Cationic cellulose surfactant, preparation method therefor, pickering emulsion using same, drug delivery composition, and hair strengthening composition

Abstract

A method for preparing a cationic cellulose surfactant, according to the present invention, comprises the steps of: providing cellulose to a basic solution and dispersing same so as to prepare a base solution; and providing a cationic epoxy to the base solution and reacting same so as to prepare a cationic cellulose solution containing cellulose nanofibers, wherein, in the step of preparing the cationic cellulose solution, cationic functional groups can be provided on the surface of the cellulose nanofibers.

Description

Cationic cellulose surfactant, method for producing the same, Pickering emulsion using the same, drug delivery composition, and hair strengthening composition

[0001] The present invention relates to a cationic cellulose surfactant, a method for producing the same, a Pickering emulsion using the same, a drug delivery composition, and a hair strengthening composition, and more particularly, to a cationic cellulose surfactant having a cationic functional group provided on the surface of cellulose nanofibers, a method for producing the same, a Pickering emulsion using the same, a drug delivery composition, and a hair strengthening composition.

[0002] The environmental pollution and skin safety issues of petrochemical-derived surfactants, raised by consumers' growing environmental sensitivity and ethical awareness, have recently emerged as issues in the international cosmetics and pharmaceutical industries.

[0003] To this end, synthetic cationic polymer surfactants, including Polyquaternium-7, which has low skin permeability, have been developed. However, the environmental hazards of these surfactants remain unresolved, as they do not undergo microbial degradation, leading to long-term accumulation in aquatic environments and toxicity. Consequently, the need for alternative materials based on bio-derived polymers such as single-chain cellulose or guar gum has emerged.

[0004] Cellulose, the most abundant naturally occurring polymer on Earth, possesses a high aspect ratio and surface area, making it advantageous for substrate adsorption. Furthermore, it possesses excellent mechanical properties and biodegradability, making it a promising alternative to conventional petroleum-derived surfactants. However, cellulose's high hydrophilicity poses a challenge, making it difficult to achieve thermodynamically stable adsorption at interfaces.

[0005] To overcome these problems, Korean Patent Publication No. 10-0681704 attempted to produce an emulsion by increasing the hydrophobicity of cellulose, such as by introducing an alkyl ether. However, this method suffers from the problem that stable emulsifying power is not achieved without the addition of a small amount of surfactant.

[0006] Therefore, the present invention provides a cationic functional group on the surface of cellulose nanofibers without an amphiphilic modification process such as introducing an alkyl group, thereby producing a Pickering emulsion that improves the mechanical properties of the interfacial film and maintains a stable droplet shape for a long period of time by a mechanism of electrostatically adsorbing the cationic functional group on the oil / water interface, which itself has a negative charge.

[0007] The technical problem to be solved by the present invention is to provide a cationic cellulose surfactant having a negatively charged oil / water interface and improved adsorptive power.

[0008] Another technical problem to be solved by the present invention is to provide a Pickering emulsion in which the droplet form is stably maintained for a long period of time.

[0009] Another technical problem to be solved by the present invention is to provide a drug delivery composition in which the size of the droplets is controlled according to the concentration of the salt provided in the continuous phase.

[0010] Another technical problem to be solved by the present invention is to provide a hair strengthening composition that improves the tensile strength of hair.

[0011] Another technical problem that the present invention seeks to solve is to provide a method for manufacturing cationic cellulose nanofibers with reduced manufacturing process costs.

[0012] Another technical problem to be solved by the present invention is to provide a method for manufacturing cationic cellulose nanofibers with a shortened manufacturing time.

[0013] Another technical problem to be solved by the present invention is to provide a method for producing cationic cellulose nanofibers that are easy to mass-produce.

[0014] The technical problems to be solved by the present invention are not limited to those described above.

[0015] To solve the above technical problem, the present invention provides a method for producing a cationic cellulose surfactant.

[0016] According to one embodiment, the method for preparing the cationic cellulose surfactant includes the steps of providing and dispersing cellulose in a basic solution to prepare a base solution, and providing and reacting a cationic epoxy in the base solution to prepare a cationic cellulose solution including cellulose nanofibers, wherein the step of preparing the cationic cellulose solution may include providing a cationic functional group on the surface of the cellulose nanofibers.

[0017] According to one embodiment, in the step of preparing the cationic cellulose solution, the cationic epoxy is provided to the base solution after heat-treating the base solution, and the hydroxide (O) of the cellulose nanofibers is provided in the heat-treated base solution. - ) and the cationic epoxy may undergo a nucleophilic addition reaction, thereby providing the cationic functional group on the surface of the cellulose nanofiber.

[0018] According to one embodiment, the base solution may include heat treatment at 70°C to 80°C, and the nucleophilic addition reaction time may be controlled to 1 hour to 2 hours.

[0019] According to one embodiment, in the step of preparing the base solution, some of the hydroxyl groups (OH) of the cellulose are converted to hydroxide (O) by the basic solution.- ) and the pH of the base solution may be controlled to 13.

[0020] According to one embodiment, the method for producing the cationic cellulose surfactant may further include the step of providing distilled water to the cationic cellulose solution and centrifuging and washing to obtain the cationic cellulose surfactant.

[0021] In one embodiment, the cationic epoxy comprises either glycidyltrimethylammonium chloride (GTAC) or (3-chloro-2-hydroxypropyl)trimethylammonium chloride, and the cationic functional group is a substituted or unsubstituted quaternary ammonium (NR3 + , NR3Cl), and the basic solution may include either potassium hydroxide or sodium hydroxide.

[0022] To solve the above technical problem, the present invention provides a cationic cellulose surfactant manufactured by the above-described manufacturing method.

[0023] According to one embodiment, the cationic cellulose surfactant may include cellulose nanofibers and cationic functional groups provided on the surface of the cellulose nanofibers.

[0024] According to one embodiment, the zeta potential of the cationic cellulose surfactant may include 5 mV to 50 mV.

[0025] According to one embodiment, the average length of the cellulose nanofibers may be from 1,000 nm to 2,000 nm, the average thickness of the cellulose nanofibers may be from 5 nm to 20 nm, and the aspect ratio of the cellulose nanofibers may be from 50 to 400.

[0026] According to one embodiment, the cationic functional group may be provided in a ratio of 1 mmol to 8 mmol based on 1 g of the cellulose nanofiber.

[0027] In one embodiment, the cationic functional group is a substituted or unsubstituted quaternary ammonium (NR3 + , NR3Cl) may include at least one or more.

[0028] In order to solve the above technical problem, the present invention provides a Pickering emulsion to which the cationic cellulose surfactant described above is applied.

[0029] According to one embodiment, the Pickering emulsion comprises a cationic cellulose surfactant that electrostatically binds to the negative charge of the interface between the dispersed phase and the continuous phase, which are different liquids, to form an interfacial film, and the cationic cellulose surfactant may include cellulose nanofibers and cationic functional groups provided on the surface of the cellulose nanofibers.

[0030] According to one embodiment, the dispersed phase may include an oil phase comprising an oil containing neutral hydrocarbons having a net charge of 0 and fatty acids having a negative charge, and the continuous phase may include a water phase comprising water having a pH of 3 to 14.

[0031] According to one embodiment, the weight ratio of the cationic cellulose surfactant may include 0.1 wt% or more relative to the continuous phase.

[0032] To solve the above technical problem, the present invention provides a drug delivery composition to which the cationic cellulose surfactant described above is applied.

[0033] According to one embodiment, the drug delivery composition comprises a dispersed phase and a continuous phase, which are different liquids, and a cationic cellulose surfactant that electrostatically binds to the negative charge of the interface between the dispersed phase and the continuous phase to form an interfacial film, wherein the cationic cellulose surfactant may include cellulose nanofibers and cationic functional groups provided on the surface of the cellulose nanofibers.

[0034] According to one embodiment, the stability of the interfacial film and the emulsifying power of the cationic cellulose surfactant can be controlled depending on the concentration of salt provided within the continuous phase.

[0035] According to one embodiment, the salt may include any one of sodium chloride, potassium chloride, barium sulfide, or calcium sulfide, and the concentration of the salt may be controlled to be from 0.0 mol / L to 1.8 mol / L.

[0036] According to one embodiment, the dispersed phase may include an oil phase comprising an oil containing neutral hydrocarbons having a net charge of 0 and fatty acids having a negative charge, and the continuous phase may include a water phase comprising water having a pH of 3 to 14.

[0037] In order to solve the above technical problem, the present invention provides a hair strengthening composition to which the cationic cellulose surfactant described above is applied.

[0038] According to one embodiment, the hair strengthening composition comprises a dispersed phase and a continuous phase, which are different liquids, and a cationic cellulose surfactant that electrostatically binds to a negative charge of an interface between the dispersed phase and the continuous phase to form an interfacial film, wherein the cationic cellulose surfactant may include cellulose nanofibers and a cationic functional group provided on the surface of the cellulose nanofibers.

[0039] According to one embodiment, the hair strengthening composition may include electrostatic bonding between the cationic functional group provided on the surface of the cationic cellulose surfactant and the negatively charged hair cuticle, thereby strengthening the hair.

[0040] According to one embodiment, the dispersed phase may include an oil phase comprising an oil containing neutral hydrocarbons having a net charge of 0 and fatty acids having a negative charge, and the continuous phase may include a water phase comprising water having a pH of 3 to 14.

[0041] A method for producing a cationic cellulose surfactant according to the present invention may include a step of providing and dispersing cellulose in a basic solution to produce a base solution, and a step of providing and reacting a cationic epoxy in the base solution to produce a cationic cellulose solution including cellulose nanofibers.

[0042] In the step of preparing the cationic cellulose solution, the ratio of the cationic epoxy (e.g., GTAC, glycidyltrimethylammonium chloride) provided in the base solution can be controlled to be 36 mmol or more and 45 mmol or less based on 1 g of the cellulose (e.g., bacterial cellulose) in the base solution. Accordingly, the cationic cellulose surfactant having an improved level of adsorption to a negatively charged oil / water interface can be provided, and a Pickering emulsion in which the shape of the droplet is stably maintained for a long period of time can be provided.

[0043] The Pickering emulsion may include a cationic cellulose surfactant that electrostatically binds to the negative charge of the interface between the dispersed phase (e.g., n-decane) and the continuous phase, which are different liquids, to form an interfacial film.

[0044] The cationic cellulose surfactant may include the cellulose nanofibers and a cationic functional group provided on the surface of the cellulose nanofibers.

[0045] Accordingly, the interface between the negatively charged dispersed phase and the continuous phase and the cationic functional groups of the cationic cellulose surfactant are electrostatically bonded, so that a plurality of cationic cellulose surfactants can be easily adsorbed to the interface. Accordingly, after a plurality of cationic cellulose surfactants are adsorbed to the interface, they can be hydrogen-bonded to each other by the hydroxyl groups (OH) remaining on the surface of the cellulose nanofibers of the cationic cellulose surfactant. Accordingly, the interfacial film surrounding the dispersed phase at the interface, having a network structure, and having improved mechanical properties due to hydrogen bonding can be provided. Due to this, the droplet form of the Pickering emulsion can be stably maintained for a long period of time. Accordingly, the Pickering emulsion can be applied to the hair strengthening composition and the drug delivery composition.

[0046] FIG. 1 is a flowchart illustrating a method for manufacturing a cationic cellulose surfactant according to an embodiment of the present invention.

[0047] Figure 2 is a drawing for explaining a method for manufacturing a base solution according to an embodiment of the present invention.

[0048] FIG. 3 is a drawing for explaining a method for producing a cationic cellulose solution according to an embodiment of the present invention.

[0049] FIG. 4 is a drawing for explaining a method for obtaining a cationic cellulose surfactant from a cationic cellulose solution according to an embodiment of the present invention.

[0050] FIG. 5 is a flowchart illustrating a method for producing a Pickering emulsion using a cationic cellulose surfactant according to an embodiment of the present invention.

[0051] FIG. 6 is a drawing for explaining a Pickering emulsion according to an embodiment of the present invention.

[0052] Figure 7 is a graph for comparing the surface activity levels of cellulose according to Comparative Example 1 of the present invention and cationic cellulose surfactants according to experimental examples.

[0053] Figure 8 is a graph for comparing the surface activity levels of an anionic cellulose surfactant according to Comparative Example 2 of the present invention and a cationic cellulose surfactant according to Experimental Examples 1-5.

[0054] Figure 9 is a graph for comparing the surface activity levels of a cationic cellulose surfactant according to Comparative Example 3 of the present invention and a cationic cellulose surfactant according to Experimental Examples 1-5.

[0055] Figure 10 is a graph showing the zeta potential measured at different pH levels at an interface (oil / water interface) according to an experimental example of the present invention.

[0056] Figure 11 is a graph for comparing the results of Raman wavelength analysis of Pickering emulsions according to Comparative Example 4, Comparative Example 3, and Experimental Examples 1-5 of the present invention.

[0057] FIG. 12 is a graph for comparing the droplet size and long-term stability of the droplets of Pickering emulsions according to Comparative Example 1 of the present invention and Experimental Examples 1-1 to 1-5.

[0058] Figure 13 is a graph and photograph for comparing the rheological behavior and long-term stability of Pickering emulsions according to Experimental Examples 1-5 and Comparative Example 2 of the present invention.

[0059] FIG. 14 is a graph and photograph for comparing the interfacial properties according to the salt concentration of an anionic cellulose surfactant according to Comparative Example 2 of the present invention and a cationic cellulose surfactant according to Experimental Examples 1-5, and the droplet sizes according to the salt concentration of Pickering emulsions according to Comparative Examples 2-1 to 2-4 and Experimental Examples 1-5-1 to 1-5-4.

[0060] Figures 15 to 18 are drawings, photographs, and graphs for verifying whether the Pickering emulsion according to Experimental Examples 1 to 5 of the present invention can be used as a hair strengthening composition.

[0061] Figure 19 is a graph for comparing zeta potential according to the nucleophilic addition reaction time of cationic cellulose surfactants according to experimental examples of the present invention.

[0062] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the technical concept of the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete and to sufficiently convey the spirit of the present invention to those skilled in the art.

[0063] In this specification, when a component is referred to as being on another component, it means that it can be formed directly on the other component, or a third component may be interposed between them. In addition, in the drawings, the thicknesses of films and regions are exaggerated for the purpose of effectively explaining the technical contents.

[0064] Also, although terms such as first, second, and third have been used to describe various components in various embodiments of this specification, these components should not be limited by these terms. These terms are only used to distinguish one component from another. Thus, what is referred to as a first component in one embodiment may be referred to as a second component in another embodiment. Each embodiment described and illustrated herein also includes its complementary embodiments. Also, the term "and / or" has been used herein to mean including at least one of the components listed before and after.

[0065] In the specification, singular expressions include plural expressions unless the context clearly dictates otherwise. In addition, terms such as "comprise" or "have" are intended to specify the presence of a feature, number, step, component, or combination thereof described in the specification, and should not be construed as excluding the presence or addition of one or more other features, numbers, steps, components, or combinations thereof. In addition, the term "connection" is used in the present specification to mean both indirectly connecting multiple components and directly connecting them.

[0066] In addition, when describing the present invention below, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

[0067]

[0068] FIG. 1 is a flowchart for explaining a method for producing a cationic cellulose surfactant according to an embodiment of the present invention, FIG. 2 is a diagram for explaining a method for producing a base solution according to an embodiment of the present invention, FIG. 3 is a diagram for explaining a method for producing a cationic cellulose solution according to an embodiment of the present invention, FIG. 4 is a diagram for explaining a method for obtaining a cationic cellulose surfactant from a cationic cellulose solution according to an embodiment of the present invention, FIG. 5 is a flowchart for explaining a method for producing a Pickering emulsion using a cationic cellulose surfactant according to an embodiment of the present invention, and FIG. 6 is a diagram for explaining a Pickering emulsion according to an embodiment of the present invention.

[0069] Referring to FIGS. 1 and 2, a base solution (120) is prepared by providing and dispersing cellulose (100) in a basic solution (110) (S110).

[0070] In the step of preparing the base solution (120), the cellulose (100) is converted into hydroxide (O) by the basic solution (110) in part of the hydroxyl group (OH) on the surface of the cellulose (100). - ) can be ionized. Accordingly, when the cationic epoxy (130) described below is provided, the hydroxide (O) on the surface of the cellulose (100) - ) acts as a nucleophile, and carbon with a relatively low electron density in the cationic epoxy (130) described below acts as an electrophile, so that a nucleophilic addition reaction can occur. For example, the cellulose (100) may be bacterial cellulose having a bundle shape. For example, the basic solution (110) may be potassium hydroxide or sodium hydroxide. For example, the pH of the base solution (120) may be controlled to 13. For example, the weight ratio of the cellulose (100) in the base solution (120) may be 0.25 wt% with respect to the basic solution (110).

[0071] Referring to FIGS. 1 and 3, the cationic epoxy (130) described above is provided to the base solution (120) and reacted to produce a cationic cellulose solution (200) including cellulose nanofibers (S120).

[0072] In the step of manufacturing the cationic cellulose solution (200), after heat-treating the base solution (120), the cationic epoxy (130) may be provided to the base solution (120). Then, when the base solution (120) provided with the cationic epoxy (130) is heat-treated for a specific period of time at the same temperature as the temperature at which the base solution (120) is heat-treated, the hydroxide (O) on the surface of the cellulose nanofibers of the base solution (120) provided with the cationic epoxy (130) is formed. -) and the cationic epoxy (130) may undergo a nucleophilic addition reaction, thereby providing a cationic functional group on the surface of the cellulose nanofibers. Accordingly, the cationic functional group provided on the surface of the cellulose nanofibers may be easily electrostatically adsorbed to a negatively charged oil / water interface. For example, the cationic epoxy (130) may be glycidyltrimethylammonium chloride (GTAC) or (3-chloro-2-hydroxypropyl)trimethylammonium chloride. For example, the cationic functional group may be a substituted quaternary ammonium (NR3 + ) or unsubstituted quaternary ammonium (NR3Cl). For example, the base solution may be heat-treated at 70°C to 80°C. For example, the nucleophilic addition reaction time may be 1 hour to 2 hours. For example, some of the remaining hydroxyl groups (OH) on the surface of the cellulose nanofibers may remain on the surface of the cellulose nanofibers.

[0073] According to one embodiment, in the step of preparing the cationic cellulose solution (200), the ratio of the cationic epoxy (130) provided in the base solution (120) can be controlled to be 36 mmol or more and 45 mmol or less based on 1 g of the cellulose (100) of the base solution (120). Accordingly, the adsorption level of the cationic cellulose surfactant described later on the negatively charged oil / water interface is improved, and the shape of the droplets of the Pickering emulsion described later can be stably maintained for a long period of time.

[0074] In contrast, when the ratio of the cationic epoxy (130) provided in the base solution (120) is controlled to be less than 36 mmol based on 1 g of the cellulose (100) of the base solution (120), the adsorption level of the cationic cellulose surfactant described below on the negatively charged oil / water interface is reduced, and the shape of the droplets of the Pickering emulsion described below may not be stably maintained for a long period of time.

[0075] And, when the ratio of the cationic epoxy (130) provided in the base solution (120) is controlled to exceed 45 mmol based on 1 g of the cellulose (100) of the base solution (120), the interfacial tension and storage coefficient of the cationic cellulose surfactant described below may be substantially saturated and not improved.

[0076] Therefore, according to an embodiment of the present application, in the step of preparing the cationic cellulose solution (200), the ratio of the cationic epoxy (130) provided in the base solution (120) can be controlled to be 36 mmol or more and 45 mmol or less based on 1 g of the cellulose (100) of the base solution (120). Accordingly, the cationic cellulose surfactant described below, which has an improved level of adsorption to a negatively charged oil / water interface, can be provided, and the Pickering emulsion described below, in which the shape of the droplet is stably maintained for a long period of time, can be provided.

[0077] Referring to FIGS. 1 and 4, the cationic cellulose surfactant (300) described above can be obtained by providing distilled water to the cationic cellulose solution (200) and centrifuging and washing the solution. For example, the process of providing distilled water to the cationic cellulose solution (200) and centrifuging and washing the solution can be repeated until the pH of the cationic cellulose solution (200) becomes 7. Accordingly, by-products generated from the nucleophilic addition reaction between the hydroxyl group (OH) of the cellulose nanofibers (302) and the cationic epoxy (130) can be easily removed, thereby providing the cationic cellulose surfactant (300) of high purity. For example, the centrifugation rotation speed can be 8,000 rpm. For example, the centrifugation time can be 5 minutes.

[0078] The cationic cellulose surfactant (300) manufactured according to the above-described manufacturing method may include the cellulose nanofibers (302) and the cationic functional group (304) provided on the surface of the cellulose nanofibers (302), as illustrated in FIG. 4. For example, the zeta potential of the cationic cellulose surfactant (300) may be 5 mV to 50 mV. For example, the average length of the cellulose nanofibers (302) may be 1,000 nm to 2,000 nm. For example, the average thickness of the cellulose nanofibers (302) may be 5 nm to 20 nm. For example, the aspect ratio of the cellulose nanofibers (302) may be 50 to 400. For example, the cationic functional group (306) may be provided on the surface of the cellulose nanofiber (302) at a ratio of 1 mmol to 8 mmol based on 1 g of the cellulose nanofiber (320). For example, the cationic functional group may be a substituted quaternary ammonium (NR3 +) or unsubstituted quaternary ammonium (NR3Cl).

[0079] Accordingly, the cationic cellulose surfactant (300) can be easily electrostatically adsorbed to a negatively charged oil / water interface by the cationic functional group (306). In addition, a plurality of cationic cellulose surfactants (300) adsorbed to the oil / water interface can be hydrogen-bonded to each other by the hydroxyl group (OH) remaining on the surface of the cellulose nanofibers of the cationic cellulose surfactant (300). Accordingly, an interfacial film can be formed that surrounds the oil phase at the oil / water interface, has a network structure, and has improved mechanical properties due to hydrogen bonding.

[0080] In conclusion, the method for producing the cationic cellulose surfactant (300) according to the present application embodiment may include a step of providing and dispersing the cellulose (100) in the basic solution (110) to produce the base solution (120), and a step of providing and reacting the cationic epoxy (130) in the base solution (120) to produce the cationic cellulose solution (200) including the cellulose nanofibers (302).

[0081] In the step of preparing the cationic cellulose solution (200), the ratio of the cationic epoxy (130) provided in the base solution (120) can be controlled to be 36 mmol or more and 45 mmol or less based on 1 g of the cellulose (100) of the base solution (120). Accordingly, the cationic cellulose surfactant (300) having an improved level of adsorption to a negatively charged oil / water interface can be provided, and the Pickering emulsion described below, in which the shape of the droplet is stably maintained for a long period of time, can be provided.

[0082] Referring to FIG. 5, a method for producing the above-described Pickering emulsion using the cationic cellulose surfactant (300) is described.

[0083] The method for producing the above Pickering emulsion may include a step of providing and dispersing the cationic cellulose surfactant (300) in water to produce a water phase containing the cationic cellulose surfactant (300), a step of providing oil to the water phase and homogenizing the water phase and the oil to produce a preliminary Pickering emulsion, and a step of dispersing the preliminary Pickering emulsion with ultrasonic waves to produce the Pickering emulsion.

[0084] In the step of preparing the aqueous phase including the cationic cellulose surfactant (300), for example, by using a probe-type ultrasonic device, the cationic cellulose surfactant (300) can be easily dispersed in the water, so that the aqueous phase in which the cationic cellulose surfactant (300) is dispersed can be prepared. For example, the pH of the water can be controlled to be 3 to 14. For example, the weight ratio of the cationic cellulose surfactant (300) provided to the water can be 0.1 wt% or more relative to the water. In another example, the weight ratio of the cationic cellulose surfactant (300) provided to the water can be controlled to 0.3 wt% relative to the water.

[0085] And, in the step of preparing the preliminary Pickering emulsion, for example, by providing the oil dropwise to the aqueous phase in which the cationic cellulose surfactant (300) is dispersed, and then using a homogenizing device, the aqueous phase in which the cationic cellulose surfactant (300) is dispersed and the oil are homogenized, so that the preliminary Pickering emulsion can be easily prepared. For example, the oil may be an oil containing a neutral hydrocarbon having a net charge of 0 and a fatty acid having a negative charge. As a specific example, the oil may be at least one of n-decane, olive oil, mineral oil, and squalene. For example, in the preliminary Pickering emulsion, the volume ratio of the aqueous phase in which the cationic cellulose surfactant (300) is dispersed and the oil may be 8:2. For example, the rotation speed of the homogenizing device can be controlled to 12,000 rpm, and the homogenization time of the water and the oil can be controlled to 5 minutes.

[0086] Thereafter, in the step of producing the Pickering emulsion by ultrasonically dispersing the preliminary Pickering emulsion, for example, the preliminary Pickering emulsion can be easily produced by forming droplets using a homogenizer equipped with an ultrasonic tip for a probe. For example, the amplitude of the homogenizer can be controlled to 70%. For example, the application time of the ultrasonic waves can be 5 minutes. For example, the size of the droplets can be 3 um to 20 um. For example, the Pickering emulsion (400) can be an oil in water.

[0087] Referring to FIG. 6, the Pickering emulsion (400) manufactured by the above-described manufacturing method is described.

[0088] As illustrated in FIG. 6, the Pickering emulsion (400) may include a dispersed phase (410) and a continuous phase (420), which are different liquids, and a cationic cellulose surfactant (300) that electrostatically binds to the negative charges of the interface between the dispersed phase (410) and the continuous phase (420) to form an interfacial film (310). For example, the dispersed phase (410) may be an oil phase including the oil. For example, the continuous phase (420) may be an aqueous phase including the water. Accordingly, the interface may be an oil / water interface. Accordingly, the interface may itself have a negative charge due to charge transfer in which the electron density of water molecules of the continuous phase (420) is transferred to oil molecules of the dispersed phase (310).

[0089] And, the cationic cellulose surfactant (300) may include, as described above, the cellulose nanofibers (302) and the cationic functional group (304) provided on the surface of the cellulose nanofibers (302).

[0090] Accordingly, the interface between the negatively charged dispersed phase (310) and the continuous phase (420) and the cationic functional group (304) of the cationic cellulose surfactant (300) are electrostatically bonded, so that a plurality of cationic cellulose surfactants (300) can be easily adsorbed to the interface.

[0091] And, as described above, on the surface of the cellulose nanofibers (302) of the cationic cellulose surfactant (300), hydroxyl groups (OH) that have not undergone a nucleophilic addition reaction with the cationic epoxy (130) may remain. Accordingly, after a plurality of cationic cellulose surfactants (300) are adsorbed to the interface, they may be hydrogen-bonded to each other by the hydroxyl groups (OH) remaining on the surface of the cellulose nanofibers (302) of the cationic cellulose surfactant (300). Accordingly, an interfacial film (310) that surrounds the oil at the interface, has a network structure, and has improved mechanical properties due to hydrogen bonding may be provided. Due to this, the droplet form of the Pickering emulsion (400) may be stably maintained for a long period of time. Accordingly, the Pickering emulsion (400) can be applied as a hair strengthening composition and a drug delivery composition.

[0092] For example, when hair is immersed in the Pickering emulsion (400), the negatively charged cuticle of the hair and the cationic functional group (304) of the cationic cellulose surfactant (300) of the Pickering emulsion (400) electrostatically bond to each other, so that the Pickering emulsion (400) can be easily coated on the hair. As a result, the tensile strength of the hair can be improved. Accordingly, the Pickering emulsion (400) can be applied as the hair strengthening composition.

[0093] For example, when the dispersed phase (410) of the Pickering emulsion (400) includes a salt, the strength of the electrostatic attraction between the cationic functional group (304) of the cationic cellulose surfactant (300) and the negatively charged interface in the Pickering emulsion (400) can be controlled depending on the concentration of the salt in the dispersed phase (410). Accordingly, the amount of the cationic cellulose surfactant (300) adsorbed to the interface can be controlled, thereby controlling the size of the droplets of the Pickering emulsion (400). Therefore, when the dispersed phase (410) of the Pickering emulsion (400) includes the salt, the Pickering emulsion (400) can be applied as the drug delivery composition. For example, the salt may be any one of sodium chloride, potassium chloride, barium sulfide, or calcium sulfide. For example, the concentration of the salt may be controlled from 0.0 mol / L to 1.8 mol / L. For example, as the concentration of the salt in the dispersion phase (410) increases, the size of the droplets of the Pickering emulsion (400) may increase.

[0094] In conclusion, the Pickering emulsion (400) according to the embodiment of the present application may include the cationic cellulose surfactant (300) that electrostatically binds to the negative charge of the interface between the dispersed phase (410) and the continuous phase (420), which are different liquids, and the interface film (310).

[0095] The cationic cellulose surfactant (300) may include, as described above, the cellulose nanofibers (302) and the cationic functional group (304) provided on the surface of the cellulose nanofibers (302).

[0096] Accordingly, the interface between the negatively charged dispersed phase (310) and the continuous phase (420) and the cationic functional group (304) of the cationic cellulose surfactant (300) are electrostatically bonded, so that a plurality of cationic cellulose surfactants (300) can be easily adsorbed to the interface.

[0097] Accordingly, after a plurality of cationic cellulose surfactants (300) are adsorbed to the interface, they can be hydrogen-bonded to each other by the hydroxyl groups (OH) remaining on the surface of the cellulose nanofibers (302) of the cationic cellulose surfactants (300). Accordingly, an interfacial film (310) surrounding the dispersed phase (310) at the interface, having a network structure and improved mechanical properties due to hydrogen bonding, can be provided. Due to this, the droplet form of the Pickering emulsion (400) can be stably maintained for a long period of time. Accordingly, the Pickering emulsion (400) can be applied to the hair strengthening composition and the drug delivery composition.

[0098]

[0099] Hereinafter, specific experimental examples and characteristic evaluation results of cationic cellulose surfactants and Pickering emulsions according to embodiments of the present invention are described.

[0100]

[0101] Cationic cellulose surfactants according to experimental examples

[0102] Bacterial cellulose (1 g) was prepared as cellulose, sodium hydroxide (1 M, 400 g) was prepared as a basic solution, and glycidyltrimethylammonium chloride (GTAC) was prepared as a cationic epoxy.

[0103] The cellulose was provided in the above basic solution and stirred for 1 hour using a homodisper to prepare a base solution (pH 13). At this time, some of the hydroxyl groups (OH) on the surface of the cellulose were converted to hydroxide (O - ) was ionized.

[0104] Then, after heat-treating the base solution at 70°C, the cationic epoxy was provided and reacted at 70°C for 1 hour to prepare a cationic cellulose solution.

[0105] Afterwards, the cationic cellulose solution was diluted with distilled water, centrifuged at 8,000 rpm for 5 minutes, and washed, and the process was repeated until the pH of the cationic cellulose solution became 7, thereby producing a cationic cellulose surfactant according to the experimental examples.

[0106] Cellulose (bacterial cellulose) Basic solution (1M sodium hydroxide) Molar ratio of cationic epoxy (GTAC) based on 1g of cellulose Experimental example 1-11g400g9mmol Experimental example 1-21g400g18mmol Experimental example 1-31g400g27mmol Experimental example 1-41g400g36mmol Experimental example 1-51g400g45mmol Experimental example 1-61g400g54mmol Experimental example 1-71g400g72mmol

[0107]

[0108] Figure 7 is a graph for comparing the surface activity levels of cellulose according to Comparative Example 1 of the present invention and cationic cellulose surfactants according to experimental examples.

[0109] Referring to (a) of Fig. 7, bacterial cellulose was prepared using cellulose (BC) according to Comparative Example 1, and the cellulose (BC) according to Comparative Example 1 and the cationic cellulose surfactant (HNC) according to Experimental Example 1-5 + ) was photographed using TEM.

[0110] As can be seen in (a) of Fig. 7, the cationic cellulose surfactant according to Experimental Example 1-5 has a larger specific surface area than the cellulose according to Comparative Example 1. This factor is interpreted to be due to the repulsive force generated between the cationic cellulose surfactants due to the cationic functional group of the cationic cellulose surfactant according to Experimental Example 1-5.

[0111] Referring to (b) of Fig. 7, the zeta potential of the cellulose (0 mmol / g) according to Comparative Example 1 and the cationic cellulose surfactants according to Experimental Examples 1-2 (18 mmol / g) to 1-7 (72 mmol / g) was measured.

[0112] As can be seen in (b) of Fig. 7, the zeta potentials of the cationic cellulose surfactants according to Experimental Examples 1-5 to 1-7 are substantially the same at 45 mV. Therefore, in the method for producing a cationic cellulose surfactant according to an embodiment of the present application, it can be seen that when 45 mmol or more of the cationic epoxy is provided based on 1 g of cellulose, the zeta potential of the cationic cellulose surfactant is saturated at 45 mV.

[0113] Referring to Fig. 7 (c), the interfacial tension at the oil / water interface was measured in a state where no cationic cellulose surfactant was provided (Bare interface), and the interfacial tension at the oil / water interface by the cationic cellulose surfactant according to Experimental Example 1-1 (9 mmol / g), Experimental Example 1-2 (18 mmol / g), Experimental Example 1-3 (27 mmol / g), Experimental Example 1-4 (36 mmol / g), Experimental Example 1-5 (45 mmol / g), and Experimental Example 1-7 (72 mmol / g) was measured. Specifically, in the measurement of the interfacial tension at the oil / water interface, the cationic cellulose surfactant according to the experimental examples was provided in an amount of 0.3 wt% in the aqueous phase, and n-decane was used as the oil phase.

[0114] As can be seen in (c) of Fig. 7, it can be seen that the cationic cellulose surfactants according to Experimental Examples 1-5 and 1-7 significantly reduce the interfacial tension of the oil / water interface more than the cationic cellulose surfactants according to Experimental Examples 1-1 to 1-4.

[0115] Referring to Fig. 7(d), the storage coefficient at the oil / water interface was measured in a state where no cationic cellulose surfactant was provided (Bare interface), and the storage coefficient at the oil / water interface by the cationic cellulose surfactant according to Experimental Example 1-1 (9 mmol / g), Experimental Example 1-2 (18 mmol / g), Experimental Example 1-3 (27 mmol / g), Experimental Example 1-4 (36 mmol / g), Experimental Example 1-5 (45 mmol / g), and Experimental Example 1-7 (72 mmol / g) was measured. Specifically, in the measurement of the storage coefficient at the oil / water interface, the cationic cellulose surfactant according to the experimental examples was provided at 0.3 wt% in the aqueous phase, and n-decane was used as the oil phase. In addition, the strain was controlled to 0.1%, and the angular frequency was controlled to 0.5 rad / s (Du nouy ring geometry).

[0116] As can be seen in (d) of FIG. 7, it can be seen that the cationic cellulose surfactants according to Experimental Examples 1-5 and 1-7 increase the storage coefficient at the oil / water interface more than the cationic cellulose surfactants according to Experimental Examples 1-1 to 1-4. Accordingly, it can be seen that the cationic cellulose surfactants according to Experimental Examples 1-5 and 1-7 are adsorbed in greater amounts at the oil / water interface than the cationic cellulose surfactants according to Experimental Examples 1-1 to 1-4. Accordingly, it can be seen that the stability and mechanical strength of the interfacial film formed by the cationic cellulose surfactants according to Experimental Examples 1-5 and 1-7 are excellent.

[0117] In summary, in the method for producing a cationic cellulose surfactant, it can be seen that when the cationic epoxy provided is controlled to exceed 45 mmol based on 1 g of cellulose nanofibers, the zeta potential, interfacial tension, and storage coefficient at the oil / water interface are saturated.

[0118] Therefore, in the method for manufacturing a cationic cellulose surfactant according to an embodiment of the present application, it can be seen that the method of controlling the cationic epoxy provided to 45 mmol based on 1 g of cellulose nanofibers is a method of reducing the interfacial tension at the oil / water interface and improving the zeta potential and storage coefficient (degree of adsorption).

[0119]

[0120] Figure 8 is a graph for comparing the surface activity levels of an anionic cellulose surfactant according to Comparative Example 2 of the present invention and a cationic cellulose surfactant according to Experimental Examples 1-5.

[0121] Referring to (a) of Fig. 8, the anionic cellulose surfactant according to Comparative Example 2 was prepared by substituting the hydroxyl group (OH) on the surface of cellulose with a carboxyl group (COOH) using the oxidation reaction of TEMPO (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl. The interfacial tension at the oil / water interface was measured in a state where no ionic cellulose surfactant was provided (bare interface), and the anionic cellulose surfactant (HNC) according to Comparative Example 2 - ), and cationic cellulose surfactants (NHC) according to Experimental Example 1-5 + ) was used to measure the interfacial tension at the oil / water interface.

[0122] As can be seen from (a) of Fig. 8, the cationic cellulose surfactant according to Experimental Examples 1-5 has lower interfacial tension at the oil / water interface and superior interfacial stability than the anionic cellulose surfactant according to Comparative Example 2.

[0123] Referring to (b) of Fig. 8, the viscoelastic behavior at the oil / water interface was measured in a state where no ionic cellulose surfactant was provided (bare interface), and the viscoelastic behavior at the oil / water interface was measured by the anionic cellulose surfactant according to Comparative Example 2 and the cationic cellulose surfactant according to Experimental Examples 1-5.

[0124] As can be seen in (b) of Fig. 8, unlike the anionic cellulose surfactant according to Comparative Example 2, the cationic cellulose surfactant according to Experimental Examples 1-5 has a stable viscoelastic behavior at the oil / water interface. Accordingly, it can be seen that the cationic cellulose surfactant according to Experimental Examples 1-5 is adsorbed in a larger amount at the negatively charged oil / water interface than the anionic cellulose surfactant according to Comparative Example 2.

[0125]

[0126] Figure 9 is a graph for comparing the surface activity levels of a cationic cellulose surfactant according to Comparative Example 3 of the present invention and a cationic cellulose surfactant according to Experimental Examples 1-5.

[0127] Referring to (a) of Fig. 9, the cationic cellulose surfactant according to Comparative Example 3 was prepared in the same manner as the cationic cellulose surfactant according to Experimental Examples 1-5, except that the cellulose was pretreated before being provided to the basic solution. Specifically, the cellulose was pretreated by providing the cellulose (bacterial cellulose) to hydrochloric acid and acid-catalyzed hydrolysis of the amorphous region of the cellulose. Then, the cationic cellulose surfactant (LNC) according to Comparative Example 3 + ) and the cationic cellulose surfactant (HNC) according to Experimental Example 1-5 + ) was photographed using TEM.

[0128] As can be seen in (a) of Fig. 9, the average length of the cationic cellulose surfactant according to Comparative Example 3 is 200 nm to 500 nm, the average thickness is 5 nm to 10 nm, and the aspect ratio is 20 to 50. In addition, the average length of the cationic cellulose surfactant according to Experimental Examples 1-5 is 1,000 nm to 2,000 nm, the average thickness is 5 nm to 20 nm, and the aspect ratio is 50 to 400.

[0129] Therefore, it can be seen that the cationic cellulose surfactant according to Experimental Examples 1-5 has a significantly higher aspect ratio than the cationic cellulose surfactant according to Comparative Example 3.

[0130] Referring to (b) of Fig. 9, the interfacial tension of the oil / water interface was measured in a state where no cationic cellulose was provided (bare interface), the interfacial tension at the oil / water interface by the cationic cellulose surfactant according to Comparative Example 3 was measured, and the interfacial tension at the oil / water interface by the cationic cellulose surfactant according to Experimental Example 1-5 was measured.

[0131] As can be seen in (b) of Fig. 9, the cationic cellulose surfactant according to Experimental Example 1-5 has a higher aspect ratio than the cationic cellulose surfactant according to Comparative Example 3, so that the contact area with the oil / water interface increases, and the overall size of the electrostatic attraction with the oil / water interface increases, so that the interfacial tension at the oil / water interface is significantly reduced.

[0132] Referring to (c) of Fig. 9, the storage coefficient of the oil / water interface was measured in a state where no cationic cellulose was provided (bare interface), the storage coefficient at the oil / water interface by the cationic cellulose surfactant according to Comparative Example 3 was measured, and the storage coefficient at the oil / water interface by the cationic cellulose surfactant according to Experimental Examples 1-5 was measured.

[0133] As can be seen in (c) of FIG. 9, the cationic cellulose surfactant according to Experimental Examples 1-5 has a higher aspect ratio than the cationic cellulose surfactant according to Comparative Example 3, thereby increasing the contact area with the oil / water interface, thereby increasing the overall electrostatic attraction with the oil / water interface, and thus significantly increasing the storage coefficient at the oil / water interface. Therefore, it can be seen that the cationic cellulose surfactant according to Experimental Examples 1-5 has superior stability and mechanical properties of the interfacial film formed at the oil / water interface than the cationic cellulose surfactant according to Comparative Example 3.

[0134] Referring to (d) of Fig. 9, the cationic cellulose surfactants according to Experimental Examples 1-5 and Comparative Example 3 were each provided in distilled water, and an aqueous phase (100 mL) in which the cationic cellulose surfactants (0.3 wt%) according to Experimental Examples 1-5 and Comparative Example 3 were each dispersed was prepared using ultrasonic waves from a probe-type tip. Then, an oil phase (n-decane, 0.2 mL) was provided to the aqueous phase, and heat-treated at 60°C for 2 hours, and then Pickering emulsions according to Experimental Examples 1-5 and Comparative Example 3 were prepared using ultrasonic waves from a probe-type tip. Then, the Pickering emulsions according to Experimental Examples 1-5 and Comparative Example 3 were left at 50°C for 3 days, and the Turbiscan stability index was measured.

[0135] As can be seen in (d) of Fig. 9, the shape of the droplets of the Pickering emulsion according to Experimental Examples 1-5 maintained their initial shape for 3 days, but the shape of the droplets of the Pickering emulsion according to Comparative Example 3 showed phase separation and creaming phenomena immediately after the Turviscan stability index was measured.

[0136]

[0137] Figure 10 is a graph showing the zeta potential measured at different pH levels at an interface (oil / water interface) according to an experimental example of the present invention.

[0138] Referring to Fig. 10, 0.05 mL of n-decane was provided as an oil phase to 100 mL of water as an aqueous phase, and after heat treatment at 60°C for 2 hours, ultrasonic waves from a probe tip were applied to produce droplets (oil-in-water) of 300 nm in size. Then, hydrochloric acid and sodium hydroxide were provided to the aqueous phase to control the pH to 2 to 13, and the zeta potential of the droplets was measured.

[0139] As can be seen in Fig. 10, under conditions of pH 3 or higher, the zeta potential of the droplets has a negative value. Accordingly, it can be seen that the pH of the aqueous phase of the present application specification is controlled to 3 or higher, so that the interface between the dispersed phase (oil phase) and the continuous phase (aqueous phase) is inherently negatively charged.

[0140]

[0141] Figure 11 is a graph for comparing the results of Raman wavelength analysis of Pickering emulsions according to Comparative Example 4, Comparative Example 3, and Experimental Examples 1-5 of the present invention.

[0142] Referring to (a) of Fig. 11, the Pickering emulsion (Decane / D2O) according to Comparative Example 4 was prepared by using n-decane as the oil phase and D2O instead of distilled water as the water phase, and the Pickering emulsion (HNC) according to Comparative Example 3 described in (d) of Fig. 9 - -PE) and Pickering emulsion (HNC) according to Experimental Example 1-5 + -PE) was prepared. And, in order to compare the level of hydrogen bond cancellation by the surfactant adsorbed on the oil / water interface for the Pickering emulsions according to Comparative Example 4, Comparative Example 3, and Experimental Examples 1-5, Raman wavelength analysis was performed in OD stretch mode. At this time, in order to accurately identify the position of the oil / water interface, and Raman wavelength mapping was performed on one entire droplet of the Pickering emulsions according to Comparative Example 4, Comparative Example 3, and Experimental Examples 1-5, 2,500 cm -1 The OD peak corresponding to the water observed at 2,395 cm -1 The area where the peaks corresponding to the oil phase observed in overlap is considered as the oil / water interface, and Gaussian multi-curve fitting is performed to find 2,395 cm -1 / 2,500cm -1 The fraction is shown in a graph.

[0143] Referring to (b) to (d) of Fig. 11, the results of Raman wavelength analysis in OD stretch mode for the Pickering emulsions according to Comparative Example 4, Comparative Example 3, and Experimental Examples 1-5, respectively, are shown in a graph.

[0144] As can be seen from (a) to (d) of Fig. 11, unlike the Pickering emulsions according to Comparative Examples 4 and 3, the Pickering emulsions according to Experimental Examples 1-5 have a 2,395 cm -1 / 2,500cm -1 It can be seen that the fraction is significantly low. This factor is interpreted to be due to the fact that the cationic cellulose surfactant according to Experimental Examples 1-5 is adsorbed in a larger amount at the oil / water interface with an anionic charge than the anionic cellulose surfactant according to Comparative Example 3, thereby canceling out the hydrogen bond between the hydrogen atoms of the water in the water phase and the oil molecules in the oil phase at the oil / water interface.

[0145]

[0146] FIG. 12 is a graph for comparing the droplet size and long-term stability of the droplets of Pickering emulsions according to Comparative Example 1 of the present invention and Experimental Examples 1-1 to 1-5.

[0147] Referring to (a) of Fig. 12, a Pickering emulsion according to Comparative Example 1 was prepared by the following method. Cellulose (0.3 wt%) according to Comparative Example 1 described in (a) of Fig. 7 was dispersed in distilled water to prepare an aqueous phase, and the aqueous phase (80 vol%) in which the cellulose (0.3 wt%) according to Comparative Example 1 was dispersed and the oil phase (20 vol%) of n-decane were homogenized (12,000 rpm, 5 minutes) using a homogenizing device, thereby preparing a preliminary Pickering emulsion according to Comparative Example 1. Then, ultrasonic waves were applied to the preliminary Pickering emulsion according to Comparative Example 1 for 5 minutes using a homogenizer equipped with a probe-type ultrasonic tip, thereby preparing a Pickering emulsion according to Comparative Example 1. And, Pickering emulsions according to Experimental Examples 1-1 to 1-5 were prepared in the same manner as the method for preparing the Pickering emulsion according to Comparative Example 1-1 described above, except that the cationic cellulose surfactants according to Experimental Examples 1-1 to 1-5 were used instead of the cellulose according to Comparative Example 1. And, the average droplet size of the Pickering emulsions according to Experimental Examples 1-1 (9 mmol / g) to 1-5 (45 mmol / g) was measured using an optical microscope, and after the Pickering emulsions according to Experimental Examples 1-1 (9 mmol / g) to 1-5 (45 mmol / g) were allowed to stand for 14 days, the average droplet size was measured using an optical microscope, and the results were summarized in a graph.

[0148] Referring to (b) of Fig. 12, the Pickering emulsion (BC) according to Comparative Example 1 was left for 14 days and then photographed with an optical microscope, and the Pickering emulsions according to Experimental Examples 1-1 (9 mmol / g) to 1-5 (45 mmol / g) were left for 14 days and then photographed with an optical microscope.

[0149] As can be seen in (a) and (b) of FIG. 12, the droplet sizes of the Pickering emulsions according to Experimental Examples 1-4 and 1-5 are 6 μm or less on average, and the droplet sizes remain stable even after 14 days of storage. In contrast, the droplet sizes of the Pickering emulsions according to Comparative Example 1 and Experimental Examples 1-1 to 1-3 are found to significantly increase after 14 days of storage.

[0150] Therefore, in the method for manufacturing a cationic cellulose surfactant according to an embodiment of the present application, it can be seen that the method of controlling the cationic epoxy provided to 36 mmol or more per 1 g of cellulose nanofibers is a method for improving the long-term stability of droplets of Pickering emulsion.

[0151] Referring to (c) of Fig. 12, in the method for producing the Pickering emulsion according to Experimental Example 1-5, a Pickering emulsion was produced by replacing the oil with olive oil instead of n-decane, and the photograph was taken using an optical microscope. Referring to (d) of Fig. 12, in the method for producing the Pickering emulsion according to Experimental Example 1-5, a Pickering emulsion was produced by replacing the oil with mineral oil instead of n-decane, and the photograph was taken using an optical microscope. Referring to (e) of Fig. 12, in the method for producing the Pickering emulsion according to Experimental Example 1-5, a Pickering emulsion was produced by replacing the oil with squalene instead of n-decane, and the photograph was taken using an optical microscope.

[0152] As can be seen from (b) to (d) of FIG. 12, the droplet sizes of the Pickering emulsion according to Experimental Example 1-5 and the droplet sizes of the Pickering emulsion using olive oil, mineral oil, and squalene are similar.

[0153] Accordingly, it can be seen that the Pickering emulsion according to the embodiment of the present application can utilize n-decane, olive oil, mineral oil, and squalene, which contain a neutral hydrocarbon with a net charge of 0 and a fatty acid with a negative charge.

[0154]

[0155] Figure 13 is a graph and photograph for comparing the rheological behavior and long-term stability of Pickering emulsions according to Experimental Examples 1-5 and Comparative Example 2 of the present invention.

[0156] Referring to (a) of Fig. 13, the Pickering emulsion (HNC) according to Experimental Example 1-5 described in (a) of Fig. 12 + -PE) was prepared, and the anionic cellulose surfactant according to Comparative Example 2 described in (a) of FIG. 8 was used instead of the cellulose according to Comparative Example 1 described in (a) of FIG. 12, in the same manner as the method for preparing the Pickering emulsion according to Comparative Example 1, except that the anionic cellulose surfactant (HNC) according to Comparative Example 2 was used. - -PE) was manufactured. Then, the rheological behavior of the Pickering emulsions according to Experimental Examples 1-5 and Comparative Example 2 was measured according to the oscillation frequency.

[0157] As can be seen in (a) of Fig. 13, the rheological behavior of the Pickering emulsion according to Experimental Example 1-5 is stable compared to that of the Pickering emulsion according to Comparative Example 2. This is interpreted as being due to the fact that the number of hydroxyl groups on the surface of the cellulose nanofibers of the cationic cellulose surfactant according to Experimental Example 1-5 in the Pickering emulsion according to Experimental Example 1-5 is significantly greater than the number of hydroxyl groups on the surface of the cellulose nanofibers of the anionic cellulose surfactant according to Comparative Example 2 in the Pickering emulsion according to Comparative Example 2. Accordingly, it can be seen that the cationic cellulose surfactant according to Experimental Example 1-5 is adsorbed to the oil / water interface having a negative charge by the cationic functional group provided on the surface of the cellulose nanofibers, and then hydrogen bonds between the cationic celluloses are formed by the hydroxyl group on the surface of the cellulose nanofibers, thereby forming an interfacial film with improved mechanical properties, and the rheological behavior is stably maintained.

[0158] Referring to (b) of Fig. 13, after the Pickering emulsions according to Experimental Examples 1-5 and Comparative Example 2 were left for 14 days, the droplets of the Pickering emulsions according to Experimental Examples 1-5 and Comparative Example 2 were photographed using an optical microscope, and actual photographs of the droplets of the Pickering emulsions according to Experimental Examples 1-5 and Comparative Example 2 were taken with a camera (inserted photographs).

[0159] As can be seen in (b) of Fig. 13, the Pickering emulsion according to Experimental Example 1-5 was stable for 14 days, but the Pickering emulsion according to Comparative Example 2 showed phase separation. This is interpreted as being due to the fact that, as described above, there are significantly more hydroxyl groups on the surface of the cellulose nanofibers of the cationic cellulose surfactant according to Experimental Example 1-5 in the Pickering emulsion according to Experimental Example 1-5 than there are hydroxyl groups on the surface of the cellulose nanofibers of the anionic cellulose surfactant according to Comparative Example 2 in the Pickering emulsion according to Comparative Example 2.

[0160]

[0161] FIG. 14 is a graph and photograph for comparing the interfacial properties according to the salt concentration of an anionic cellulose surfactant according to Comparative Example 2 of the present invention and a cationic cellulose surfactant according to Experimental Examples 1-5, and the droplet sizes according to the salt concentration of Pickering emulsions according to Comparative Examples 2-1 to 2-4 and Experimental Examples 1-5-1 to 1-5-4.

[0162] Referring to (a) of Fig. 14, the anionic cellulose surfactant according to Comparative Example 2 described in (a) of Fig. 8 is dispersed in water (HNC) - ) were provided with salt (NaCl) in concentrations of 0.0 mol / L to 1.8 mol / L, and ultrasound was applied for 5 minutes using a probe-type ultrasonic tip, and the viscosity was measured. Then, the cationic cellulose surfactant according to Experimental Example 1-5 was dispersed in water in the aqueous phase (HNC + ) were provided with salt at concentrations of 0.0 mol / L to 1.8 mol / L, and ultrasound was applied for 5 minutes using a probe-type ultrasonic tip, and then the viscosity was measured.

[0163] As can be seen in (a) of FIG. 14, as the concentration of salt in the aqueous phase in which the anionic cellulose surfactant according to Comparative Example 2 is dispersed increases, the repulsive force between the anionic cellulose surfactants according to Comparative Example 2 decreases, and thus the interaction between the anionic cellulose surfactants according to Comparative Example 2 improves, thereby increasing the viscosity. In addition, as the concentration of salt in the aqueous phase in which the cationic cellulose surfactant according to Experimental Example 1-5 is dispersed increases, the repulsive force between the cationic cellulose surfactants according to Experimental Example 1-5 decreases, and thus the interaction between the cationic cellulose surfactants according to Experimental Example 1-5 improves, thereby increasing the viscosity.

[0164] Referring to (b) of Fig. 14, the anionic cellulose surfactant according to Comparative Example 2 is dispersed in water (HNC) - ) were provided with salt (NaCl) in concentrations of 0.0 mol / L to 1.8 mol / L, and ultrasound was applied for 5 minutes using a probe-type ultrasonic tip, and then the interfacial tension at the oil / water interface was measured. Then, the cationic cellulose surfactant according to Experimental Example 1-5 was dispersed in water in the aqueous phase (HNC + ) were provided with salt at concentrations of 0.0 mol / L to 1.8 mol / L, and ultrasound was applied for 5 minutes using a probe-type ultrasonic tip, and then the interfacial tension at the oil / water interface was measured.

[0165] As can be seen in (b) of FIG. 14, as the concentration of salt in the aqueous phase in which the anionic cellulose surfactant according to Comparative Example 2 is dispersed increases, the electrostatic repulsion between the anionic cellulose surfactant according to Comparative Example 2 and the oil / water interface decreases, so the amount of the anionic cellulose surfactant according to Comparative Example 2 adsorbed to the oil / water interface increases, and it can be seen that the interfacial tension at the oil / water interface decreases.

[0166] In contrast, as the concentration of salt in the aqueous phase in which the cationic cellulose surfactant according to Experimental Example 1-5 is dispersed increases, the electrostatic attraction between the cationic cellulose surfactant according to Experimental Example 1-5 and the oil / water interface decreases, so it can be seen that the amount of the cationic cellulose surfactant according to Experimental Example 1-5 adsorbed to the oil / water interface decreases, thereby increasing the tension at the oil / water interface.

[0167] Referring to (c) of Fig. 14, salt (NaCl) was provided in concentrations of 0 M, 0.018 M, 0.18 M, and 1.8 M to the aqueous phase in which the cationic cellulose surfactant according to Experimental Example 1-5 was dispersed, and the aqueous phase (80 vol%) and the oil phase (n-decane, 20 vol%) having different salt concentrations were homogenized at 12,000 rpm for 5 minutes using a homogenizer, and ultrasonic waves were irradiated for 5 minutes using a homogenizer equipped with a probe-type ultrasonic tip, thereby preparing Pickering emulsions according to Experimental Examples 1-5-1 (0 M) to 1-5-4 (1.8 M). Then, the droplet sizes of the Pickering emulsions according to Experimental Examples 1-5-1 (0 M) to 1-5-4 (1.8 M) were photographed using an optical microscope.

[0168] Referring to (d) of Fig. 14, salt (NaCl) was provided in concentrations of 0 M, 0.018 M, 0.18 M, and 1.8 M to the aqueous phase in which the anionic cellulose surfactant according to Experimental Example 2 was dispersed, and the aqueous phase (80 vol%) and the oil phase (n-decane, 20 vol%) having different salt concentrations were homogenized at 12,000 rpm for 5 minutes using a homogenizer, and ultrasonic waves were irradiated for 5 minutes using a homogenizer equipped with a probe-type ultrasonic tip, thereby producing Pickering emulsions according to Comparative Examples 2-1 (0 M) to 2-4 (1.8 M). Then, the droplet sizes of the Pickering emulsions according to Comparative Examples 2-1 (0 M) to 2-4 (1.8 M) were photographed using an optical microscope.

[0169] As can be seen in (c) and (d) of FIG. 14, unlike the Pickering emulsions according to Comparative Examples 2-1 to 2-4, in the Pickering emulsions according to Experimental Examples 1-5-1 to 1-5-4, as the salt concentration increases, the electrostatic attraction between the cationic cellulose surfactant according to Experimental Example 1-5 and the oil / water interface decreases, so that the droplet size of the Pickering emulsion increases.

[0170] Therefore, the Pickering emulsion containing the cationic cellulose surfactant according to Experimental Example 1-5 can be applied as a salt-reactive drug delivery formulation since the size of the droplets of the Pickering emulsion is controlled depending on the concentration of the salt.

[0171]

[0172] Figures 15 to 18 are drawings, photographs, and graphs for verifying whether the Pickering emulsion according to Experimental Examples 1 to 5 of the present invention can be used as a hair strengthening composition.

[0173] Referring to Fig. 15, the Pickering emulsion (HNC) according to Experimental Example 1-5 described in (a) of Fig. 12 + -PE) were prepared, and normal hair (control), bleached hair (normal hair treated with 10% H2O2 for 2 hours), and shampooed hair (normal hair treated with 0.5 M SDS (sodium dodecyl sulfate) for 2 hours) were prepared. Then, the normal hair, the bleached hair, and the shampooed hair were treated with the Pickering emulsion (HNC) according to Experimental Example 1-5. + - After soaking in PE for 1 hour, it was washed with distilled water.

[0174] Referring to (a) of Fig. 16, the normal hair was photographed with an SEM before / after being treated with the Pickering emulsion according to Experimental Example 1-5, and referring to (b) of Fig. 16, the bleached hair was photographed with an SEM before / after being treated with the Pickering emulsion according to Experimental Example 1-5, and referring to (c) of Fig. 16, the shampooed hair was photographed with an SEM before / after being treated with the Pickering emulsion according to Experimental Example 1-5.

[0175] Referring to (a) of Fig. 17, the normal hair was photographed using confocal laser scanning microscopy before / after being treated with the Pickering emulsion according to Experimental Example 1-5, and referring to (b) of Fig. 17, the bleached hair was photographed using confocal laser scanning microscopy before / after being treated with the Pickering emulsion according to Experimental Example 1-5, and referring to (c) of Fig. 17, the shampooed hair was photographed using confocal laser scanning microscopy before / after being treated with the Pickering emulsion according to Experimental Example 1-5.

[0176] As can be seen in FIGS. 15 to 17, when the normal hair, the bleached hair, and the shampooed hair are immersed in the Pickering emulsion according to Experimental Example 1-5, it can be seen that the normal hair, the bleached hair, and the shampooed hair are coated with the Pickering emulsion according to Experimental Example 1-5. This is interpreted to be due to the fact that the cuticles of the normal hair, the bleached hair, and the shampooed hair have a negative charge, and thus the cationic cellulose surfactant in the Pickering emulsion according to Experimental Example 1-5 is electrostatically bonded by the cationic functional group provided on the surface of the cellulose nanofibers of the cationic cellulose surfactant.

[0177] Referring to (a) of Fig. 18, the tensile strength was measured before / after treating the normal hair with the Pickering emulsion according to Experimental Example 1-5, and referring to (b) of Fig. 18, the tensile strength was measured before / after treating the bleached hair with the Pickering emulsion according to Experimental Example 1-5, and referring to (c) of Fig. 18, the tensile strength was measured before / after treating the shampooed hair with the Pickering emulsion according to Experimental Example 1-5, and referring to (d) of Fig. 18, the results measured in (a) to (c) of Figs. 18 were summarized.

[0178] As can be seen in FIGS. 15 and 18, the Pickering emulsion according to Experimental Example 1-5 increased the tensile strength of normal hair by 15%, the tensile strength of bleached hair by 45%, and the tensile strength of shampooed hair by 33%. Accordingly, it can be seen that the Pickering emulsion according to Experimental Example 1-5 can be applied as a hair treatment composition.

[0179]

[0180] Figure 19 is a graph for comparing zeta potential according to the nucleophilic addition reaction time of cationic cellulose surfactants according to experimental examples of the present invention.

[0181] Referring to FIG. 19, in the method for producing a cationic cellulose surfactant according to Experimental Examples 1-5, the nucleophilic addition reaction time was controlled to 0 hour, 0.5 hour, 1 hour, 2 hours, 4 hours, and 6 hours to produce cationic cellulose surfactants according to the Experimental Examples, and the zeta potential of the cationic cellulose surfactants according to the Experimental Examples was measured to compare the nucleophilic addition reaction efficiency.

[0182] As can be seen in Fig. 19, the cationic cellulose surfactant manufactured by controlling the nucleophilic addition reaction time to 1 hour and 2 hours has a higher zeta potential than the cationic cellulose surfactant manufactured by controlling the nucleophilic addition reaction time to 0 hour, 0.5 hour, 4 hours, and 6 hours.

[0183] Therefore, in the method for producing a cationic cellulose surfactant according to the present application example, it can be seen that the method of controlling the nucleophilic addition reaction time to 1 to 2 hours is a method for improving the reaction efficiency for the nucleophilic addition reaction.

[0184]

[0185] While the present invention has been described in detail using preferred embodiments, the scope of the present invention is not limited to the specific embodiments described above, and should be interpreted in accordance with the appended claims. Furthermore, those skilled in the art will appreciate that numerous modifications and variations are possible without departing from the scope of the present invention.

[0186]

[0187] The cationic cellulose surfactant according to an embodiment of the present invention can be used in various fields such as cosmetics, personal hygiene products, pharmaceuticals, life sciences, food industry, textile and clothing industry, etc.

Claims

1. A step of preparing a base solution by providing and dispersing cellulose in a basic solution; and Comprising the step of providing a cationic epoxy to the above base solution and reacting it to produce a cationic cellulose solution including cellulose nanofibers, A method for producing a cationic cellulose surfactant, comprising providing a cationic functional group on the surface of the cellulose nanofibers in the step of producing the cationic cellulose solution.

2. In paragraph 1, In the step of preparing the above cationic cellulose solution, After heat-treating the base solution, the cationic epoxy is provided to the base solution, Hydroxide (O) of the cellulose nanofibers in the heat-treated base solution - ) and the cationic epoxy, wherein the cationic functional group is provided on the surface of the cellulose nanofibers by a nucleophilic addition reaction.

3. In paragraph 2, The above base solution includes heat treatment at 70°C to 80°C, A method for producing a cationic cellulose surfactant, comprising controlling the nucleophilic addition reaction time to be from 1 hour to 2 hours.

4. In paragraph 1, In the step of preparing the above base solution, By the above basic solution, some of the hydroxyl groups (OH) of the cellulose are converted to hydroxide (O - ) which is ionized, A method for producing a cationic cellulose surfactant, comprising controlling the pH of the base solution to 13.

5. In paragraph 1, A method for producing a cationic cellulose surfactant, further comprising the step of providing distilled water to the cationic cellulose solution and centrifuging and washing to obtain the cationic cellulose surfactant.

6. In paragraph 1, The cationic epoxy comprises either glycidyltrimethylammonium chloride (GTAC) or (3-chloro-2-hydroxypropyl)trimethylammonium chloride, The above cationic functional group is a substituted or unsubstituted quaternary ammonium (NR3 + , NR3Cl) containing at least one of them, A method for producing a cationic cellulose surfactant, wherein the above basic solution contains either potassium hydroxide or sodium hydroxide.

7. Cellulose nanofibers; and A cationic cellulose surfactant comprising a cationic functional group provided on the surface of the above cellulose nanofibers.

8. In paragraph 7, A cationic cellulose surfactant, comprising a zeta potential of the cationic cellulose surfactant of 5 mV to 50 mV.

9. In paragraph 7, The average length of the above cellulose nanofibers includes 1,000 nm to 2,000 nm, The average thickness of the above cellulose nanofibers is 5 nm to 20 nm, A cationic cellulose surfactant comprising the cellulose nanofibers having an aspect ratio of 50 to 400.

10. In paragraph 7, A cationic cellulose surfactant comprising the cationic functional group provided in a ratio of 1 mmol to 8 mmol based on 1 g of the cellulose nanofibers.

11. In paragraph 10, The above cationic functional group is a substituted or unsubstituted quaternary ammonium (NR3 + , NR3Cl) cationic cellulose surfactant.

12. Different liquids, dispersed phase and continuous phase, and A cationic cellulose surfactant that electrostatically binds to the negative charge of the interface between the dispersed phase and the continuous phase to form an interfacial film, The above cationic cellulose surfactant is, Cellulose nanofibers; and A Pickering emulsion comprising cationic functional groups provided on the surface of the above cellulose nanofibers.

13. In paragraph 12, The above-mentioned powder phase is an oil phase including oil containing neutral hydrocarbons with a net charge of 0 and fatty acids with a negative charge, A Pickering emulsion comprising the above continuous phase as a water phase containing water having a pH of 3 to 14.

14. In paragraph 13, A Pickering emulsion comprising a weight ratio of the cationic cellulose surfactant of 0.1 wt% or more relative to the continuous phase.

15. Different liquids, dispersed phase and continuous phase, and A cationic cellulose surfactant that electrostatically binds to the negative charge of the interface between the dispersed phase and the continuous phase to form an interfacial film, The above cationic cellulose surfactant is, Cellulose nanofibers; and A drug delivery composition comprising a cationic functional group provided on the surface of the cellulose nanofibers.

16. In paragraph 15, A drug delivery composition comprising a composition in which the stability of the interfacial film and the emulsifying power of the cationic cellulose surfactant are controlled according to the concentration of salt provided in the continuous phase.

17. In paragraph 16, The salt comprises any one of sodium chloride, potassium chloride, barium sulfide, or calcium sulfide, A drug delivery composition comprising the salt concentration controlled to be 0.0 mol / L to 1.8 mol / L.

18. In paragraph 15, The above-mentioned powder phase, the above-mentioned powder phase, the above-mentioned dispersed phase is an oil phase including oil containing neutral hydrocarbons having a net charge of 0 and fatty acids having a negative charge, A drug delivery composition comprising a water phase comprising water having a pH of 3 to 14.

19. Different liquids, dispersed phase and continuous phase, and A cationic cellulose surfactant that electrostatically binds to the negative charge of the interface between the dispersed phase and the continuous phase to form an interfacial film, The above cationic cellulose surfactant is, Cellulose nanofibers; and A hair strengthening composition comprising a cationic functional group provided on the surface of the above cellulose nanofibers.

20. In paragraph 19, A hair strengthening composition comprising a cationic functional group provided on the surface of the cationic cellulose surfactant in the hair strengthening composition and a negatively charged hair cuticle electrostatically bonded to strengthen the hair.

21. In paragraph 19, The above-mentioned powder phase is an oil phase including oil containing neutral hydrocarbons with a net charge of 0 and fatty acids with a negative charge, A hair strengthening composition comprising a water phase comprising water having a pH of 3 to 14.

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