High internal phase emulsion with W / HIPE structure, preparation method of high internal phase emulsion, graded porous material and application of graded porous material

Abstract

The invention discloses a high internal phase emulsion with a W / HIPE structure and a preparation method thereof, a graded porous material and application, the high internal phase emulsion comprises an HIPE phase and a water phase, and the mass ratio of the HIPE phase to the water phase is 1: (4-10). The high internal phase emulsion provided by the invention has a two-stage nested structure, after curing, washing and drying, secondary pores of an HIPE phase and primary pores of a water phase can be reserved, and a graded porous material with a secondary pore diameter is obtained.

Description

Technical Field

[0001] This invention belongs to the field of porous materials technology, specifically relating to a W / HIPE structure high internal phase emulsion and its preparation method, hierarchical porous materials and their applications. Background Technology

[0002] Porous foam materials formed after the solidification of high internal phase emulsions possess high porosity and high connectivity, and have been applied in various fields such as biomedicine, daily chemical hygiene products, and water treatment. However, existing high internal phase emulsion materials are only single-stage "water-in-oil (W / O)" structures, resulting in single-stage pores after solidification. These pores can only meet the needs of cell adhesion and growth, and cannot handle material transport. Consequently, during thick-layer cell culture, cells die due to nutrient deficiency and accumulation of metabolic waste.

[0003] Traditional preparation methods are difficult to achieve the preparation of multi-level pores. In existing attempts to prepare hierarchical pores, the addition of pore-forming agents can easily lead to problems such as pore structure collapse and uneven size in the high internal phase emulsion skeleton due to pore formation. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a W / HIPE structure high internal phase emulsion, its preparation method, hierarchical porous material, and its applications.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a high internal phase emulsion with a W / HIPE structure, wherein the high internal phase emulsion comprises a HIPE phase and an aqueous phase, and the mass ratio of the HIPE phase to the aqueous phase is 1:(4-10), for example 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, etc.

[0007] The high internal phase emulsion provided by the present invention has a nested structure. The nested structure refers to the W / O structure of the HIPE phase itself, and the secondary structure with HIPE emulsion as the continuous phase and aqueous phase as the dispersed phase. That is, the high internal phase emulsion of the present invention has a W / HIPE structure (HIPE emulsion water-in-water structure).

[0008] Since the high internal phase emulsion provided by the present invention has both a HIPE emulsion structure and a secondary nested structure, wherein the second aqueous phase in the HIPE emulsion can form a secondary pore size, and the aqueous phase in the secondary nested structure can form a primary pore size, the high internal phase emulsion with W / HIPE structure provided by the present invention can form a porous foam material with a hierarchical porous structure after curing.

[0009] In this invention, the terms "aqueous phase" and "second aqueous phase" are used only as distinctions.

[0010] Preferably, in the high internal phase emulsion, the aqueous phase is the dispersed phase, and the particle size of the dispersed phase is 60-300 μm, such as 60 μm, 100 μm, 120 μm, 150 μm, 180 μm, 200 μm, 220 μm, 250 μm, 280 μm, 300 μm, etc.

[0011] Preferably, the aqueous phase includes deionized water, an electrolyte, and a stabilizer.

[0012] Preferably, the aqueous phase comprises 60-98% deionized water (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98%), 0.2-40% electrolyte (e.g., 0.2%, 0.5%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%), and 0.5-2% stabilizer (e.g., 0.5%, 1%, 1.2%, 1.5%, 1.8%, 2%), based on a total mass of 100%.

[0013] Preferably, the stabilizer comprises any one or a combination of at least two of polyvinyl alcohol, sodium alginate, or polyethylene glycol.

[0014] This invention introduces a water-soluble stabilizer into the dispersed aqueous phase, which forms an interface layer on the surface of the aqueous phase. This layer can prevent the stabilizer from merging with the oil phase included in the HIPE phase and from merging with the second water included in the HIPE phase, thus achieving dual stability of the "W / HIPE" interface.

[0015] Preferably, the HIPE phase comprises an oil phase and a second aqueous phase, wherein the oil phase comprises polymeric monomers and crosslinking monomers, as well as initiators and emulsifiers.

[0016] Preferably, the viscosity (40-50℃) of the HIPE phase is 1500-5000 cP, such as 1500 cP, 2000 cP, 2500 cP, 3000 cP, 3500 cP, 4000 cP, 4500 cP, 5000 cP, etc.

[0017] By selecting a viscosity of 1500-5000 cP for the HIPE phase at 40-50℃, the present invention enables the subsequent transport of the HIPE phase via microfluidics.

[0018] In this invention, the polymerizing monomers and crosslinking monomers, the second aqueous phase, the emulsifier, and the initiator in the HIPE phase are all components commonly used in HIPE emulsions. This invention does not impose excessive limitations; it is sufficient that the final viscosity of the HIPE phase meets the limitations of this invention. This invention only provides illustrative examples here:

[0019] Preferably, the polymeric monomer accounts for 5-97% of the weight of the oil phase, such as 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 97%, etc., and more preferably 40-80%. It may contain at least one water-insoluble monofunctional alkyl acrylate or alkyl methacrylate, vinyl monomer or biodegradable polymeric monomer.

[0020] Preferably, the functional alkyl acrylate or alkyl methacrylate includes C4-C18 alkyl acrylate and / or C2-C18 alkyl methacrylate.

[0021] Preferably, the vinyl monomers include styrene, vinyl chloride, vinylidene chloride, isoprene, and chloroprene, etc.

[0022] Preferably, the biodegradable polymeric monomers include PLA prepolymer (polylactic acid prepolymer), PCL prepolymer (polycaprolactone prepolymer), or PLGA prepolymer (polylactic acid-glycolic acid copolymer prepolymer).

[0023] Preferably, the crosslinking agent accounts for about 2-40% of the oil phase by weight, such as 2%, 5%, 10%, 20%, 30%, 40%, etc., and more preferably 2-30%; this type of crosslinking monomer includes any one or a combination of at least two of acrylate, methacrylate or divinylbenzene crosslinking agents containing two or more double bonds.

[0024] Preferably, the crosslinking agent is a multifunctional crosslinking monomer, including ethylene glycol dimethacrylate (EGDMA), hexanediol diacrylate (HDDA), polyethylene glycol diacrylate (PEGDA), trimethylolpropane trimethacrylate (TMPTA), divinylbenzene, etc.

[0025] Similarly, the present invention does not limit the amount or specific type of emulsifier; any HLB value that can meet the requirements of high internal phase emulsion is acceptable.

[0026] Preferably, the emulsifier includes any one or a combination of at least two of Span 80, Span 60, polyglycerol ricinoleate, polyglycerol stearate, and polyglycerol oleate.

[0027] Preferably, the amount of emulsifier added is 1-20% of the mass of the oil phase, for example, 1%, 2%, 3%, 5%, 8%, 10%, 12%, 15%, 18%, 20%.

[0028] Similarly, this invention does not limit the amount or specific type of initiator. Any initiator that can meet the requirements of HIPE emulsion polymerization can be used in this invention. The initiator can be an oil-soluble initiator or a water-soluble initiator, and this invention preferably uses an oil-soluble initiator. Exemplary examples of this invention are listed below:

[0029] Preferably, the initiator is an oil-soluble initiator, and the amount of the oil-soluble initiator added is 0.05-10% of the mass of the oil phase, such as 0.05%, 1%, 2%, 5%, 10%, etc. The oil-soluble initiator includes peroxides, such as benzoyl peroxide, or amines, and azo compounds, such as azobisisobutyronitrile.

[0030] Preferably, the initiator is a water-soluble initiator, and the amount of the initiator can be 1-20% of the molar amount of the polymerizable monomer in the oil phase, such as 1%, 2%, 5%, 10%, 15%, 20%, etc., or 0.001-10% of the mass of the aqueous phase, such as 0.001%, 0.01%, 0.1%, 1%, 2%, 5%, 10%, etc.

[0031] Preferably, the initiator is an oil-soluble initiator, including any one or a combination of at least two of thermal initiators or photoinitiators.

[0032] The thermal initiator includes any one or a combination of at least two of benzoyl peroxide (BPO), azobisisobutyronitrile (AIBN), azobisisoheptanenitrile (ABVN), di-tert-butyl peroxide (DTBP), or cumene peroxide (CHP), and is added at 0.1-10% of the oil phase mass, for example, 0.1%, 1%, 2%, 5%, 10%, etc., suitable for 70-95℃ thermosetting processes.

[0033] The photoinitiator includes any one or a combination of at least two of 2-hydroxy-2-methyl-1-phenyl-1-propanone (1173), 2,4,6-trimethylbenzoylphosphine oxide (TPO), isopropylthioxanthone (ITX), or 2-methyl-2-(4-morpholino)-1-[4-(methylthio)phenyl]-1-propanone (907), with an addition amount of 0.1-5% of the oil phase mass, such as 0.1%, 1%, 2%, 3%, 4%, 5%, etc. (photoinitiators are more efficient and can be used in amounts lower than thermal initiators), and is suitable for room temperature UV curing processes (light source wavelength 240-440 nm, such as 240 nm, 250 nm, 300 nm, 350 nm, 400 nm, 440 nm, etc., curing time 5-30 min, such as 5 min, 10 min, 15 min, 20 min, 25 min, 30 min).

[0034] In this invention, the second aqueous phase is also a conventional choice in the art, and this invention does not impose excessive limitations, but only provides an exemplary description:

[0035] In this invention, the second aqueous phase includes deionized water and may also include a water-soluble electrolyte. Introducing a water-soluble electrolyte into the second aqueous phase can reduce the solubility of the oil phase components in water and maintain the structural stability of the water-in-oil system.

[0036] Preferably, the water-soluble electrolyte comprises chlorides or sulfates of alkaline earth metals (e.g., calcium or magnesium) or chlorides or sulfates of alkali metals (e.g., sodium).

[0037] Preferably, the amount of water-soluble electrolyte added is 0.2-40% based on the total mass of the second aqueous phase as 100%, for example, 0.2%, 1%, 2%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, etc.

[0038] Preferably, the second aqueous phase accounts for 75-97% of the total volume of the HIPE phase, such as 75%, 78%, 80%, 82%, 85%, 88%, 90%, 92%, 95%, 97%, etc.

[0039] Preferably, the HIPE phase of the present invention further comprises an oil-soluble solvent, preferably ethyl acetate, toluene, xylene, etc., and preferably added in an amount of 2-10% of the mass of the oil phase, such as 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc. The oil-soluble solvent of the present invention can further reduce the viscosity of the HIPE phase.

[0040] Preferably, the mass ratio of the oil phase to the second aqueous phase is 1:(8-20), such as 1:8, 1:10, 1:12, 1:15, 1:18, 1:20, etc.

[0041] In this invention, the method for preparing the HIPE phase includes:

[0042] (1) Mix the emulsifier, polymerizing monomer, crosslinking monomer and initiator (oil-soluble initiator) to obtain an oil phase mixture;

[0043] (2) Deionized water and optionally an electrolyte are mixed to obtain a second aqueous phase. Preferably, the mixing stirring rate is 500-1000 rpm, such as 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, etc., and the mixing time is preferably 5-20 min, such as 5 min, 8 min, 10 min, 15 min, 20 min, etc.

[0044] (3) The second aqueous phase is added dropwise to the oil phase mixture. After the addition is complete, stirring is continued to obtain the HIPE phase.

[0045] Preferably, in step (1), the mixing speed is 500-1000 rpm, such as 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, etc., the mixing time is preferably 10-30 min, such as 10 min, 15 min, 20 min, 25 min, 30 min, etc., and the mixing temperature is preferably 25-35℃, such as 25℃, 28℃, 30℃, 32℃, 35℃, etc.

[0046] Preferably, in step (3), the dropping rate is 2-10 mL / s, such as 2 mL / s, 3 mL / s, 4 mL / s, 5 mL / s, 6 mL / s, 7 mL / s, 8 mL / s, 9 mL / s, 10 mL / s, etc., and the stirring rate is preferably 800-1500 rpm, such as 800 rpm, 1000 rpm, 1200 rpm, 1500 rpm, etc., and the temperature of the entire process of step (3) is preferably 40-50℃, such as 40℃, 42℃, 45℃, 48℃, 50℃, etc., within this temperature range, the HIPE phase has a low viscosity.

[0047] In this invention, the HIPE phase serves as the oil phase framework and has secondary micropores with pore sizes ranging from 30 to 60 μm, such as 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, and 60 μm. Simultaneously, the aqueous phase encapsulated by the HIPE phase can form primary macropores with pore sizes ranging from 60 to 300 μm, such as 60 μm, 100 μm, 150 μm, 200 μm, 250 μm, and 300 μm.

[0048] In a second aspect, the present invention provides a method for preparing a W / HIPE structure high internal phase emulsion as described in the first aspect, the preparation method comprising:

[0049] The HIPE phase and the aqueous phase are mixed using a microfluidic method to obtain the high internal phase emulsion.

[0050] In the preparation method of this invention, the interface stability between the HIPE continuous phase and the aqueous dispersed phase is successfully ensured without destroying the "water-in-oil" structure of the HIPE continuous phase itself. Finally, a high internal phase emulsion with a nested structure of "HIPE emulsion as continuous phase encapsulating the dispersed phase (aqueous phase)" is successfully constructed. The high internal phase emulsion has a W / HIPE structure (HIPE emulsion encapsulating water) structure, which solves the problem of "phase interface fusion and pore structure loss of control" that occurs when preparing graded pore sizes in the current prior art.

[0051] Preferably, the method for preparing the aqueous phase includes: mixing deionized water, electrolyte and stabilizer, preferably at a mixing temperature of 60-80°C, such as 60°C, 65°C, 70°C, 72°C, 75°C, 78°C, 80°C, etc., as this temperature is conducive to the dissolution of the stabilizer, and preferably the mixing time is such that the aqueous phase forms a homogeneous solution.

[0052] Preferably, the preparation method includes:

[0053] The HIPE phase and the aqueous phase are respectively introduced into different channels of the microfluidic device. After the HIPE phase flow rate reaches the required level, the aqueous phase is introduced to mix with the HIPE phase, thereby obtaining the high internal phase emulsion.

[0054] This invention enables the stable delivery of viscous high internal phase emulsions through a synergistic optimization design of "HIPE phase viscosity adjustment - microfluidic phase interface stabilization - low shear drive". It also controllably constructs high internal phase emulsions with nested structures. After curing, washing and drying, the high internal phase emulsion can be used to obtain a hierarchical porous foam material based on the nested structure of the high internal phase emulsion.

[0055] Preferably, the flow rate of the HIPE phase is 150-180 μL / min, for example 150, 155, 160, 165, 170, 175, 180.

[0056] Preferably, the flow rate of the aqueous phase is 15-30 μL / min, such as 15 μL / min, 18 μL / min, 20 μL / min, 22 μL / min, 25 μL / min, 26 μL / min, 28 μL / min, 30 μL / min, etc.

[0057] Preferably, the ratio of the channel diameter for conveying the HIPE phase to the channel diameter for conveying the aqueous phase is (2-4):1, such as 2:1, 2.5:1, 3:1, 3.5:1, 4:4, etc.

[0058] Preferably, the inner diameter of the channel for conveying the HIPE phase is 150-200 μm, such as 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, etc., and preferably 200 μm. The present invention can achieve stable delivery of HIPE emulsion by expanding the inner diameter of the channel and reducing the viscosity of the HIPE phase, while supplementing it with a peristaltic pump and low shear drive of nitrogen pressure.

[0059] Preferably, the output flow rate of the high internal phase emulsion is 165-210 μL / min, such as 165 μL / min, 170 μL / min, 175 μL / min, 180 μL / min, 185 μL / min, 190 μL / min, 195 μL / min, 200 μL / min, 205 μL / min, 210 μL / min, etc.

[0060] Preferably, the preparation method is carried out at a temperature of 40-60°C, such as 40°C, 45°C, 50°C, 55°C, 60°C, etc.

[0061] The preparation method provided by this invention requires controlling the preparation temperature to be constant. At the same time, within this temperature range, the HIPE phase has a low viscosity, which facilitates its transport.

[0062] This invention solves the problem of transporting viscous high internal phase emulsions in microfluidic fine pipelines by adjusting the composition of the high internal phase emulsion and combining it with specific microfluidic parameters, thus ensuring process stability.

[0063] This invention achieves a nested morphology of "HIPE emulsion encapsulated in water" through precise microfluidic technology, avoiding the merging of the aqueous dispersion phase and the continuous HIPE phase caused by traditional shear mixing, ultimately resulting in a "W / HIPE" hierarchical structure. In particular, the porous material with hierarchical structure obtained by curing solves the problem that "a single pore structure cannot simultaneously meet the needs of cell growth and material transport" in traditional 3D cell culture scaffolds, and can be widely used in 3D cell culture, tissue engineering scaffolds and other fields.

[0064] As a preferred embodiment of the present invention, the preparation method includes:

[0065] A. Prepare a dual-channel microfluidic device, maintain the internal and external temperature of the device at 50℃, and transport the HIPE phase using a PTFE hydrophobic tube with an inner diameter of 150-200 μm, driven by a peristaltic pump and nitrogen pressure.

[0066] B. The aqueous phase is transported using pipes with an inner diameter of 50-80 μm;

[0067] C. Start the HIPE phase. After the HIPE phase forms a stable sheath flow (flow rate 150-180 μL / min) in the pipeline, start the aqueous phase injection pump.

[0068] D. Observe the mixing zone at the outlet using a microscope, adjust the aqueous phase flow rate to 15-30 μL / min to ensure the formation of spherical nested units that encapsulate the aqueous phase with "HIPE phase", and collect continuously.

[0069] Thirdly, the present invention provides a hierarchical porous material prepared from a W / HIPE structure high internal phase emulsion as described in the first aspect.

[0070] This invention utilizes microfluidics to form nested units of "HIPE emulsion encapsulated in water". After curing, washing and drying, the secondary pores of the HIPE phase and the primary pores of the aqueous phase are retained, resulting in a porous material with high internal phase emulsion foam and dual-stage pore size.

[0071] Fourthly, the present invention provides a method for preparing a hierarchical porous material as described in the first aspect, the method comprising:

[0072] The W / HIPE structure high internal phase emulsion described in the first aspect is subjected to a curing reaction and dried to obtain the hierarchical porous material.

[0073] Fifthly, the present invention provides the application of the W / HIPE structure high internal phase emulsion described in the first aspect or the hierarchical porous material described in the third aspect in 3D cell culture, daily chemical hygiene products or tissue engineering scaffolds.

[0074] The graded porous material described in this invention can be used in the field of sanitary napkins, dressings, and other daily chemical hygiene products. One or more layers of graded porous material with the same or different pore sizes are used as the core of sanitary napkins, dressings, and other daily chemical hygiene products. Through its high porosity, high connectivity, and controllable pore size, it can absorb, guide, lock in water, prevent backflow, or release liquids such as moisture, menstrual blood, blood, body fluids, and nutrients, giving the product excellent properties such as thinness, dryness, long-lasting effect, and slow release.

[0075] Compared with the prior art, the present invention has the following beneficial effects:

[0076] (1) Multi-level nested structure: The present invention constructs a nested structure system of "W / HIPE (HIPE emulsion water-in-water)" to obtain a hierarchical pore interconnection structure, which can realize the functions of "first-level macropores supporting cell adhesion and growth" and "second-level micropores providing material transport".

[0077] (2) Microfluidic delivery process: The present invention prepares a low-viscosity HIPE phase by “viscosity control-solvent dilution-temperature assistance”, and combines it with a large inner diameter delivery path and low shear drive to obtain a stable microfluidic synergistic optimization process;

[0078] (3) Controllable pore structure: The first-level macropores of the hierarchical porous material obtained by the present invention are precisely controlled by the flow rate of the aqueous phase dispersion, and the second-level micropores are determined by the pore size of the HIPE phase itself, which can realize independent control of the two-level size. Attached Figure Description

[0079] Figure 1 This is a SEM image of the hierarchical porous material prepared in Example 2. Detailed Implementation

[0080] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0081] Unless otherwise specified, the raw materials involved in the following specific embodiments of the present invention are all conventional materials in the art, and can be purchased from commercially available products. Some raw material information is as follows:

[0082] PLA prepolymer: purchased from NatureWorks, model number 4032;

[0083] PLGA prepolymer: purchased from Sigma-Aldrich, model number P1941;

[0084] SPAN 80: Purchased from Heda, food grade;

[0085] PVA: Purchased from Aladdin, model number 1788;

[0086] Sodium alginate: purchased from Sigma-Aldrich, model number W201502.

[0087] Example 1

[0088] This embodiment provides a W / HIPE structured high internal phase emulsion and hierarchical porous material, as detailed below:

[0089] 1. A high internal phase emulsion with a W / HIPE structure, consisting of a HIPE phase and an aqueous phase in a mass ratio of 1:6, wherein:

[0090] 1.1. HIPE phase: PLA prepolymer 50 parts, HDDA 25 parts, ethyl acetate 10 parts, SPAN 80 10 parts, AIBN 5 parts; second aqueous phase (deionized water 1000 parts, calcium chloride 50 parts), the mass ratio of oil phase to second aqueous phase is 1:10. The preparation method is as follows: PLA prepolymer, HDDA, ethyl acetate, SPAN 80, and AIBN are mixed at 30℃ and 500 rpm for 20 min to obtain the oil phase; deionized water and calcium chloride are mixed at 500 rpm for 20 min to obtain the second aqueous phase. The second aqueous phase is added dropwise to the oil phase at 40℃ and 1000 rpm at a dropping rate of 5 mL / s. After the addition, stirring is continued to obtain a HIPE phase with a viscosity of 2600 cP.

[0091] 1.2. Aqueous phase: 1000 parts deionized water, 50 parts calcium chloride, and 10 parts PVA. The preparation method is as follows: mix the above components at 60℃ and 800 rpm until completely dissolved to obtain the aqueous phase.

[0092] 1.3. Preparation method of W / HIPE structure high internal phase emulsion

[0093] 1.3.1 Prepare a dual-channel microfluidic device, maintain the internal and external temperature of the device at 50℃, and transport the HIPE phase using a PTFE hydrophobic tube with an inner diameter of 200μm, driven by a peristaltic pump and nitrogen pressure.

[0094] 1.3.2 The aqueous phase is transported using a pipe with an inner diameter of 80 μm;

[0095] 1.3.3. Start the HIPE phase. After the HIPE phase forms a stable sheath flow (flow rate 160 μL / min) in the pipeline, start the aqueous phase injection pump and adjust the aqueous phase flow rate to 20 μL / min to obtain a high internal phase emulsion. Output the emulsion using a pipeline with an inner diameter of 200 μm.

[0096] 2. Hierarchical porous materials

[0097] The high internal phase emulsion was injected into a polytetrafluoroethylene mold (5 cm × 5 cm × 0.5 cm), placed in an oven for heating and curing at 90°C for 2 h, washed and dried to obtain the hierarchical porous material.

[0098] Example 2

[0099] This embodiment provides a W / HIPE structured high internal phase emulsion and hierarchical porous material.

[0100] The difference from Example 1 is that in this example, the stabilizer PVA in the aqueous phase is replaced with sodium alginate.

[0101] Examples 3-6

[0102] This embodiment provides a W / HIPE structured high internal phase emulsion and hierarchical porous material.

[0103] The difference from Example 1 is that, in this example, the mass percentage of stabilizer PVA in the aqueous phase is 0.5% (Example 3), 2% (Example 4), 0.2% (Example 5), and 3% (Example 6), based on the total mass of the aqueous phase as 100%.

[0104] Examples 7-10

[0105] This embodiment provides a W / HIPE structured high internal phase emulsion and hierarchical porous material.

[0106] The difference from Example 1 is that in this example, the mass ratio of HIPE phase to aqueous phase is 1:4 (Example 7), 1:7 (Example 8), 1:9 (Example 9), and 1:10 (Example 10).

[0107] Example 11

[0108] This embodiment provides a W / HIPE structured high internal phase emulsion and hierarchical porous material, as detailed below:

[0109] 1. A high internal phase emulsion with a W / HIPE structure, consisting of a HIPE phase and an aqueous phase in a mass ratio of 1:6, wherein:

[0110] 1.1. HIPE phase: PLA prepolymer 60 parts, EGDMA 20 parts, toluene 8 parts, SPAN 80 8 parts, BPO 4 parts, deionized water 1000 parts, magnesium sulfate 40 parts, oil phase to second aqueous phase mass ratio 1:12, viscosity at 45℃ 2200 cP;

[0111] 1.2. Aqueous phase: 1000 parts deionized water, 50 parts calcium chloride, and 10 parts PVA. The preparation method is as follows: mix the above components at 60℃ and 800 rpm until completely dissolved to obtain the aqueous phase.

[0112] 1.3. Preparation method of W / HIPE structure high internal phase emulsion

[0113] 1.3.1 Prepare a dual-channel microfluidic device, maintain the internal and external temperature of the device at 50℃, and transport the HIPE phase using a PTFE hydrophobic tube with an inner diameter of 200μm, driven by a peristaltic pump and nitrogen pressure.

[0114] 1.3.2 The aqueous phase is transported using a pipe with an inner diameter of 80 μm;

[0115] 1.3.3. Start the HIPE phase. After the HIPE phase forms a stable sheath flow (flow rate 150 μL / min) in the pipeline, start the aqueous phase injection pump and adjust the aqueous phase flow rate to 15 μL / min to obtain a high internal phase emulsion. Output the emulsion using a pipeline with an inner diameter of 200 μm.

[0116] 2. Hierarchical porous materials

[0117] The high internal phase emulsion was injected into a polytetrafluoroethylene mold (5 cm × 5 cm × 0.5 cm), placed in an oven for heating and curing at 90°C for 2 h, washed and dried to obtain the hierarchical porous material.

[0118] Hierarchical porous material: primary pore size 140 μm, secondary pore size 35 μm, other conditions are the same as in Example 1.

[0119] Example 12

[0120] This embodiment provides a W / HIPE structured high internal phase emulsion and hierarchical porous material, as follows:

[0121] 1. A high internal phase emulsion with a W / HIPE structure, consisting of a HIPE phase and an aqueous phase in a mass ratio of 1:8, wherein:

[0122] 1.1. HIPE phase: 40 parts PLGA prepolymer, 30 parts TMPTA, 10 parts xylene, 15 parts polyglycerol ricinoleate, 5 parts DCP, second aqueous phase (1000 parts deionized water + 30 parts sodium chloride), oil phase to second aqueous phase mass ratio 1:15, viscosity at 45℃ 4800 cP;

[0123] 1.2. Aqueous phase: 1000 parts deionized water, 50 parts calcium chloride, and 10 parts PVA. The preparation method is as follows: mix the above components at 60℃ and 800 rpm until completely dissolved to obtain the aqueous phase.

[0124] 1.3. Preparation method of W / HIPE structure high internal phase emulsion

[0125] 1.3.1 Prepare a dual-channel microfluidic device, maintain the internal and external temperature of the device at 40℃, and transport the HIPE phase using a PTFE hydrophobic tube with an inner diameter of 200μm, driven by a peristaltic pump and nitrogen pressure.

[0126] 1.3.2 The aqueous phase is transported using a pipe with an inner diameter of 80 μm;

[0127] 1.3.3. Start the HIPE phase. After the HIPE phase forms a stable sheath flow (flow rate 180 μL / min) in the pipeline, start the aqueous phase injection pump and adjust the aqueous phase flow rate to 30 μL / min to obtain a high internal phase emulsion. Output the emulsion using a pipeline with an inner diameter of 200 μm.

[0128] 2. Hierarchical porous materials

[0129] The high internal phase emulsion was injected into a polytetrafluoroethylene mold (5 cm × 5 cm × 0.5 cm), placed in an oven for heating and curing at 90°C for 2 h, washed and dried to obtain the hierarchical porous material.

[0130] Hierarchical porous material: primary pore size 270 μm, secondary pore size 55 μm, other conditions are the same as in Example 1.

[0131] Comparative Example 1

[0132] This comparative example provides a high internal phase emulsion and a porous material.

[0133] The difference from Example 1 is that, in this comparative example, no aqueous phase is introduced, and the HIPE phase is directly used as a high internal phase emulsion for step 2 curing.

[0134] Comparative Example 2

[0135] This comparative example provides a high internal phase emulsion and a porous material.

[0136] The difference from Example 1 is that, in this comparative example, the stabilizer PVA is not introduced into the aqueous phase.

[0137] Performance testing

[0138] The performance of the samples provided in the examples and comparative examples was tested using the following methods:

[0139] (1) Graded pore size: The diameters of 50 primary pores and 100 secondary pores were randomly measured using a scanning electron microscope (SEM, TESCAN MIRA3), and the average value was taken.

[0140] Figure 1 The image shows a SEM image of the hierarchical porous material prepared in Example 2 of the present invention. As can be seen from the image, the porous material provided by the present invention has a nested structure, which includes a primary pore size formed by the aqueous phase and a secondary pore size formed by the HIPE phase.

[0141] (2) Porosity: Liquid displacement method (anhydrous ethanol), the sample was weighed after vacuum drying (m1), weighed after immersion in ethanol for degassing (m2), and the volume V was measured by water displacement method. The following calculations were performed:

[0142] Porosity = (m2 - m1) / (ρethanol × V) × 100%;

[0143] (3) Compression modulus: universal testing machine (Instron 5967), sample size 10mm×10mm×5mm, compression rate 1 mm / min, stress at 8% strain;

[0144] (4) Material transport rate: FITC fluorescent probe (1 mg / mL) was dropped onto the material surface, and the diffusion distance was observed within 2 hours using a confocal microscope. The transport rate (μm / h) was then calculated.

[0145] (5) Cell viability: Inoculated with vascular endothelial cells (1×10⁻⁶) 5 (number / mL), after 7 days of incubation, the results were tested using the CCK-8 assay and the following calculations were performed:

[0146] Survival rate = (OD of test group - OD of blank group) / (OD of control group - OD of blank group) × 100%;

[0147] The control group consisted of culture medium without any added scaffold material.

[0148] The test results are as follows:

[0149] Table 1

[0150]

[0151] As demonstrated by the examples and performance tests, the high internal phase emulsion provided by the present invention can produce porous materials with hierarchical porous structures. Its material transport rate is significantly higher than that of single-pore materials (Comparative Examples 1-2), and the cell survival rate is increased by more than 10%, which fully verifies the synergistic advantages of hierarchical porous structures.

[0152] The present invention has been illustrated through the above embodiments, but the present invention is not limited to the above process steps, that is, it does not mean that the present invention must rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A W / HIPE structure high internal phase emulsion, characterized in that, The high internal phase emulsion comprises a HIPE phase and an aqueous phase, wherein the mass ratio of the HIPE phase to the aqueous phase is 1:(4-10).

2. The W / HIPE structured high internal phase emulsion according to claim 1, characterized in that, In the high internal phase emulsion, the aqueous phase is the dispersed phase, and the particle size of the dispersed phase is 60-300 μm; And / or, the aqueous phase includes deionized water, electrolytes, and stabilizers.

3. The W / HIPE structured high internal phase emulsion according to claim 2, characterized in that, The aqueous phase comprises 60-98% deionized water, 0.2-40% electrolyte, and 0.5-2% stabilizer, based on a total mass of 100%. And / or, the stabilizer includes any one or a combination of at least two of polyvinyl alcohol, sodium alginate, or polyethylene glycol.

4. The W / HIPE structure high internal phase emulsion according to any one of claims 1-3, characterized in that, The HIPE phase includes an oil phase and an aqueous phase, wherein the oil phase includes polymeric monomers and crosslinking monomers, as well as initiators and emulsifiers; Preferably, the viscosity of the HIPE phase is 1500-5000 cP; Preferably, the mass ratio of the oil phase to the second aqueous phase is 1:(8-20); Preferably, the amount of the initiator added is 0.1-10% of the mass of the oil phase; Preferably, the amount of emulsifier added is 1-20% of the mass of the oil phase.

5. A method for preparing a W / HIPE high internal phase emulsion according to any one of claims 1-4, characterized in that, The preparation method includes: The HIPE phase and the aqueous phase are mixed using a microfluidic method to obtain the high internal phase emulsion.

6. The preparation method according to claim 5, characterized in that, The preparation method includes: The HIPE phase and the aqueous phase are respectively introduced into different channels of the microfluidic device. After the HIPE phase flow rate reaches the required level, the aqueous phase is introduced to mix with the HIPE phase, thereby obtaining the high internal phase emulsion.

7. The preparation method according to claim 6, characterized in that, The flow rate of the HIPE phase is 150-180 μL / min; And / or, the flow rate of the aqueous phase is 15-30 μL / min; And / or, the ratio of the channel diameter for conveying the HIPE phase to the channel diameter for conveying the aqueous phase is (2-4):

1.

8. A hierarchical porous material, characterized in that, It is prepared from the W / HIPE high internal phase emulsion according to any one of claims 1-4.

9. A method for preparing a hierarchical porous material as described in claim 8, characterized in that, The preparation method includes: The W / HIPE high internal phase emulsion of any one of claims 1-4 is subjected to a curing reaction and dried to obtain the hierarchical porous material.

10. The use of the W / HIPE structure high internal phase emulsion of any one of claims 1-4 or the hierarchical porous material of claim 8 in 3D cell culture, daily chemical hygiene products or tissue engineering scaffolds.

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