Polymeric carbon nitride, specific crystalline forms of the polymeric carbon nitride and use thereof for blocking ultraviolet radiation

Abstract

Disclosed are a polymer carbon nitride, a specific crystal form of the polymer carbon nitride, and a cosmetic composition, an ultraviolet blocking composition, and a skin external agent composition containing the same. The polymer carbon nitride and the crystal form prepared through a specific preparation example thereof can absorb both UVA and UVB, and thus can effectively protect the skin from ultraviolet rays, and, since it is non-toxic, biocompatible, and has no photoactivity, can be used in a cosmetic composition, an ultraviolet blocking composition, and a skin external agent composition suitable for living organisms. In addition, the specific crystal form of the polymer carbon nitride has different characteristics according to the preparation method, and thus can be used in various ways according to its characteristics. In particular, since the crystal form of the polymer carbon nitride has the characteristic that it can be adjusted to various colors according to the preparation method, in use, a composition of a desired color can be adjusted, and thus can be appropriately used to prepare products of various colors suitable for different skin colors.

Description

Technical Field

[0001] This invention relates to a polymeric carbon nitride, a specific crystal form of the polymeric carbon nitride, and its use in blocking ultraviolet light. This patent application claims priority to Korean Patent Application No. 10-2020-0168538 and Korean Patent Application No. 10-2020-0168537, filed with the Korean Patent Office on December 4, 2020, the disclosures of which are incorporated herein by reference. Background Technology

[0002] Ultraviolet (UV) radiation is sunlight with wavelengths ranging from 280 to 400 nanometers. Excessive exposure to UV radiation can induce skin damage such as aging, burns, and skin cancer. In particular, UVA, with wavelengths ranging from 320 to 400 nanometers, is known to damage skin lipids in the epidermis or induce melanin production in the basal layer, thus accelerating skin aging. Furthermore, UVB, with wavelengths ranging from 280 to 320 nanometers, is known to induce skin erythema and burns, directly damaging the skin. Therefore, there is a need to develop substances that protect the skin from UV radiation by simultaneously blocking both UVA and UVB.

[0003] In particular, excessive exposure to ultraviolet (UV) rays can lead to skin cancer, thus necessitating a UV blocker to prevent life-threatening diseases and skin wrinkles. Two commonly used inorganic UV blockers are zinc oxide (ZnO) and titanium dioxide (TiO2), but their use can cause serious health problems. These photoactive metal oxide semiconductor sunscreens generate hydroxyl (·OH) and peroxide (O2·-) radicals during UV absorption. The generation of these highly reactive oxygen species (ROS) not only decomposes the organic additives in the UV blocker but also induces oxidative stress in skin tissue, causing damage at the cellular level and accelerating DNA modification and inflammatory responses. Therefore, research into developing a safer UV blocker that can replace zinc oxide (ZnO) and titanium dioxide (TiO2) is ongoing (Korean Patent Publication No. 10-2020-0047249).

[0004] Therefore, recent research is underway on removing carcinogenic ROS by covering inorganic and organic matter, but its commercialization potential has not yet been confirmed. Thus, there is a need for a substance that can absorb the entire UV spectrum of light energy, is highly stable, has low photocatalytic activity, is biocompatible, and non-toxic, while addressing the problems described above. Summary of the Invention

[0005] Technical issues

[0006] The purpose of this invention is to provide a polymeric carbon nitride, a specific crystal form of the polymeric carbon nitride, and its use in blocking ultraviolet light, in order to solve the problems described above.

[0007] One object of the present invention is to provide a crystal form of polymeric carbon nitride (PCN) selected from the group consisting of crystal forms A to G.

[0008] Another object of the present invention is to provide a cosmetic composition, an ultraviolet blocking composition, and a topical skin composition comprising polymeric carbon nitride or a specific crystal form of said polymeric carbon nitride.

[0009] Another object of the present invention is to provide a method for preparing a cosmetic composition, an ultraviolet blocking composition, or a topical skin composition, comprising the step of adding polymeric carbon nitride or a specific crystal form of said polymeric carbon nitride.

[0010] Another object of the present invention is to provide the use of polymeric carbon nitride, a particular crystal form of said polymeric carbon nitride, or a composition comprising the thereof for blocking ultraviolet radiation.

[0011] However, the technical problem to be solved by the present invention is not limited to the above-mentioned problems, and those skilled in the art can clearly understand other problems not mentioned from the following description.

[0012] Technical solution

[0013] According to an embodiment of the present invention, a crystal form is provided as a crystal form of polymeric carbon nitride (PCN) selected from the group consisting of crystal forms A to G having the following X-ray powder diffraction patterns measured using CuKα rays, wherein the X-ray powder diffraction pattern of crystal form A includes peaks at one or more diffraction angles selected from the group consisting of 2θ = 10.7656 ± 0.2°, 19.8006 ± 0.2°, and 29.7456 ± 0.2°; the X-ray powder diffraction pattern of crystal form B includes peaks at one or more diffraction angles selected from the group consisting of 2θ = 10.7396 ± 0.2° and 29.7456 ± 0.2°; and the X-ray powder diffraction pattern of crystal form C includes peaks at one or more diffraction angles selected from the group consisting of 2θ = 10.7006 ± 0.2°, 22.1406 ± 0.2°, and 27.8606 ± 0.2°. The X-ray powder diffraction pattern of crystal form D includes peaks at one or more diffraction angles selected from the group consisting of 2θ = 10.6356 ± 0.2° and 27.8216 ± 0.2°; the X-ray powder diffraction pattern of crystal form E includes peaks at one or more diffraction angles selected from the group consisting of 2θ = 10.7266 ± 0.2° and 27.5096 ± 0.2°; the X-ray powder diffraction pattern of crystal form F includes peaks at a diffraction angle of 2θ = 27.1586 ± 0.2°; and the X-ray powder diffraction pattern of crystal form G includes peaks at one or more diffraction angles selected from the group consisting of 2θ = 13.8076 ± 0.2° and 27.1586 ± 0.2°.

[0014] The “polymer carbon nitride” may include repeating units represented by the following chemical formula 1:

[0015] [Chemical Formula 1]

[0016]

[0017] In the chemical formula 1, n is an integer, for example, it can be an integer between 1 and 1,000,000. The molecular weight of the polymer carbon nitride having the chemical formula 1 can be a polymer having a molecular weight of, for example, about 200 to 5,000,000 amu, about 400 to 4,000,000 amu, about 600 to 3,000,000 amu, or about 800 to 2,000,000 amu.

[0018] One aspect of the polymeric carbon nitride crystal form is that of a highly stable polymer both thermally and chemically, appears white to the naked eye, and is easily dispersed when included in a composition. In one specific embodiment, the novel crystal form of the polymeric carbon nitride was confirmed to possess novel properties, which were then specifically identified.

[0019] On one hand, the polymeric carbon nitride crystal forms A to G may have the following absorption peaks. Specifically, the polymeric carbon nitride crystal forms A to G may have a characteristic (or property) selected from the group consisting of: in the infrared spectrum (IR) of crystal form A, at 775±2 cm⁻¹ -1 1417cm -1 1456cm -1 1691cm -1 1730cm -1 3074cm -1 and 3311cm -1 The region includes a characteristic absorption peak; in the IR of crystal form B, at 777±2 cm⁻¹ -1 1677±2cm -1 1735±2cm -1 3085±2cm -1 and 3315±2cm -1 The region includes characteristic absorption peaks; in the IR of the crystal form C, at 777±2 cm⁻¹ -1 1467±2cm -1 1666±2cm -1 1734±2cm -1 3120±2cm -1 and 3320±2cm -1 The region includes a characteristic absorption peak; in the IR of the crystal form D, at 777±2 cm⁻¹ -1 1465±2cm -1 1660±2cm -1 1734±2cm -1 3085±2cm -1 and 3330±2cm -1 The region includes characteristic absorption peaks; in the IR of the crystal form E, at 810±2 cm⁻¹ -1 1270±2cm -1 1420±2cm -1 1612±2cm -1 3105±2cm -1 and 3330±2cm -1 The region includes characteristic absorption peaks; in the IR of the crystal form F, at 810±2 cm⁻¹ -1 1265±2cm -1 1325±2cm -1 1417±2cm -1 1618±2cm -1 and 3230±2cm -1 The region includes characteristic absorption peaks; and in the IR of the crystal form G, at 810±2 cm⁻¹-1 1240±2cm -1 1317±2cm -1 1410±2cm -1 1560±2cm -1 1635±2cm -1 and 3250±2cm -1 The region includes characteristic absorption peaks.

[0020] Furthermore, when analyzed using X-ray photoelectron spectroscopy (XPS), the polymer carbon nitride crystal forms of A to G may have a C (carbon) peak in the range of about 280 to 290 eV, an N (nitrogen) peak in the range of about 390 to 400 eV, and an O (oxygen) peak in the range of about 530 to 540 eV.

[0021] Furthermore, the crystal forms A to G can absorb UV rays from sunlight with high absorptivity, for example, they can absorb UVA with wavelengths of approximately 320 to 400 nm and UVB with wavelengths of approximately 280 to 320 nm, thereby preventing skin damage caused by ultraviolet radiation. Therefore, the polymeric carbon nitride crystal forms A to G can strongly absorb light energy in wavelength regions such as approximately 200 to 400 nm, approximately 220 to 400 nm, or approximately 280 to 400 nm.

[0022] The average particle size of the polymer carbon nitride crystal forms A to G can be, for example, about 1 to 10 nm, about 2 to 8 nm, about 3 to 6 nm, or about 4 to 5 nm. In one specific embodiment, the average particle size of the polymer carbon nitride crystal forms A to G was confirmed by atomic force microscopy (AFM).

[0023] The polymer carbon nitride crystal forms A to G can form 2D nanosheets with a thickness (height) of, for example, about 1 to 10 nm, about 2 to 8 nm, about 3 to 6 nm, or about 4 to 5 nm. The thickness of these nanosheets can effectively cover the skin surface.

[0024] The color of the polymeric carbon nitride crystal form is adjustable and can be adapted to different skin tones. Because the polymeric carbon nitride crystal form has the characteristic of adjusting its color according to the preparation method, it can be adjusted to create a composition with the desired color during use, thus allowing it to be appropriately used to prepare products of various colors suitable for different skin tones.

[0025] The polymer carbon nitride crystal forms A to G may not exhibit cytotoxicity and may not generate reactive oxygen species (ROS) when irradiated with UV.

[0026] According to another embodiment of the present invention, a cosmetic composition, an ultraviolet blocking composition, and a topical skin composition comprising a polymeric carbon nitride including repeating units represented by the following chemical formula 1 are provided:

[0027] [Chemical Formula 1]

[0028]

[0029] In the chemical formula 1, n is an integer, for example, it can be an integer between 1 and 1,000,000. The molecular weight of the polymer carbon nitride having the chemical formula 1 can be a polymer having a molecular weight of, for example, about 200 to 5,000,000 amu, about 400 to 4,000,000 amu, about 600 to 3,000,000 amu, or about 800 to 2,000,000 amu.

[0030] The composition may contain the polymer carbon nitride as an active ingredient.

[0031] The polymeric carbon nitride contained in the composition may comprise one or more crystal forms selected from the group consisting of polymeric carbon nitride crystal forms A to G.

[0032] The color of the polymeric carbon nitride is tunable and can be applied to different skin tones. Because the polymeric carbon nitride is color-tunable when prepared using suitable methods in the art, the desired color can be adjusted and prepared when used to prepare cosmetic compositions, UV-blocking compositions, and topical skin compositions.

[0033] In the instructions, "cosmetic composition" refers to an article used on the human body to enhance attractiveness, improve appearance, or maintain or promote the health of skin and hair by making the body neat and beautiful. The cosmetic composition may be used to block ultraviolet rays.

[0034] The polymeric carbon nitride may be included therein in amounts of about 0.001 to 35 wt%, about 0.01 to 30 wt%, about 0.1 to 30 wt%, about 0.1 to 25 wt%, about 0.5 to 35 wt%, about 0.5 to 30 wt%, about 0.5 to 25 wt%, about 0.5 to 20 wt%, about 0.5 to 15 wt%, about 0.5 to 10 wt%, about 1 to 35 wt%, about 1 to 30 wt%, about 1 to 25 wt%, about 1 to 20 wt%, about 1 to 15 wt%, about 1 to 10 wt%, about 5 to 35 wt%, about 5 to 30 wt%, about 5 to 25 wt%, about 5 to 20 wt%, about 5 to 15 wt%, about 5 to 10 wt%, about 1 wt%, about 5 wt%, about 10 wt%, or about 15 wt%, relative to the total weight of the composition. If the content of the polymer carbon nitride is lower than the specified content, the composition will not have the effect of blocking ultraviolet light; if it is higher than the specified content, the formulation stability of the composition may be significantly reduced.

[0035] In addition to the ingredients described herein, the composition may further comprise one or more selected from the group consisting of purified water, preservatives, stabilizers, surfactants, thickeners, solubilizers, humectants, emollients, UV absorbers, preservatives, bactericides, emulsifiers, antioxidants, pH adjusters, organic and inorganic pigments, fragrances, carriers, coolants, and antiperspirants. For example, it may further comprise additives commonly used in the art. Those skilled in the art can readily determine the amount of the added ingredients, such as the preservatives, without prejudice to the purpose and effects of the invention, and the amount may be from about 0.001 to 30% by weight (w / w) relative to the total weight of the composition. However, those skilled in the art may choose any added ingredient and / or its amount so that the beneficial properties of the composition according to this specification are not adversely affected by the intended addition or are substantially unaffected by it.

[0036] The composition may further comprise organic and / or inorganic UV blocking agents, such as ethylhexyl methoxycinnamate, titanium dioxide, zinc oxide, butyl methoxydibenzoylmethane, isoamyl p-methoxycinnamate, ethylhexyl salicylate, octocrylene, homosalate, phenylbenzimidazole sulfonic acid, diethylaminohydroxybenzoylhexyl benzoate, ethylhexyl triazine, terephthalimide dicamphor sulfonic acid, polysilicon-15, avobenzone, and hydroxybenzophenone. The additional UV blocking agent may be included in the composition at about 1 to 50% by weight, about 5 to 45% by weight, about 5 to 40% by weight, about 5 to 30% by weight, about 5 to 20% by weight, about 5 to 10% by weight, about 10 to 30% by weight, or about 15 to 25% by weight, relative to the total weight of the composition.

[0037] When one aspect of the composition further includes or uses additional organic and / or inorganic UV blockers, a synergistic effect in UV blocking can be observed. In this specification, "used in combination" means that the composition simultaneously contains polymeric carbon nitride and additional organic and / or inorganic UV blockers.

[0038] The polymeric carbon nitride or polymeric carbon nitride crystal forms A to G contained in the composition can absorb UV rays from sunlight with high absorptivity and can strongly absorb light energy in the wavelength region of about 200 to 400 nm, for example, it can absorb UVA with a wavelength of about 320 to 400 nm and UVB with a wavelength of about 280 to 320 nm, thereby preventing skin damage caused by ultraviolet radiation. Therefore, the polymeric carbon nitride or the composition containing polymeric carbon nitride crystal forms A to G can absorb light energy in the wavelength region of about 200 to 400 nm, about 220 to 400 nm, or about 280 to 400 nm. Specifically, the composition can absorb UVA with a wavelength of about 320 to 400 nm and UVB with a wavelength of about 280 to 320 nm.

[0039] The composition can be prepared into skin cleansers (lotions), emollients, toners, astringents, lotions, milk cleansers, moisturizing lotions, nourishing lotions, massage creams, creams, sunscreens, nourishing creams, moisturizing creams, hand creams, foundations, serums, nourishing serums, face masks, soaps, cleansing foams, cleansing washes, cleansing creams, body lotions, body cleansers, suspensions, gels, powders, pastes, pressed powders, face masks or sheets, or aerosols, etc. The composition of such preparations can be prepared according to conventional methods in the art.

[0040] The topical skin agent may be a cream, gel, ointment, skin emulsifier, skin suspension, transdermal patch, medicated bandage, lotion, or a combination thereof. The topical skin agent may be formulated with ingredients commonly used in cosmetics or pharmaceuticals, such as aqueous components, oily components, powder components, alcohols, moisturizers, thickeners, UV absorbers, whitening agents, preservatives, antioxidants, surfactants, fragrances, colorants, various skin nutrients, or combinations thereof, as needed. The topical skin preparation may be appropriately combined with metal chelating agents such as disodium edetate, trisodium edetate, sodium citrate, sodium polyphosphate, sodium metaphosphate, and gluconic acid; caffeine; tannins; berapamil; licorice extract; glycyrrhizin; hot water extract of galangal; various herbs; tocopherol acetate; glycyrrhizic acid; tranexamic acid and its derivatives or salts; vitamin C; magnesium ascorbate phosphate; ascorbate glucoside; arbutin; kojic acid; glucose; fructose; and trehalose.

[0041] The skin includes all parts of the body, including the face, hands, arms, legs, feet, chest, abdomen, back, buttocks, and scalp.

[0042] The composition of one aspect can be applied, administered, and coated onto an individual. The term "individual" includes all mammals, such as humans or non-human primates, mice, dogs, cats, horses, and cattle.

[0043] In the context of the composition, any mention of a crystal form in the description of the crystal form shall be understood as a reference to the crystal form described above.

[0044] According to another embodiment of the present invention, a method for preparing a cosmetic composition, a composition for blocking ultraviolet light, or a composition for topical skin application is provided, comprising the step of introducing a polymeric carbon nitride comprising repeating units represented by the following chemical formula 1:

[0045] [Chemical Formula 1]

[0046]

[0047] In the chemical formula 1, n is an integer, for example, it can be an integer between 1 and 1,000,000. The molecular weight of the polymer carbon nitride having the chemical formula 1 can be a polymer having a molecular weight of, for example, about 200 to 5,000,000 amu, about 400 to 4,000,000 amu, about 600 to 3,000,000 amu, or about 800 to 2,000,000 amu.

[0048] The polymeric carbon nitride may include one or more crystal forms selected from the group consisting of the polymeric carbon nitride crystal forms A to G.

[0049] In the context of the method, references to the crystal form and composition in the description of the crystal form and composition shall be understood as references to the crystal form and composition described above.

[0050] According to another embodiment of the present invention, there is a use for blocking ultraviolet light comprising a polymeric carbon nitride including repeating units represented by the following chemical formula 1 or a composition comprising the same:

[0051] [Chemical Formula 1]

[0052]

[0053] In the chemical formula 1, n is an integer, for example, it can be an integer between 1 and 1,000,000. The molecular weight of the polymer carbon nitride having the chemical formula 1 can be a polymer having a molecular weight of, for example, about 200 to 5,000,000 amu, about 400 to 4,000,000 amu, about 600 to 3,000,000 amu, or about 800 to 2,000,000 amu.

[0054] The polymeric carbon nitride may include one or more crystal forms selected from the group consisting of the polymeric carbon nitride crystal forms A to G.

[0055] In the context of the use of these terms or elements, references to the crystal form, composition, and method shall be understood as references to the crystal form, composition, and method described above.

[0056] Beneficial effects

[0057] Because the polymeric carbon nitride and its specific preparation examples contain crystal forms that can absorb both UVA and UVB, they effectively protect the skin from ultraviolet radiation. Furthermore, due to their non-toxicity, biocompatibility, and lack of photoactivity, they can be used in cosmetic compositions, UV-blocking compositions, and topical skin formulations suitable for biological applications. Moreover, the specific crystal forms of the polymeric carbon nitride exhibit different characteristics depending on the preparation method, allowing for various uses based on these properties. In particular, because the crystal forms of the polymeric carbon nitride can be adjusted to various colors depending on the preparation method, compositions of desired colors can be formulated during use, making them suitable for preparing products in various colors appropriate for different skin tones. Attached Figure Description

[0058] Figure 1A This diagram illustrates that when polymeric carbon nitride (PCN) is prepared using the preparation method described in one aspect, not only white crystals but also crystals of various colors can be prepared.

[0059] Figure 1B The graph illustrates the color difference and the difference in dispersion to water-soluble solvents between conventionally yellow PCN, which is difficult to disperse, and well-dispersed white PCN prepared by the preparation method described in one aspect.

[0060] Figure 2A To show the spectrum of sample CN-400-4 confirmed by X-ray photoelectron spectroscopy.

[0061] Figure 2B This is a graph showing the spectrum of sample CN-550-2 as confirmed by X-ray photoelectron spectroscopy.

[0062] Figure 3AThe figure shows the results of X-ray diffraction (XRD) analysis confirming the selection of CN-400-4 and CN-550-2 for ultraviolet blocking applications.

[0063] Figure 3B Figures showing the results of confirming the XRD patterns of CN-350-2, CN-400-0.5, CN-400-1, CN-400-2 and CN-400-8, and the XRD patterns of CN-400-4 and CN-550-2.

[0064] Figure 3C The graph shows the XRD results confirming the formation of PCN (CN-400-0.5, CN-400-1, CN-400-2, CN-400-4 and CN-400-8) prepared at a polycondensation temperature of 400°C.

[0065] Figure 4A As a result of the confirmation of the chemical structure of the prepared PCN samples by Fourier transform infrared (FT-IR) spectroscopy, a graph is shown showing the IR results of the confirmation of CN-400-4 and CN-550-2.

[0066] Figure 4B As a result of the confirmation of the chemical structure of the prepared PCN samples by FT-IR spectroscopy, a graph is shown showing the IR results of the confirmation of CN-350-2, CN-400-0.5, CN-400-1, CN-400-2, CN-400-8, CN-400-4 and CN-550-2.

[0067] Figure 5 The figures show the results of confirming the surface of CN-400-4 by scanning electron microscopy (SEM) (A), by transmission electron microscopy (TEM) (B), by AFM microscopy (C), and by confirming the height of its particles (D).

[0068] Figure 6 The figures show the results of confirming the surface of CN-400-2 by SEM microscopy (A), the results of confirming it by TEM microscopy (B), the results of confirming it by AFM microscopy (C), and the results of confirming the height of its particles (D).

[0069] Figure 7The figures show the results of confirming the surface of CN-550-2 by SEM microscopy (A), the results of confirming it by TEM microscopy (B), the results of confirming it by AFM microscopy (C), and the results of confirming the height of its particles (D).

[0070] Figure 8A The figure shows the results of ROS generation levels of TiO2, ZnO, and CN-400-4 confirmed by photocatalytic decomposition analysis using RhB.

[0071] Figure 8B The figure shows the results of quantitative analysis of ROS generation levels in TiO2, ZnO, and CN-400-4 using a fluorescent probe analysis that detects OH radicals using coumarin.

[0072] Figure 8C The figure shows the results confirming the photoluminescence effects of TiO2, ZnO, CN-400-1, CN-400-2, and CN-400-4.

[0073] Figure 9A The figure shows the results confirming the UV-Vis diffuse reflectance spectra of TiO2, ZnO, and CN-400-4.

[0074] Figure 9B The figure shows the results confirming the UV blocking effect of samples prepared by mixing CN-400-4 and CN-550-2 with a sunscreen (SPF=15) containing commercially available UV-filtering ingredients.

[0075] Figure 10A A figure showing the results confirming the cytotoxicity of CN-400-4 on embryonic fibroblast cells (NIH-3T3).

[0076] Figure 10B A diagram illustrating the results confirming the cytotoxicity of ZnO on embryonic fibroblast cells (NIH-3T3).

[0077] Figure 10C A graph showing the results confirming the cytotoxicity of CN-400-4 on human dermal fibroblasts (HS-68).

[0078] Figure 11 The figure shows the results of assessing cell viability by live / dead cell imaging using CN-400-4 (A and B) and the results of visualizing and confirming it using dihydroxyethidium (DHE) as an indicator of ROS (C).

[0079] Figure 12 To illustrate the results of performing hematoxylin-eosin (H&E) staining to confirm the extent of skin damage by treating CN-400-4 in artificial skin membranes (Franz Cell Membrane, FCM) and culturing for 4 hours with a control group as the untreated group, a figure is shown.

[0080] Figure 13 The figure shows the results of cross-sections of FCM confirmed by SEM to observe the skin surface morphology of the CN-400-4 coated group and the untreated group as a control.

[0081] Figure 14 A graph showing the results of a CN-400-4 patch test on subjects to assess skin irritation. Detailed Implementation

[0082] Each feature of the various experimental examples and embodiments of the present invention may be combined or integrated with each other in part or in whole, and those skilled in the art will fully understand that various linkages and drives can be made technically, and each experimental example and embodiment may be implemented independently of each other or may be implemented together in an associated relationship.

[0083] When interpreting constituent elements, even if there is no separate explicit description, it is interpreted as including the range of error.

[0084] The shapes, dimensions, ratios, angles, quantities, etc., disclosed in the accompanying drawings for the purpose of describing experimental examples and embodiments of the present invention are exemplary, and therefore the present invention is not limited to what is shown. Furthermore, in describing the present invention, detailed descriptions of related known technologies will be omitted if it is determined that such detailed descriptions may unnecessarily obscure the gist of the invention. The terms "comprising," "having," and "constituting" used in this specification allow for the addition of other parts unless the terms are used in conjunction with the term "only." When a constituent element is expressed as a singular, the plural should be included unless otherwise expressly stated.

[0085] The invention will be described in more detail below with reference to experimental examples and embodiments. However, these experimental examples and embodiments are intended to exemplify one or more specific embodiments, and the scope of the invention is not limited to these experimental examples and embodiments.

[0086] Example 1. Confirmation of experimental materials

[0087] TiO2 (P-25, Degussa) was purchased from Degussa, and ZnO was purchased from Alfa-Aesar. The organic UV-filtering components of avobenzone (catalog number PHR1073) and oxybenzone (catalog number H36206), which are used as UV blockers, were purchased from Sigma-Aldrich (USA).

[0088] Purchase and use a moisturizing cream from Nivea and a sunscreen from Biotherm, Lait Solaire Hydratant SPF15.

[0089] Dulbecco's Modified Eagle's Medium (DMEM), phosphate-buffered saline (PBS) 1X pH 7.4 solution, fetal bovine serum (FBS), penicillin / streptomycin, and live / dead analysis of NIH-3T3 cell cultures were purchased from Gibcoby Life Technologies. Dihydroxyethidium (DHE) and neutral buffered formalin (NBF, 10%) were purchased from Sigma Aldrich, USA. 3-(4,5-dimethylthiazolyl-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was purchased from ACROS Organics. Mitotracker deep red was purchased from Thermo Fisher, USA. Products from APURES Co., Ltd., South Korea were also purchased and used. Franz Cell Membrane (FCM) artificial skin.

[0090] Example 2. Synthesis of Polymeric Carbon Nitride (PCN)

[0091] The PCN used in this embodiment was prepared by heat-treating 99% urea (purchased from Aldrich) under ambient pressure. Melamine, dicyandiamide, cyanamide, or urea was used as a precursor. The precursor was placed in a chamber furnace (UAF, Lenton) and heated in a muffle furnace (UAF, Lenton) at 450°C to 550°C for 0.5 to 8 hours to complete the polycondensation reaction. The product was washed with deionized water to remove residual species and then dried overnight at 80°C to prepare the PCN used in the following embodiments. The PCN prepared and finally confirmed by one aspect of the method described above is as follows: Figure 1A and Figure 1B As shown. Figure 1A As shown, in the case of a crystal form prepared by one method, various colors can be prepared by changing the temperature conditions or adding additives during the preparation process. Furthermore, as... Figure 1B As confirmed in the study, compared to conventional methods, when preparing PCN by one particular method (e.g., CN-350-2, CN-400-0.5, CN-400-1, CN-400-2, CN-400-4, and CN-400-8, which are PCNs polycondensed at approximately 300 to 500°C for approximately 0.3 to 10 hours), it was confirmed that white PCN, unlike conventional yellow PCN, can be prepared, and that the white PCN thus prepared is better dispersed in water-soluble solvents compared to conventional yellow PCN. Experiments were performed below to confirm the characteristics of the PCN prepared in this example.

[0092] Example 3. Confirmation of the physical properties of PCN with crystallization as the central focus.

[0093] 3.1 Confirmation of characteristics using PCN photoelectron spectroscopy (XPS)

[0094] The structure of the prepared PCN was confirmed by X-ray photoelectron spectroscopy (XPS). The spectra of samples CN-400-4 and CN-550-2 are shown below. Figure 2A and Figure 2B As shown. According to Figure 2A and Figure 2B Based on the data, the relative atomic percentages (%) of C, N, and O elements on the sample surface were calculated accordingly. For example... Figure 2A and Figure 2BAs confirmed by scanning spectroscopy, both samples contained carbon, nitrogen, and oxygen. In CN-400-4, peaks were confirmed at 288 eV for C, 398 eV for N, and 531 eV for O. In CN-550-2, peaks were confirmed at 288 eV for C, 398 eV for N, and 532 eV for O. Furthermore, it was confirmed that the small oxygen peak in sample CN-550-2 was caused by trace amounts of partially polymerized urea present in the sample. On the other hand, a considerably high concentration of oxygen was observed in the XPS spectrum of CN-400-4, and it was confirmed that this high concentration was caused by chemically bonded oxygen species in the partially polymerized urea.

[0095] 3.2 Confirmation of characteristics by X-ray diffraction (XRD) analysis of PCN

[0096] Various PCNs with diverse physical, chemical, optical, and electronic structural properties were prepared by thermal condensation of urea in air under different polymerization conditions. Since the prepared polymeric carbon nitrides possess a triazine-based crystalline structure, the final product can be characterized as polymeric carbon nitride (PCN). X-ray diffraction (XRD) patterns were collected using an X-ray diffractometer (X'Pert PRO MPD, PANalytical) with monochromatized CuKα (l = 0.1541 nm) rays at 40 kV and 30 mA.

[0097] The crystal structure of PCN samples prepared by polycondensation at different temperatures under atmospheric pressure was analyzed by X-ray diffraction (XRD). The XRD results of CN-400-4 and CN-550-2, selected for use in UV blocking applications, were confirmed as follows. Figure 3A As shown, the XRD patterns of CN-350-2, CN-400-0.5, CN-400-1, CN-400-2, and CN-400-8, and the XRD results of CN-400-4 and CN-550-2, were confirmed as other prepared PCN samples. Figure 3B As shown, the XRD results of PCN prepared by polycondensation at a temperature of 400 °C confirm the following. Figure 3C As shown.

[0098] like Figure 3AThe XRD pattern of CN-400-4, a PCN polycondensed at 400 °C for 4 hours, was confirmed. It exhibited two distinct diffraction peaks at 10.7656° and 27.4316°, with no other impurity phases. The XRD pattern of CN-550-2, a PCN prepared by polycondensation at 550 °C for 2 hours, was also confirmed. It exhibited two distinct diffraction peaks at 13.6516° and 27.4316°, with no other impurity phases. The XRD pattern of the CN-550-2 sample was confirmed to be similar to that of bulk graphitic carbon nitride (g-C3N4) with a strong peak at 27.4° on the (002) plane, and it was confirmed that this was caused by the interlayer stacking of bonded aromatic segments with a d-spacing of 0.326 nm. Through this interlayer stacking, it was confirmed that the CN-550-2 sample is similar to crystalline graphite (d = 0.335 nm), and is harder than the packing of carbon with graphene units (d = 0.353 nm), thus the prepared PCN exhibits structural stability. The weak peak at 13.6516° on the (100) plane corresponds to the planar structural stacking motif of the CN-550-2 sample with repeating units of 0.618 nm, but it was confirmed to be missing in the XRD patterns of other prepared PCNs, including CN-400-4. This was confirmed to be caused by incomplete or partial condensation of urea at calcination temperatures below 400 °C. In the evaluation of the XRD crystal structure results, it was confirmed that the urea contained in the CN-400-4 and CN-550-2 samples was partially or completely converted into the bulk phase g-C3N4, respectively. This was confirmed to be due to the complete thermal condensation of urea mainly at higher temperatures.

[0099] like Figure 3BThe results confirmed that CN-350-2, as a PCN polycondensed at 350°C for 2 hours, exhibited diffraction peaks at 10.7656°, 19.8006°, and 29.7456°; CN-400-0.5, as a PCN polycondensed at 400°C for 0.5 hours, exhibited diffraction peaks at 10.7396° and 29.7456°; and CN-400-1, as a PCN polycondensed at 400°C for 1 hour, exhibited diffraction peaks at 10.7006°, 22.1406°, and 27.8606°. PCN CN-400-2, which underwent polycondensation at 0℃ for 2 hours, showed diffraction peaks at 10.6356° and 27.8216°, confirming its identity as PCN. Similarly, CN-400-4, which underwent polycondensation at 400℃ for 4 hours, showed diffraction peaks at 10.7266° and 27.5096°, confirming its identity as PCN. CN-400-8, which underwent polycondensation at 400℃ for 8 hours, showed diffraction peaks at 27.1586°, confirming its identity as PCN. Finally, CN-550-2, which underwent polycondensation at 550℃ for 2 hours, showed diffraction peaks at 13.8076° and 27.1586°.

[0100] In addition, such as Figure 3C The results confirmed that CN-400-0.5, a PCN that underwent polycondensation at 400℃ for 0.5 hours, exhibited diffraction peaks at 10.7526° and 29.9146°; CN-400-1, a PCN that underwent polycondensation at 400℃ for 1 hour, exhibited diffraction peaks at 10.6746° and 27.7956°; CN-400-2, a PCN that underwent polycondensation at 400℃ for 2 hours, exhibited diffraction peaks at 10.6876° and 27.7046°; CN-400-4, a PCN that underwent polycondensation at 400℃ for 4 hours, exhibited diffraction peaks at 10.7266° and 27.3666°; and CN-400-8, a PCN that underwent polycondensation at 400℃ for 8 hours, exhibited a diffraction peak at 27.2236°.

[0101] 3.3 Confirmation of characteristics via FT-IR spectroscopy of PCN

[0102] To confirm the crystal structure of the prepared PCN, the chemical structure of the prepared PCN samples was determined by FT-IR spectroscopy. The FT-IR spectroscopy results for CN-400-4 and CN-550-2 are as follows: Figure 4A As shown, the results of simultaneously confirming the IR values ​​of CN-350-2, CN-400-0.5, CN-400-1, CN-400-2, CN-400-8, CN-400-4, and CN-550-2 are as follows: Figure 4B As shown.

[0103] like Figure 4AAs confirmed in [the document], CN-550-2 was found to be present in 810, 890, 1240, 1317, 1410, 1456, 1560, 1635, and 3250 cm. -1 Peaks appeared at 808, 1270, 1323, 1420, 1560, 1612, 3105, and 3330 cm⁻¹. CN-400-4 was confirmed to have peaks at these values. -1 A peak appeared at [location missing]. This confirmed that the FT-IR spectrum of CN-550-2 was similar to that of the bulk g-C3N4, but the CN-400-4 sample (thermally condensed at 400℃ for 4 hours) showed a broad absorption peak. Similar to XRD studies, the results confirming this IR peak indicate that the FT-IR analysis was due to the formation of intermediate products and the degree of incomplete polymerization.

[0104] like Figure 4B As confirmed in [the document], CN-350-2 was found in 775, 1417, 1456, 1691, 1730, 3074, and 3311 cm. -1 A peak appeared at [value missing]. This confirmed the presence of CN-400-0.5 at 777, 1677, 1735, 3085, and 3315 cm⁻¹. -1 A peak appeared at 777, 1467, 1666, 1734, 3120, and 3320 cm⁻¹. This confirmed that CN-400-1 showed peaks at these values. -1 A peak appeared at 777, 1465, 1660, 1734, 3085, and 3330 cm⁻¹. This confirmed that CN-400-2 showed peaks at 777, 1465, 1660, 1734, 3085, and 3330 cm⁻¹. -1 Peaks appeared at 810, 1270, 1420, 1612, 3105, and 3330 cm⁻¹. This confirmed the presence of CN-400-4 at these peaks. -1 A peak appeared at 810, 1265, 1325, 1417, 1618, and 3230 cm⁻¹. This confirmed the presence of CN-400-8 at these peaks. -1 A peak appeared at 810, 1240, 1317, 1410, 1560, 1635, and 3250 cm⁻¹. This confirmed the presence of CN-550-2 at these peaks. -1 A peak appears at that location.

[0105] Example 4. Confirmation of the surface morphology and microstructure of PCN

[0106] The scanning electron microscope (SEM) images were obtained using field emission (FE)-SEM (JEOL JSM-7401F, JEOL). The powder sample was coated into a thin Pt layer by sputtering (Hitachi Sputter, E-1045) and examined by scanning electron microscopy (SEM).

[0107] The surface of heterogeneous UV-filtering particles plays a crucial role in the preparation of UV blockers because it eliminates the often-concerning opacity from metal oxides containing UV blockers. To confirm the surface morphology and microstructure of CN-400-4, CN-400-2, and CN-550-2, analysis was performed using field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The results confirmed by atomic force microscopy (AFM) and the thickness measurements of the PCN 2D thin nanosheets prepared thereby are shown in the figures. Figure 5 , 6 and 7.

[0108] like Figure 5 (A) Figure 6 (A) and Figure 7 As confirmed in (A), FE-SEM microscopy revealed a layered polymer scaffold with a relatively rough surface morphology, and its contribution to the sheet structure of both samples was confirmed, thus confirming the rough surface morphology of the prepared PCN, which is related to the polymerization conditions. Figure 5 (B) Figure 6 (B) and Figure 7 As confirmed in (B), the TEM images show that all three prepared PCN samples are two-dimensional nanosheets with some ripples and wrinkles on the surface and are wrinkled. The TEM images also confirm that the prepared PCN sheets have a smooth texture and high transparency, and the size of the sheets ranges from a few nanometers to micrometers.

[0109] like Figure 5 (C and D) Figure 6 (C and D) and Figure 7 As confirmed in (C and D), as a result of the analysis of AFM images and this height profile, the thickness of the PCN 2D nanosheets in samples CN-400-4 and CN-550-2 is less than about 4 nm, and the thickness of the nanosheets in sample CN-400-2 is less than about 5 nm. This confirms that all three samples have formed nanosheets of thickness that can be used to effectively cover the skin surface.

[0110] Example 5. Confirmation of the effect of PCN in inhibiting ROS production through quantitative and qualitative analysis of reactive oxygen species.

[0111] 5.1 Decomposition of photochemical dyes

[0112] The photocatalytic decomposition of RhB was performed in a Pyrex reactor using a 300W Xe lamp (Xe Arc lamp source, Oriel) equipped with one solar filter (Oriel) as the light source. A silicon detector (Peccell Technologies, Japan) at 100mW / cm² was used. 2Photometric measurements were performed. 10 mg of powder was added to an RhB solution containing 100 mL of deionized water and 1 mg of RhB, and then ultrasonically dispersed for 10 minutes. To confirm adsorption / desorption equilibrium, the suspension was kept in the dark with continuous stirring for 24 hours. After 24 hours, illumination was applied and photocatalytic decomposition of RhB was performed. During the 1-hour reaction period, including the equilibrium point, 5 mL of the suspension was extracted every 10 minutes. The extracted suspension was centrifuged for 20 minutes to precipitate the powder. After centrifugation, the absorbance of the solution was collected by UV-Vis spectroscopy using a UV-3600 (Shimadzu). The photocatalytic activity was compared with the change in the intensity of the absorption peak at 552 nm.

[0113] 5.2 Fluorescent probe method

[0114] OH radicals were measured using a fluorescent probe method. Coumarin reacts with OH radicals to form umbelliferone, which has a fluorescent peak at 455 nm. Therefore, coumarin was used to detect OH radicals generated in a UV blocker from TiO2, ZnO, and the prepared PCN. Thus, using this method, the sample producing a higher concentration of OH radicals can be determined by comparing the fluorescence intensity of all samples at 455 nm. 50 mg of TiO2, ZnO, and the prepared PCN were added to 20 mL of a 0.03 mM coumarin solution. The fluorescence intensity was measured in an Xe lamp with a solar filter at 100 mW / cm². 2 The suspension was irradiated with an intensity of [insert concentration here] for 120 seconds. 5 mL of the suspension was extracted before irradiation and at 60 and 120 seconds after irradiation. The extracted suspension was centrifuged for 20 minutes. Furthermore, the fluorescence spectrum of umbelliferone was obtained using a fluorescence intensity meter (CaryEclipse, Varian). Then, calibration was performed to confirm whether the fluorescence intensity at 455 nm was proportional to the fluorescence intensity of umbelliferone.

[0115] 5.3 The effectiveness of PCN in inhibiting ROS generation was confirmed by comparison with TiO2 and ZnO, which are commercially available UV filter components.

[0116] It is known that encapsulating or coating UV filter components in some inorganic, polymeric, and bioadhesive matrices cannot prevent ROS generation, but can effectively remove them. However, 100% encapsulation of UV filter components is not an easy process, and ROS will still be generated on the surface without the UV filter component coverage. Therefore, to prevent ROS generation, a highly efficient flat-band site engineered PCN UV filter component was prepared. The prepared PCN generated a low concentration of ROS because the unoptimized flat-band sites (conduction band (CB) and valence band (VB)) reduce and oxidize O2 and H2O to O2*- and *OH, respectively, thus eliminating the need to limit ROS generation. The concentration of photogenerated ROS in the UV filter component plays a crucial role in its suitability for use as a commercial UV blocker; therefore, various ROS analysis methods were applied to qualitatively and quantitatively assess O2*- and *OH, demonstrating high levels of sensitivity and accuracy. To accurately measure ROS generation, quantitative analysis was performed by chemical analysis, direct dye decomposition, photoluminescence spectroscopy detected by fluorescence products, and UV-Vis absorption spectroscopy.

[0117] To investigate the ROS generation trend of the prepared PCN, experiments were performed comparing it with commercially available TiO2 and ZnO particles by analyzing the dye gradient potential values, and the results are presented below. Figure 8A The primary ROS exhibits high reactivity, reacting rapidly with organic molecules or dyes present in the reaction solution. Compared to the prepared PCN, the photocatalytic dye of this commercially available UV filter component was confirmed by the photodecomposition of rhodamine B (RhB) in aqueous solution under UV-visible light irradiation, thus evaluating ROS generation. The ROS and RhB reactions of the prepared PCN and the commercially available UV filter component are as follows: Figure 8A As shown.

[0118] like Figure 8A As confirmed in the study, the RhB dye decomposes slowly in the prepared PCN suspension, thus confirming a relatively low ROS generation in the PCN nanosheets prepared under illumination. However, when commercially available UV filter components are used, strong photochemical dye decomposition activity is confirmed. In particular, such as Figure 8A As confirmed in the study, when TiO2 particles were added to the RhB solution, nearly 50% of the RhB decomposed after 60 minutes of irradiation, while approximately 95% of the dye decomposed upon the addition of ZnO particles, thus confirming the high ROS generation rate in the presence of these metal oxides. These results confirm that TiO2 and ZnO possess flat band positions suitable for ROS (O2*- and *OH) generation; however, the prepared PCN exhibits low *OH generation efficiency and almost no potential for O2*- generation.

[0119] Photoluminescence spectroscopy and XTT colorimetric assays were performed to further quantify the concentrations of *OH and O2*- free radicals in the UV-filtered components. The prepared PCN, TiO2, and ZnO suspensions were reacted under UV-visible light for 1 hour and 2 hours, respectively. The fluorescence spectra of the coumarin solution and the fluorescent 7-hydroxycoumarin compound generated during the reaction of coumarin with *OH were then confirmed and presented. Figure 8B In the middle. For example Figure 8B The λ, which is equivalent to 7-hydroxycoumarin, was confirmed in [the study]. MAX The dashed arrow at 455 nm indicates that the peak intensity increases with increasing *OH radical concentration during the photochemical reaction, confirming that this corresponds to the same result as the increase in *OH radical concentration during the photochemical reaction. This is a result of dye decomposition experiments, such as... Figure 8A and Figure 8B As confirmed by the photoluminescence experiments, ZnO is the most photoactive substance. The concentration of *OH radicals was quantified using a calibration curve of 7-hydroxycoumarin in deionized water. These results confirm that the UV filter component prepared from the prepared PCN has no or negligible *OH radical generation, thus eliminating the generation of *OH radicals and allowing the prepared PCN UV filter component to be used without carcinogenic ROS.

[0120] As confirmed in the embodiments described, the ROS generated by the PCN UV filter component prepared by ROS analysis results is much lower than that of commercially available TiO2 and ZnO UV filter components, and the amount of ROS generated can be regarded as no ROS generated. This confirms that there is no need for surface shielding and encapsulation to suppress ROS generation, and it can be directly used in products that block ultraviolet rays.

[0121] 5.4 Confirm the photoluminescence effect of PCN

[0122] The photoluminescence effects of the prepared PCN and commercially available UV filter components (ZnO and TiO2) were analyzed.

[0123] Specifically, after exciting the sample at approximately 300 nm using a photoluminescence measurement device, photoluminescence observed in the wavelength band beyond approximately 320 nm was measured. Photoluminescence occurs when excited electrons and holes move to the surface and meet and recombine before participating in a chemical reaction; therefore, more photoluminescence means that the excited electron-hole pairs cannot be used for other chemical reactions.

[0124] like Figure 8C As shown, almost no photoluminescence was observed in the presence of TiO2 and ZnO, but significant photoluminescence was observed in the prepared PCNs (CN-400-1, CN-400-2, and CN-400-4). In particular, it was confirmed that CN-400-1 exhibited the best photoluminescence effect among the prepared PCNs.

[0125] It can be inferred from this example that, in the case of TiO2 and ZnO, most of the excited electrons reach the surface and are used for chemical reactions such as ROS generation, which supports the high photocatalytic activity of TiO2 and ZnO, as confirmed in "Example 5.3". Furthermore, it can be inferred from this example that, unlike TiO2 and ZnO, in the case of the prepared PCN, the excited electron-hole pairs cannot be used for other chemical reactions, which supports the low photocatalytic activity of the prepared PCN, as confirmed in "Example 5.3".

[0126] Example 6. Confirmation of the UV blocking effect of PCN

[0127] 6.1 The UVR absorption effect of PCN was confirmed by comparison with TiO2 and ZnO, which are commercially available UV filter components.

[0128] To protect the skin from UV rays, ultraviolet radiation must be absorbed to prevent the harmful effects of sunlight. Therefore, the UVR absorption efficiency, which measures the extent to which the prepared PCN absorbs ultraviolet radiation, is measured to confirm the effectiveness of the ultraviolet blocking material. This is used to confirm the UV-Vis diffuse reflectance spectra of the prepared PCN, TiO2, and ZnO, and the results are presented below. Figure 9A middle.

[0129] Specifically, the UV-Vis diffuse reflectance spectra of the sample powder were obtained using a UV-Vis diffuse reflectance spectrophotometer (UV-3600, Shimadzu) with an integrating sphere (ISR-240A, Shimadzu), and BaSO4 was used as a reference. The band gap energy of the sample was determined by a Tauc plot generated from the Kubelka-Munk transform of the diffuse reflectance spectrum.

[0130] like Figure 9A The results confirmed that TiO2 particles only showed absorption up to 360 nm, while ZnO covered up to 385 nm. However, the prepared PCN was confirmed to cover the entire UV spectrum (200-400 nm) and to protect the skin from harmful UVA and UVB rays.

[0131] 6.2 Measure the sun protection factor (SPF) and protection against ultraviolet A (PA) of the PCN.

[0132] The prepared PCN (CN-400-4, etc.) sample was mixed with a moisturizing cream (SPF=1) or sunscreen (SPF=15) at 600 rpm for 24 hours using a magnetic stirrer. The entire mixing process was carried out in a dark room at room temperature. The sunscreen included an inorganic UV blocker (titanium dioxide) and an organic UV blocker (octocrylene, butyl methoxydibenzoylmethane, ethylhexyl triazine terephthalimide dicamphor sulfonic acid) as commercially available UV filtering ingredients. A mixed sample of the sunscreen and the prepared PCN was prepared such that the prepared PCN was contained in approximately 10% of the mixture. Mixed samples of the moisturizing cream were prepared such that the prepared PCN was contained in approximately 1% and approximately 5% of the mixture, respectively. As a control group, samples in which avobenzone, oxybenzone, ZnO, and TiO2 as commercially available UV filtering ingredients were mixed with the moisturizing cream were used instead of the prepared PCN.

[0133] The prepared PCN mixture samples, namely the mixture of PCN and moisturizing cream (SPF=1) and the mixture of PCN and sunscreen (SPF=15), were applied to a clean quartz slab surface using 7.5cm 3M Transformer tape. 2 On the sample (2 mg / cm³). 2 Then, gently rub the plate surface with your finger coated with a ferrule to spread the coating over the entire surface. Dry the prepared sample in a dark room for 20 minutes, blocking out light.

[0134] UV transmittance was measured using a Cary 50UV-vis spectrophotometer with a solid sample holder (Agilent Technologies, USA). Four points were scanned for each sample, and each data point was measured within the range of UVB (290–320 nm) to UVA (320–400 nm). All transmittance data were collected at 1 nm intervals. After measuring UV transmittance, the in vitro assessment of the sun protection factor (SPF) was performed using the following equation.

[0135]

[0136] Where Eλ represents the erythema spectral effect, Sλ represents the solar spectral effect, and Tλ represents the spectral transmittance of the sample.

[0137] In addition, the UVA protection factor (UVA PF) assessment is performed using the following formula.

[0138]

[0139] Where Iλ represents the biological effect spectrum of UVA. In this case, Eλ and Iλ are both equal to 1 for all UVA wavelengths.

[0140] As shown in Table 1, it was confirmed that the mixed samples of moisturizing creams containing the prepared CN-400-1, CN-400-2, CN-400-4, CN-400-8, and CN-550-2, respectively, showed substantially higher SPF and UVA PF values ​​compared to mixed samples containing commercially available UV filter ingredients. In particular, it was confirmed that the mixed sample containing CN-400-4 showed the highest SPF and UVA PF values ​​among the mixed samples containing the prepared PCN, and exhibited significantly higher SPF and UVA PF values ​​compared to mixed samples containing commercially available UV filter ingredients.

[0141] Table 1

[0142]

[0143] In addition, such as Figure 9B As shown, the sample containing both the prepared CN-400-4 and the sunscreen agent exhibited superior UV blocking performance in the UVA region compared to the mixed sample containing the prepared CN-550-2. Furthermore, as a result of calculating the SPF and UVA PF values, when the sunscreen agent with an SPF of 15 was mixed with 10% of the prepared CN-400-4, a final SPF value of 45.4 and a final UVA PF value of 31 were confirmed. And when the sunscreen agent with an SPF of 15 was mixed with 10% of the prepared CN-550-2, a final SPF value of 38 and a final UVA PF value of 17.5 were confirmed.

[0144] Therefore, it was confirmed that the prepared PCN exhibits superior UV blocking performance compared to commercially available UV filter components. Furthermore, in order to prepare UV blocking products with high SPF and UVA PF values, it was confirmed that the prepared PCN can be used effectively, and that the SPF and UVA PF values ​​can be effectively improved by mixing the prepared PCN with commercially available UV filter components, thereby further maximizing the UV blocking effect.

[0145] Example 7. Confirmation of the biological application of PCN as a UV blocker

[0146] 7.1 Analytical conditions for UV radiation sources and MTT identified as bio-applications

[0147] The UV radiation source was a 300W light-emitting solar stimulator (91160, Newport) irradiated with sunlight. MTT assays were obtained using a multimode microplate reader (SpectraMax M5e, Molecular Devices).

[0148] 7.2 Confirmation of PCN cytotoxicity

[0149] Cell culture

[0150] NIH-3T3 cells were purchased from the American Type Culture Collection (ATCC, USA). Cells were cultured in DMEM medium supplemented with 10% fetal bovine serum (FBS), 100 U / mL penicillin, and 100 μg / mL streptomycin. All cells were cultured in a humidified environment of 37°C and 5% CO2. For MTT assay, cells were cultured at 5 x 10⁶ cells / well. 3 Cells were seeded at a density in 96-well plates. Twenty-four hours after seeding, a series of sample solutions (five concentrations and a control) were added to each well. After 1 hour of incubation, the cells were exposed to light for 1 minute, followed by another 5 hours of incubation. 10 μL of MTT solution (5 mg / mL) was added to each well, and the cells were incubated at 37°C for 2 days, followed by another 4 hours. Then, 100 μL of SDS-HCl solution was added to terminate the reduction reaction and dissolve the purple formazan. The absorbance of each well at 595 nm was measured using a multimode microplate reader. Cytotoxicity analysis was performed three times, and the average of the three measurements was obtained.

[0151] CLSM image of NIH-3T3 cells (generated by ROS)

[0152] Laser scanning confocal microscopy (CLSM) images were obtained using a ZIESS LSM 780. For ROS experiments, 1*10... 4 NIH-3T3 cells were seeded at a density in 8-well Lab-tek II coverslips (Nunc). After culturing NIH-3T3 cells in a cell culture device for 24 hours, 20 μg / ml of nanoparticles were added to the cells along with the culture medium. After culturing for 1 hour, the cells were exposed to light for 1 minute. After culturing for another 5 hours with culture medium, HeLa cells were washed three times. Mitochondria were stained with MitoTrackerDeep Red at a concentration of 1 μM for 10 minutes. After washing the cells with the remaining culture medium, the cells were immediately stored in CLSM medium.

[0153] Live / dead analysis

[0154] Live / dead analysis images were obtained using EVOS fluorescence microscopy. For Live / dead analysis, 5*10... 4NIH-3T3 cells were seeded at a density in 24-well cell culture plates. After culturing NIH-3T3 cells in a cell culture vessel for 24 hours, 20 μg / ml of nanoparticles were added to the cells along with the culture medium. After culturing for 1 hour, the cells were exposed to light for 1 minute. After culturing for another 5 hours, HeLa cells were washed three times with culture medium. Live / dead analysis was performed by staining mitochondria at a concentration of 1 μM for 10 minutes. Cells were washed with the finished culture medium. The culture medium was replaced with a LIVE / DEAD imaging solution mixture according to the manufacturer's protocol. The cell culture was cultured for 20 minutes and imaged using fluorescence microscopy using the green (live cells) and red (dead cells) channels.

[0155] Confirmation of the actual cytotoxicity of PCN

[0156] An experiment was performed to confirm whether the prepared PCN for UV blocking applications could be used in biological applications. An experiment was also performed to confirm whether cytotoxicity occurred when CN-400-4 was used in the prepared PCN. To assess biotoxicity, cell viability was evaluated using NIH-3T3 cells, an embryonic fibroblast cell line, via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl bromide tetrazolium (MTT) assay. The results are as follows: Figure 10A As shown, ZnO was used as a positive control group under the same experimental conditions, and the experimental results obtained were as follows. Figure 10B As shown.

[0157] like Figure 10A As confirmed in the study, CN-400-4 was non-toxic to NIH-3T3 cells, and no toxicity was observed even when using concentrations up to 50 μg / ml, even after UV irradiation for 24 hours of culture. On the other hand, as... Figure 10B The study confirmed that, compared to CN-400-4, NIH-3T3 cells showed a 50% survival rate in the positive control group ZnO nanoparticles at 10 μg / ml, but the survival rate decreased to less than 40% when irradiated with UV.

[0158] Furthermore, to further investigate the cytotoxicity of the prepared CN-400-4 to human skin cells, the HS-68 cell line, used as human dermal fibroblasts, was selected for experiments to confirm cytotoxicity and cell viability. The experimental results are presented below. Figure 10C middle.

[0159] like Figure 10C The study confirmed that CN-400-4 did not exhibit toxicity to HS-68 cells, a human skin cell line, even at concentrations as high as 10 μg / ml, resulting in a survival rate equivalent to over 90%.

[0160] Furthermore, when using CN-400-4, cell viability was assessed via Life / Dead cell imaging and displayed on [the image / data]. Figure 11 In (A and B). For example... Figure 11 As confirmed in (A and B), CN-400-4, after 6 hours of culture with UV light, showed no similar degree of toxicity to untreated NIH-3T3 cells, thus exhibiting live cells with bright green fluorescence and almost no red fluorescence as in dead cells. Furthermore, to demonstrate that CN-400-4 produces almost no reactive oxygen species (ROS) even in cells, dihydroxyethidium (DHE), an indicator of ROS in cells, was used for visualization and is shown in [the diagram / image / etc.]. Figure 11 (C) in. For example... Figure 11 As confirmed in (C), similar to the control group NIH-3T3 which was the untreated group, no ROS was generated in NIH-3T3 under illumination, even when irradiated with CN-400-4 light.

[0161] 7.3 Confirmation of PCN's skin protection as a UV blocker

[0162] right UV exposure (histological analysis) of Franz Cell Membrane (FCM)

[0163] Purchase and use 2cm×2cm×600μm size from APURES Co., Ltd. FranzCell Membrane (FCM). Nanoparticles were added to 12 wells containing FCM. After 1 hour of incubation, the wells were exposed to light using a sunlight simulator for 30 minutes. After another 3 hours of incubation, the wells were washed three times with PBS. The FCM was then stored overnight in NBF solution. For histochemical staining, the fixed FCM was washed with graded concentrations of ethanol, inserted into paraffin blocks, sectioned, stained with H&E staining agents, and analyzed.

[0164] The in vitro skin penetration probe in PCN was confirmed by SEM image recognition of FCM.

[0165] CN-400-4 nanoparticles were added to 12 wells containing FCM, and PBS solution was added to the FCM. After 4 hours of incubation, the samples were washed three times with PBS. The washed FCM was lyophilized for SEM measurements. A Hitachi sputter was used to prepare the samples by sputtering a Pt coating at a current of 20 mA for 60 seconds.

[0166] Confirming the skin protection effect of PCN

[0167] For an effective UV blocker to be effective, it must remain in the stratum corneum, i.e., the skin surface, without penetrating into the epidermis. Therefore, an experiment was performed when CN-400-4 was applied to the skin to verify whether it effectively prevented UV-induced skin damage while remaining in the epidermis within a synthetic skin membrane (Franz Cell Membrane, FCM). When CN-400-4 was applied to the synthetic skin, it was incubated in FCM for 4 hours after 30 minutes of light exposure, washed three times with PBS, and then H&E staining was performed to confirm the degree of skin damage. The results are shown below. Figure 12 In the middle. For example Figure 12 As confirmed in the study, CN-400-4 remains in the stratum corneum of the skin surface. As shown in the right figure, even when exposed to UV radiation, the skin remains undamaged and protected. However, in the control group (left figure), skin damage was confirmed, i.e., the stratum corneum was torn due to UV radiation and the epidermis was damaged. Therefore, it is confirmed that because CN-400-4 is retained in the stratum corneum, it can effectively prevent skin damage caused by UV radiation, and thus does not cause damage to the stratum corneum and epidermis when applied.

[0168] Furthermore, to confirm whether the FCM was effectively retained on the skin surface without penetrating the epidermis, the skin surface of the FCM was examined using scanning electron microscopy (SEM) to observe the shape of the skin surface after CN-400-4 was applied. The CN-400-4 sample was processed in the FCM and washed three times with PBS. The FCM was then lyophilized to confirm the SEM results. Figure 13 As shown. Figure 13 As confirmed in the figure below, CN-400-4 improves the interaction between the stratum corneum and CN-400-4, as indicated by the arrows, thereby remaining on the outermost surface of the stratum corneum in a sheet-like structure. On the other hand, as... Figure 13 As confirmed in the above figure, unlike the treatment group of CN-400-4, the surface of the untreated FCM shows a smooth skin, without any uneven patterns on its surface.

[0169] 7.4 Results of skin irritation (patch) test to confirm its stability as a UV blocker.

[0170] This experiment was conducted with IRB approval at the Se-Ming University Bio-Industry Clinical Trial Center, which is certified for use on human skin. Skin irritation was confirmed in all 30 subjects at 30 minutes, 24 hours, and 48 hours. This experiment was conducted and certified according to the standards of the International Contact Dermatitis Research Group (ICDRG). Patch testing was performed to confirm that CN-400-4 does not cause irritation even under actual skin irritation. CN-400-4 patches were prepared for 30 subjects, and the reaction of the CN-400-4 patches was confirmed three times on the subjects' skin at 30 minutes, 24 hours, and 48 hours. Figure 14 As shown. Figure 14 As confirmed in the study, the CN-400-4 patch was 100% negative in all 30 subjects, confirming no skin irritation. Therefore, it is demonstrated that CN-400-4 is non-toxic and non-irritating to the skin, ensuring its stability for effective use on human skin.

[0171] The foregoing has described specific aspects of the present invention in detail. It will be clear to those skilled in the art that these specific techniques are merely preferred embodiments, and the scope of the present invention is not limited thereto. Therefore, the essential scope of the present invention will be defined by the appended claims and their equivalents.

Claims

1. A crystal form, said crystal form being selected from the group consisting of crystal forms C to G having the following X-ray powder diffraction patterns measured using CuKα rays, wherein, The polymeric carbon nitride comprises repeating units represented by the following chemical formula 1. The crystal form C exhibits characteristic peaks at diffraction angles 2θ of 10.7006±0.2°, 22.1406±0.2°, and 27.8606±0.2° in its X-ray powder diffraction pattern. The crystal form D exhibits characteristic peaks at diffraction angles 2θ of 10.6356±0.2° and 27.8216±0.2° in the X-ray powder diffraction pattern. The crystal form E exhibits characteristic peaks at diffraction angles 2θ of 10.7266±0.2° and 27.5096±0.2° in the X-ray powder diffraction pattern. The crystal form G exhibits characteristic peaks at diffraction angles 2θ of 13.8076±0.2° and 27.1586±0.2° in the X-ray powder diffraction pattern. [Chemical Formula 1] (In the chemical formula 1, n is an integer from 1 to 1,000,000).

2. The crystal form according to claim 1, wherein, In the IR of the crystal form C, at 777±2 cm -1 1467±2 cm -1 1666±2 cm -1 1734±2 cm -1 3120±2 cm -1 and 3320±2 cm -1 There is a characteristic peak at this location; In the IR of the crystal form D, at 777±2 cm -1 1465±2 cm -1 1660±2 cm -1 1734±2 cm -1 3085±2 cm -1 and 3330±2 cm -1 There is a characteristic peak at this location; In the IR of the crystal form E, at 810±2 cm -1 1270±2 cm -1 1420±2 cm -1 1612±2 cm -1 3105±2 cm -1 and 3330±2 cm -1 There are characteristic peaks at this location; and In the IR of the crystal form G, at 810±2 cm -1 1240±2 cm -1 1317±2 cm -1 1410±2 cm -1 1560±2 cm -1 1635±2 cm -1 and 3250±2 cm -1 There is a characteristic peak at this location.

3. The crystal form according to claim 1, wherein, When the crystal form is analyzed using X-ray photoelectron spectroscopy (XPS), In the crystal form, there is a C (carbon) peak in the range of 280 eV to 290 eV, an N (nitrogen) peak in the range of 390 eV to 400 eV, and an O (oxygen) peak in the range of 530 eV to 540 eV.

4. The crystal form according to claim 1, wherein, The crystal form absorbs light energy in the wavelength range of 200 nm to 400 nm.

5. The crystal form according to claim 1, wherein, The average grain size of the crystal form is 1 nm to 10 nm.

6. The crystal form according to claim 1, wherein, The crystal form does not exhibit cytotoxicity in fibroblasts and does not generate reactive oxygen species when irradiated with UV light.

7. A cosmetic composition comprising polymeric carbon nitride, the polymeric carbon nitride comprising repeating units represented by the following chemical formula 1: [Chemical Formula 1] (In the chemical formula 1, n is an integer from 1 to 1,000,000). The polymeric carbon nitride described herein comprises a crystal form selected from the group consisting of crystal forms C to G, having the following X-ray powder diffraction patterns measured using CuKα rays. The crystal form C exhibits characteristic peaks at diffraction angles 2θ of 10.7006±0.2°, 22.1406±0.2°, and 27.8606±0.2° in the X-ray powder diffraction pattern. The crystal form D exhibits characteristic peaks at diffraction angles 2θ of 10.6356±0.2° and 27.8216±0.2° in the X-ray powder diffraction pattern. The crystal form E exhibits characteristic peaks at diffraction angles 2θ of 10.7266±0.2° and 27.5096±0.2° in the X-ray powder diffraction pattern. The crystal form G exhibits characteristic peaks at diffraction angles 2θ of 13.8076±0.2° and 27.1586±0.2° in the X-ray powder diffraction pattern, and... The content of the polymer carbon nitride relative to the total weight of the composition is from 0.001 wt% to 35 wt%.

8. The cosmetic composition according to claim 7, wherein, The cosmetic composition is used to block ultraviolet rays.

9. The cosmetic composition according to claim 7, wherein, The cosmetic composition further comprises one or more selected from the group consisting of organic and inorganic ultraviolet blocking agents.

10. The cosmetic composition according to claim 7, wherein, The color of the polymer carbon nitride is adjustable and can be applied to different skin tones.

11. The cosmetic composition according to claim 7, wherein, The cosmetic composition absorbs light energy in the wavelength range of 200 nm to 400 nm.

12. A composition for blocking ultraviolet light, the composition comprising polymeric carbon nitride, the polymeric carbon nitride comprising repeating units represented by the following chemical formula 1: [Chemical Formula 1] (In the chemical formula 1, n is an integer from 1 to 1,000,000). The polymeric carbon nitride described herein comprises a crystal form selected from the group consisting of crystal forms C to G, having the following X-ray powder diffraction patterns measured using CuKα rays. The crystal form C exhibits characteristic peaks at diffraction angles 2θ of 10.7006±0.2°, 22.1406±0.2°, and 27.8606±0.2° in the X-ray powder diffraction pattern. The crystal form D exhibits characteristic peaks at diffraction angles 2θ of 10.6356±0.2° and 27.8216±0.2° in the X-ray powder diffraction pattern. The crystal form E exhibits characteristic peaks at diffraction angles 2θ of 10.7266±0.2° and 27.5096±0.2° in the X-ray powder diffraction pattern. The crystal form G exhibits characteristic peaks at diffraction angles 2θ of 13.8076±0.2° and 27.1586±0.2° in the X-ray powder diffraction pattern, and... The content of the polymer carbon nitride relative to the total weight of the composition is from 0.001 wt% to 35 wt%.

13. A topical skin composition comprising polymeric carbon nitride, the polymeric carbon nitride comprising repeating units represented by the following chemical formula 1: [Chemical Formula 1] (In the chemical formula 1, n is an integer from 1 to 1,000,000). The polymeric carbon nitride described herein comprises a crystal form selected from the group consisting of crystal forms C to G, having the following X-ray powder diffraction patterns measured using CuKα rays. The crystal form C exhibits characteristic peaks at diffraction angles 2θ of 10.7006±0.2°, 22.1406±0.2°, and 27.8606±0.2° in the X-ray powder diffraction pattern. The crystal form D exhibits characteristic peaks at diffraction angles 2θ of 10.6356±0.2° and 27.8216±0.2° in the X-ray powder diffraction pattern. The crystal form E exhibits characteristic peaks at diffraction angles 2θ of 10.7266±0.2° and 27.5096±0.2° in the X-ray powder diffraction pattern. The crystal form G exhibits characteristic peaks at diffraction angles 2θ of 13.8076±0.2° and 27.1586±0.2° in the X-ray powder diffraction pattern, and... The content of the polymer carbon nitride relative to the total weight of the composition is from 0.001 wt% to 35 wt%.

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