Water-in-water dual emulsion with three-phase system as well as preparation method and application of water-in-water dual emulsion

Abstract

The invention belongs to the technical field of emulsion production and preparation, and particularly relates to a water-in-water dual emulsion with a three-phase system and a preparation method and application thereof. The method comprises the following steps: mixing aqueous solutions of three polymer systems to obtain a mixed solution with a three-phase system, taking the phase with the smallest volume as a first inner water phase, taking the phase with the smaller volume as a second inner water phase, and taking the phase with the largest volume as an outer water phase; and then emulsifying the mixed solution to obtain the water-in-water double emulsion with the first inner water phase and the second inner water phase wrapped by the outer water phase in one step, and the preparation method has the advantages of simplicity, feasibility, low operation difficulty, low production cost, high benefit and the like, and is suitable for batch production. In addition, the water-in-water dual emulsion constructed by the invention is good in stability and controllable in particle size, and has wide application prospects in the fields of substance purification and separation, 3D cell culture, tissue engineering, delivery carrier application or preparation and the like.

Description

Technical Field

[0001] This application belongs to the technical field of emulsion production and preparation. More specifically, it relates to a water-in-water double emulsion with a three-phase system, its preparation method and application. Background Art

[0002] An emulsion is a colloidal system composed of two thermodynamically incompatible phases, where the dispersed phase is distributed in the other phase in the form of droplets. Through the action of stabilizers (particles, surfactants), the structure of emulsion droplets is maintained. Due to its unique physical and chemical properties, emulsions play an important role as delivery carriers for active components in many fields such as food, medicine, and cosmetics. In recent years, with the in-depth study of the structure and function of emulsions, multiple emulsions have received extensive attention due to their special multi-phase structure.

[0003] Currently, common double emulsions include oil-in-water-in-oil (O / W / O), water-in-oil-in-water (W / O / W), and oil-in-water-in-water (O / W / W) emulsions. However, these emulsions have two oil-water interfaces, and the osmotic pressures of the solutions inside and outside the two interfaces are different, resulting in easy demulsification of multiple emulsions and difficulty in stable construction, which limits their application in industry. As a double emulsion, the water-in-water double (W / W / W) emulsion is a fully aqueous phase system, and there is no osmotic pressure difference inside and outside the two interfaces, which can reduce the occurrence of emulsion instability. However, the microstructure of the water-in-water double emulsion is complex, and special polymer polymers need to be introduced or strict preparation conditions are required to construct a stable water-in-water double emulsion. For example, patent document CN113499697A prepares a water-in-water double monodisperse double emulsion through a microfluidic device, and the literature (Mytnyk et al., RSC Advances, 2017, 7, 11331) prepares a water-in-water double emulsion through a polydimethylsiloxane (PDMS) device. However, the above preparation methods all have problems such as difficult collection and storage, complex and expensive devices, and the need to design special channels, making it difficult to mass-produce. Summary of the Invention

[0004] Aiming at the defects of the prior art, the purpose of this application is to provide a water-in-water double emulsion with a three-phase system, its preparation method and application, aiming to solve the problems of poor stability, difficult preparation, and difficulty in mass production of existing double emulsions.

[0005] To achieve the above purpose, in the first aspect, this application provides a preparation method for a water-in-water double emulsion with a three-phase system, including the following steps: S1. Mix the aqueous solutions of the first polymer system, the second polymer system, and the third polymer system to obtain a mixed solution with a three-phase system, where the phase with the smallest volume is used as the first internal water phase, the phase with the smaller volume is used as the second internal water phase, and the phase with the largest volume is used as the external water phase; Each of the above-mentioned first polymer system, the second polymer system, and the third polymer system independently contains one or more water-soluble polymers, wherein the water-soluble polymer in the first polymer system is a polyol; The absolute value of the difference between the solubility parameter of the water-soluble polymer contained in the second polymer system or the water-soluble polymer contained in the third polymer system with respect to water and the solubility parameter of the polyol with respect to water is greater than 0.5 (Cal / cm 3 ) 0.5 ; the absolute value of the difference between the solubility parameter of the water-soluble polymer contained in the second polymer system with respect to water and the solubility parameter of the water-soluble polymer contained in the third polymer system with respect to water is greater than 0.5 (Cal / cm 3 ) 0.5 ; and the volume ratio of the aqueous solution of the first polymer system to the aqueous solution of the second polymer system is 1:(1~30), and the volume ratio of the total volume of the aqueous solutions of the first polymer system and the second polymer system to the aqueous solution of the third polymer system is (1~2):2; S2. Emulsify the above-mentioned mixed solution to obtain a water-in-water double emulsion in which the above-mentioned outer aqueous phase encapsulates the above-mentioned first inner aqueous phase and the above-mentioned second inner aqueous phase.

[0006] Preferably, in step S1, the mass percentage of the polyol in the aqueous solution of the first polymer system is 2wt%~20wt%, the mass percentage of the water-soluble polymer in the aqueous solution of the second polymer system is 2wt%~20wt%, and the mass percentage of the water-soluble polymer in the aqueous solution of the third polymer system is 2wt%~20wt%.

[0007] Preferably, the above-mentioned water-soluble polymer is selected from water-soluble synthetic macromolecules, water-soluble natural polysaccharides, and water-soluble proteins.

[0008] More preferably, the above-mentioned water-soluble synthetic macromolecule polymer is one or more of hydroxypropyl methylcellulose, cationic hydroxyethyl cellulose, polyol, and polyethylene oxide; the above-mentioned water-soluble natural polysaccharide is one or more of starch, pullulan, dextran, chitosan, agarose, konjac glucomannan, dextrin, carrageenan, and guar gum; the above-mentioned water-soluble protein is one or more of gelatin, collagen, and casein.

[0009] Preferably, the above-mentioned polyol is one or more of polyethylene glycol, glycerol, and dibutyl alcohol.

[0010] Preferably, in step S2, the temperature of the above-mentioned emulsification treatment is 10 °C~60 °C.

[0011] Preferably, in step S2, the emulsification treatment method is mechanical stirring emulsification or membrane emulsification.

[0012] Preferably, the rotation speed of the mechanical stirring emulsification is 300 r / min to 5000 r / min, and the time is 20 min to 60 min.

[0013] In a second aspect, the present application provides a water-in-water double emulsion with a three-phase system prepared by the above preparation method.

[0014] In a third aspect, the present application provides the application of the above water-in-water double emulsion with a three-phase system in material purification and separation, cell culture, tissue engineering, and as a delivery carrier or for preparing a delivery carrier.

[0015] In a fourth aspect, the present application provides a water-in-water double Pickering emulsion, which is obtained by emulsifying a mixture of a particle stabilizer and the above water-in-water double emulsion with a three-phase system.

[0016] Preferably, the above particle stabilizer is a water-insoluble micro-nano particle, which is one or more of inorganic nano-particles, organic nano-particles, and composite nano-particles.

[0017] Preferably, the dosage of the above particle stabilizer is 0.01 wt% to 3 wt% of the total mass of the above water-in-water double emulsion.

[0018] Generally speaking, compared with the prior art by the above technical solutions conceived by the present application, the following technical advantages are mainly achieved: (1) The present application provides a preparation method of a water-in-water ((W1 + W2) / W3) double emulsion with a three-phase system. By mixing aqueous solutions of three polymer systems to obtain a mixed solution with a three-phase system, the phase with the smallest volume is used as the first inner water phase, the phase with a smaller volume is used as the second inner water phase, and the phase with the largest volume is used as the outer water phase; then the above mixed solution is subjected to emulsification treatment, and a water-in-water double emulsion in which the outer water phase encapsulates the first inner water phase and the second inner water phase can be obtained in one step. The preparation method provided by the present application does not require complex equipment or strict operating conditions, and emulsification can be achieved only through mechanical stirring or a microporous membrane. It has the advantages of simple and easy preparation method, low operation difficulty, low production cost, high efficiency, etc., and is suitable for batch production.

[0019] (2) By regulating the types and concentrations of water-soluble polymers used in the three polymer systems, the volume ratio between the polymer systems, and the parameters of the emulsification treatment, etc., the present application can regulate the particle size of the water-in-water ((W1 + W2) / W3) double emulsion, improve the overall stability of the emulsion, and construct a stable water-in-water ((W1 + W2) / W3) double emulsion.

[0020] (3) The water-in-water ((W1+W2) / W3) double emulsion with a three-phase system prepared in this application is an all-aqueous phase system, which has excellent biocompatibility and non-toxicity. In addition, the water-in-water double emulsion constructed in this application has good stability and the particle size of the emulsion can be controlled, and it has broad application prospects in the fields of material purification and separation, 3D cell culture, tissue engineering, being used as or preparing a delivery carrier, etc.

[0021] (4) The water-in-water ((W1+W2) / W3) double emulsion provided in this application has three immiscible aqueous phases. In practical applications, according to different product requirements, quality standards and production scales, the performance of each aqueous phase can be regulated by regulating the types of water-soluble polymers used in the outer aqueous phase, the first inner aqueous phase and the second inner aqueous phase. In addition, the water-in-water ((W1+W2) / W3) double emulsion provided in this application is expected to produce more phase separations, so as to form an emulsion with a more complex structure, and is expected to be used for the co-embedding and delivery of various functional substances. Description of the Drawings

[0022] Figure 1 is the macroscopic phase separation diagram of the mixed solution prepared in Example 1 of this application using HPMC aqueous solution, DEX aqueous solution, PEG aqueous solution and MD aqueous solution with different volume ratios; Figure 2 is the macroscopic phase separation diagram of the mixed solution prepared in Example 2 of this application using HPMC aqueous solution, PEO aqueous solution, PEG aqueous solution and MD aqueous solution with different volume ratios; Figure 3 is the macroscopic phase separation diagram of the mixed solution prepared in Example 3 of this application using HPMC aqueous solution, Agarose aqueous solution, PEG aqueous solution and MD aqueous solution with different volume ratios; Figure 4 is the optical microscope diagram of the emulsion prepared by emulsifying the mixture of HPMC aqueous solution, DEX aqueous solution, PEG aqueous solution and MD aqueous solution in Example 4 of this application; Figure 5 is the macroscopic phase separation diagram of the mixed solution prepared in Example 6 of this application using HPMC aqueous solution, Agarose aqueous solution, PEG aqueous solution and MD aqueous solution and the optical microscope diagram of the emulsified emulsion, where content a is the macroscopic diagram of the mixed solution and content b is the optical microscope diagram of the emulsified emulsion; Figure 6 is the macroscopic phase separation diagram of the mixed solution prepared in Example 7 of this application using HPMC aqueous solution, Gelatin aqueous solution, PEG aqueous solution and MD aqueous solution and the optical microscope diagram of the emulsified emulsion, where content a is the macroscopic diagram of the mixed solution and content b is the optical microscope diagram of the emulsified emulsion; Figure 7It is the macroscopic phase separation diagram of the mixed solution prepared with HPMC aqueous solution, MC aqueous solution, PEG aqueous solution and MD aqueous solution in Example 8 of the present application, as well as the optical microscope diagram of the emulsion prepared by emulsification. Among them, content a is the macroscopic phase separation diagram of the mixed solution, and content b is the optical microscope diagram of the emulsion prepared by emulsification; Figure 8 It is the macroscopic phase separation diagram of the mixed solution prepared with HPMC aqueous solution, HEC aqueous solution, PEG aqueous solution and MD aqueous solution in Example 9 of the present application, as well as the optical microscope diagram of the emulsion prepared by emulsification. Among them, content a is the macroscopic phase separation diagram of the mixed solution, and content b is the optical microscope diagram of the emulsion prepared by emulsification; Figure 9 It is the macroscopic diagram of the mixed solution prepared with HPMC aqueous solution, Gelatin aqueous solution and MD aqueous solution in Comparative Example 3 of the present application, as well as the optical microscope diagram of the emulsion prepared by emulsification. Among them, content a is the macroscopic diagram of the mixed solution, and content b is the optical microscope diagram of the emulsion prepared by emulsification; Figure 10 It is the macroscopic diagram of the mixed solution prepared with HPMC aqueous solution, HEC aqueous solution and MD aqueous solution in Comparative Example 4 of the present application, as well as the optical microscope diagram of the emulsion prepared by emulsification. Among them, content a is the macroscopic diagram of the mixed solution, and content b is the optical microscope diagram of the emulsion prepared by emulsification; Figure 11 It is the optical microscope diagram of the water-in-water double Pickering emulsion prepared in Example 10 of the present application. Detailed implementation manners

[0023] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0024] In the description of the specification and claims of the present application, terms such as "first", "second" and "third" are used to distinguish different objects, rather than to describe the specific order of the objects, and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features.

[0025] In the description of the embodiments of the present application, words such as "exemplary" or "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Exactly speaking, the use of words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner.

[0026] In the description of the embodiments of the present application, unless otherwise specified, the meaning of "a plurality" refers to two or more.

[0027] Existing double emulsions for delivering multiple functional substances, such as water-in-water-in-water emulsions, facilitate the generation of water-in-water-in-water emulsions by means of improvements in the preparation device. However, this preparation method has deficiencies such as difficult collection and storage, complex and expensive devices, and the need to design special channels, making it difficult to generate in batches. Based on this, the present application provides a water-in-water ((W1 + W2) / W3) double emulsion with a unique three-phase structure and its preparation method, which can simply and conveniently construct a stable water-in-water double emulsion. By dissolving functional substances with different solubility properties in different aqueous phases respectively, the co-encapsulation and delivery of multiple functional substances can be achieved, which is of great significance for realizing the co-encapsulation and delivery of multiple functional substances.

[0028] The present application provides a preparation method for a water-in-water ((W1 + W2) + W3) double emulsion with a three-phase system, comprising the following steps: S1. Mix an aqueous solution of a first polymer system, an aqueous solution of a second polymer system, and an aqueous solution of a third polymer system to obtain a mixed solution with a three-phase system, wherein the phase with the smallest volume serves as the first internal aqueous phase (i.e., W1), the phase with a smaller volume serves as the second internal aqueous phase (i.e., W2), and the phase with the largest volume serves as the external aqueous phase (i.e., W3); Each of the above-mentioned first polymer system, the above-mentioned second polymer system, and the above-mentioned third polymer system independently contains one or more water-soluble polymers, and the water-soluble polymer contained in the first polymer system is a polyol; The absolute value of the difference between the solubility parameter of the water-soluble polymer contained in the above-mentioned second polymer system or the water-soluble polymer contained in the above-mentioned third polymer system with respect to water and the solubility parameter of the above-mentioned polyol with respect to water is greater than 0.5 (Cal / cm 3 ) 0.5 ; the absolute value of the difference between the solubility parameter of the water-soluble polymer contained in the above-mentioned second polymer system with respect to water and the solubility parameter of the water-soluble polymer contained in the above-mentioned third polymer system with respect to water is greater than 0.5 (Cal / cm 3 ) 0.5 ; and the volume ratio of the aqueous solution of the first polymer system to the aqueous solution of the second polymer system is 1:(1 - 30), and the volume ratio of the total volume of the aqueous solutions of the first polymer system and the second polymer system to the aqueous solution of the third polymer system is (1 - 2):2; S2. Emulsify the above-mentioned mixed solution to obtain a water-in-water double emulsion in which the above-mentioned external aqueous phase encapsulates the above-mentioned first internal aqueous phase and the above-mentioned second internal aqueous phase.

[0029] The inventors of the present application accidentally discovered in experiments that a three-phase system can be produced by mixing an aqueous solution of polyol with an aqueous solution of other suitable water-soluble polymers in a suitable volume ratio. Further, by mixing an aqueous solution of polyol with an aqueous solution of other suitable water-soluble polymers and then performing an emulsification treatment, a double emulsion with a water-in-water ((W1 + W2) / W3) structure can be prepared, in which the outer aqueous phase (W3) encapsulates the immiscible first inner aqueous phase (W1) and second inner aqueous phase (W2).

[0030] In some embodiments, the volume ratio of the aqueous solution of the first polymer system to the aqueous solution of the second polymer system is 1:(1 to 30), preferably 1:(1.5 to 29); the volume ratio of the total volume of the aqueous solution of the first polymer system and the aqueous solution of the second polymer system to the aqueous solution of the third polymer system is (1 to 2):2. By mixing the aqueous solutions of the above three polymer systems in a suitable volume ratio, based on the different distribution ratios of water in different water-soluble polymers, that is, the water in the water-soluble polymer with weak water-holding capacity will migrate to the water-soluble polymer with strong water-holding capacity, a mixed solution with a three-phase system can be obtained.

[0031] The preparation method of the water-in-water double emulsion provided by the present application is theoretically applicable to any three water phases that are immiscible with each other and can be used to prepare a water-in-water double emulsion, namely the outer aqueous phase, the first inner aqueous phase, and the second inner aqueous phase. According to the Flory-Huggins polymer solution theory, the Huggins constant χ1, also called the polymer-solvent interaction parameter, is a quantity that characterizes the degree of interaction between solvent molecules and polymers (solvation degree), with a value between -1 and 1. When χ1 < 1 / 2, it is a good solvent; when χ1 > 1 / 2, it is a poor solvent. The solubility parameter is a parameter that characterizes the polymer-solvent interaction, where the solvent is water. The cohesive properties of a substance can be quantitatively characterized by the cohesive energy. The cohesive energy density per unit volume is called the cohesive energy density, and the square root of it is called the solubility parameter. The solubility parameter can be used as a good indicator to measure whether two materials are compatible. When the solubility parameters of two materials are similar, they can be blended with each other and have good compatibility.

[0032] The basis for preparing the water-in-water ((W1 + W2) / W3) double emulsion in the present application is the outer aqueous phase, the first inner aqueous phase, and the second inner aqueous phase that can undergo phase separation. Therefore, according to the above polymer solution theory, when the water-soluble polymers used in the present application are represented by solubility parameters, the types of polymers are selected such that the absolute value of the difference between the solubility parameter of the water-soluble polymer used in the first polymer system with respect to water and the solubility parameter of the water-soluble polymer used in the second polymer system with respect to water is greater than 0.5 (Cal / cm 3 ) 0.5; The absolute value of the difference between the solubility parameter of the water-soluble polymer used in the first polymer system with respect to water and the solubility parameter of the water-soluble polymer used in the third polymer system with respect to water is greater than 0.5 (Cal / cm 3 ) 0.5 ; The absolute value of the difference between the solubility parameter of the water-soluble polymer used in the second polymer system with respect to water and the solubility parameter of the water-soluble polymer used in the third polymer system with respect to water is greater than 0.5 (Cal / cm 3 ) 0.5 , to prepare a mixed solution with a three-phase system for preparing a stable water-in-water ((W1 + W2) / W3) double emulsion. The solubility parameters of some of the water-soluble polymers used in this application can be obtained by looking up tables, some can be preliminarily calculated according to theoretical parameters, or measured by conventional methods.

[0033] In some embodiments, each of the first polymer system, the second polymer system, and the third polymer system in this application independently contains one or more water-soluble polymers. Among them, the water-soluble polymer has the meaning of water-soluble in a broad sense. The water-soluble polymer includes polymers that dissolve quickly in water and also includes water-swellable polymers with a slow dissolution rate. When the first polymer system, the second polymer system, and the third polymer system contain multiple water-soluble polymers, the solubility parameter of the water-soluble polymer with respect to water in each system can be determined by the sum of the products of the mole percentages of the respective water-soluble polymers in the system and their corresponding solubility parameters.

[0034] It can be understood that the water-soluble polymers in this application refer to water-soluble macromolecules with a relative molecular mass ranging from several thousand to several million. In some embodiments, the water-soluble polymers are selected from water-soluble synthetic macromolecular polymers, water-soluble natural polysaccharides, and water-soluble proteins. Among them, water-soluble synthetic macromolecular polymers include, but are not limited to, hydroxypropyl methylcellulose, cationic hydroxyethylcellulose, polyols, polyethylene oxide, etc.; water-soluble natural polysaccharides include, but are not limited to, starch, pullulan, dextran, chitosan, agarose, konjac glucomannan, dextrin, carrageenan, guar gum, etc.; water-soluble proteins include, but are not limited to, gelatin, collagen, casein, etc. The above polyols include, but are not limited to, polyethylene glycol, glycerol, dibutyl alcohol, polyether polyols, etc.

[0035] In some embodiments, the water-soluble polymer selected in the above-mentioned first polymer system is a polyol, including but not limited to polyethylene glycol, glycerol, dibutyl alcohol, polyether polyols, etc.; the water-soluble polymer selected in the above-mentioned second polymer system is one or more of dextrin, pullulan, polyethylene oxide, starch, konjac glucomannan, agarose, chitosan, dextran, carrageenan, guar gum, gelatin, collagen, casein, methyl cellulose, cationic hydroxyethyl cellulose; the water-soluble polymer selected in the above-mentioned third polymer system is hydroxypropyl methyl cellulose.

[0036] Compared with water-in-water (W / W) emulsion, oil-in-water-in-oil (O / W / O) emulsion, water-in-oil-in-water (W / O / W) emulsion and oil-in-water-in-water (O / W / W) emulsion, the water-in-water ((W1 + W2) / W3) double emulsion with a three-phase system provided by the present application has more complex properties, and the concentration of the water-soluble polymer in each water phase and the volume ratio between the water phases will affect the change of the water-water interfacial tension and the stability of the water-in-water ((W1 + W2) / W3) double emulsion. In some embodiments, the mass percentage concentration of the polyol in the above-mentioned first polymer system is 2wt% - 20wt%, preferably 2wt% - 15wt%; the mass percentage concentration of the water-soluble polymer in the above-mentioned second polymer system is 2wt% - 20wt%, preferably 2wt% - 15wt%; the mass percentage concentration of the water-soluble polymer in the above-mentioned third polymer system is 2wt% - 20wt%, preferably 2wt% - 15wt%. By selecting suitable water-soluble polymers and controlling the concentration and volume ratio of the polymers in the aqueous solutions of the first polymer system, the second polymer system and the third polymer system within a suitable range, the present application can prepare a water-in-water ((W1 + W2) / W3) double emulsion with a three-phase system and regulate the particle size of the emulsion.

[0037] In some embodiments, in step S2, the temperature of the above-mentioned emulsification treatment is 10 °C - 60 °C, preferably 20 °C - 30 °C.

[0038] In some embodiments, the above-mentioned emulsification treatment method is mechanical stirring emulsification or membrane emulsification.

[0039] In some embodiments, the above emulsification treatment method is mechanical stirring emulsification. During this process, the first internal aqueous phase and the second internal aqueous phase can be dropped into the external aqueous phase, or the first internal aqueous phase, the second internal aqueous phase and the external aqueous phase can be directly mixed and then emulsified by mechanical stirring. Among them, the rotation speed of mechanical stirring is 300 r / min to 5000 r / min, preferably 300 r / min to 600 r / min; the time of mechanical stirring is 20 min to 60 min, preferably 20 min to 40 min. It can be understood that those skilled in the art can adaptively adjust the stirring speed, extend or shorten the stirring time according to actual stirring needs to adjust the particle size of the emulsion, which are all within the protection scope of this application.

[0040] In some other embodiments, the above emulsification treatment method is membrane emulsification, specifically, the first internal aqueous phase and the second internal aqueous phase are dispersed into the external aqueous phase through the membrane emulsification process.

[0041] When preparing the water-in-water ((W1 + W2) / W3) double emulsion in this application, the preferred emulsification method is mechanical stirring emulsification. The successful preparation of the water-in-water double emulsion can be achieved only by simple mechanical stirring. It has the advantages of simple and easy preparation method, low cost, etc., greatly reducing the operation difficulty and technical threshold. Moreover, the mechanical stirring device adopted has strong scalability, high flexibility and cost-effectiveness, and can be adjusted according to different product requirements, quality standards and production scales.

[0042] This application also provides a water-in-water double emulsion with a three-phase system prepared by using the above preparation method.

[0043] The water-in-water ((W1 + W2) / W3) double emulsion with a three-phase system provided by this application is an all-aqueous phase system, which has excellent biocompatibility and no toxicity. Before forming the emulsion, the external aqueous phase, the first internal aqueous phase and the second internal aqueous phase will not be miscible, and the particle size of the emulsion is controllable. It has broad application prospects in the fields of material purification and separation, 3D cell culture, tissue engineering, being used as or preparing delivery carriers, etc. For example, specific functionalized substances are enriched in the three aqueous phases of the water-in-water ((W1 + W2) / W3) double emulsion prepared by this application, so that the specific functionalized substances are retained in different aqueous phases. The water-in-water double emulsion is easy to be functionalized. By using the different affinities of each functionalized substance for the external aqueous phase, the first internal aqueous phase and the second internal aqueous phase, the embedding and delivery of the functionalized substances are realized.

[0044] Based on this, this application also provides the application of the above water-in-water ((W1 + W2) / W3) double emulsion with a three-phase system in material purification and separation, cell culture, tissue engineering, being used as or preparing delivery carriers.

[0045] On the other hand, the present application also provides a Pickering emulsion, which is obtained by emulsifying a particulate stabilizer and the above water-in-water ((W1+W2) / W3) double emulsion after mixing them.

[0046] In the present application, the particulate stabilizer mentioned above functions as an emulsifier used in the preparation of traditional emulsions, and all water-insoluble particulate stabilizers that can play an emulsifying and stabilizing role are within the protection scope of the present application. In some embodiments, the particulate stabilizer is a water-insoluble micro-nano particle, which is one or more of inorganic nano particles, organic nano particles, composite nano particles and microorganisms. Among them, the inorganic nano particles are one or more of silicon dioxide, calcium carbonate, zinc oxide, rectorite, calcium phosphate, graphene (such as graphene nanosheets). The organic nano particles are one or more of water-insoluble polysaccharide nano particles, protein nano particles and liposome nano particles, such as cellulose solid particles. The composite nano particles are polysaccharide / protein composite solid particles (such as cellulose / soybean protein isolate solid particle complex). The microorganisms include but are not limited to inactivated yeasts and other microorganisms.

[0047] In some embodiments, the dosage of the particulate stabilizer is 0.01 wt% - 3 wt% of the total mass of the water-in-water double emulsion, which can play an emulsifying and stabilizing role and will not damage the stability of the three-phase system in the water-in-water double emulsion. In some embodiments, the particle size range of the particulate stabilizer can be but is not limited to 0.1 nm - 20 μm, and the Zeta potential can be ±10 mV - ±40 mV.

[0048] In some embodiments, the particle size of the water-in-water double emulsion is 1 μm - 80 μm, preferably 2 μm - 60 μm, more preferably 5 μm - 30 μm. The water-in-water double emulsion has good stability, and the polymerization rate between droplets is slow. When adding a stabilizer subsequently, the stabilizer can be well adsorbed on the interface. In practical applications, those skilled in the art can select water-in-water double emulsions with different particle sizes according to different needs, and its particle size can be 2 μm, 5 μm, 10 μm, 20 μm, 30μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, etc., all within the protection scope of the present application.

[0049] In some embodiments, the viscosity of the water-in-water double emulsion is less than or equal to 25 Pa·s, preferably 0.05 Pa·s - 10 Pa·s. The viscosity of the water-in-water double emulsion is moderate. When it is used in a cosmetic, food or drug delivery system, it is convenient for spreading, dispersing, absorbing, etc. Excessive viscosity makes the operations such as processing, mixing and transporting of the emulsion more difficult, and the fluidity of the emulsion is poor, and the movement of the emulsion is restricted, affecting the uniformity of the emulsion.

[0050] To construct a stable water-in-water double Pickering emulsion, numerous emulsification methods in the prior art can be used, including mechanical stirring emulsification, membrane emulsification, and microfluidic emulsification, etc. The preferred emulsification method for preparing the Pickering emulsion in this application is mechanical stirring emulsification, which can precisely control the emulsification process. By adjusting the stirring speed and time, the particle size distribution of the water-in-water double Pickering emulsion can be effectively controlled, and large-scale preparation can be better realized. In addition, it can ensure the overall stability and functionality of the emulsion, which helps to improve the usability of the emulsion. During the experimental process of this application, for the same system, the high-pressure homogenization method was used for emulsification. Due to the excessive local ultrasonic field strength, it is easy to break the macromolecular chain and cause degradation. At the same time, it will also destroy the stability of the water-water interface, and a stable water-in-water double Pickering emulsion cannot be prepared. The steps of preparing the emulsion by using the impinging stream-assisted emulsification technology are complex, highly dependent on equipment, and not conducive to popularization and production. The cost of preparing the emulsion by using the microfluidic technology is high and the production efficiency is low, making it difficult to achieve large-scale production.

[0051] In this application, the water-in-water double emulsion is prepared by mechanical stirring or membrane emulsification, and then mixed with the particle stabilizer and emulsified to prepare the water-in-water double Pickering emulsion. The method is simple, can well realize large-scale preparation, and the emulsion has good stability and can be applied to the co-embedding and delivery of various substances.

[0052] It should be understood that materials with the same or similar types, models, qualities, properties or functions as the reagents and instruments used in the following examples can be used to implement this application. The experimental methods used in the following examples are all conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples can be obtained from commercial channels unless otherwise specified.

[0053] In the specific embodiments of this application, the first polymer system used to prepare the water-in-water double emulsion is exemplified by the polyol substance polyethylene glycol, and other polyol substances such as glycerol, dibutyl alcohol, or polyether polyol, etc. can be used to prepare the water-in-water double emulsion with a three-phase system.

[0054] The following are examples and comparative examples: Example 1 Prepare aqueous solutions A of hydroxypropyl methylcellulose (HPMC) with a mass fraction of 8 wt% (molecular weight 80,000 Da, viscosity 15 Pa·s, solubility parameter 18.3 (Cal / cm 3 ) 0.5 ), and aqueous solutions B of maltodextrin (MD) with a mass fraction of 8 wt% (molecular weight 3,000 Da, solubility parameter 25.1 (Cal / cm 3 ) 0.5), an 8 wt% aqueous solution B of dextran (DEX) (molecular weight 500,000 Da, solubility parameter 23.1 (Cal / cm 3 ) 0.5 ), and an 8 wt% aqueous solution C of polyethylene glycol (PEG) (molecular weight 88,000 Da, solubility parameter 9.38 (Cal / cm 3 ) 0.5 ). PEG was fluorescently stained with a Cyanine5 stain, and then the above aqueous solutions were mixed in different volume ratios and allowed to stand.

[0055] Figure 1 The macroscopic phase separation diagram of the mixed solution is shown. Among the a1 group to a8 group, the volume ratios of the PEG aqueous solution, DEX aqueous solution, MD aqueous solution, and HPMC aqueous solution are 1:1:28:40, 1:1:13:20, 3:3:24:40, 2:2:11:20, 2:3:10:20, 2:4:9:20, 2:5:8:20, and 2:6:7:20, respectively. It can be seen that a three-phase system can be generated when the above solutions are mixed in different volume ratios and allowed to stand. According to the volume of each phase, the phase with the largest volume is taken as the outer aqueous phase (W3), and the water-soluble polymer in the outer aqueous phase is HPMC; the phase with the smallest volume is taken as the first inner aqueous phase (W1), and the water-soluble polymer in the first inner aqueous phase is PEG; the phase with a smaller volume is taken as the second inner aqueous phase (W2), and the water-soluble polymers in the second inner aqueous phase include DEX and MD. The reason for the analysis may be that the volumes of the DEX aqueous solution and MD aqueous solution are significantly smaller than that of the HPMC aqueous solution, and the hydrophilicity and hydrophobicity of DEX and MD are not competitive compared with other water-soluble polymers (HPMC, PVA) that can form phase separation, so they form one phase after mixing.

[0056] Example 2 Prepare an 8 wt% aqueous solution A of hydroxypropyl methylcellulose (HPMC) (molecular weight 80,000 Da, viscosity 15 Pa·s, solubility parameter 18.3 (Cal / cm 3 ) 0.5 ), an 8 wt% aqueous solution B of maltodextrin (MD) (molecular weight 3,000 Da, solubility parameter 25.1 (Cal / cm 3 ) 0.5 ), an 8 wt% aqueous solution B of polyethylene oxide (PEO) (molecular weight 100,000 Da, solubility parameter 22.5 (Cal / cm 3 ) 0.5 ), and an 8 wt% aqueous solution C of polyethylene glycol (PEG) (molecular weight 88,000 Da, solubility parameter 9.38 (Cal / cm3 ) 0.5 ) Fluorescently label PEG with Cyanine5 stain, and then mix the above aqueous solutions in different volume ratios and let them stand still.

[0057] Figure 2 The macroscopic phase separation diagram of the mixed solution is shown as follows. In groups b1 to b8, the volume ratios of the aqueous PEG solution, aqueous PEO solution, aqueous MD solution, and aqueous HPMC solution are 1:1:28:40, 1:1:13:20, 3:3:24:40, 2:2:11:20, 2:3:10:20, 2:4:9:20, 2:5:8:20, and 2:6:7:20 respectively. It can be seen that a three-phase system can be generated when the above solutions are mixed in different volume ratios and allowed to stand still. According to the volume of each phase, the phase with the smallest volume is taken as the first internal aqueous phase (W1), the phase with a smaller volume is taken as the second internal aqueous phase (W2), and the phase with the largest volume is taken as the external aqueous phase (W3). Among them, the water-soluble polymer in the first internal aqueous phase is PEG, the water-soluble polymers in the second internal aqueous phase include PEO and MD, and the water-soluble polymer in the external aqueous phase is HPMC.

[0058] Example 3 Prepare aqueous solutions A of hydroxypropyl methylcellulose (HPMC) with a mass fraction of 8 wt% (molecular weight 80,000 Da, viscosity 15 Pa·s, solubility parameter 18.3 (Cal / cm 3 ) 0.5 ), aqueous solutions B of maltodextrin (MD) with a mass fraction of 8 wt% (molecular weight 3,000 Da, solubility parameter 25.1 (Cal / cm 3 ) 0.5 ), aqueous solutions B of agarose with a mass fraction of 8 wt% (agarose is purchased from MACKLIN, CAS number: 9012-36-6, EINECS number: 232-731-8, solubility parameter 25 - 30 (Cal / cm 3 ) 0.5 ), and aqueous solutions C of polyethylene glycol (PEG) with a mass fraction of 8 wt% (molecular weight 88,000 Da, solubility parameter 9.38 (Cal / cm 3 ) 0.5 ) Fluorescently label PEG with Cyanine5 stain, and then mix the above aqueous solutions in different volume ratios and let them stand still.

[0059] Figure 3The figure shows the macroscopic phase separation diagram of the mixed solution. In groups c1 to c8, the volume ratios of the aqueous PEG solution, aqueous Agarose solution, aqueous MD solution, and aqueous HPMC solution are 1:1:28:40, 1:1:13:20, 3:3:24:40, 2:2:11:20, 2:3:10:20, 2:4:9:20, 2:5:8:20, and 2:6:7:20, respectively. It can be seen that when the above solutions are mixed in different volume ratios and allowed to stand, a three-phase system can be generated. According to the volume of each phase, the phase with the smallest volume is taken as the first internal aqueous phase (W1), the phase with a smaller volume is taken as the second internal aqueous phase (W2), and the phase with the largest volume is taken as the external aqueous phase (W3). Among them, the water-soluble polymer in the first internal aqueous phase is PEG, the water-soluble polymers in the second internal aqueous phase include Agarose and MD, and the water-soluble polymer in the external aqueous phase is HPMC.

[0060] Example 4 The preparation method of the water-in-water ((W1 + W2) / W3) double emulsion with a three-phase system provided in this example includes the following steps: S1. Prepare an aqueous solution A of hydroxypropyl methylcellulose (HPMC) with a mass fraction of 8 wt% (molecular weight 80,000 Da, viscosity 15 Pa·s, solubility parameter 18.3 (Cal / cm 3 ) 0.5 ), an aqueous solution B of maltodextrin (MD) with a mass fraction of 8 wt% (molecular weight 3,000 Da, solubility parameter 25.1 (Cal / cm 3 ) 0.5 ), an aqueous solution B of dextran (DEX) with a mass fraction of 8 wt% (molecular weight 500,000 Da, solubility parameter 23.1 (Cal / cm 3 ) 0.5 ), and an aqueous solution C of polyethylene glycol (PEG) with a mass fraction of 8 wt% (molecular weight 88,000 Da, solubility parameter 9.38 (Cal / cm 3 ) 0.5 ). Mix 8 mL of the aqueous polyethylene glycol solution, 8 mL of the aqueous dextran solution, 44 mL of the aqueous maltodextrin solution, and 80 mL of the aqueous hydroxypropyl methylcellulose solution (volume ratio 2:2:11:20) to obtain a mixed solution with a three-phase system. Among them, the phase with the smallest volume is taken as the first internal aqueous phase (W1), and the water-soluble polymer in the first internal aqueous phase is PEG; the phase with a smaller volume is taken as the second internal aqueous phase (W2), and the water-soluble polymers in the second internal aqueous phase include DEX and MD; the phase with the largest volume is taken as the external aqueous phase (W3), and the water-soluble polymer in the external aqueous phase is HPMC.

[0061] S2. Emulsify the above mixed solution with a mechanical stirring device at a speed of 500 r / min for 30 min to generate a water-in-water ((W1 + W2) / W3) double emulsion with a three-phase system through a one-step method.

[0062] The macroscopic phase separation diagram of the mixed solution is as shown in Figure 1 group a4 in it. It can be seen that a three-phase system can be formed. The optical microscope diagram of the water-in-water ((W1 + W2) / W3) double emulsion prepared in this example is as shown in Figure 4 . It can be seen that the basic structure of the prepared emulsion is that the outer water phase W3 contains the first inner water phase W1 and the second inner water phase W2, and the first inner water phase and the second inner water phase are immiscible with each other, successfully realizing the water-in-water ((W1 + W2) / W3) double structure, and the average particle size of the emulsion is 9.96 μm ± 4.59 μm.

[0063] Example 5 The preparation method of the water-in-water ((W1 + W2) / W3) double emulsion with a three-phase system provided in this example includes the following steps: S1. Prepare an aqueous solution A of hydroxypropyl methylcellulose (HPMC) with a mass fraction of 8 wt% (molecular weight 80,000 Da, viscosity 15 Pa·s, solubility parameter 18.3 (Cal / cm 3 ) 0.5 ), an aqueous solution B of maltodextrin (MD) with a mass fraction of 8 wt% (molecular weight 3,000 Da, solubility parameter 25.1 (Cal / cm 3 ) 0.5 ), an aqueous solution B of polyethylene oxide (PEO) with a mass fraction of 8 wt% (molecular weight 100,000 Da, solubility parameter 22.5 (Cal / cm 3 ) 0.5 ), and an aqueous solution C of polyethylene glycol (PEG) with a mass fraction of 8 wt% (molecular weight 88,000 Da, solubility parameter 9.38 (Cal / cm 3 ) 0.5 ). Mix the above 6 mL of polyethylene glycol aqueous solution, 6 mL of polyethylene oxide aqueous solution, 48 mL of maltodextrin aqueous solution, and 80 mL of hydroxypropyl methylcellulose aqueous solution (volume ratio 3:3:24:40) to obtain a mixed solution with a three-phase system. The phase with the smallest volume is used as the first inner water phase (W1), and the water-soluble polymer in the first inner water phase is PEG; the phase with a smaller volume is used as the second inner water phase (W2), and the water-soluble polymers in the second inner water phase include PEO and MD; the phase with the largest volume is used as the outer water phase (W3), and the water-soluble polymer in the outer water phase is HPMC.

[0064] S2. Emulsify the above mixed solution with a mechanical stirring device at a speed of 500 r / min for 30 min to generate a water-in-water ((W1 + W2) / W3) double emulsion with a three-phase system by a one-step method, where the average particle size of the emulsion is 4.8 μm ± 1.6 μm.

[0065] Example 6 The preparation method of the water-in-water ((W1 + W2) / W3) double emulsion with a three-phase system provided in this example includes the following steps: S1. Prepare an aqueous solution A of hydroxypropyl methylcellulose (HPMC) with a mass fraction of 8 wt% (molecular weight 80,000 Da, viscosity 15 Pa·s, solubility parameter 18.3 (Cal / cm 3 ) 0.5 ), an aqueous solution B of maltodextrin (MD) with a mass fraction of 8 wt% (molecular weight 3,000 Da, solubility parameter 25.1 (Cal / cm 3 ) 0.5 ), an aqueous solution B of agarose (purchased from MACKLIN, CAS No.: 9012 - 36 - 6, EINECS No.: 232 - 731 - 8, solubility parameter 25 - 30 (Cal / cm 3 ) 0.5 ), and an aqueous solution C of polyethylene glycol (PEG) with a mass fraction of 8 wt% (molecular weight 88,000 Da, solubility parameter 9.38 (Cal / cm 3 ) 0.5 ). Mix 8 mL of the prepared polyethylene glycol aqueous solution, 8 mL of the agarose aqueous solution, 44 mL of the maltodextrin aqueous solution, and 80 mL of the hydroxypropyl methylcellulose aqueous solution (volume ratio 2:2:11:20) to obtain a mixed solution with a three-phase system, where the phase with the smallest volume is used as the first inner aqueous phase (W1), and the water-soluble polymer in the first inner aqueous phase is PEG; the phase with a smaller volume is used as the second inner aqueous phase (W2), and the water-soluble polymers in the second inner aqueous phase include agarose and MD; the phase with the largest volume is used as the outer aqueous phase (W3), and the water-soluble polymer in the outer aqueous phase is HPMC.

[0066] S2. Emulsify the above mixed solution with a mechanical stirring device at a speed of 500 r / min for 30 min to generate a water-in-water ((W1 + W2) / W3) double emulsion with a three-phase system by a one-step method.

[0067] Figure 5As shown in Content a, the macroscopic phase separation diagram of the mixed solution shows that a three-phase system can be formed. The optical microscope image of the water-in-water ((W1 + W2) / W3) double emulsion prepared in this example is as Figure 5 shown in Content b. It can be seen that the basic structure of the prepared emulsion is that the outer aqueous phase W3 contains the first inner aqueous phase W1 and the second inner aqueous phase W2, and the first inner aqueous phase and the second inner aqueous phase are immiscible with each other, successfully realizing the water-in-water ((W1 + W2) / W3) double structure, 13.2 μm ± 3.9 μm.

[0068] Example 7 The preparation method of the water-in-water ((W1 + W2) / W3) double emulsion with a three-phase system provided in this example includes the following steps: S1. Prepare an aqueous solution A of hydroxypropyl methylcellulose (HPMC) with a mass fraction of 8 wt% (molecular weight 80,000 Da, viscosity 15 Pa·s, solubility parameter 18.3 (Cal / cm 3 ) 0.5 , an aqueous solution B of maltodextrin (MD) with a mass fraction of 8 wt% (molecular weight 3,000 Da, solubility parameter 25.1 (Cal / cm 3 ) 0.5 , an aqueous solution B of gelatin with a mass fraction of 8 wt% (molecular weight 300,000 Da, solubility parameter 23.8 (Cal / cm 3 ) 0.5 , and an aqueous solution C of polyethylene glycol (PEG) with a mass fraction of 8 wt% (molecular weight 88,000 Da, solubility parameter 9.38 (Cal / cm 3 ) 0.5 . Mix 4 mL of the polyethylene glycol aqueous solution, 4 mL of the gelatin aqueous solution, 52 mL of the maltodextrin aqueous solution, and 80 mL of the hydroxypropyl methylcellulose aqueous solution (volume ratio 1:1:13:20) to obtain a mixed solution with a three-phase system. The phase with the smallest volume is used as the first inner aqueous phase (W1), and the water-soluble polymer in the first inner aqueous phase is PEG; the phase with a smaller volume is used as the second inner aqueous phase (W2), and the water-soluble polymers in the second inner aqueous phase include Gelatin and MD; the phase with the largest volume is used as the outer aqueous phase (W3), and the water-soluble polymer in the outer aqueous phase is HPMC.

[0069] S2. Emulsify the above mixed solution with a mechanical stirring device at a speed of 500 r / min for 30 min to generate a water-in-water ((W1 + W2) / W3) double emulsion with a three-phase system.

[0070] Figure 6As shown in Content a, the macroscopic phase separation diagram of the mixed solution shows that a three-phase system can be formed. The optical microscopy image of the water-in-water ((W1+W2) / W3) double emulsion prepared in this example is as Figure 6 shown in Content b. It can be seen that the prepared emulsion has a water-in-water ((W1+W2) / W3) double structure, and the average particle size of the emulsion is 8.6 μm ± 1.9 μm.

[0071] Example 8 The preparation method of the water-in-water double emulsion with a three-phase system provided in this example includes the following steps: S1. Prepare an aqueous solution A of hydroxypropyl methylcellulose (HPMC) with a mass fraction of 8 wt% (molecular weight 80,000 Da, viscosity 15 Pa·s, solubility parameter 18.3 (Cal / cm 3 ) 0.5 ), an aqueous solution B of maltodextrin (MD) with a mass fraction of 8 wt% (molecular weight 3,000 Da, solubility parameter 25.1 (Cal / cm 3 ) 0.5 ), an aqueous solution B of methylcellulose (MC) with a mass fraction of 8 wt% (viscosity 1500 mPa.s, solubility parameter 23.5 (Cal / cm 3 ) 0.5 ) and an aqueous solution C of polyethylene glycol (PEG) with a mass fraction of 8 wt% (molecular weight 88,000 Da, solubility parameter 9.38 (Cal / cm 3 ) 0.5 ). Mix 6 mL of the polyethylene glycol aqueous solution, 6 mL of the methylcellulose aqueous solution, 36 mL of the maltodextrin aqueous solution and 50 mL of the hydroxypropyl methylcellulose aqueous solution (volume ratio 3:3:18:25) to obtain a mixed solution with a three-phase system. The phase with the smallest volume is used as the first inner water phase (W1), and the water-soluble polymer in the first inner water phase is PEG; the phase with a smaller volume is used as the second inner water phase (W2), and the water-soluble polymers in the second inner water phase include MC and MD; the phase with the largest volume is used as the outer water phase (W3), and the water-soluble polymer in the outer water phase is HPMC.

[0072] S2. Emulsify the above mixed solution with a mechanical stirring device at a speed of 500 r / min for 30 min to generate a water-in-water ((W1+W2) / W3) double emulsion with a three-phase system by a one-step method.

[0073] Figure 7 As shown in Content a, the macroscopic phase separation diagram of the mixed solution shows that a three-phase system can be formed. The optical microscopy image of the water-in-water ((W1+W2) / W3) double emulsion prepared in this example is as Figure 7As shown in Content b, it can be seen that the prepared emulsion has a water-in-water ((W1 + W2) / W3) double structure, and the average particle size of the emulsion is 5.0 μm ± 1.5 μm.

[0074] Example 9 The preparation method of the water-in-water double emulsion with a three-phase system provided in this example includes the following steps: S1. Prepare an aqueous solution A of hydroxypropyl methylcellulose (HPMC) with a mass fraction of 8 wt% (molecular weight 80,000 Da, viscosity 15 Pa·s, solubility parameter 18.3 (Cal / cm 3 ) 0.5 ), an aqueous solution B of maltodextrin (MD) with a mass fraction of 8 wt% (molecular weight 3,000 Da, solubility parameter 25.1 (Cal / cm 3 ) 0.5 ), an aqueous solution B of cationic hydroxyethyl cellulose (HEC) with a mass fraction of 8 wt% (molecular weight 30,000 Da, solubility parameter 23 - 28 (Cal / cm 3 ) 0.5 ), and an aqueous solution C of polyethylene glycol (PEG) with a mass fraction of 8 wt% (molecular weight 88,000 Da, solubility parameter 9.38 (Cal / cm 3 ) 0.5 ). Mix 24 mL of the polyethylene glycol aqueous solution, 8 mL of the cationic hydroxyethyl cellulose aqueous solution, 28 mL of the maltodextrin aqueous solution, and 80 mL of the hydroxypropyl methylcellulose aqueous solution (volume ratio 6:2:7:20) to obtain a mixed solution with a three-phase system. The phase with the smallest volume is used as the first internal water phase (W1), and the water-soluble polymer in the first internal water phase is PEG; the phase with a smaller volume is used as the second internal water phase (W2), and the water-soluble polymers in the second internal water phase include HEC and MD; the phase with the largest volume is used as the external water phase (W3), and the water-soluble polymer in the external water phase is HPMC.

[0075] S2. Emulsify the above mixed solution with a mechanical stirring device at a speed of 500 r / min for 30 min to generate a water-in-water ((W1 + W2) / W3) double emulsion with a three-phase system by a one-step method.

[0076] Figure 8 As shown in Content a is the macroscopic phase separation diagram of the mixed solution, and it can be seen that a three-phase system can be formed. The optical microscope image of the water-in-water ((W1 + W2) / W3) double emulsion prepared in this example is as shown in Figure 8 Content b. It can be seen that the prepared emulsion has a water-in-water ((W1 + W2) / W3) double structure, and the average particle size of the emulsion is 19.8 μm ± 5.9 μm.

[0077] Comparative Example 1 Prepare the mixed solution according to the a4 group in Example 1, except that the aqueous solution of polyol polyethylene glycol is not added. It is found through experiments that the mixed solution prepared in this comparative example cannot form three phases.

[0078] Comparative Example 2 Prepare the mixed solution according to the b3 group in Example 2, except that the aqueous solution of polyol polyethylene glycol is not added. It is found through experiments that the mixed solution prepared in this comparative example cannot form three phases.

[0079] Comparative Example 3 Prepare aqueous solutions A of hydroxypropyl methylcellulose (HPMC) with a mass fraction of 8 wt% (molecular weight 80,000 Da, viscosity 15 Pa·s, solubility parameter 18.3 (Cal / cm 3 ) 0.5 ), aqueous solutions B of maltodextrin (MD) with a mass fraction of 8 wt% (molecular weight 3,000 Da, solubility parameter 25.1 (Cal / cm 3 ) 0.5 ), and aqueous solutions B of gelatin with a mass fraction of 8 wt% (molecular weight 300,000 Da, solubility parameter 23.8 (Cal / cm 3 ) 0.5 ) according to Example 7 respectively. Mix 4 mL of the gelatin aqueous solution, 24 mL of the maltodextrin aqueous solution, and 80 mL of the hydroxypropyl methylcellulose aqueous solution (volume ratio 1:6:20), and observe whether the mixed solution can form a three-phase system.

[0080] Then emulsify the above mixed solution through a mechanical stirring device at a speed of 500 r / min for 30 min, and observe whether the emulsion has a water-in-water ((W1 + W2) / W3) double structure.

[0081] Figure 9 The macroscopic view of the mixed solution shown in Content a shows that a three-phase system cannot be formed. The optical microscope image of the emulsion prepared in this comparative example is as shown in Figure 9 Content b, from which it can be seen that a water-in-water ((W1 + W2) / W3) double structure is not formed.

[0082] Comparative Example 4 Prepare aqueous solutions A of hydroxypropyl methylcellulose (HPMC) with a mass fraction of 8 wt% (molecular weight 80,000 Da, viscosity 15 Pa·s, solubility parameter 18.3 (Cal / cm 3 ) 0.5), an 8 wt% aqueous solution B of cationic hydroxyethyl cellulose (HEC) (with a molecular weight of 30,000 Da and a solubility parameter of 23 - 28 (Cal / cm 3 ) 0.5 ), and an 8 wt% aqueous solution B of maltodextrin (MD) (with a molecular weight of 3,000 Da and a solubility parameter of 25.1 (Cal / cm 3 ) 0.5 ). Mix 8 mL of the aqueous solution of cationic hydroxyethyl cellulose, 28 mL of the aqueous solution of maltodextrin, and 80 mL of the aqueous solution of hydroxypropyl methylcellulose (volume ratio 2:7:20), and observe whether a three-phase system can be formed in the mixed solution.

[0083] Then emulsify the above mixed solution by mechanical stirring at a speed of 500 r / min for 30 min, and observe whether the emulsion has a water-in-water ((W1 + W2) / W3) double structure.

[0084] Figure 10 As shown in Macroscopic View a of the mixed solution, it can be seen that a three-phase system cannot be formed. The optical microscope image of the emulsion prepared in this comparative example is as Figure 10 shown in Content b, and it can be seen that a water-in-water ((W1 + W2) / W3) double structure is not formed.

[0085] Comparative Example 5 Prepare an 8 wt% aqueous solution A of hydroxypropyl methylcellulose (HPMC) (with a molecular weight of 80,000 Da, a viscosity of 15 Pa·s, and a solubility parameter of 18.3 (Cal / cm 3 ) 0.5 ), a 4 wt% aqueous solution B of chitosan (with a viscosity of 200 - 400 mPa·s, a molecular weight of 30,000 Da, and a solubility parameter of 30 - 35 (Cal / cm 3 ) 0.5 ), and a 4 wt% aqueous solution B of maltodextrin (MD) (with a molecular weight of 3000 Da and a solubility parameter of 25.1 (Cal / cm 3 ) 0.5 ). Mix 2 mL of the aqueous solution of chitosan, 18 mL of the aqueous solution of maltodextrin, and 40 mL of the aqueous solution of hydroxypropyl methylcellulose (volume ratio 1:9:20). It is found experimentally that the mixed solution prepared in this comparative example cannot form a three-phase.

[0086] Comparative Example 6 The others are the same as in Example 5, except that an 8 wt% aqueous solution of polyvinylpyrrolidone (with a molecular weight of 58,000 Da and a solubility parameter of 21 (Cal / cm 3 )0.5 Replace the 8 wt% polyethylene glycol (PEG) aqueous solution. Experiments found that the mixed solution prepared in this comparative example could not form three phases.

[0087] It can be seen from Comparative Example 1 to Comparative Example 5 that when preparing water-in-water ((W1+W2) / W3) double emulsions, polyols were not added, and only by adjusting the volume ratio between other aqueous solutions, the prepared mixed solution could not form three phases. In addition, using hydrophilic macromolecular compounds such as polyvinylpyrrolidone (Comparative Example 6) to replace polyethylene glycol also could not prepare water-in-water ((W1+W2) / W3) double emulsions with a three-phase system.

[0088] Example 10 (preparation of water-in-water double Pickering emulsion) S1. Prepare an 8 wt% hydroxypropyl methylcellulose (HPMC) aqueous solution A (molecular weight 80,000 Da, viscosity 15 Pa·s, solubility parameter 18.3 (Cal / cm 3 ) 0.5 ), a 14 wt% maltodextrin (MD) aqueous solution B (molecular weight 3000 Da, solubility parameter 25.1 (Cal / cm 3 ) 0.5 ), a 14 wt% dextran (DEX) aqueous solution B (molecular weight 500,000 Da, solubility parameter 23.1(Cal / cm 3 ) 0.5 ), and a 10 wt% polyethylene glycol (PEG) aqueous solution C (molecular weight 88,000 Da, solubility parameter 9.38 (Cal / cm 3 ) 0.5 ). Mix the above 8 mL polyethylene glycol aqueous solution, 8 mL dextran aqueous solution, 24 mL maltodextrin aqueous solution, and 80 mL hydroxypropyl methylcellulose aqueous solution (volume ratio 2:2:6:20) to obtain a mixed solution with a three-phase system. The phase with the smallest volume is used as the first inner water phase (W1), and the water-soluble polymer in the first inner water phase is PEG; the phase with a smaller volume is used as the second inner water phase (W2), and the water-soluble polymers in the second inner water phase include DEX and MD; the phase with the largest volume is used as the outer water phase (W3), and the water-soluble polymer in the outer water phase is HPMC.

[0089] S2. The above-mentioned mixed solution was emulsified by a mechanical stirring device at a speed of 500 r / min for 30 min to generate a water-in-water ((W1+W2) / W3) double emulsion with a three-phase system through a one-step method. Then, calcium carbonate powder as a particle stabilizer with a mass fraction of 1.875 wt% was added to the three-phase system, and a calcium carbonate-stabilized water-in-water double Pickering emulsion was prepared by mechanical stirring.

[0090] Figure 11 The optical microscope image of the water-in-water double Pickering emulsion is shown. It can be seen that the calcium carbonate particle stabilizer is adsorbed at the interface of the emulsion, forming a Pickering emulsion with an average particle size of 17.73 μm ± 5.61 μm.

[0091] It is easy for those skilled in the art to understand that the above are only the preferred embodiments of the present application, and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A method for preparing a water-in-water double emulsion having a three-phase system, characterized in that: The steps include: S1, mixing an aqueous solution of a first polymer system, an aqueous solution of a second polymer system, and an aqueous solution of a third polymer system to obtain a mixed solution having a three-phase system, wherein the phase with the smallest volume is used as a first inner aqueous phase, the phase with a smaller volume is used as a second inner aqueous phase, and the phase with the largest volume is used as an outer aqueous phase; The first polymer system, the second polymer system and the third polymer system each independently comprise one or more water-soluble polymers, wherein the water-soluble polymer contained in the first polymer system is a polyol; The absolute value of the difference between the solubility parameter of the water-soluble polymer contained in the second polymer system or the water-soluble polymer contained in the third polymer system relative to water and the solubility parameter of the polyol relative to water is greater than 0.5 (Cal / cm 3 ) 0.5 The absolute value of the difference between the solubility parameter of the water-soluble polymer contained in the second polymer system relative to water and the solubility parameter of the water-soluble polymer contained in the third polymer system relative to water is greater than 0.5 (Cal / cm 3 ) 0.5 ; and the volume ratio of the aqueous solution of the first polymer system to the aqueous solution of the second polymer system is 1:(1-30), and the volume ratio of the sum of the volumes of the aqueous solution of the first polymer system and the aqueous solution of the second polymer system to the aqueous solution of the third polymer system is (1-2):2; S2. Emulsifying the mixed solution to obtain a water-in-water double emulsion in which the outer water phase envelops the first inner water phase and the second inner water phase.

2. The preparation method according to claim 1, characterized in that: In step S1, the mass percentage of the polyol in the aqueous solution of the first polymer system is 2wt%~20wt%, the mass percentage of the water-soluble polymer in the aqueous solution of the second polymer system is 2wt%~20wt%, and the mass percentage of the water-soluble polymer in the aqueous solution of the third polymer system is 2wt%~20wt%.

3. The preparation method according to claim 1 or 2, characterized in that: The water-soluble polymer is selected from water-soluble synthetic macromolecules, water-soluble natural polysaccharides and water-soluble proteins.

4. The preparation method according to claim 3, characterized in that: The water-soluble synthetic macromolecular polymer is one or more of hydroxypropyl methylcellulose, cationic hydroxyethyl cellulose, polyol, and polyethylene oxide; The water-soluble natural polysaccharide is one or more of starch, pullulan, dextran, chitosan, agarose, konjac glucomannan, dextrin, carrageenan, and guar gum; The water-soluble protein is one or more of gelatin, collagen, and casein; Preferably, the polyol is one or more of polyethylene glycol, glycerol, and dibutyl alcohol.

5. The preparation method according to claim 1, characterized in that In step S2, the temperature of the emulsification treatment is 10°C to 60°C, and the emulsification treatment is carried out by mechanical stirring emulsification or membrane emulsification.

6. The preparation method according to claim 5, characterized in that The mechanical stirring emulsification has a rotation speed of 300 r / min to 5000 r / min and a time of 20 min to 60 min.

7. A water-in-water double emulsion having a three-phase system prepared by the preparation method according to any one of claims 1 to 6.

8. Use of the water-in-water double emulsion with a three-phase system as claimed in claim 7 in substance purification and separation, cell culture, tissue engineering, and as or in the preparation of a delivery carrier.

9. A water-in-water double Pickering emulsion, characterized in that: The invention is obtained by mixing a particle stabilizer and the water-in-water double emulsion with a three-phase system as claimed in claim 7 and then emulsifying the mixture.

10. The water-in-water double Pickering emulsion according to claim 9, characterized in that: The particle stabilizer is water-insoluble micro-nano particles, which are one or more of inorganic nanoparticles, organic nanoparticles and composite nanoparticles; The particle stabilizer is used in an amount of 0.01 wt% to 3 wt% of the total mass of the water-in-water double emulsion.

Images