High-stability oleophylic emulsifier and preparation method thereof

Abstract

The invention discloses a high-stability oleophylic emulsifier and a preparation method thereof, and relates to the technical field of emulsifiers, and the preparation method comprises the following steps: preparing materials, weighing nano silicon dioxide particles, adding the nano silicon dioxide particles into a proper amount of absolute ethyl alcohol, dispersing the mixed solution in an ultrasonic cleaner, and then preparing the high-stability oleophylic emulsifier according to a determined HLB value, the preparation method comprises the following steps: selecting a proper surfactant for compounding, mixing a nano silicon dioxide suspension subjected to ultrasonic dispersion with the surfactant, adding a high-molecular polymer, an antioxidant, a preservative and part of a pH regulator, carrying out microcapsule embedding to obtain a microcapsule suspension, adding a thickening agent, and stirring for 30 minutes to obtain a finished product. And finally, carrying out spray drying or freeze drying to obtain the oleophylic emulsifier. The dispersity and stability of the emulsifier in an oil phase are improved through the micro-nano carrier, the emulsifying effect of the emulsifier is improved, the emulsifier is ensured to stably exist in an oil-water interface in combination with an appropriate HLB value, and the emulsion is not prone to layering and demulsification under different temperature storage conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of emulsifiers, and specifically provides a highly stable lipophilic emulsifier and a preparation method thereof. Background Art

[0002] Lipophilic emulsifiers are mainly used to disperse the oil phase in the water phase to form a stable emulsion. However, traditional lipophilic emulsifiers are prone to emulsion stratification and demulsification under extreme conditions such as high temperature, low temperature, and high salt, which affect the product quality and performance, and there are certain defects.

[0003] The defects of existing emulsifiers are as follows:

[0004] 1. In the patent document CN102250271A, it mainly considers how to improve the emulsifying and dispersing performance of the emulsifier, without considering that the existing lipophilic emulsifiers are prone to emulsion stratification and demulsification under extreme conditions;

[0005] 2. In the application document CN117143614A, it mainly considers how to improve the lubricating effect of the emulsifier, reduce friction and wear, without considering that the existing lipophilic emulsifiers cannot meet the emulsification requirements of different oil phases, and the versatility of the emulsifier is poor;

[0006] 3. In the application document CN118048159A, it mainly considers how to achieve demulsification and dehydration only by adjusting the PH, without considering that the existing lipophilic emulsifiers have poor emulsification effects;

[0007] 4. In the patent document CN101992042A, it mainly considers how to improve the emulsifying property and penetrability of the emulsifier, without considering that the existing lipophilic emulsifiers have poor physical stability. Summary of the Invention

[0008] The purpose of the present invention is to provide a highly stable lipophilic emulsifier and a preparation method thereof to solve the problems raised in the above background art.

[0009] To achieve the above purpose, the present invention provides the following technical solution: A preparation method of a highly stable lipophilic emulsifier, and the preparation method is as follows:

[0010] S1. Material preparation: including surfactants, nano carriers, wall materials, organic solvents, high molecular polymers, and additives. Among them, natural oils and fats are selected, surfactants are Span-80 and Tween-60, nano carriers are nano-silica particles, and additives are antioxidants, preservatives, thickeners, and PH regulators;

[0011] S2. Micro-nano carrier treatment: Weigh nano-silica particles and add them to an appropriate amount of absolute ethanol. Then, place the mixture in an ultrasonic cleaner and perform ultrasonic treatment for 30 minutes with the ultrasonic power set at 260W to form a stable suspension;

[0012] S3. Dissolve surfactants: Select appropriate surfactants for compounding according to the determined HLB value;

[0013]

[0014] where HLB A and HLB B are the HLB values of Span-80 and Tween-60 respectively, and m A and m B are the masses of Span-80 and Tween-60;

[0015] S4. Mix the surfactant with the nano-silica suspension: Slowly pour the ultrasonically dispersed nano-silica suspension into the transparent solution prepared in S3, and at the same time start high-speed stirring to form a surfactant-nano-silica complex;

[0016] S5. Add polymer and some additives: After forming the surfactant-nano-silica complex, add the pre-weighed polymer to the complex and continue stirring for 20 minutes. Then, add antioxidants, preservatives and some pH regulators and stir for 15 minutes;

[0017] S6. Microcapsule embedding to obtain a microcapsule suspension;

[0018] S7. After the microcapsule suspension is formed, slowly add the pre-weighed thickener to the suspension and stir for 30 minutes;

[0019] S8. Remove the excess solvent by spray drying or freeze drying to obtain a microencapsulated lipophilic emulsifier loaded with surfactant.

[0020] Preferably, in S2, the mass-volume ratio of nano-silica particles to absolute ethanol is 1:15.

[0021] Preferably, in S3, it also includes:

[0022] Add accurately weighed Span-80 and Tween-60 to an appropriate amount of organic solvent, stir evenly to form a clear and transparent solution, where the amount of organic solvent used is 10 times the total mass of the surfactants, and the organic solvent used is cyclohexane.

[0023] Preferably, in S4, the stirring speed is set at 1000 - 1500 r / min and the stirring time is 30 minutes.

[0024] Preferably, in S5, the polymer is polyvinyl alcohol, the antioxidant is butylated hydroxyanisole and vitamin E, and the preservative is sodium benzoate.

[0025] Preferably, in S6, the specific steps of microcapsule embedding are as follows:

[0026] S6-1. Prepare the wall material solution: Select gelatin as the wall material, weigh an appropriate amount of gelatin and add it to deionized water. The mass ratio of gelatin to deionized water is 2:50. Heat and stir in a water bath at 50°C to form a uniform wall material solution, and control the stirring speed at 200-300 r / min;

[0027] S6-2. Microcapsule formation: Slowly drop the prepared wall material solution into the mixture containing the surfactant-nanosilica complex, control the dropping speed at 1.5 mL / min. After dropping, continue to stir for 30-60 minutes, and keep the stirring speed at 800-1000 r / min. At the same time, adjust the temperature and pH value. During this process, the conformation of gelatin molecules changes under the action of temperature and pH value, and gradually aggregates around the surfactant-nanosilica complex to form microcapsules by encapsulation.

[0028] Preferably, in S6-2, lower the temperature to 40°C, and then slowly adjust the pH value to 4.5 with dilute hydrochloric acid or dilute sodium hydroxide solution.

[0029] Preferably, in S7, xanthan gum is selected as the thickener.

[0030] Preferably, in S8, it further includes:

[0031] S8-1. Spray drying: Transport the microcapsule suspension to the spray dryer through a peristaltic pump, set the inlet air temperature at 150°C, control the outlet air temperature at 90°C, and the atomization pressure at 2.7 bar;

[0032] S8-2. Freeze drying: First, pre-freeze the microcapsule suspension to about -40°C and keep it for 2-3 hours, and then put it into the freeze dryer for drying under the condition that the vacuum degree is lower than 10 Pa.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] 1. The present invention enhances the strength of the emulsion interfacial film through micro-nano carriers, and enables emulsifier molecules to adhere to the surface or inside of the micro-nano carriers through physical adsorption or chemical bonding, increasing the dispersibility and stability of the emulsifier in the oil phase, improving its emulsification effect. The microcapsule embedding method provides a physical barrier and combines with an appropriate HLB value to ensure the stable existence of the emulsifier at the oil-water interface, enabling the emulsion to remain stable under conditions such as centrifugation and storage at different temperatures, and not easily stratifying or demulsifying.

[0035] 2. The present invention regulates the HLB value by precisely calculating and selecting surfactant combinations to meet the emulsification requirements of different oil phases and improve the versatility of the emulsifier.

[0036] 3. The present invention promotes the adsorption of the emulsifier at the oil-water interface through the high specific surface area of the micro-nano carriers, reduces the surface tension, enables the oil phase to be evenly dispersed into small-sized oil droplets, and enhances the emulsification effect.

[0037] 4. The present invention forms a firm adsorption layer at the oil-water interface through the long-chain molecular structure of the polymer, hindering the mutual aggregation between droplets, thereby enhancing the physical stability of the emulsion. Due to its specific solubility and molecular weight, it can provide the necessary steric hindrance effect in the continuous phase, and further prevent the emulsion from breaking. Specific Embodiments

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0039] Example 1:

[0040] The preparation method of the highly stable lipophilic emulsifier is as follows:

[0041] S1. Material preparation: including surfactants, nano carriers, wall materials, organic solvents, polymers, and additives. Among them, natural oils are selected, Span-80 and Tween-60 are selected as surfactants, nano-silica particles are selected as nano carriers, and antioxidants, preservatives, thickeners, and pH regulators are used as additives;

[0042] S2. Micro-nano carrier treatment: Weigh nano-silica particles and add them to an appropriate amount of absolute ethanol, then place the mixture in an ultrasonic cleaner and perform ultrasonic treatment for 30 minutes with the ultrasonic power set at 260W to form a stable suspension. The mass-volume ratio of nano-silica particles to absolute ethanol is 1:15;

[0043] S3. Dissolve the surfactant: Select appropriate surfactants for compounding according to the determined HLB value;

[0044]

[0045] where HLB A and HLB B are the HLB values of Span-80 and Tween-60 respectively, and m A and m B are the masses of Span-80 and Tween-60;

[0046] Add accurately weighed Span-80 and Tween-60 to an appropriate amount of organic solvent, stir evenly to form a clear and transparent solution. The dosage of the organic solvent is 10 times the total mass of the surfactant, and the organic solvent used is cyclohexane;

[0047] S4. Mix the surfactant with the nano-silica suspension: Slowly pour the ultrasonically dispersed nano-silica suspension into the transparent solution prepared in S3, and at the same time start high-speed stirring to form a surfactant-nano-silica complex, where the stirring speed is 1000 - 1500 r / min and the stirring time is 30 minutes;

[0048] S5. Add the polymer and some additives: After forming the surfactant-nano-silica complex, add the pre-weighed polyvinyl alcohol to the complex and continue stirring for 20 minutes, then add butylated hydroxyanisole, vitamin E, sodium benzoate and some pH regulators;

[0049] S6. Microencapsulation to obtain a microcapsule suspension;

[0050] In S6, the specific steps of microencapsulation are as follows:

[0051] S6-1. Prepare the wall material solution: Select gelatin as the wall material, weigh an appropriate amount of gelatin and add it to deionized water. The mass ratio of gelatin to deionized water is 2:50. Heat and stir in a water bath at 50 °C to form a uniform wall material solution, and control the stirring speed at 200 - 300 r / min;

[0052] S6-2, Microcapsule formation: Slowly drop the prepared wall material solution into the mixture containing the surfactant-nano silica complex at a dropping rate of 1.5 mL / min. After the dropping is completed, continue stirring for 30 - 60 minutes, and keep the stirring speed at 800 - 1000 r / min. Meanwhile, adjust the temperature and pH value. Lower the temperature to 40 °C, and then slowly adjust the pH value to 4.5 with dilute hydrochloric acid or dilute sodium hydroxide solution. During this process, the conformation of gelatin molecules changes under the action of temperature and pH value, and gradually aggregates around the surfactant-nano silica complex to form microcapsules by encapsulation.

[0053] S7. After the microcapsule suspension is formed, slowly add the pre-weighed thickener to the suspension and stir for 30 minutes. The thickener selected is xanthan gum;

[0054] S8. Remove the excess solvent by spray drying or freeze drying to obtain the microencapsulated lipophilic emulsifier loaded with surfactant. Spray drying: Transport the microcapsule suspension to the spray dryer through a peristaltic pump, set the inlet air temperature to 150 °C, control the outlet air temperature at 90 °C, and the atomization pressure is 2.7 bar;

[0055] Freeze drying: First, pre-freeze the microcapsule suspension to about -40 °C and keep it for 2 - 3 hours, then put it into the freeze dryer and dry it under the condition that the vacuum degree is lower than 10 Pa.

[0056] Furthermore, in S2, the nano silica particles have a high specific surface area and good chemical stability and can be used as carriers. Prepare an appropriate amount of nano-sized silica particles to ensure that their purity and particle size meet the requirements. Generally, the particle size can be selected between 50 - 200 nm to ensure the performance of the carrier. Combine with the surfactant in the subsequent steps to improve the performance of the emulsifier. It is mixed with absolute ethanol at a mass-volume ratio of 1:15, and ultrasonic treatment can make it uniformly dispersed in ethanol to form a stable suspension, providing a good dispersion basis for the subsequent combination with the surfactant.

[0057] S3. Span-80 is a non-ionic surfactant with strong lipophilicity and a low HLB value, which can effectively reduce the surface tension of the oil phase and make it more easily dispersed. Tween-60 has a certain hydrophilicity. By compounding the two, the overall hydrophilic-lipophilic balance value can be adjusted to meet the emulsification requirements of different oil phases.

[0058] Different HLB values are applicable to different types of oil phases, and its calculation formula is:

[0059]

[0060] The desired HLB value can be obtained by compounding with an exact mass ratio. For lipophilic emulsifiers, the appropriate HLB value range is usually between 3 and 6. Span-80 with an HLB value of 4.3 and Tween-60 with an HLB value of 14.9 are selected and compounded in a certain proportion. After calculation, when the mass ratio of Span-80 to Tween-60 is about 7:3, the HLB value of the mixed surfactant is about 5.6, meeting the requirements of lipophilic emulsification.

[0061] The accurately weighed Span-80 and Tween-60 are added to an appropriate amount of organic solvent cyclohexane. The amount of the organic solvent should be sufficient to completely dissolve the surfactant, and generally, it can be added at 10 times the total mass of the surfactant. For example, 10 g of surfactant is added to 100 mL of cyclohexane and stirred at a stirring speed of 300 - 500 r / min to fully dissolve the surfactant in cyclohexane, forming a clear and transparent solution.

[0062] S4. The ultrasonically dispersed nano-silica suspension is slowly poured into the cyclohexane solution containing the surfactant, and at the same time, high-speed stirring is started. The stirring speed is set at 1000 - 1500 r / min and stirred continuously for 30 minutes. During this process, the nano-silica particles interact with the surfactant molecules by virtue of their high specific surface area, and the surfactant molecules gradually adsorb on the surface of the nano-silica particles, forming a surfactant-nano-silica complex.

[0063] S5. Polyvinyl alcohol has good hydrophilicity and viscosity and can form a stable network structure in the emulsion to improve the stability of the emulsion. The antioxidants can be butylated hydroxyanisole and vitamin E. These antioxidants can prevent the oil phase in the emulsifier from being oxidized during storage and use, extending the shelf life of the emulsifier. Sodium benzoate can inhibit the growth and reproduction of microorganisms, ensuring the quality and safety of the emulsifier. The pH regulator can be hydrochloric acid, sodium hydroxide, or citric acid, etc. The pH regulator is used to adjust the pH value of the system, providing a suitable pH environment for the formation of microcapsules, ensuring that the wall material can successfully aggregate to form a microcapsule structure during the microencapsulation process, and also helping to maintain the stability of the emulsifier in different application scenarios. The specific addition amount depends on the actual pH adjustment requirements.

[0064] S6. Gelatin, as the wall material, has good biocompatibility and film-forming properties and is used in the microencapsulation step. Under certain conditions, it can aggregate around the surfactant-nano-silica complex to form microcapsules, providing physical protection and stability;

[0065] Weigh 2 g of gelatin and add it to 50 mL of deionized water. Place it in a water bath at 50 °C and heat. During the heating process, stir at a stirring speed of 200 - 300 r / min to fully dissolve the gelatin and form a uniform wall material solution. The stirring time is about 20 - 30 minutes to ensure that the gelatin is completely dissolved without caking.

[0066] Microcapsule formation: Slowly drip the prepared wall material solution into a mixture containing a surfactant-nanosilica complex, a polymer, and some additives at a rate of 1.5 mL / min. After the dripping is complete, continue to stir for 30 - 60 minutes, and keep the stirring speed at 800 - 1000 r / min. At the same time, lower the temperature to 40 °C. Select according to the system pH value. For example, slowly adjust the pH value to 4.5 using dilute hydrochloric acid or dilute sodium hydroxide solution. During this process, the gelatin molecules undergo conformational changes under the action of temperature and pH value, and gradually aggregate around the surfactant-nanosilica complex to form a microcapsule suspension by encapsulation. During the microcapsule formation process, the remaining pH regulator can be added in a timely manner according to the actual situation to precisely adjust the pH value and ensure the formation effect of the microcapsules.

[0067] S7. Yellow gelatin is used to increase the viscosity of the emulsion, improve stability, prevent oil droplets from aggregating and separating due to factors such as gravity or Brownian motion, and enhance the stability of the emulsion;

[0068] After the microcapsule suspension is formed, slowly add the pre-weighed thickener to the suspension and stir for 30 minutes to fully dissolve the thickener and evenly disperse it in the system. The addition of the thickener can further adjust the viscosity of the emulsion and improve the stability of the emulsifier. After adding the thickener, check the pH value of the system again. If necessary, continue to use the pH regulator for fine-tuning to ensure that the pH value of the system is within a suitable range to meet the performance requirements of the emulsifier.

[0069] S8. Spray drying: Transport the adjusted microcapsule suspension to a spray dryer through a peristaltic pump. Set the inlet air temperature to 150 °C, the outlet air temperature to 90 °C, and the atomization pressure to 2.7 bar. During the spray drying process, the microcapsule suspension is atomized into tiny droplets, and under the action of hot air, the solvent rapidly evaporates to obtain a microencapsulated lipophilic emulsifier powder loaded with a surfactant.

[0070] Freeze drying: First, pre-freeze the microcapsule suspension to -40 °C and hold for 3 hours. Then place the pre-frozen suspension in a freeze dryer and dry it under a vacuum of less than 10 Pa for 11 - 23 hours. During the freeze drying process, the water directly sublimes from the solid state to the gaseous state, and a microencapsulated lipophilic emulsifier solid loaded with a surfactant is obtained after removing the solvent.

[0071] Product Packaging and Storage: Collect the microencapsulated lipophilic emulsifier powder or solid obtained by spray drying or freeze drying, and pack it into a sealed container, such as a glass bottle or an aluminum foil bag. Place the packaged product in a dry and cool environment for storage, avoiding direct sunlight and high temperature and humid environment to ensure the stability and performance of the emulsifier.

[0072] Comparative Example 1,

[0073] Without adding nano-silica particles, and the remaining steps are the same as those in Example 1.

[0074] Comparative Example 2,

[0075] Do not select surfactant as one of the emulsifier raw materials, and instead use natural oil as one of the raw materials. The remaining steps are the same as those in Example 1.

[0076] Comparative Example 3,

[0077] Without adding polymer, and the remaining steps are the same as those in Example 1.

[0078] Comparative Example 4,

[0079] Without microencapsulation, and the remaining steps are the same as those in Example 1.

[0080] Experimental Example

[0081] Mix the emulsifiers prepared in Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4 with vegetable oil and water in a mass ratio of 1:4:5, and homogenize them at a speed of 10000 r / min for 5 minutes in a high-speed homogenizer to prepare an emulsion.

[0082] Centrifugal Stability: Take 50 mL of the emulsion and place it in a centrifuge tube, denoted as Sample 1, Sample 2, Sample 3, Sample 4 and Sample 5 in turn, and centrifuge it at a speed of 3000 r / min for 30 minutes.

[0083] After centrifugation, carefully take out the centrifuge tube and observe whether the emulsion is stratified. It can be observed from the naked eye whether the upper and lower interfaces of the emulsion are clear, whether there is obvious oil phase aggregation on the upper or lower layer. If the emulsion still remains uniform and there is no obvious oil-water stratification interface, it indicates that the emulsion has good centrifugal stability.

[0084]

[0085] Thermal Stability: Place the emulsion in a constant temperature environment of 4°C, 25°C and 50°C for one month respectively, and observe the stratification and demulsification conditions and time. The storage experiments at different temperatures can evaluate the stability of the emulsifier at different ambient temperatures, and can understand the stability of the emulsion under different temperature conditions. If the emulsion does not show stratification and demulsification phenomena for a long time, it indicates that the emulsifier has good thermal stability at the corresponding temperature.

[0086] Equal amounts of the emulsions prepared in Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4 were respectively dispensed into multiple sealed containers, and these containers were respectively placed in a constant temperature incubator at 4°C, 25°C, and 50°C. Timing was started. During storage, the appearance of the emulsion was observed at regular intervals to check for phenomena such as stratification, demulsification, oil droplet floating, or precipitation, and the time when these unstable phenomena first occurred was recorded.

[0087]

[0088]

[0089] HLB value verification: Using the cloud point method, the emulsifiers prepared in the examples, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4 were labeled as Sample 1, Sample 2, Sample 3, Sample 4, and Sample 5. Then, each sample was respectively prepared into aqueous solutions with concentrations of 0.1%, 0.5%, and 1%, and stirred evenly on a magnetic stirrer to ensure that the emulsifier was fully dissolved. The solution was placed in a heating jacket, a thermometer was inserted, and the solution was slowly heated while stirring. The heating rate was controlled at 1°C / min. The state of the solution was carefully observed. When the solution started to become turbid from the clear state, the temperature at this time was recorded, which was the cloud point.

[0090] Then, according to the known cloud point - HLB value relationship curve or empirical formula, the measured cloud point was converted into the corresponding HLB value.

[0091]

[0092]

[0093] Particle size analysis: Using a laser particle size analyzer to measure the oil droplet particle size, the average particle size and particle size distribution information of the oil droplets can be obtained. A smaller and more uniform particle size distribution indicates that the emulsifier has a good emulsifying effect, can disperse the oil phase into smaller and more uniform oil droplets, and helps to form a stable emulsion.

[0094] Operating procedure: Dilute multiple groups of the prepared emulsions by 30 times, and label them as Sample 1, Sample 2, Sample 3, Sample 4, and Sample 5 in sequence. Then, inject the diluted emulsions into the sample cell of the laser particle size analyzer, and according to the operation instructions of the instrument, start the measurement program, and record the average particle size and particle size distribution data of the oil droplets in the emulsion.

[0095]

[0096] Surface tension test: A lower surface tension indicates that the emulsifier can effectively reduce the energy at the oil - water interface, which is beneficial to the formation and stability of the emulsion.

[0097] Add the emulsifier prepared in Example 1 to the oil-water system. Then, immerse the ring or pendant drop probe of the surface tensiometer into the oil-water system containing the emulsifier, ensuring that the ring or probe is clean and free of bubbles. According to the operation instructions of the surface tensiometer, measure the surface tension of the oil-water interface, record the measurement results, and repeat the above steps with the emulsifiers prepared in Comparative Examples 1 to 4, measure the surface tension of the oil-water interface, and compare it with Example 1.

[0098] Sample Surface tension (mN / m) Example 1 25 Comparative Example 1 32 Comparative Example 2 45 (Due to the instability of the emulsion, the measured values fluctuate greatly) Comparative Example 3 30 Comparative Example 4 35

[0099] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

Claims

1. A method for preparing a high-stability lipophilic emulsifier, characterized in that: The preparation method is as follows: S1. Material preparation: including surfactants, nanocarriers, wall materials, organic solvents, high molecular polymers and additives, among which natural oils are selected, Span-80 and Tween-60 are selected as surfactants, nano-silica particles are selected as nanocarriers, and antioxidants, preservatives, thickeners and pH regulators are selected as additives; S2. Micro-nano carrier treatment: Weigh nano-silica particles and add them to an appropriate amount of anhydrous ethanol, then place the mixture in an ultrasonic cleaner and perform ultrasonic treatment for 30 minutes with the ultrasonic power set to 260 W to form a stable suspension; S3, dissolving surfactant: according to the determined HLB value, select the appropriate surfactant for compounding; Among them HLB A , HLB B are the HLB values ​​of Span-80 and Tween-60, respectively. A 、m B The quality of Span-80 and Tween-60; S4, mixing surfactant and nano-silica suspension: slowly pour the nano-silica suspension dispersed by ultrasound into the transparent solution prepared in S3, while starting high-speed stirring to form a surfactant-nano-silica composite; S5, adding high molecular polymer and some additives: after the surfactant-nanosilica composite is formed, the high molecular polymer weighed in advance is added to the composite and stirred for 20 minutes, then, an antioxidant, a preservative and some pH regulator are added and stirred for 15 minutes; S6, microcapsule embedding to obtain a microcapsule suspension; S7. After the microcapsule suspension is formed, slowly add the pre-weighed thickener into the suspension and stir for 30 minutes; S8. Remove excess solvent by spray drying or freeze drying to obtain a microencapsulated lipophilic emulsifier loaded with a surfactant.

2. The method for preparing a high-stability lipophilic emulsifier according to claim 1, characterized in that: In S2, the mass volume ratio of nano-silica particles to anhydrous ethanol is 1:

15.

3. The method for preparing a high-stability lipophilic emulsifier according to claim 1, characterized in that: In S3, it also includes: Accurately weighed Span-80 and Tween-60 are added to an appropriate amount of organic solvent and stirred evenly to form a clear and transparent solution, wherein the amount of the organic solvent used is 10 times the total mass of the surfactant, and the organic solvent used is cyclohexane.

4. The method for preparing a high-stability lipophilic emulsifier according to claim 1, characterized in that: In S4, the stirring speed is set to 1000-1500 r / min, and the stirring time is 30 minutes.

5. The method for preparing a high-stability lipophilic emulsifier according to claim 1, characterized in that: In S5, the high molecular polymer is polyvinyl alcohol, the antioxidants are butylated hydroxyanisole and vitamin E, and the preservative is sodium benzoate.

6. The method for preparing a high-stability lipophilic emulsifier according to claim 1, characterized in that: In S6, the specific steps of microcapsule embedding are as follows: S6-1. Prepare a wall material solution: select gelatin as the wall material, weigh an appropriate amount of gelatin and add it to deionized water, the mass ratio of gelatin to deionized water is 2:50, heat and stir in a 50°C water bath to form a uniform wall material solution, and control the stirring speed at 200-300 r / min; S6-2. Microcapsule formation: slowly add the prepared wall material solution to the mixed solution containing the surfactant-nano-silica complex, and control the dropping speed at 1.5 mL / min. After the dropping is completed, continue stirring for 30-60 minutes, and keep the stirring speed at 800-1000 r / min. At the same time, adjust the temperature and pH value. In this process, the gelatin molecules undergo conformational changes under the influence of temperature and pH value, and gradually condense around the surfactant-nano-silica complex to wrap and form microcapsules.

7. The method for preparing a high-stability lipophilic emulsifier according to claim 1, characterized in that: In S6-2, the temperature is lowered to 40°C, and then the pH value is slowly adjusted to 4.5 with dilute hydrochloric acid or dilute sodium hydroxide solution.

8. The method for preparing a high-stability lipophilic emulsifier according to claim 1, characterized in that: In S7, xanthan gum is used as the thickener.

9. The method for preparing a high-stability lipophilic emulsifier according to claim 1, characterized in that: In S8, it also includes: S8-1, spray drying: the microcapsule suspension is transported to the spray dryer through a peristaltic pump, the inlet air temperature is set to 150°C, the outlet air temperature is controlled at 90°C, and the atomization pressure is 2.7 bar; S8-2, freeze drying, first pre-freeze the microcapsule suspension to about -40°C, keep it for 2-3 hours, then put it into a freeze dryer and dry it under the condition of vacuum degree less than 10Pa.

10. A high-stability lipophilic emulsifier prepared by the method for preparing a high-stability lipophilic emulsifier according to any one of claims 1 to 9.

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