / % VOCs removal rate (%) Odor intensity reduction rate / % 93 90 89 92 In addition, the stability test was carried out on the odorant prepared in Example 1, and the storage temperature was set to three stages: low temperature condition: 5°C (simulating winter or cold storage environment); normal temperature condition: 25°C (conventional storage at room temperature); high temperature condition: 40°C (simulating high temperature in summer or transportation conditions). The pH change, particle size distribution and component concentration change under different storage times were tested respectively, wherein the particle size distribution was measured by a dynamic light scattering DLS instrument to measure the particle size range, and the component concentration change was measured by high performance liquid chromatography to detect the total concentration change of key components such as cyclodextrin and lemon essential oil. The test results are shown in Table 4 below.

[0067] Table 4: In addition, the deodorizing effect of the deodorant in this application under different environmental conditions was tested. The humidity and temperature were adjusted in the simulated odor room, and the odor concentrations were set to low concentration (hydrogen sulfide concentration was 1 ppm, ammonia concentration was 5 ppm, and VOCs concentration was 1 mg / m 3 ), medium concentration (hydrogen sulfide concentration is 8ppm, ammonia concentration is 20ppm, VOCs concentration is 10mg / m 3 ) and high concentration (hydrogen sulfide concentration is 20ppm, ammonia concentration is 35ppm, VOCs concentration is 20mg / m3), the deodorant in Example 1 is diluted according to the volume ratio of 1:1000 and then sprayed, and the hydrogen sulfide removal rate, ammonia removal rate and VOCs removal rate as well as the odor intensity score after 6h (0-5 points, 0 point is odorless, 5 points is extremely odorous) and the residual concentration after 6h are tested. The test results of the deodorant in Example 1 of the present application are shown in Table 5 below.

[0068] Table 5: In addition, the sodium hypochlorite solution in Comparative Example 5 was treated according to the above method, and the treatment results are shown in Table 6 below. In addition, lemon essential oil was used alone for treatment according to the above method, and the treatment results are shown in Table 7 below, wherein the deodorant, sodium hypochlorite solution and lemon essential oil were used in the same amount.

[0069] Table 6: Table 7: In summary, it can be seen that the deodorant prepared in the embodiment of the present application has a comprehensive removal rate of more than 90% for hydrogen sulfide, ammonia and VOCs, which is much better than sodium hypochlorite, and the residual odor concentration within 6 hours after spraying is less than 2ppm, which is significantly lower than the sodium hypochlorite and single essential oil control groups, and has better long-term control ability. In addition, the deodorant in the present application does not contain chlorides or other harmful ingredients, avoiding secondary pollution caused by sodium hypochlorite. The dilution ratio is 1:500-1:1000, which reduces the amount of stock solution used and reduces operating costs. When applying it, atomization spraying or conventional spraying can be used. Atomization spraying is suitable for odor spaces with strong diffusion, such as depilatory rooms and tanning workshops, and can efficiently capture hydrogen sulfide and ammonia in the air. Conventional spraying is suitable for areas with high local odor concentrations such as wastewater pools, which can accurately cover the odor source and decompose volatile fatty acids.

[0070] In addition, the deodorant in the present application can be used not only for odor control in tanneries, but also for odor control in landfills and garbage transfer stations (the odor components are mainly hydrogen sulfide, ammonia and fatty acids), sewage treatment plants (the odor mainly comes from hydrogen sulfide, methyl mercaptan and volatile fatty acids), food processing and farms (the odor components are mostly ammonia, amines and volatile fatty acids), chemical plants and pharmaceutical plants (volatile organic compounds (VOCs) and sulfides are the main components) and other industries.

[0071] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A long-acting deodorant, characterized in that: It includes cyclodextrin / plant essential oil mother liquor, wherein the cyclodextrin / plant essential oil mother liquor includes the following raw materials in percentage by weight: Cyclodextrin 5-10%, hydrogen peroxide solution 8-15%, acetic acid solution 15-25%, lemon essential oil 8-15%, stabilizer 0.1-1%, emulsifier 1-3%, thickener 3-8%, and the balance is water.

2. A long-acting deodorant according to claim 1, characterized in that: The stabilizer is gallic acid, the emulsifier is Tween, and the thickener is glycerol.

3. A long-acting deodorant according to claim 1, characterized in that: The cyclodextrin / plant essential oil mother solution is prepared by the following method: 1) Mix 1 / 4-1 / 3 of water with cyclodextrin to prepare a cyclodextrin solution; 2) Add hydrogen peroxide solution to the remaining water, then add acetic acid solution, and stir to obtain a liquid mixture; 3) Mix lemon essential oil with thickener and emulsifier and then shear and homogenize to obtain oil phase emulsion; 4) The prepared cyclodextrin solution, liquid mixture, oil phase emulsion and stabilizer are mixed and homogenized by ultrasonication to obtain a cyclodextrin / plant essential oil mother solution.

4. A long-acting deodorant according to claim 3, characterized in that: During the preparation of the cyclodextrin / plant essential oil mother solution, the shear rate in step 3) is 4000±200rpm, and the shear homogenization treatment is performed for 10-15min; In step 4), the ultrasonic homogenization time is 5-10 min, and the ultrasonic frequency is 20±2 kHz.

5. A long-acting deodorant according to claim 1, characterized in that: The long-acting deodorant further comprises molecularly imprinted particles, wherein the molecularly imprinted particles comprise hydrogen sulfide MIP particles and ammonia MIP particles in a mass ratio of 1:(0.8-1.2), and the content of the molecularly imprinted particles in the long-acting deodorant is 1-3wt%.

6. A long-acting deodorant according to claim 5, characterized in that: The hydrogen sulfide MIP particles are prepared by the following method: Methacrylic acid, ethylene glycol dimethacrylate and initiator are dissolved in dimethylformamide and stirred evenly to obtain a monomer solution. Then, a sodium sulfide aqueous solution is added and stirred at room temperature for 20-40 minutes. The solution is treated at a constant temperature of 55-70°C in a water bath for 10-13 hours to form a polymer. The sodium sulfide is then washed with water to remove the sodium sulfide to obtain sodium sulfide MIP particles.

7. A long-acting deodorant according to claim 5, characterized in that: Ammonia MIP particles are prepared by the following method: Methacrylic acid, ethylene glycol dimethacrylate and initiator were dissolved in acetonitrile, and then ammonium chloride solution was added and stirred evenly, and then reacted under ultraviolet light reaction conditions for 5-7h, and then washed with ethanol and water alternately to remove the ammonium chloride to obtain ammonia MINP particles.

8. A long-acting deodorant according to claim 6, characterized in that: During the preparation of hydrogen sulfide MIP particles, each raw material is added according to the following mass percentages: 15-25% sodium sulfide aqueous solution, 5-10% methacrylic acid, 10-20% ethylene glycol dimethacrylate, 0.5-1.5% initiator and the balance dimethylformamide, the concentration of the sodium sulfide aqueous solution is 5-8wt%.

9. A long-acting deodorant according to claim 7, characterized in that: During the preparation of ammonia MIP particles, the raw materials are added according to the following mass percentages: Ammonium chloride solution 20-30%, methacrylic acid 8-15%, ethylene glycol dimethacrylate 15-25%, initiator 0.5-1.5%, the balance is acetonitrile, and the concentration of the ammonium chloride solution is 5-10wt%.

10. The method for preparing the long-acting deodorant according to any one of claims 5 to 9, characterized in that: The following steps are involved: The cyclodextrin / plant essential oil mother solution and the molecular imprinted particles are mixed in proportion and then ultrasonically homogenized and dispersed to prepare a long-acting deodorant.

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