Method for preparing liquid-supported polymer and hydrophilic porous polymer, liquid-supported polymer and hydrophilic porous polymer prepared therefrom, and technology for preparing water-in-water emulsion with maximized stability

Abstract

A method for preparing a hydrophilic porous polymer of the present invention comprises the steps of: preparing a high internal buoyancy emulsion (HIPE); obtaining a liquid-supported polymer by UV-curing the HIPE; and obtaining a hydrophilic porous polymer by drying the liquid-supported polymer. In addition, a water-in-water pickering emulsion of the present invention forms an aqueous two-phase system (ATPS), and comprises an interface between a polymer and a polymer or between a polymer and a salt.

Description

Method for producing a liquid-supporting polymer and a hydrophilic porous polymer, a liquid-supporting polymer and a hydrophilic porous polymer produced thereby, and a technology for producing a water-in-water emulsion with maximized stability

[0001] The present invention relates to a method for producing a liquid-supporting polymer and a hydrophilic porous polymer, a liquid-supporting polymer and a hydrophilic porous polymer produced thereby, and a technology for producing a water-in-water emulsion with maximized stability.

[0002] Porous polymer materials are widely used in various fields due to their lightweight properties and large surface area. For example, they are used as energy materials for membranes (e.g., water / oil separators and battery separators), as biomaterials for drug delivery patches, and as scaffolds for cell culture.

[0003] In addition, in the case of polymer materials containing liquids (such as drugs) used in pharmaceuticals, etc., their use is limited due to difficulties in their synthesis methods, but their potential is limitless in that they can encapsulate the desired liquid, protect it from deterioration, etc., and use it when desired.

[0004] Recently, biotoxicity has been reported due to residual components (such as oil and surfactants) on the surface of porous materials, and therefore, it is difficult to secure a high survival rate (>90%) of injected cultured cells.

[0005] As lithium-ion batteries age, environmental pollution through electrolyte leakage and battery explosions due to loss of separator functionality are frequently reported, greatly emphasizing the importance of developing highly functional, bio- and environmentally friendly porous materials.

[0006] Additionally, the hassle of creating polymers that encapsulate liquids that can be used as pharmaceuticals is also a problem.

[0007] Aqueous two-phase systems (ATPS) possess several advantages over conventional oil-in-water systems, primarily because they consist solely of water. Formed by water-soluble additives, ATPS are particularly biocompatible because neither phase contains an organic solvent, suggesting diverse applications. Examples include model systems mimicking the intracellular environment, ATPS-based compartmentalization that increases local reactant concentration, cell patterning utilizing low interfacial tension, and continuous microfluidic devices utilizing the affinity of hydrophilic polymers. Furthermore, ATPS exhibits interfacial permeability, enabling free diffusion and exchange of substances. This property allows for the transport and export of molecular units (e.g., DNA and water molecules) between the external and internal phases, demonstrating exceptionally high permeability. For these reasons, ATPS-based water-in-water emulsions have recently demonstrated wide-ranging potential applications in cosmetics, food, biomedicine, and drug delivery. However, in the case of water-in-water emulsions, it is very difficult to achieve excellent stability, so their use as products is quite limited.

[0008] ATPS can be classified into polymer / polymer systems or salt / polymer systems. Recently, studies on the stability of water-in-water emulsions using ATPS have been reported, and in particular, in the case of salt / polymer systems, studies have shown excellent stabilization effects using inorganic stabilizer particles (silica particles) modified with DDS (DichloroDimethyl-Silane). Although these salt / polymer systems have higher interfacial tension than polymer / polymer systems, they exhibit in vivo toxicity of salts (cell death, etc. depending on concentration), making them unsuitable for use as products. In contrast, studies on excellent emulsion stability for polymer / polymer systems that can be used as products are still insufficient, and much research in this area is needed.

[0009] The background technology described above is something that the inventor possessed or acquired in the process of deriving the disclosure of the present application, and cannot necessarily be said to be a publicly known technology disclosed to the general public prior to the present application.

[0010] The present invention aims to solve the above-described problems by providing a highly functional, bio- and environmentally friendly liquid-bearing polymer and a hydrophilic porous polymer and a method for producing the same.

[0011] In addition, the present invention aims to provide a water-in-water Pickering emulsion with maximized stability and a method for producing the same to solve the above-described problem.

[0012] Specifically, according to the present invention, a Pickering emulsion is an emulsion system that utilizes colloidal particles, rather than surfactants, as emulsion stabilizers. The colloidal stabilizer particles are adsorbed to the interface due to a decrease in free energy at the liquid-liquid interface, and this decrease in free energy can be a driving force for the irreversible adsorption of the stabilizer particles at the interface. In addition, the colloidal stabilizer particles adsorbed to the interface can provide an excellent barrier to the droplet particles by preventing direct contact with adjacent droplet particles, thereby providing a water-in-water Pickering emulsion with maximized stability and a method for preparing the same.

[0013] However, the problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned can be clearly understood by a person having ordinary skill in the relevant technical field from the description below.

[0014] The method for producing a hydrophilic porous polymer of the present invention comprises the steps of: preparing a HIPE (high internal buoyancy emulsion); curing the HIPE with UV to obtain a liquid-supporting polymer; and drying the liquid-supporting polymer to obtain a hydrophilic porous polymer.

[0015] According to one embodiment, in the step of preparing the HIPE (high internal buoyancy emulsion), the HIPE comprises a water-in-water (W / W) interface, and the interface comprises at least one selected from the group consisting of polyethylene glycol (PEG), dextran (DEX), polyvinyl alcohol (PVA), gelatin (Gel), maltodextrin (MAL), sodium caseinate, starch, sodium sulfate, magnesium sulfate, corn starch, alginate (Alg), amylopectin (AMP), xyloglucan (XG), xanthan gum, pectin, polyethylene glycol diacrylate (PEGDA), and gelatin methacryloyl (GelMA), and the HIPE comprises an emulsion stabilizer, and the emulsion stabilizer comprises colloidal particles, and the colloidal particles are silica particles, polystyrene particles, gold nanoparticles, liposomes, protein particles, zinc oxide particles, or titanium dioxide. A colloidal particle comprising particles, wherein the colloidal particles may comprise at least one hydrophilic polymer chain selected from the group consisting of polyethylene glycol (PEG), dextran (DEX), polyvinyl alcohol (PVA), deoxyribonucleic acid (DNA), chitosan, hyaluronic acid, alginic acid, gelatin, collagen, and cellulose.

[0016] According to one embodiment, the step of preparing the HIPE (high internal buoyancy emulsion) further includes a step of adding a monomer, a crosslinking agent, and a photoinitiator, wherein the monomer includes at least one selected from the group consisting of acrylic acid (AA), acrylamide (AAM), gelatin methacryloyl (GelMA), polyethylene glycol diacrylate (PEGDA), polyethylene glycol methacrylate (PEGMA), and polyethylene glycol dimethacrylate (PEGDMA), wherein the crosslinking agent is N,N'-methylenebisacrylamide (MBAA), and the photoinitiator is benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylanino acetophenone, lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP), A polymer comprising at least one selected from the group consisting of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiope (Irgacure 2959) benzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethylketal, acetophenone dimethylketal and 2-hydroxy-2-methylpropiope (Darocur 1173), wherein the monomer is 1 wt% to 10 wt% of the HIPE, and the crosslinker is 2 wt% of the HIPE. The following is provided, and the photoinitiator may be present in an amount of 0.1 wt% to 0.5 wt% of the HIPE.

[0017] The hydrophilic porous polymer of the present invention is a hydrophilic porous polymer manufactured by the manufacturing method of the present invention, and when the colloidal particles in the HIPE are 1 w / v% to 5 w / v%, it has an open cell shape including interconnected pores, and when the colloidal particles in the HIPE are 5 w / v% to 10 w / v%, it has a closed cell shape including non-interconnected pores.

[0018] According to one embodiment, when the size of the colloidal particles of the hydrophilic porous polymer is 1 μm or more, the colloidal particles may be exposed on the surface of the hydrophilic porous polymer membrane.

[0019] The water-in-water Pickering emulsion of the present invention forms an aqueous two-phase system (ATPS) and includes an interface between polymers or polymers and salts.

[0020] According to one embodiment, the interface comprises at least one selected from the group consisting of polyethylene glycol (PEG), dextran (DEX), polyvinyl alcohol (PVA), gelatin (Gel), maltodextrin (MAL), sodium caseinate, starch, sodium sulfate, magnesium sulfate, corn starch, alginate (Alg), amylopectin (AMP), xyloglucan (XG), xanthan gum, pectin, polyethylene glycol diacrylate (PEGDA), and gelatin methacryloyl (GelMA), the emulsion comprises an emulsion stabilizer, the emulsion stabilizer comprises colloidal particles, the colloidal particles comprise silica particles, polystyrene particles, gold nanoparticles, liposomes, protein particles, zinc oxide particles, or titanium dioxide particles, and the colloidal particles comprise polyethylene glycol (PEG), dextran (DEX), polyvinyl alcohol (PVA), It may comprise at least one hydrophilic polymer chain selected from the group consisting of deoxyribonucleic acid (DNA), chitosan, hyaluronic acid, alginic acid, gelatin, collagen, and cellulose.

[0021] According to one embodiment, the diameter of the colloidal particles may be 0.01 μm to 100 μm, the colloidal particles may be 1 w / v% to 10 w / v% of the emulsion, the molecular weight of the hydrophilic polymer chain may be 100 to 500,000, and the weight ratio of the hydrophilic polymer chain and the colloidal particles may be 0.001:1 to 10:1.

[0022] According to one embodiment, the emulsion is a HIPE (high internal phase emulsion) having an internal phase volume ratio of 74% or more in the emulsion, droplets of the HIPE are in a polygonal dispersion form, and the droplet size of the HIPE may be 10 ㎛ to 3000 ㎛.

[0023] The method for producing a water-in-water Pickering emulsion of the present invention comprises the steps of dispersing a hydrophilic polymer chain in DI water to obtain a solution; dispersing colloidal particles in the solution to obtain an emulsion; and homogenizing the emulsion at a speed of 2000 rpm to 20,000 rpm for 1 to 5 minutes.

[0024] The present invention can provide a liquid-supporting polymer and a hydrophilic porous polymer and a method for producing the same.

[0025] According to the present invention, a polymer synthesized using a water-water emulsion does not cause problems such as residual oil because it utilizes a water-water interface rather than a water-oil interface, and does not require additional processes (washing and hydrophilic coating) to impart hydrophilicity to the synthesized polymer, and can be produced by simple polymerization (freeze-drying after photopolymerization). Since the emulsion can be stabilized using spherical colloidal particles rather than surfactants, side effects caused by residual surfactants can be prevented, and by controlling the size of the spherical colloidal particles, the surface of the particles can be exposed to the polymer surface, thereby imparting the properties of the particles (functional groups, etc.) to the polymer. For example, in the case of a polymer synthesized using a water-water emulsion stabilized using 1 μm silica particles, the silica particles can be exposed to the polymer surface after synthesis, resulting in the effect of having -OH groups. This can reduce the need for additional processes such as modification with polydopamine to impart -OH groups.

[0026] In addition, in order to fill existing liquids (such as drugs), a process such as applying strong pressure or absorbing the corresponding liquid through surface modification was required, but since water-water emulsions are made entirely of water, the liquid to be filled is added in the initial stage to prepare the emulsion, and then polymerizing this into a polymer can easily synthesize a polymer loaded with the desired liquid. Since a water-water emulsion produced from two immiscible substances appears as an aqueous system as a whole, a porous material synthesized from this can easily exhibit bio- and environmentally friendly properties.

[0027] The present invention can provide a water-in-water Pickering emulsion with maximized stability and a method for producing the same.

[0028] The water-in-water Pickering emulsion according to the present invention has a wide range of potential applications, from applications in cosmetics, foods, and pharmaceuticals to serving as a template for synthesizing various polymeric materials (e.g., porous polymeric materials and colloidal particles). Furthermore, the development of water-in-water emulsion formulations is essential for environmental friendliness and biocompatibility. Furthermore, water-in-water emulsion formulations can serve as excellent templates for formulations with reported environmental hazards, such as those causing environmental pollution, and for products containing functional materials comprised of hydrophilic substances.

[0029] In particular, the HIPE (high internal buoyancy emulsion) according to the present invention is an emulsion having a structure in which the dispersed phase droplets are very close to each other and the shape is no longer spherical due to the presence of strong internal pressure, and this shape is very similar to the arrangement state of cells in a living body, so it may be more suitable for an artificial cell system.

[0030] FIG. 1 is a schematic diagram of a method for manufacturing a hydrophilic porous polymer according to one embodiment of the present invention and a macroscopic image of the hydrophilic porous polymer.

[0031] FIG. 2a is a fluorescence microscope image of a water-in-water HIPE having 5 w / v% of colloidal particles including hydrophilic polymer chains according to one embodiment of the present invention, and FIG. 2b is a fluorescence microscope image of a liquid-supporting polymer obtained by UV curing the water-in-water HIPE of FIG. 2a.

[0032] FIG. 3a is a SEM image of an open-cell type hydrophilic porous polymer including a water-in-water HIPE having 1 w / v% of colloidal particles including hydrophilic polymer chains according to one embodiment of the present invention, and FIG. 3b is a SEM image of a closed-cell type hydrophilic porous polymer including a water-in-water HIPE having 5 w / v% of colloidal particles including hydrophilic polymer chains.

[0033] FIG. 4a is a fluorescence microscope image of a water-in-water HIPE having 5 w / v% of colloidal particles including hydrophilic polymer chains according to one embodiment of the present invention, and FIG. 4b is a fluorescence microscope image of a liquid-supporting polymer obtained by UV curing the water-in-water HIPE of FIG. 4a.

[0034] FIG. 5a is a SEM image of an open-cell type hydrophilic porous polymer including a water-in-water HIPE having 1 w / v% of colloidal particles including hydrophilic polymer chains according to one embodiment of the present invention, and FIG. 5b is a SEM image of a closed-cell type hydrophilic porous polymer including a water-in-water HIPE having 5 w / v% of colloidal particles including hydrophilic polymer chains.

[0035] FIG. 6a is a hydrophilic porous polymer having an open-cell structure according to an embodiment of the present invention, and FIG. 6b is a macroscopic image of a hydrophilic porous polymer having a closed-cell structure.

[0036] Figure 7 is an image of polymerization after leaving the underwater HIPE according to an embodiment of the present invention for 25 hours or more.

[0037] FIG. 8a is a state diagram of a hydrophilic polymer chain mixture according to one embodiment of the present invention and a macroscopic image of an ATPS including the mixture, FIG. 8b is a schematic diagram showing the depletion force at a water-in-water interface, FIG. 8c is an image showing the results of observing the behavior of colloidal particles at a water-in-water interface over time and a schematic diagram of colloidal particle aggregation at a water-in-water interface due to the depletion force, FIG. 8d is an image showing the results of increasing the size of colloidal aggregates over time due to capillary attraction, and FIG. 8e is an image showing the interfacial desorption process of large colloidal particle aggregates within 1 minute.

[0038] Figure 9 is a cross-sectional view showing the behavior of colloidal particles at an underwater water interface according to one embodiment of the present invention.

[0039] FIG. 10a is a schematic diagram showing colloidal particles including hydrophilic polymer chains at a water-in-water interface preventing particle aggregation according to one embodiment of the present invention, and an image showing experimental observation results for the behavior of colloidal particles including hydrophilic polymer chains at a water-in-water interface over time, FIG. 10b is a graph showing the stability duration of water-in-water emulsions surface-modified with different mass ratios of hydrophilic polymer chains to colloidal particles and changes in zeta potential of colloidal particles, and FIG. 10c is a graph showing the stability duration of water-in-water emulsions surface-modified with different lengths of hydrophilic polymer chains at a fixed mass ratio.

[0040] FIG. 11a is a SEM image of polystyrene particles according to an embodiment of the present invention, FIG. 11b is a SEM image of colloidal particles including carboxyl groups, and FIG. 11c is an image observing the density of polystyrene particles in ATPS through a centrifugation process.

[0041] FIG. 12a is a schematic diagram of the formation mechanism of an underwater HIPE according to an embodiment of the present invention, FIG. 12b is a DIC (differential interference contrast) microscopy image of an underwater HIPE filled with hexagons on the surface of a droplet, FIG. 12c is a fluorescence microscopy image of an underwater HIPE rich in hydrophilic polymer chains encapsulated in a colloidal particle layer, FIG. 12d is an optical microscopy image of an underwater HIPE rich in hydrophilic polymer chains encapsulated in a colloidal particle layer after 1 hour, and FIG. 12e is an optical microscopy image of an underwater HIPE rich in hydrophilic polymer chains encapsulated in a colloidal particle layer after 24 hours.

[0042] Fig. 13a is a graph showing the change in droplet size of HIPE in water according to the change in colloidal particle concentration according to an embodiment of the present invention, and Fig. 13b is a graph showing the change in droplet size of HIPE in water according to the change in homogenization speed.

[0043] Hereinafter, embodiments are described in detail with reference to the attached drawings. However, the embodiments may be modified in various ways, and the scope of the patent application is not limited or restricted by these embodiments. It should be understood that all modifications, equivalents, or alternatives to the embodiments are included within the scope of the patent application.

[0044] The terms used in the examples are for illustrative purposes only and should not be construed as limiting. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "comprise" or "have" are intended to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but should be understood to not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0045] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the embodiments pertain. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0046] In addition, when describing with reference to the attached drawings, the same components will be given the same reference numerals regardless of the drawing numbers, and redundant descriptions thereof will be omitted. When describing an embodiment, if a detailed description of a related known technology is judged to unnecessarily obscure the gist of the embodiment, the detailed description thereof will be omitted. In addition, when describing components of the embodiment, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only to distinguish the components from other components, and the nature, order, or sequence of the components are not limited by the terms.

[0047] Components included in one embodiment and components with common functions will be described using the same names in other embodiments. Unless otherwise stated, the descriptions given in one embodiment may also apply to other embodiments, and detailed descriptions will be omitted to the extent of overlap.

[0048] Hereinafter, a semiconductor wind speed sensor including a through hole with an inclined side surface and a method for manufacturing the same according to the present invention will be described in detail with reference to examples and drawings. However, the present invention is not limited to these examples and drawings.

[0049]

[0050] The method for producing a hydrophilic porous polymer of the present invention comprises the steps of: preparing a HIPE (high internal buoyancy emulsion); curing the HIPE with UV to obtain a liquid-supporting polymer; and drying the liquid-supporting polymer to obtain a hydrophilic porous polymer.

[0051] FIG. 1 is a schematic diagram of a method for manufacturing a hydrophilic porous polymer according to one embodiment of the present invention and a macroscopic image of the hydrophilic porous polymer.

[0052] Referring to Figure 1, a schematic diagram illustrating a manufacturing process of a hydrophilic porous polymer is provided. It can be confirmed that a HIPE (high internal buoyancy emulsion) is prepared, a liquid-supporting polymer is obtained by UV curing the HIPE, and a hydrophilic porous polymer is obtained by drying the liquid-supporting polymer. In addition, a macroscopic image of the hydrophilic porous polymer confirms that it has been well obtained.

[0053] In one embodiment, the liquid-carrying polymer may be a system in which the continuous phase is initially polymerized to form a polymer film, while the liquid remains in the dispersed phase (=internal phase) without polymerization. This may be capable of encapsulating a desired liquid and protecting it from deterioration, etc.

[0054] According to one embodiment, since the HIPE (high internal buoyancy emulsion) is composed entirely of water, including a water-in-water (W / W) interface, the emulsion can be prepared by adding the liquid to be filled in the initial stage, and then polymerizing it into a polymer, thereby easily synthesizing a polymer loaded with the desired liquid, thereby reducing constraints on time / process, etc., and allowing polymerization in various forms according to the form to be applied, which has the advantage of being possible.

[0055] According to one embodiment, the hydrophilic porous polymer can be simply manufactured without problems caused by conventional surface residual substances (oil, surfactant, etc.) and without requiring additional processes (washing and hydrophilic coating) for a hydrophilic surface.

[0056] In one embodiment, the hydrophilic porous polymer may be a highly functional, bio- and environmentally friendly hydrophilic porous polymer in which the entire system appears as an aqueous solution.

[0057]

[0058] According to one embodiment, in the step of preparing the HIPE (high internal buoyancy emulsion), the HIPE comprises a water-in-water (W / W) interface, and the interface comprises at least one selected from the group consisting of polyethylene glycol (PEG), dextran (DEX), polyvinyl alcohol (PVA), gelatin (Gel), maltodextrin (MAL), sodium caseinate, starch, sodium sulfate, magnesium sulfate, corn starch, alginate (Alg), amylopectin (AMP), xyloglucan (XG), xanthan gum, pectin, polyethylene glycol diacrylate (PEGDA), and gelatin methacryloyl (GelMA), and the HIPE comprises an emulsion stabilizer, and the emulsion stabilizer comprises colloidal particles, and the colloidal particles are silica particles, polystyrene particles, gold nanoparticles, liposomes, protein particles, zinc oxide particles, or titanium dioxide. A colloidal particle comprising particles, wherein the colloidal particles may comprise at least one hydrophilic polymer chain selected from the group consisting of polyethylene glycol (PEG), dextran (DEX), polyvinyl alcohol (PVA), deoxyribonucleic acid (DNA), chitosan, hyaluronic acid, alginic acid, gelatin, collagen, and cellulose.

[0059] In one embodiment, the HIPE may comprise a water-in-water (W / W) interface, and an aqueous two-phase system (ATPS) may be formed, comprising an interface of polymer and polymer or polymer and salt.

[0060] In one embodiment, the interface may include at least one selected from the group consisting of polyethylene glycol (PEG), dextran (DEX), polyvinyl alcohol (PVA), gelatin (Gel), maltodextrin (MAL), sodium caseinate, starch, sodium sulfate, magnesium sulfate, corn starch, alginate (Alg), amylopectin (AMP), xyloglucan (XG), xanthan gum, pectin, polyethylene glycol diacrylate (PEGDA), and gelatin methacryloyl (GelMA).

[0061] In one embodiment, the HIPE may have a slow phase separation rate by including an emulsion stabilizer.

[0062] According to one embodiment, the emulsion stabilizer of the HIPE may include colloidal particles so that the HIPE may be a Pickering emulsion.

[0063] In one embodiment, the colloidal particles are adsorbed at the interface due to a decrease in free energy at the liquid-liquid interface, and this decrease in free energy may be a driving force for the irreversible adsorption of the stabilizer particles at the interface. Furthermore, the colloidal stabilizer particles adsorbed at the interface may provide an excellent barrier to the droplet particles by preventing direct contact with adjacent droplet particles.

[0064] In one embodiment, the colloidal particles may include silica particles or polystyrene particles, wherein the silica particles or polystyrene particles have a high density, which allows the particles to better gather together, thereby accelerating particle detachment from the interface.

[0065] In one embodiment, the colloidal particles may have hydrophilic polymer chains attached thereto to prevent the particles from agglomerating with each other.

[0066]

[0067] According to one embodiment, the step of preparing the HIPE (high internal buoyancy emulsion) further includes a step of adding a monomer, a crosslinking agent, and a photoinitiator, wherein the monomer includes at least one selected from the group consisting of acrylic acid (AA), acrylamide (AAM), gelatin methacryloyl (GelMA), polyethylene glycol diacrylate (PEGDA), polyethylene glycol methacrylate (PEGMA), and polyethylene glycol dimethacrylate (PEGDMA), wherein the crosslinking agent is N,N'-methylenebisacrylamide (MBAA), and the photoinitiator is benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylanino acetophenone, lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP), A polymer comprising at least one selected from the group consisting of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiope (Irgacure 2959) benzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethylketal, acetophenone dimethylketal and 2-hydroxy-2-methylpropiope (Darocur 1173), wherein the monomer is 1 wt% to 10 wt% of the HIPE, and the crosslinker is 2 wt% of the HIPE. The following is provided, and the photoinitiator may be present in an amount of 0.1 wt% to 0.5 wt% of the HIPE.

[0068] In one embodiment, the monomer may be present in an amount of 1 wt% to 10 wt%; 3 wt% to 10 wt%; 5 wt% to 10 wt%; 7 wt% to 10 wt%; 9 wt% to 10 wt%; 1 wt% to 9 wt%; 1 wt% to 7 wt%; 1 wt% to 5 wt%; 1 wt% to 3 wt%; 1 wt% to 2 wt% of the HIPE.

[0069] According to one embodiment, if the monomer is less than 1 wt% of the HIPE, there may be a problem in that the continuous phase is not evenly polymerized, and if it is more than 10 wt%, there may be a problem due to unreacted monomer remaining after photopolymerization.

[0070] In one embodiment, when the crosslinking agent exceeds 2 wt% of the HIPE, there may be a problem in that an excessively hard material is synthesized.

[0071] In one embodiment, the photoinitiator may be present in an amount of 0.1 wt% to 0.5 wt%; 0.15 wt% to 0.5 wt%; 0.2 wt% to 0.5 wt%; 0.25 wt% to 0.5 wt%; 0.3 wt% to 0.5 wt%; 0.35 wt% to 0.5 wt%; 0.4 wt% to 0.5 wt%; 0.45 wt% to 0.5 wt%; 0.1 wt% to 0.4 wt%; 0.1 wt% to 0.3 wt%; 0.1 wt% to 0.2 wt%; 0.1 wt% to 0.15 wt% of the HIPE.

[0072] According to one embodiment, when the photoinitiator is less than 0.1 wt% of the HIPE, there may be a problem in that the continuous phase is not polymerized evenly, and when it is more than 0.5 wt%, there may be a problem in that the polymerization is performed without distinction between the dispersed phase and the continuous phase due to excessive polymerization.

[0073] According to one embodiment, the step of preparing the HIPE (high internal buoyancy emulsion) may further include the step of adding a thermal initiator, and the thermal initiator may be a peroxide compound or an azo compound.

[0074] In one embodiment, the thermal initiator is, more specifically, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile) and 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), tetramethylbutylperoxy neodecanoate, bis(4-butylcyclohexyl)peroxydicarbonate, di(2-ethylhexyl)peroxy carbonate, butylperoxy neodecanoate, dipropyl peroxy dicarbonate, diisopropyl peroxy dicarbonate, diethoxyethyl peroxy dicarbonate, diethoxyhexylperoxy dicarbonate, hexyl peroxy dicarbonate, dimethoxybutyl peroxy dicarbonate, At least one selected from the group consisting of bis(3-methoxy-3-methoxybutyl) peroxy dicarbonate, dibutyl peroxy dicarbonate, dicetyl peroxy dicarbonate, dimyristyl peroxy dicarbonate, 1,1,3,3-tetramethylbutyl peroxy pivalate, hexyl peroxy pivalate, butyl peroxy pivalate, trimethyl hexanoyl peroxide, dimethyl hydroxy butyl peroxy neo decanoate, amyl peroxy neo decanoate, butyl peroxy neo decanoate, t-butylperoxy neoheptanoate, amylperoxy pivalate, t-butylperoxy pivalate, t-amyl peroxy-2-ethylhexanoate, lauryl peroxide, dilauroyl peroxide, didecanoyl peroxide, benzoyl peroxide and dibenzoyl peroxide It may include.

[0075]

[0076] The hydrophilic porous polymer of the present invention is a hydrophilic porous polymer manufactured by the manufacturing method of the present invention, and when the colloidal particles in the HIPE are 1 w / v% to 5 w / v%, it has an open cell form including interconnected pores, and when the colloidal particles in the HIPE are 5 w / v% to 10 w / v%, it has a closed cell form including non-interconnected pores.

[0077] According to one embodiment, the hydrophilic porous polymer of the present invention may have an open cell form including interconnected pores or a closed cell form including non-interconnected pores, regardless of the type of the colloidal particles in the HIPE, depending on the w / v% of the colloidal particles.

[0078] FIG. 3a is a SEM image of an open-cell type hydrophilic porous polymer including a water-in-water HIPE having 1 w / v% of colloidal particles including hydrophilic polymer chains according to one embodiment of the present invention, and FIG. 3b is a SEM image of a closed-cell type hydrophilic porous polymer including a water-in-water HIPE having 5 w / v% of colloidal particles including hydrophilic polymer chains.

[0079] Referring to FIG. 3a, it can be confirmed that it is an SEM image of an open-cell type hydrophilic porous polymer containing 1 w / v% of silica (SP) particles containing PEG chains in water-in-water HIPE, and the scale bar may be 50 μm, and the scale bar of the image showing the enlarged internal structure on the upper left may be 20 μm.

[0080] Referring to FIG. 3b, it can be confirmed that it is an SEM image of a closed-cell hydrophilic porous polymer containing 5 w / v% of silica (SP) particles containing PEG chains in water-in-water HIPE, and the scale bar may be 50 μm, and the scale bar of the image showing the enlarged internal structure on the upper left may be 20 μm.

[0081] FIG. 5a is a SEM image of an open-cell type hydrophilic porous polymer including a water-in-water HIPE having 1 w / v% of colloidal particles including hydrophilic polymer chains according to one embodiment of the present invention, and FIG. 5b is a SEM image of a closed-cell type hydrophilic porous polymer including a water-in-water HIPE having 5 w / v% of colloidal particles including hydrophilic polymer chains.

[0082] Referring to FIG. 5a, it can be confirmed that it is an SEM image of an open-cell type hydrophilic porous polymer containing 1 w / v% of polystyrene (PS) particles containing PEG chains, HIPE in water, and the scale bar may be 50 μm, and the scale bar of the image showing the enlarged internal structure on the upper left may be 20 μm.

[0083] Referring to FIG. 5b, it can be confirmed that it is a SEM image of a closed-cell hydrophilic porous polymer containing 5 w / v% of polystyrene (PS) particles containing PEG chains in water-in-water HIPE, and the scale bar may be 50 μm, and the scale bar of the image showing the enlarged internal structure on the upper left may be 20 μm.

[0084] According to one embodiment, the hydrophilic porous polymer of the present invention may have a problem with emulsion stability when the colloidal particles in the HIPE are less than 1 w / v%, and when they are more than 10 w / v%, there may be a problem with the polymerized polymer film becoming thicker.

[0085]

[0086] According to one embodiment, when the size of the colloidal particles of the hydrophilic porous polymer is 1 μm or more, the colloidal particles may be exposed on the surface of the hydrophilic porous polymer membrane.

[0087] According to one embodiment, when the size of the colloidal particles of the hydrophilic porous polymer is 1 μm or more, the colloidal particles are exposed on the surface of the hydrophilic porous polymer membrane, and a functional group exhibiting the characteristics of the colloidal particles is imparted to the hydrophilic porous polymer, thereby allowing the hydrophilic porous polymer to have the characteristics of the colloidal particles.

[0088] For example, in the case of a hydrophilic porous polymer synthesized as a water-in-water HIPE (High Internal Phase Emulsion) stabilized using 1 μm silica particles, the silica particles are exposed to the polymer surface after synthesis, resulting in the effect of -OH groups. This can reduce the need for additional modification processes such as polydopamine to provide -OH groups.

[0089] According to one embodiment, when the size of the colloidal particles in the hydrophilic porous polymer is less than 1 μm, there may be a problem in that the colloidal particles are trapped in the polymerized polymer film and are not exposed to the surface.

[0090] According to one embodiment, the hydrophilic porous polymer may have polyhedral pores with a substantially constant wall thickness, and may have good mechanical strength for application in various fields, so that it may be applied in various fields.

[0091]

[0092] The water-in-water Pickering emulsion of the present invention forms an aqueous two-phase system (ATPS) and includes an interface between polymers or polymers and salts.

[0093] In one embodiment, an aqueous two-phase system (ATPS) is a phase-separated system that occurs due to incompatibility between hydrophilic polymers in an aqueous solution, and a water-in-water interface can be formed. The ATPS has permeability at the interface, allowing free diffusion and exchange of substances. In a water-in-water emulsion utilizing this property, molecular units (such as DNA and water molecules) can be introduced and exported between the external and internal phases, which can exhibit extremely high permeability. The advantages of a water-in-water emulsion include that it is a highly biocompatible and harmless system, that it can deliver active ingredients through droplets (dispersed phase), that it can form an oil-free system, and that it can form a water-in-water interface with naturally occurring ingredients such as gelatin, maltodextran, starch, and locust bean gum (LBG).

[0094] In one embodiment, an aqueous two-phase system (ATPS) may include a polymer / salt system and a polymer / polymer system. For example, a polymer / salt system has high interfacial tension, allowing for emulsion stabilization with silica particles and exhibiting excellent emulsion stability (over one year). However, salt systems have the disadvantage of being difficult to apply to biological systems due to the in vivo toxicity of the salt (e.g., cell death depending on concentration). In contrast, the present invention provides a water-in-water Pickering emulsion comprising an interface of a polymer and a polymer or a polymer and a salt, thereby utilizing the advantages of water-in-water emulsions.

[0095]

[0096] According to one embodiment, the interface comprises at least one selected from the group consisting of polyethylene glycol (PEG), dextran (DEX), polyvinyl alcohol (PVA), gelatin (Gel), maltodextrin (MAL), sodium caseinate, starch, sodium sulfate, magnesium sulfate, corn starch, alginate (Alg), amylopectin (AMP), xyloglucan (XG), xanthan gum, pectin, polyethylene glycol diacrylate (PEGDA) and gelatin methacryloyl (GelMA), the emulsion comprises an emulsion stabilizer, the emulsion stabilizer comprises colloidal particles, the colloidal particles comprise silica particles, polystyrene particles, gold nanoparticles, liposomes, protein particles, zinc oxide particles or titanium dioxide particles, and the colloidal particles comprise polyethylene glycol (PEG), dextran (DEX), polyvinyl alcohol (PVA), It may comprise at least one hydrophilic polymer chain selected from the group consisting of deoxyribonucleic acid (DNA), chitosan, hyaluronic acid, alginic acid, gelatin, collagen, and cellulose.

[0097] In one embodiment, the emulsion may have a slow phase separation rate by including an emulsion stabilizer.

[0098] According to one embodiment, the emulsion stabilizer of the emulsion may include colloidal particles so that the emulsion may be a Pickering emulsion.

[0099] In one embodiment, the colloidal particles are adsorbed at the interface due to a decrease in free energy at the liquid-liquid interface, and this decrease in free energy may be a driving force for the irreversible adsorption of the stabilizer particles at the interface. Furthermore, the colloidal stabilizer particles adsorbed at the interface may provide an excellent barrier to the droplet particles by preventing direct contact with adjacent droplet particles.

[0100] In one embodiment, the colloidal particles may include silica particles, polystyrene particles, gold nanoparticles, liposomes, protein particles, zinc oxide particles, or titanium dioxide particles, wherein the particles are better brought together by depletion force, thereby accelerating particle detachment from the interface.

[0101] According to one embodiment, the colloidal particles may have hydrophilic polymer chains attached thereto to prevent the particles from agglomerating with each other due to various interactions (depletion forces and capillary forces).

[0102] According to one embodiment, since the types of the particles and the hydrophilic polymer chains can be used without limitation, colloidal particles synthesized by a complex method can be omitted, and thus, the particles can be easily supplied at a low price, which is economical, and high stability of water-in-water emulsions can be secured through a very simple method, and additionally, HIPEs having polygonal droplets can be easily obtained.

[0103] Figure 9 is a cross-sectional view showing the behavior of colloidal particles at an underwater water interface according to one embodiment of the present invention.

[0104] Referring to Fig. 9, , And,

[0105] F t > F g : There is no interfacial desorption of particles,

[0106] F t < F g : Interfacial desorption of particles occurs.

[0107] = interfacial tension, r = particle agglomeration radius, = particle density, V = total volume (particle agglomeration), and g = acceleration due to gravity.

[0108]

[0109] According to one embodiment, the diameter of the colloidal particles may be 0.01 μm to 100 μm, the colloidal particles may be 1 w / v% to 10 w / v% of the emulsion, the molecular weight of the hydrophilic polymer chain may be 100 to 500,000, and the weight ratio of the hydrophilic polymer chain and the colloidal particles may be 0.001:1 to 10:1.

[0110] In one embodiment, the diameter of the colloidal particles is 0.01 μm to 100 μm; 0.1 μm to 100 μm; 1 μm to 100 μm; 5 μm to 100 μm; 10 μm to 100 μm; 30 μm to 100 μm; 50 μm to 100 μm; 70 μm to 100 μm; 90 μm to 100 μm; 0.01 μm to 90 μm; 0.01 μm to 80 μm; 0.01 μm to 50 μm; 0.01 μm to 20 μm; 0.01 μm to 10 μm; 0.01 μm to 5 μm; 0.01 μm to 1 μm; 0.01 μm to 0.1 μm; It could be.

[0111] According to one embodiment, when the diameter of the colloidal particles is less than 0.01 μm, there may be a problem with interfacial adsorption of the colloidal particles due to the extremely low interfacial tension of the water-in-water interface, and when it is more than 100 μm, there may be a problem with stabilization of the Pickering emulsion due to the particles not being uniformly dispersed in the continuous phase.

[0112]

[0113] In one embodiment, the colloidal particles are present in the emulsion at 1 w / v% to 10 w / v%; 1 w / v% to 8 w / v%; 1 w / v% to 6 w / v%; 1 w / v% to 4.5 w / v%; 1 w / v% to 4 w / v%; 1 w / v% to 3.5 w / v%; 1 w / v% to 3 w / v%; 1 w / v% to 2.5 w / v%; 1 w / v% to 2 w / v%; 1 w / v% to 1.5 w / v%; 1.5 w / v% to 10 w / v%; 2 w / v% to 10 w / v%; 2.5 w / v% to 10 w / v%; It may be 3.5 w / v% to 10 w / v%; 4 w / v% to 10 w / v%; 5.5 w / v% to 10 w / v%; 7 w / v% to 10 w / v%.

[0114] According to one embodiment, when the colloidal particles are less than 1 w / v% in the emulsion, there may be a problem due to insufficient colloidal particles for stabilizing the interface, and when the colloidal particles are more than 10 w / v%, there may be a problem due to the colloidal particles being included in greater concentration than necessary for stabilizing the interface.

[0115]

[0116] In one embodiment, the molecular weight of the hydrophilic polymer chain is 100 to 500,000; 500 to 500,000; 1,000 to 500,000; 2,000 to 500,000; 5,000 to 500,000; 10,000 to 500,000; 50,000 to 500,000; 100,000 to 500,000; 200,000 to 500,000; 300,000 to 500,000; 400,000 to 500,000; 100 to 400,000; 100 to 300,000; 100 to 200,000; It may be 100 to 100,000; 100 to 50,000; 100 to 10,000; 100 to 5,000; 100 to 1,000;

[0117] According to one embodiment, when the molecular weight of the hydrophilic polymer chain is less than 100, there may be a problem in that it is difficult to prevent various interactions (depletion force and capillary force) at the water-in-water interface due to the polymer chain length being too short, and when it exceeds 500,000, there may be a problem in that the hydrophilic polymer chains become entangled with each other, thereby hindering the attachment of the hydrophilic polymer chains to the colloidal particles.

[0118]

[0119] According to one embodiment, the weight ratio of the hydrophilic polymer chain and the colloidal particle is 0.001:1 to 10:1; 0.005:1 to 10:1; 0.01:1 to 10:1; 0.05:1 to 10:1; 0.1:1 to 10:1; 0.5:1 to 10:1; 0.8:1 to 10:1; 1:1 to 10:1; 3:1 to 10:1; 5:1 to 10:1; 7:1 to 10:1; 0.001:1 to 9:1; 0.001:1 to 5:1; 0.001:1 to 1:1; It may be 0.001:1 to 0.5:1; 0.001:1 to 0.1:1; 0.001:1 to 0.05:1; 0.001:1 to 0.03:1; 0.001:1 to 0.01:1;

[0120] According to one embodiment, if the weight ratio of the hydrophilic polymer chain and the colloidal particle is outside the above range, there may be a problem in that the hydrophilic polymer chain is insufficient or too much to attach to the colloidal particle, thereby interfering with surface attachment.

[0121]

[0122] According to one embodiment, the emulsion is a HIPE (high internal phase emulsion) having an internal phase volume ratio of 74% or more in the emulsion, droplets of the HIPE are in a polygonal dispersion form, and the droplet size of the HIPE may be 100 ㎛ to 3000 ㎛.

[0123] According to one embodiment, the emulsion may be a HIPE (high internal phase emulsion) having an internal phase volume ratio of 74% or more in the emulsion.

[0124] In one embodiment, the HIPE (high internal buoyancy emulsion) may be observed by increasing the viscosity of the continuous phase by increasing the concentration of particles.

[0125] According to one embodiment, the droplets of the HIPE may have a polygonal dispersion shape and may have high stability to withstand gravity and maintain their shape.

[0126] In one embodiment, the emulsion may have the problem of not being a high internal phase emulsion having a very high surface area to volume ratio when the internal phase volume ratio of the emulsion is less than 74%.

[0127] In one embodiment, the droplet size of the HIPE is 10 μm to 3000 μm; 100 μm to 3000 μm; 200 μm to 3000 μm; 400 μm to 3000 μm; 600 μm to 3000 μm; 800 μm to 3000 μm; 1000 μm to 3000 μm; 1200 μm to 3000 μm; 1500 μm to 3000 μm; 1800 μm to 3000 μm; 2000 μm to 3000 μm; 2200 μm to 3000 μm; 2500 μm to 3000 μm; 2800 μm to 3000 μm; It may be 10 ㎛ to 2500 ㎛; 10 ㎛ to 2000 ㎛; 10 ㎛ to 1500 ㎛; 10 ㎛ to 1000 ㎛; 10 ㎛ to 500 ㎛; 10 ㎛ to 300 ㎛; 10 ㎛ to 100 ㎛.

[0128] According to one embodiment, the HIPE can be easily manufactured and has the advantage of being able to control the droplet size of the HIPE in various ways.

[0129]

[0130] The method for producing a water-in-water Pickering emulsion of the present invention comprises the steps of dispersing a hydrophilic polymer chain in DI water to obtain a solution; dispersing colloidal particles in the solution to obtain an emulsion; and homogenizing the emulsion at a speed of 2000 rpm to 20,000 rpm for 1 to 5 minutes.

[0131] In one embodiment, the step of homogenizing the emulsion at a speed of 2000 rpm to 20,000 rpm for 1 to 5 minutes; wherein the emulsion is homogenized at a speed of 2000 rpm to 20,000 rpm; 3000 rpm to 20,000 rpm; 5000 rpm to 20,000 rpm; 7000 rpm to 20,000 rpm; 9000 rpm to 20,000 rpm; 10,000 rpm to 20,000 rpm; 12,000 rpm to 20,000 rpm; 15,000 rpm to 20,000 rpm; 17,000 rpm to 20,000 rpm; 2000 rpm to 18,000 rpm; 2000 rpm to 15,000 rpm; It can be homogenized at a speed of 2000 rpm to 10000 rpm; 2000 rpm to 8000 rpm; 2000 rpm to 6000 rpm; 2000 rpm to 4000 rpm.

[0132] According to one embodiment, when the emulsion is homogenized at a speed less than 2000 rpm, there may be a problem of uneven homogenization, and when the emulsion is homogenized at a speed exceeding 20000 rpm, there may be a problem of deformation of hydrophilic polymer chains due to heat generation in the homogenizer.

[0133]

[0134] In one embodiment, the step of homogenizing the emulsion at a speed of 2000 rpm to 20,000 rpm for 1 minute to 5 minutes may include homogenizing the emulsion for 1 minute to 5 minutes; 2 minutes to 5 minutes; 3 minutes to 5 minutes; 4 minutes to 5 minutes; 1 minute to 4 minutes; 1 minute to 3 minutes; 1 minute to 2 minutes; 2 minutes to 3 minutes; 3 minutes to 4 minutes.

[0135] In one embodiment, when the emulsion is homogenized for less than 1 minute, there may be a problem of insufficient homogenization, and when the emulsion is homogenized for more than 5 minutes, there may be a problem of deteriorating the stability of the emulsion due to an excessive homogenization process.

[0136] In one embodiment, the step of homogenizing the emulsion may have the advantage of being easy to mass-produce at low cost.

[0137]

[0138]

[0139] Hereinafter, the present invention will be described in more detail by way of examples and comparative examples.

[0140] However, the following examples are only intended to illustrate the present invention, and the content of the present invention is not limited to the following examples.

[0141]

[0142] Example 1: Preparation of hydrophilic porous polymer

[0143] Formation of water-in-water (W / W) HIPEs containing monomers

[0144] Polyethylene glycol (PEG) stock solution was prepared by dissolving 7.64 wt% of PEG in DI water and dispersing 5k-PEG chain-attached silica colloidal particles and 5k-PEG chain-attached polystyrene colloidal particles (SP-PEG and PS-PEG) at concentrations of 1 and 5 w / v%.

[0145] Next, 7 wt% of acrylic acid as a monomer, 2.5 wt% of N,N'-methylenebisacrylamide (99%, Sigma-Aldrich) as a crosslinking agent, and lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP,) as a radical photoinitiator were added. 95%, Sigma-Aldrich) was added to the solution at a ratio of 1.30 mol% to acrylic acid.

[0146] Dextran (DEX) stock solution was prepared by dissolving 10.29 wt% DEX in DI water. All stock solutions were made to the final concentration.

[0147] The prepared PEG and DEX aqueous solutions were placed in a glass bottle and stirred at 11,000 rpm for 3 minutes using a homogenizer to form W / W HIPE, and then left in a dark room until a stable W / W HIPE was formed.

[0148]

[0149] Polymerization of water-in-water (W / W) HIPEs

[0150] Next, the emulsion was photopolymerized by exposing it to 700 W UV light for 30 minutes using a UV curing device (RX-CB1500D-DJT, Raynics).

[0151] To clearly observe the internal structure of the polymerized W / W HIPEs, 0.05 w / v% of FITC-labeled dextran (which emits green light with excitation / emission wavelengths of 495 / 525 nm) was initially dissolved in the DEX-rich phase, and the internal structure was thoroughly examined using a confocal microscope (LSM 800 Bio, Carl Zeiss).

[0152]

[0153] FIG. 2a is a fluorescence microscope image of a water-in-water HIPE having 5 w / v% of colloidal particles including hydrophilic polymer chains according to one embodiment of the present invention, and FIG. 2b is a fluorescence microscope image of a liquid-supporting polymer obtained by UV curing the water-in-water HIPE of FIG. 2a.

[0154] Referring to Fig. 2a, a water-in-water HIPE having 5 w / v% silica (SP) particles containing PEG chains can be confirmed, and referring to Fig. 2b, a liquid support polymer obtained by photopolymerizing the HIPE using a UV curing device can be confirmed. The system can be composed of a continuous phase of a polymerized polymer support and an internal phase including a DEX-rich phase.

[0155] FIG. 4a is a fluorescence microscope image of a water-in-water HIPE having 5 w / v% of colloidal particles including hydrophilic polymer chains according to one embodiment of the present invention, and FIG. 4b is a fluorescence microscope image of a liquid-supporting polymer obtained by UV curing the water-in-water HIPE of FIG. 4a.

[0156] Referring to Fig. 4a, a water-in-water HIPE having 5 w / v% polystyrene (PS) particles containing PEG chains can be confirmed, and referring to Fig. 4b, a liquid support polymer obtained by photopolymerizing the HIPE using a UV curing device can be confirmed. The system can be composed of a continuous phase of a polymerized polymer support and an internal phase including a DEX-rich phase.

[0157]

[0158] Formation of hydrophilic porous polymers

[0159] After hardening the W / W HIPEs, they were frozen in liquid nitrogen and freeze-dried in a freeze dryer (FDU-1200, Sunileella) for 48 to 72 hours to remove the internal phase.

[0160] Additionally, the morphology of poly-HIPEs was characterized using a scanning electron microscope (SEM, Tescan VEGA3) at 15.0 kV. All samples were completely dried and sputter-coated with platinum before observation.

[0161]

[0162] FIG. 6a is a hydrophilic porous polymer having an open-cell structure according to an embodiment of the present invention, and FIG. 6b is a macroscopic image of a hydrophilic porous polymer having a closed-cell structure.

[0163] Referring to FIGS. 6a and 6b, the scale bar is 1 cm, and it can be seen that a hydrophilic porous polymer with open-cell and closed-cell structures is well formed.

[0164]

[0165] Figure 7 is an image of polymerization after leaving the underwater HIPE according to an embodiment of the present invention for 25 hours or more.

[0166] Referring to Fig. 7, it can be confirmed that when HIPE is manufactured and left for a sufficient period of time (more than 25 hours), a structure is created in which the dispersed phase is polymerized into an open-cell structure during polymerization.

[0167]

[0168] Conclusions for Example 1

[0169] In conclusion, long-term stability of HIPEs in water was successfully achieved by attaching polymer chains to typical colloidal particles. Since this improvement primarily stems from entropic effects, this approach can be universally applied regardless of the type of polymer chain (e.g., PEG, DEX, and PVA) or particle type (e.g., silica and PS).

[0170] By involving a continuous phase polymerization process, a semi-solid system in which droplets are surrounded by a polymer matrix was successfully prepared, and a macroporous polymer material was easily prepared through an additional evaporation process of the dispersed phase.

[0171]

[0172] Example 2: Building a phase diagram

[0173] Phase density measurement

[0174] The phase density for constructing the phase diagram was determined using a pycnometer (10 ml, DAIHAN scientific). Two empty pycnometers were marked 1 and 2 and the weights were , was measured. After adding distilled water (DI water) to each pycnometer, the volume of the pycnometer was calculated using the well-known density of distilled water. and was re-weighted. ( )

[0175] 1.8618 g of polyethylene glycol (PEG, Mw=20k, Sigma-Aldrich) and 2.5076 g of dextran (DEX, Mw=40k, Sigma-Aldrich) were dissolved in 20 mL of DI water and phases were separated. Specific amounts of the PEG-rich phase and the DEX-rich phase were added separately to pycnometers 1 and 2, and the total mass of each pycnometer was measured. , The density of each rich phase was calculated using the following formula ( ) was calculated using the equation. The density of each phase was calculated as 1.0208 g / ml for the PEG-rich phase and 1.0876 g / ml for the DEX-rich phase.

[0176]

[0177] Sangdo composition

[0178] The phase diagram of an aqueous two-phase system (ATPS) containing PEG and DEX was established through a turbidity titration experiment. 3 ml of PEG and DEX solutions with concentrations that allowed phase separation were placed in a 15 ml tube and centrifuged at 4500 rpm for 10 minutes using a centrifuge (Cef-8, DAIHAN scientific) to confirm phase separation. Subsequently, 0.1 ml of DI water was added to the solution, mixed, and centrifuged repeatedly until no phase separation occurred after centrifugation.

[0179] The composition of the solution was calculated by the mass of DEX, PEG, and DI water, excluding the mass of the last added DI water. (The mass fraction of each polymer is represented by X and Y in the equation below.)

[0180] The above experimental process was repeated for 16 solutions of PEG and DEX with different concentrations to obtain each composition, and the equation for the binodal curve was obtained using the curve fitting method using the obtained composition ( ).

[0181]

[0182] FIG. 8a is a state diagram of a hydrophilic polymer chain mixture according to one embodiment of the present invention and a macroscopic image of an ATPS including the mixture, FIG. 8b is a schematic diagram showing the depletion force at a water-in-water interface, FIG. 8c is an image showing the results of observing the behavior of colloidal particles at a water-in-water interface over time and a schematic diagram of colloidal particle aggregation at a water-in-water interface due to the depletion force, FIG. 8d is an image showing the results of increasing the size of colloidal aggregates over time due to capillary attraction, and FIG. 8e is an image showing the interfacial desorption process of large colloidal particle aggregates within 1 minute.

[0183] Referring to Figure 8a, the left drawing is a phase diagram of a mixture of 20k-PEG and 40k-DEX measured at room temperature. The binodal curve (solid black line) in which the upper right region represents ATPS and the lower left region represents a one-phase system was determined using turbidity titration experiments, and the tie line (dashed black line) was estimated from the equation developed by Atefi et al.

[0184] The right drawing is a macroscopic image of an ATPS system containing 7.64 wt% 20k-PEG and 10.29 wt% 40k-DEX, indicated by black stars in the phase diagram. The upper phase represents the PEG-rich phase, and the lower phase represents the DEX-rich phase.

[0185] Referring to Fig. 8a, in the first step, a mixture of polyethylene glycol (PEG), a hydrophilic polymer, and dextran (DEX) in water was selected to spontaneously induce ATPS, and ATPS was clearly observed under the experimental conditions of PEG (Mw= 20K, 7.64 wt%) and DEX (Mw= 40K, 10.29 wt%).

[0186] Referring to Figure 8b, a schematic diagram depicting the depletion force at the water-submerged interface is provided. Here, d and h represent the size of the depleting material and the distance between particles, respectively. The arrows indicate the direction of the depletion interaction, which in turn generates the attractive force between particles.

[0187] Interestingly, these two hydrophilic polymers are also expected to function as depleting agents to induce depletion forces between colloidal particles, leading to the formation of particle aggregates at the interface, as shown in Figure 8b. Here, the magnitude of the depletion pressure can ideally be scaled by the osmotic pressure and can be as high as 16.8 kPa at 17.93 wt% concentration of 20K-PEG and 40K-DEX. In reality, the effect of the excluded depleting agent volume can also be considered, which can provide a depletion pressure one order of magnitude larger than the ideal depletion pressure, which agrees well with the 312 kPa obtained from the osmotic pressure measurement. Since the radius of gyration of 20K-PEG and 40K-DEX in water is expected to be ~6.0 nm, the effective distance over which the depletion force acts can be similar to this magnitude.

[0188] Furthermore, when particles are adsorbed at the liquid-liquid interface, deformation of the interface easily occurs, inducing capillary interactions to minimize deformation and form particle aggregates. Here, the interfacial tension between the PEG-rich and DEX-rich phases has been reported to be ~266 μN / m, and therefore the magnitude of the pressure exerted by capillary interactions is expected to be ~1 kPa, especially within the effective length scale of the depletion force.

[0189] Therefore, the depletion force appears to primarily induce particle agglomeration, which can lead to a spontaneous increase in particle agglomeration size at or near the water-in-water interface. Consequently, when gravity begins to dominate over the force retaining the agglomerates at the interface due to interfacial tension, particle agglomeration desorption can ultimately occur. This particle desorption at the interface may be the root cause of the low stability of conventional water-in-water emulsions. The side-view observation of silica particles at the interface successfully supports the aforementioned assertion, as shown in Figures 8c to 8e.

[0190] Figures 8c to 8e show the results of observing particle behavior at the water-submersible interface over time.

[0191] Referring to Fig. 8c, particle aggregates are formed during the first 1 to 2 hours at the water-submerged interface, and the aggregate size grows slowly due to the presence of depletion attraction, the left figure is the result of observing particle behavior at the water-submerged interface over time, and the right figure is a schematic diagram of particle aggregates at the water-submerged interface due to depletion attraction.

[0192] Referring to Fig. 8c, specifically, after applying particles to the interface, a thin particle layer initially appears to exist across the entire interface, and after ~1 hour, relatively small particle aggregates begin to be observed, and the size of the particle aggregates gradually increases over ~1 hour.

[0193] Referring to Fig. 8d, it can be seen that when these particle aggregates are nearby, they come closer to each other through capillary interactions, forming significantly larger aggregates.

[0194] Referring to Figure 8e, once gravity begins to dominate the force that holds the aggregates at the interface due to interfacial tension, particle agglomeration detachment can finally occur within one minute. It should be noted that the time required for particle detachment may vary depending on the number of particles applied and the total surface area of ​​the water-in-water interface.

[0195]

[0196] Example 3: Estimation of various interactions at the water-water interface

[0197] capillary interaction

[0198] When the radius of the particles is less than 5 μm, the capillary interaction between the two particles is , , where γ, Q, L and R represent the interfacial tension, capillary charge, interparticle distance and particle radius, respectively.

[0199] Inequality to express the maximum capillary interaction between two identical particles In Q k Assuming the value is equal to R It becomes.

[0200] Therefore, the maximum magnitude of the pressure induced by capillary interaction is can be simply expressed as, and as a result It becomes 1 kPa.

[0201]

[0202] Depleted workforce

[0203] The ideal value of the depletion pressure is given by the general equation It was calculated from the osmotic pressure expressed as where C, R and T represent the molar concentration of DEX or PEG dispersed in the solution, the universal gas constant and the absolute temperature (Kelvin). The molar concentration calculated from the mass of DEX, PEG and water in the mixture was substituted into the above equation, and the resulting ideal value of the depletion pressure was It became.

[0204] Meanwhile, in an actual case, the osmotic pressure of each phase was measured using an osmometer (Osmomat 030-D, Gonotec) to obtain the osmotic pressure value, and 50 μL of each of the DEX-rich phase and the PEG-rich phase were used.

[0205] As a result, the osmolality of the PEG-rich phase and the DEX-rich phase was measured as 171 mOsm / kg and 120 mOsm / kg, respectively. The measured values ​​were converted to kPa units (PEG-rich phase: 371 kPa, DEX-rich phase: 253 kPa).

[0206] Then, the depletion pressure of the entire mixture based on the average osmotic pressure of the two phases is It was estimated to be.

[0207]

[0208] Example 4: Synthesis of polymer particles

[0209] PS particle synthesis

[0210] Polystyrene (PS) particles were synthesized via dispersion polymerization. Prior to the reaction, styrene (≥99%, Sigma-Aldrich) was passed through a column filled with aluminum oxide (Sigma-Aldrich) to remove reaction inhibitors. Other reagents were used without further purification.

[0211] 10.0 g of styrene, 1.5 g of poly(vinylpyrrolidone) (PVP40, Mw=40k, Sigma-Aldrich), 0.2 g of 2,2-azobis(2-methylpropionitrile) (AIBN, 98%, JUNSEI), and 100.0 g of absolute ethanol (99.5%, DAEJUNG) were added to a 250 mL three-necked reaction flask.

[0212] The reactor was immersed in an oil bed and reacted while stirring using a hot plate stirrer.

[0213] The reaction solution was gradually heated to 70°C with a stirring speed of 200 rpm for 30 minutes while deoxygenating with nitrogen gas. After the temperature reached 70°C, the nitrogen gas injection was stopped and the reaction was allowed to proceed for 12 hours.

[0214] The obtained polystyrene particles were filtered / washed with ethanol to remove unreacted monomers using methyl alcohol (99.8%, DAEJUNG), and then dried in a vacuum oven at 60 °C for 12 hours.

[0215]

[0216] Density of polystyrene particles

[0217] Through experiments to determine the density of each phase, it was confirmed that the densities of the PEG-rich phase and the DEX-rich phase were 1.02 g / ml and 1.08 g / ml, respectively.

[0218] To measure the density of synthesized polystyrene particles, two aqueous solutions of PEG and DEX, each containing 7.64% and 10.29%, respectively, were first prepared, and the polystyrene particles were dispersed in the 1 w / v% PEG solution. Subsequently, each solution was poured into a 1.5 ml tube at a 1:1 ratio and centrifuged at 12,000 rpm for 10 minutes.

[0219] After centrifugation, polystyrene particles were observed to be preferentially located at the water-water interface, forming a thin film, which strongly indicates that the density of the PS particles ranges from 1.02 g / ml to 1.08 g / ml.

[0220]

[0221] PS-COOH particle synthesis

[0222] Carboxylic polystyrene particles (PS-COOH) were synthesized through dispersion polymerization.

[0223] 1.44 g of poly(vinylpyrrolidone) (PVP55, Sigma-Aldrich, Mw= ~55k), 0.45 g of Triton X-100 (TX100, Sigma-Aldrich), 2.55 g of DI water, 48.45 g of ethanol, 9 g of styrene, and 0.36 g of AIBN were added to a 500 mL three-necked reaction flask.

[0224] After a homogeneous solution was formed at room temperature, the solution was deoxygenated by bubbling nitrogen gas at room temperature for 30 minutes.

[0225] The flask was then placed in a 70°C oil bed and mechanically stirred at 150 rpm. A 250-ml three-neck flask was charged with 1.08 g of acrylic acid (AA, 99%, Sigma-Aldrich), 9 g of styrene, 48.45 g of ethanol, and 2.55 g of DI water.

[0226] The AA solution was then deoxygenated by bubbling nitrogen gas at 70°C for 30 minutes. After polymerization for 1 hour, the hot AA solution was added to the reaction flask. The reaction was continued for 16 hours, followed by a cooling process for 30 minutes. After washing with ethanol and DI water and drying, PS-COOH was obtained.

[0227] The morphology of the particles (PS, PS-COOH) was characterized using field emission scanning electron microscopy (FE-SEM, JEOL JSM-6700F) at a voltage of 10.0 kV.

[0228]

[0229] FIG. 11a is a SEM image of polystyrene particles according to an embodiment of the present invention, FIG. 11b is a SEM image of colloidal particles including carboxyl groups, and FIG. 11c is an image observing the density of polystyrene particles in ATPS through a centrifugation process.

[0230] Referring to FIG. 11a, an SEM image of polystyrene (PS) particles according to an embodiment of the present invention shows that the average diameter is about 1.7 μm.

[0231] Referring to FIG. 11b, an SEM image of carboxylic polystyrene (PS-COOH) particles according to an embodiment of the present invention shows that the average diameter is about 2.3 μm.

[0232] Referring to FIG. 11c, a macroscopic image [12000 rpm for 10 minutes (rcf: 9659 xg)] of a polystyrene particle solution (1 w / v%) containing 7.64 wt% of PEG and 10.29 wt% of DEX after a centrifugation process according to an embodiment of the present invention is shown.

[0233] To obtain SEM (scanning electron microscope) images, all samples were coated with platinum and then images were taken. The scale bar of the macroscopic images is 1 cm, and all scale bars of the SEM images are 3 μm.

[0234] The polystyrene particles are preferentially located between the two aqueous phases, which may strongly indicate that the density of the synthesized polystyrene particles is in the range of 1.021 g / ml (density of the PEG-rich phase) to 1.088 g / ml (density of the DEX-rich phase).

[0235]

[0236] Example 5: Particle surface modification EDC coupling reaction

[0237] Polymer chains were attached to the surface of colloidal particles via EDC reaction.

[0238] Experimental details are given below.

[0239] First, 0.1M MES hydrate ( MES buffer solution was prepared by dissolving 99.5%, Sigma-Aldrich) in DI water, and the pH of the buffer solution was adjusted to 6.0 using 0.1 N NaOH (DAEJUNG).

[0240] 0.1 g of carboxylic silica particles (SP-COOH, 0.5 μm or 1 μm, Polysciences) or carboxylic polystyrene particles (PS-COOH) were dissolved in 2.5 mL of MES buffer.

[0241] Next, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC, 0.0383 g of N-hydroxysuccinimide (NHS, 99.0%, Sigma-Aldrich) was added and reacted for 30 minutes to activate the carboxyl group, and then 0.023 g of N-hydroxysuccinimide (NHS, 98% Sigma-Aldrich) was added and reacted for 1 hour.

[0242]

[0243] Silica particles with attached PEG chains

[0244] Surface modification of silica particles was performed using methoxypolyethylene glycol amine (mPEG-NH2, Mw= 5k / 10k, Sigma-Aldrich).

[0245] The reaction solution was prepared by mixing activated SP-COOH (0.5 μm or 1 μm) and mPEG-NH2 in a buffer solution at various mass ratios (1:X) and reacting at 37°C overnight.

[0246] After washing with DI water, a sample of silica particles with attached PEG chains (SP-PEG) was obtained through a vacuum drying process.

[0247] To compare the effect of molecular weight of attached polymer chains on colloidal particles, mPEG-NH2 (Mw= 750 / 2k, Sigma-Aldrich) of different molecular weights was also applied in the same manner using a fixed mass ratio of particles to polymer chains (1:0.1).

[0248]

[0249] To maintain particles adsorbed on the interface for a long time, it is necessary to introduce physical interactions that counteract the depletion attraction. Therefore, when particles are located very close to each other, the entropy loss of the attached polymer chains increases, which can prevent the formation of particle aggregates, so that R of a few nanometers g The polymer chains having 5k-PEG chains are irreversibly attached to the particle surface. As a result, the behavior of the surface-modified 1 μm-silica particles with various mass ratios of 5k-PEG chains to the particle (SP-PEG, 0.001, 0.01, 0.1, 1) at the water-water interface is significantly different compared to the bare silica particles and carboxyl silica particles.

[0250] Specifically, carboxyl silica particles also readily desorbed from the interface, similar to the behavior of bare silica particles, but for particles surface-attached with 5k-PEG chains having various mass ratios, a thin particle layer was observed primarily over the entire interface, and no particles desorbed even after 48 hours.

[0251] FIG. 10a is a schematic diagram showing colloidal particles including hydrophilic polymer chains at a water-in-water interface preventing particle aggregation according to one embodiment of the present invention, and an image showing experimental observation results for the behavior of colloidal particles including hydrophilic polymer chains at a water-in-water interface over time, FIG. 10b is a graph showing the stability duration of water-in-water emulsions surface-modified with different mass ratios of hydrophilic polymer chains to colloidal particles and changes in zeta potential of colloidal particles, and FIG. 10c is a graph showing the stability duration of water-in-water emulsions surface-modified with different lengths of hydrophilic polymer chains at a fixed mass ratio.

[0252] Referring to Fig. 10a, the behavior of PEG-silica particles at a water-water interface over time is shown. The left drawing is a schematic diagram of preventing particle aggregation at a water-water interface by overcoming the depletion force, and the right drawing is an experimental observation result of particle behavior at a water-water interface over time, and it can be seen that a thin particle layer is maintained for a long period of time mainly without desorption.

[0253] Referring to Fig. 10a, since no desorption occurs at all for 48 hours even when PEG chains of different mass ratios are applied to silica particles, the stability of particles whose surfaces are covered with PEG chains of different concentrations at the water-in-water interface can be indirectly investigated by recording the stability duration of various emulsions stabilized with such particles.

[0254] A stable emulsion state can be defined as a state in which the shape of the emulsion phase is maintained both macroscopically and microscopically even as the size of the droplets increases over time.

[0255] Referring to FIG. 10b, it is a graph showing the stabilization duration of the water-in-water emulsion and the change in zeta potential of the silica particles according to surface modification with different mass ratios of 5k-PEG chains to the particles (0.001, 0.01, 0.1, and 1).

[0256] Referring to Figure 10b, it is clearly shown that a mass ratio of 0.1 of 5k-PEG chains appears to provide the most effective stabilization of particles at the water-in-water interface. For example, increasing the mass ratio from 0.001 to 0.1 significantly increases the duration of the stabilized emulsion from 1 hour to over 6 months, but a sharp decrease is observed when the mass ratio exceeds 0.1. This suggests that the adsorption of 5k-PEG chains on the particle surface is likely already saturated at a PEG concentration of 0.1, which can also be corroborated by zeta potential measurements. The magnitude of the zeta potential decreases with decreasing mass ratio up to 0.1, but remains approximately constant above this value. When the ratio exceeds 0.1, the PEG chains on the particles may be linked by free PEG chains remaining in the solution, thereby reducing the entropic contribution of the polymer chains.

[0257] Referring to Fig. 10c, a graph showing the change in the stabilization duration of water-in-water emulsions according to surface modification by varying the length of the PEG chain at a fixed mass ratio of 0.1 (750, 2k, 5k, and 10k) is shown. As a result, 5k-PEG with a mass ratio of 0.1 appears to provide the most effective stabilization of particles at the interface under the given experimental conditions.

[0258] Referring to Figure 10c, to support the claim that polymer chain attachment primarily provides entropic contributions, the effect of PEG chain length on the stability of particles at the interface was also investigated by varying the chain lengths to 750, 2k, 5k, and 10k. As expected, longer chains on the particle surface may provide greater entropy loss when the particles are very close to each other, increasing the length of the PEG chains attached to the silica particles at a fixed mass ratio of 0.1 yields longer stability times up to a length of 5k, as expected. However, when PEG chains of 10k are applied, the stability stability time is significantly reduced. The zeta potential magnitude of 10k-PEG gradually decreases as the mass ratio increases from 0.01 to 1, and the magnitude values ​​are significantly larger than those of 5k-PEG at the same mass ratios of 0.01, 0.1, and 1. This may strongly indicate that there are not enough 10k-PEG chains attached to the particle surface at a mass ratio of 1. Additionally, silica particles attached by other hydrophilic polymer chains, such as DEX and polyvinyl alcohol (PVA), can also provide similar results.

[0259]

[0260] Zeta potential measurement

[0261] To confirm changes in the degree of surface modification, zeta potential analysis was performed using a zeta potential analyzer (ELSZ-2000ZS, Otsuka Electronics). To increase the accuracy of zeta potential measurements, 0.5 μm silica particles were used as a model system for stabilizers in water-soluble HIPES, and changes in the degree of surface modification were indirectly confirmed.

[0262] Here, surface modification of 0.5 μm-silica particles was performed using various mass ratios of 5k-PEG chains to particles of 0.001, 0.01, 0.1, and 1, respectively.

[0263] Additionally, surface modification of 0.5 μm-silica particles was performed using various mass ratios of 10k-PEG chains to particles of 0.01, 0.1, and 1, respectively.

[0264] Before measurement, all samples were dispersed in DI water at a concentration of 0.1 wt%.

[0265]

[0266] DEX chain-attached silica particles

[0267] To synthesize silica particles with attached DEX chains, amine groups were attached to DEX. 10 g of dextran (Mw= 40k, Sigma-Aldrich) dissolved in 70 ml of dimethyl sulfoxide (DMSO, ≥99.9%, Sigma-Aldrich) was mixed with 2 g of CDI (Sigma-Aldrich) solution dissolved in 5 ml of DMSO, and the activation reaction was carried out at 50°C for 15 min.

[0268] Then, 5 ml of ethylenediamine (≥99%, Sigma-Aldrich) was added, and the mixture was stirred at 50°C for 18 hours.

[0269] The reaction solution was dialyzed against running water for 24 h using dialysis tubing [avg. flat width 23 mm (0.9 in.), MWCO 14000, 99.99% retention, Sigma-Aldrich], and then dialyzed twice against DI water (3 L) for 1.5 h each.

[0270] Subsequently, amino-DEX was recovered through lyophilization. A reaction solution was prepared by mixing activated SP-COOH (1 μm) and amino-DEX in a buffer solution at a mass ratio (1:0.1) and reacting at 37 °C overnight.

[0271] After washing with DI water, a sample of silica particles with attached DEX chains (SP-DEX) was obtained through a vacuum drying process.

[0272]

[0273] PVA chain-attached silica particles

[0274] A reaction solution was prepared by mixing activated SP-COOH (1 μm) and polyvinyl alcohol (PVA, Mw = 30–70 k, Sigma-Aldrich) in a mass ratio (1:0.1) in a buffer solution, and then reacting at 37°C overnight.

[0275] After washing with DI water, a sample of PVA chain-attached silica particles (SP-PVA) was obtained through a vacuum drying process.

[0276]

[0277] PS particles with attached PEG chains

[0278] A reaction solution was prepared by mixing activated PS-COOH and mPEG-NH2 (Mw=5k) in a mass ratio (1:0.1) in a buffer solution and reacting at 37 °C overnight.

[0279] After washing with DI water, a sample of polystyrene particles with attached PEG chains (PS-PEG) was obtained through a vacuum drying process.

[0280]

[0281] Example 6: Observation of the underwater water interface

[0282] 1.8618 g of PEG and 2.5076 g of DEX were dissolved in 20 mL of DI water.

[0283] The mixed solution was transferred to a cuvette and left until phase separation was complete.

[0284] Then, 10 μL of a particle solution containing silica particles (SP, 1 μm, Polysciences) dispersed in DI water at a concentration of 10 wt% was injected into the air / water interface of the solution.

[0285] After the particles settled due to gravity and were absorbed at the water-water interface by the interfacial tension of the system, the behavior of the particles at the water-water interface could be observed using a custom-made side-view microscope.

[0286] Experiments were performed similarly for SP-COOH, SP-PEG, SP-DEX, and SP-PVA.

[0287]

[0288] Example 7: Preparation of water-in-water emulsion

[0289] Formation of water-in-water emulsion

[0290] To prepare the emulsion, PEG and DEX were dispersed in DI water at concentrations of 15.70 wt% and 20.05 wt%, respectively, using a vortex mixer (MaXshakeVM30, DAIHAN Scientific).

[0291] Colloidal particles were dispersed in PEG solutions at various fractions ranging from 1 to 5 w / v% based on the total volume of the emulsion.

[0292] Water-in-water Pickering emulsions were formed in small vials (each PEG / DEX solution was added in a 1:1 volume ratio) using a homogenizer (HG-15D, DAIHAN Scientific) at various rpms ranging from 2,000 to 20,000 for 3 min.

[0293]

[0294] FIG. 12a is a schematic diagram of the formation mechanism of an underwater HIPE according to an embodiment of the present invention, FIG. 12b is a DIC (differential interference contrast) microscopy image of an underwater HIPE filled with hexagons on the surface of a droplet, FIG. 12c is a fluorescence microscopy image of an underwater HIPE rich in hydrophilic polymer chains encapsulated in a colloidal particle layer, FIG. 12d is an optical microscopy image of an underwater HIPE rich in hydrophilic polymer chains encapsulated in a colloidal particle layer after 1 hour, and FIG. 12e is an optical microscopy image of an underwater HIPE rich in hydrophilic polymer chains encapsulated in a colloidal particle layer after 24 hours.

[0295] Referring to Fig. 12a, a schematic diagram of the formation mechanism of an underwater HIPE is provided. HIPE refers to the process in which gravity compresses a spherical droplet while the force acting by the interfacial tension maintains the spherical shape, thereby creating a polyhedral dispersion droplet in an extremely thin continuous phase.

[0296] Referring to Fig. 12a, when SP-PEG is utilized as a stabilizer, numerous particles are observed on the surface of dispersed droplets formed by stabilizing an aqueous mixture. In the initial stage of the stabilization process, the droplets are very small in size and have a large interfacial area, so that the droplet surface can be partially covered by the particles, which is expected to facilitate the coalescence of the droplets. Therefore, the droplet surface becomes more filled with particles over time as the droplet size increases, resulting in the formation of a hexagonally packed particle monolayer on the surface, as shown in Fig. 12b. Referring to Fig. 12c, the fluorescence microscopy image may successfully demonstrate that the dextran-rich phase still remains well within the tightly packed particle layer.

[0297] Referring to Figure 12a, stabilized dispersed droplets gradually settle under gravity, and after a certain period of time, all droplets can contact each other. If the droplets are sufficiently stable to prevent agglomeration under the compressive force still present due to gravity, the droplets can survive in a deformed form, and the degree of deformation is determined by the balance between the compressive force and the force due to the interfacial tension, resulting in the formation of polyhedral droplets.

[0298] Figures 12d and 12e show that the HIPE in water of the PEG / DEX system is stabilized with PEG chain-attached colloidal particles (5 w / v%). All optical microscope images are taken under a horizontal microscope.

[0299] Referring to Figure 12d, this is an image of HIPE (after 1 hour) in water using SP-PEG, where FITC-dextran (Mw=40k, 0.05 w / v%) is added to the DEX-rich phase to clearly distinguish the emulsion region.

[0300] Referring to Fig. 12d, direct observation of the emulsion phase demonstrates for the first time that a high internal phase Pickering emulsion (HIPE) can be successfully achieved at the water-in-water interface using SP-PEG as a stabilizer. After 1 hour of stabilization, the water-in-water HIPE can be clearly observed in dispersed droplets with a diameter of ~170 μm. Interestingly, the internal structure of the water-in-water HIPE appears to be very similar to that of dry foam, which may strongly indicate a fairly high volume fraction of the dispersed phase (~99%). This intriguing emulsion structure, which is difficult to achieve even in water-in-oil or oil-in-water emulsions, may be possible because the droplets can be easily deformed due to the extremely low interfacial tension at the droplet surface. Consequently, this may allow the droplets to easily fill the voids between droplets in a confined space, significantly reducing the volume fraction of the continuous phase.

[0301] Moreover, a typical HIPE can behave like a solid because the polyhedral droplets of the HIPE are interlocked. For example, even if a glass bottle is turned over, the HIPE structure can still be maintained.

[0302] Referring to Figure 12e, an image of a HIPE (24 hours later) containing PEG-labeled polystyrene particles (PS-PEG) in water is shown. Even when the vial containing the HIPE is inverted, the HIPE structure remains intact. Here, DI water is added to the PEG-rich phase to fill the vial.

[0303] Referring to Fig. 12e, the HIPE structure can still be maintained even when the vial is inverted, which may be a good indication that the HIPE is stabilized by PEG chain-attached polystyrene particles (PS-PEG). The HIPE structure can easily become unstable when the droplet comes into contact with air during the inversion process. This may be caused by particle flow due to the significant difference in tension between the air-water interface (~ 72 mN / m) and the water-in-water interface (~ 266 μN / m). Here, in the case of HIPE with added PS-PEG, a diameter of ~116 μm is clearly observed from 24 hours after stabilization, which is significantly longer than that of HIPE with added SP-PEG. This is probably because the density of PS particles is much lower than that of silica particles, and the droplet size is significantly smaller than that of droplets stabilized by SP-PEG. The synthesized PS particles have a density between the two aqueous phases, which facilitates the particle placement at the interface, resulting in a smaller droplet size than that of SP-PEG. Additionally, synthetic bare polystyrene (PS) particles can also stabilize underwater HIPEs, but can become completely unstable within a few weeks, unlike PS-PEG, which remains stable for at least 6 months.

[0304]

[0305] Fig. 13a is a graph showing the change in droplet size of HIPE in water according to the change in colloidal particle concentration according to an embodiment of the present invention, and Fig. 13b is a graph showing the change in droplet size of HIPE in water according to the change in homogenization speed.

[0306] Referring to Figures 13a and 13b, the droplet sizes of HIPE using SP-PEG and PS-PEG were measured 1 hour and 24 hours after stabilization, respectively. Figure 13a shows the droplet size changes according to changes in particle concentration (1, 3, 5 w / v%), and Figure 13b shows the droplet size changes according to changes in homogenization speed (2000, 5000, 11000, 15000, 20000 rpm). The scale bar of the optical microscope images taken with a horizontal microscope is 500 μm.

[0307] Referring to Figure 13a, in addition to successfully achieving HIPE using colloidal particles attached to polymer chains, other important parameters determining droplet size, such as particle concentration and settling velocity, are also thoroughly examined. Here, surface modification can also be performed at a mass ratio of 0.1 5k-PEG chains to particles, as particles modified at this ratio likely provide the greatest amount of particle adsorption during stabilization.

[0308] Interestingly, droplet size can be significantly varied by varying both particle concentration and homogenization rate, respectively. At a fixed homogenization rate of 11,000 rpm, changing the particle concentration from 1 w / v% to 5 w / v% resulted in approximately a 10-fold decrease in both SP-PEG and PS-PEG.

[0309] Referring to Figure 13b, in contrast, at a fixed concentration of 5 w / v%, the homogenization rate initially reduces the droplet size up to 11,000 rpm for SP-PEG and 15,000 rpm for PS-PEG, but above these values, the size begins to increase significantly. This may occur because the high homogenization rate promotes particle desorption, which may lead to larger droplet sizes. Additionally, because the density of silica particles is much higher than that of PS particles, particle desorption may occur more easily compared to PS particles, which may result in a slower settling rate to achieve the smallest droplets.

[0310] Therefore, it was successfully demonstrated that the droplet size of underwater HIPE can be stably controlled from 100 μm to over 1000 μm by changing the particle type, particle concentration, and settling velocity based on the control of these parameters.

[0311]

[0312] Optical Microscopy Imaging

[0313] After homogenization, the emulsions in small vials were imaged at various magnifications using a side-view optical microscope to observe the stability of the emulsions over time and the high internal phase emulsion (HIPE) structure.

[0314] Droplet size within the emulsion was quantified by measuring the size of droplets > 100 using Image J software.

[0315]

[0316] Fluorescence microscopy imaging

[0317] To visualize the dispersed phase, DEX-rich phase, in the water-in-water emulsion, 0.05 w / v% fluorescein isothiocyanate-dextran (FITC-dextran, Mw= 40k, Sigma-Aldrich) was added to the DEX solution before stabilizing the emulsion.

[0318] The morphology of the water-in-water emulsion was confirmed using an upright optical microscope (BX53M, Olympus) equipped with a fluorescence filter cube (excitation: 455–495 nm / emission: 505–555 nm, TLV-U-FF-FITC, Olympus) and a camera (KSS3-10S camera, Korea LABTECH). As a result, the fluorescent DEX-rich phase remained green, whereas the PEG-rich phase did not fluoresce and appeared dark.

[0319]

[0320] Conclusions on Examples 2 to 7

[0321] In conclusion, based on our understanding of the causes of the poor stability of water-in-water emulsions, this may be the first report of successful long-term stability of water-in-water emulsions achieved by attaching polymer chains to typical colloidal particles. Since this improvement primarily stems from entropic effects, this approach is universally applicable regardless of the type of polymer chain (e.g., PEG, DEX, and PVA) and particle type (e.g., silica and PS). Furthermore, we successfully demonstrated that water-in-water emulsions are controllable and amenable to further processing, similar to conventional water-in-oil or oil-in-water emulsions. Specifically, the droplet size of water-in-water emulsions can be controlled from 100 μm to over 1,000 μm by varying the particle type, particle concentration, and settling velocity, respectively. Therefore, in addition to their excellent stability and easy controllability, the extremely high dispersed phase fraction and excellent water-transferability of water-in-water emulsions make them ideal candidates for biocompatible and environmentally friendly applications, such as novel drug patch systems, artificial cell reactors, cell growth support, and even semi-solid electrolytes. Furthermore, our findings and understanding of water-in-water emulsions are expected to meet the growing demand for water-in-water emulsions as products in the pharmaceutical, cosmetic, and food industries, which are closely related to our daily lives.

[0322]

[0323] Although the embodiments have been described above, those skilled in the art will appreciate that various technical modifications and variations can be made based on the above. For example, appropriate results can still be achieved even if the described techniques are performed in a different order than described, and / or components of the described systems, structures, devices, circuits, etc. are combined or combined in a different manner than described, or are replaced or substituted by other components or equivalents.

[0324] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims described below.

[0325] Although the embodiments described above have been described with limited drawings, those skilled in the art will appreciate that various technical modifications and variations can be applied based on the above. For example, appropriate results can still be achieved even if the described techniques are performed in a different order than described, and / or components of the described systems, structures, devices, circuits, etc. are combined or combined in a different manner than described, or are replaced or substituted with other components or equivalents.

[0326] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims described below.

Claims

1. Step for preparing HIPE (high internal buoyancy emulsion); A step of UV curing the above HIPE to obtain a liquid-carrying polymer; and A step of drying the liquid-containing polymer to obtain a hydrophilic porous polymer; comprising; Method for producing a hydrophilic porous polymer.

2. In paragraph 1, In the step of preparing the above HIPE (high internal buoyancy emulsion), The above HIPE includes a water-in-water (W / W) interface, The above interface comprises at least one selected from the group consisting of polyethylene glycol (PEG), dextran (DEX), polyvinyl alcohol (PVA), gelatin (Gel), maltodextrin (MAL), sodium caseinate, starch, sodium sulfate, magnesium sulfate, corn starch, alginate (Alg), amylopectin (AMP), xyloglucan (XG), xanthan gum, pectin, polyethylene glycol diacrylate (PEGDA), and gelatin methacryloyl (GelMA). The above HIPE contains an emulsion stabilizer, The above emulsion stabilizer contains colloidal particles, The colloidal particles include silica particles, polystyrene particles, gold nanoparticles, liposomes, protein particles, zinc oxide particles or titanium dioxide particles. The colloidal particles include at least one hydrophilic polymer chain selected from the group consisting of polyethylene glycol (PEG), dextran (DEX), polyvinyl alcohol (PVA), deoxyribonucleic acid (DNA), chitosan, hyaluronic acid, alginic acid, gelatin, collagen, and cellulose. Method for producing a hydrophilic porous polymer.

3. In paragraph 1. The step of preparing the above HIPE (high internal buoyancy emulsion) is; It further includes a step of adding a monomer, a crosslinking agent and a photoinitiator; The above monomer comprises at least one selected from the group consisting of acrylic acid (AA), acrylamide (AAM), gelatin methacryloyl (GelMA), polyethylene glycol diacrylate (PEGDA), polyethylene glycol methacrylate (PEGMA), and polyethylene glycol dimethacrylate (PEGDMA). The above cross-linking agent is N,N'-methylenebisacrylamide (MBAA), The above photoinitiator is selected from the group consisting of benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylanino acetophenone, lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP), 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiope (Irgacure 2959) benzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, Containing at least one selected from the group consisting of 2,4-diethylthioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal and 2-hydroxy-2-methylpropiope (Darocur 1173), The above monomer is 1 wt% to 10 wt% of the above HIPE, The crosslinking agent is 2 wt% or less of the HIPE, The above photoinitiator is 0.1 wt% to 0.5 wt% of the HIPE. Method for producing a hydrophilic porous polymer.

4. A hydrophilic porous polymer manufactured by any one of the manufacturing methods of clauses 1 to 3, When the colloidal particles in the above HIPE are 1 w / v% to 5 w / v%, it is an open cell form including interconnected pores, In the case where the colloidal particles of the above HIPE are 5 w / v% to 10 w / v%, the closed cell type including pores without interconnection, Hydrophilic porous polymer.

5. In paragraph 4, In the case where the size of the colloidal particles of the hydrophilic porous polymer is 1 ㎛ or more, the colloidal particles are exposed on the surface of the hydrophilic porous polymer membrane. Hydrophilic porous polymer.

6. An mercury two-phase system (ATPS) is formed, Comprising an interface between a polymer and a polymer or a polymer and a salt, Water-in-water Pickering emulsion.

7. In paragraph 6, The above interface comprises at least one selected from the group consisting of polyethylene glycol (PEG), dextran (DEX), polyvinyl alcohol (PVA), gelatin (Gel), maltodextrin (MAL), sodium caseinate, starch, sodium sulfate, magnesium sulfate, corn starch, alginate (Alg), amylopectin (AMP), xyloglucan (XG), xanthan gum, pectin, polyethylene glycol diacrylate (PEGDA), and gelatin methacryloyl (GelMA). The above emulsion contains an emulsion stabilizer, The above emulsion stabilizer contains colloidal particles, The colloidal particles include silica particles, polystyrene particles, gold nanoparticles, liposomes, protein particles, zinc oxide particles or titanium dioxide particles. The colloidal particles include at least one hydrophilic polymer chain selected from the group consisting of polyethylene glycol (PEG), dextran (DEX), polyvinyl alcohol (PVA), deoxyribonucleic acid (DNA), chitosan, hyaluronic acid, alginic acid, gelatin, collagen, and cellulose. Water-in-water Pickering emulsion.

8. In paragraph 7. The diameter of the above colloidal particles is 0.01 ㎛ to 100 ㎛, The colloidal particles are present in an amount of 1 w / v% to 10 w / v% in the emulsion, The molecular weight of the hydrophilic polymer chain is 100 to 500,000, The weight ratio of the hydrophilic polymer chain and the colloidal particles is 0.001:1 to 10:

1. Water-in-water Pickering emulsion.

9. In paragraph 6. The above emulsion is a HIPE (high internal phase emulsion) having an internal phase volume ratio of 74% or more among the above emulsions, The above HIPE droplets are in a polygonal dispersion shape, The droplet size of the above HIPE is 10 ㎛ to 3000 ㎛. Water-in-water Pickering emulsion.

10. A step of dispersing hydrophilic polymer chains in DI water to obtain a solution; A step of dispersing colloidal particles in the solution to obtain an emulsion; and A step of homogenizing the above emulsion at a speed of 2000 rpm to 20,000 rpm for 1 to 5 minutes; A method for producing an underwater Pickering emulsion of the sixth paragraph.

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