A spinning solution, nanofiber membrane and preparation method

Abstract

A spinning solution, a nanofiber membrane, and a preparation method thereof belong to the field of electrospinning technology. The spinning solution comprises 20 wt%–50 wt% of a mixed polymer material, 0.05 wt%–1 wt% of a cationic surfactant, 0.05 wt%–1 wt% of a first surfactant, and 50 wt%–80 wt% of a mixed solvent. The first surfactant is selected from anionic or nonionic surfactants; both anionic and cationic surfactants contain aromatic groups, and the nonionic surfactant has an HLB > 8. Using the above-mentioned surfactants in a compound formulation can improve the solubility of the spinning solution, reduce the probability of phase separation and uneven dispersion, improve the morphological uniformity of the prepared nanofiber membrane, reduce the solvent residue in the nanofiber membrane, and improve the safety of the nanofiber membrane.

Description

Technical Field

[0001] This application relates to the field of electrospinning technology, and more specifically, to a spinning solution, a nanofiber membrane, and a preparation method thereof. Background Technology

[0002] Electrospinning is an advanced technology that utilizes a high-voltage electric field to overcome the surface tension of the spinning solution, generating a jet that, along with solvent evaporation, solidifies, and stretches into nanofibers, ultimately depositing them at the receiving site to form a nanofiber film. In-situ (or portable) electrospinning, using a handheld in-situ electrospinning device, leverages a high-voltage electrostatic field to achieve in-situ deposition of nanofiber films at the receiving site, integrating the preparation and application processes into one.

[0003] Currently, electrospinning solutions typically contain two or more polymer materials. These polymer materials are generally difficult to dissolve, thus requiring solvents with high solubility. These solvents with high solubility often have a certain degree of toxicity. To reduce the toxicity of the spinning solution, a low-toxicity solvent is usually mixed into the high-solubility solvent.

[0004] When mixed with low-toxicity solvents, various polymer materials are prone to uneven dispersion and phase separation, resulting in uneven morphology of the prepared nanofiber membranes and affecting their performance. Furthermore, when in-situ electrospinning technology is applied in the medical field, nanofiber films are directly deposited on the surface of human skin. However, when using existing spinning solutions for in-situ electrospinning, the nanofiber membranes directly deposited on the skin surface usually retain a significant amount of solvent. Even with the use of low-toxicity solvents for blending to reduce solvent toxicity, if the residual solvent in the nanofiber membrane exceeds a certain limit, it can still harm human health. Summary of the Invention

[0005] In view of the above-mentioned shortcomings, this application provides a spinning solution, a nanofiber membrane and a preparation method thereof, in order to improve the uneven morphology and safety issues of nanofiber membranes in related technologies.

[0006] This application is implemented as follows:

[0007] In a first aspect, an example of this application provides a spinning solution comprising 20 wt% to 50 wt% of a mixed polymer material, 0.05 wt% to 1 wt% of a cationic surfactant, 0.05 wt% to 1 wt% of a first surfactant, and 50 wt% to 80 wt% of a mixed solvent. The first surfactant is selected from anionic or nonionic surfactants, both of which contain aromatic groups, and the nonionic surfactant has an HLB > 8.

[0008] In the above-mentioned process, by combining 0.05wt% to 1wt% of a cationic surfactant containing aromatic groups with 0.05wt% to 1wt% of an anionic surfactant containing aromatic groups, or by combining the above-mentioned cationic surfactant with 0.05wt% to 1wt% of a nonionic surfactant with HLB>8, the solubility of the spinning solution can be improved, enabling various polymer materials to be uniformly dispersed in the spinning solution to form a stable homogeneous system, thereby reducing the probability of phase separation in the spinning solution. When using the above-mentioned spinning solution for electrospinning, the probability of generating bicontinuous phase fibers with uneven diameter distribution can be reduced, thereby improving the morphological uniformity of the nanofiber membrane.

[0009] Furthermore, when performing in-situ electrospinning at target locations such as the human skin surface using the aforementioned spinning solution, the combination of cationic surfactant and the first surfactant can improve spinning efficiency while reducing the amount of solvent residue in the nanofiber membrane directly deposited at target locations such as the human skin surface. This reduces the impact of solvent on human health to an acceptable range and improves the safety of the nanofiber membrane.

[0010] In conjunction with the first aspect, in some possible embodiments, the sum of the mass of the cationic surfactant and the first surfactant accounts for 0.1% to 1.05% of the total mass of the spinning solution.

[0011] Optionally, the spinning solution includes 0.05 wt% to 0.5 wt% of a cationic surfactant.

[0012] Optionally, the spinning solution includes 0.5 wt% to 1 wt% of a first surfactant.

[0013] In the above process, the sum of the mass of the cationic surfactant and the first surfactant accounts for 0.1wt% to 1.05wt% of the total mass of the spinning solution. This can improve the spinning efficiency, further reduce the probability of phase separation in the spinning solution, and reduce the amount of solvent residue in the spun fiber membrane, thereby improving the morphological uniformity and safety of the nanofiber membrane.

[0014] In conjunction with the first aspect, in some possible embodiments, the cationic surfactant includes at least one of alkylpyridines or benzyl quaternary ammonium salts.

[0015] Optionally, alkylpyridines include at least one of oxytinididine dihydrochloride, hexadecyl bromopyridine, or dodecyl pyridine chloride.

[0016] Optionally, benzyl quaternary ammonium salts include at least one of dodecylbenzyl dimethyl ammonium chloride or hexadecylbenzyl dimethyl ammonium chloride.

[0017] In conjunction with the first aspect, in some possible embodiments, the anionic surfactant includes at least one of alkylbenzene sulfonates, alkylnaphthalene sulfonates, or phenolic polyether phosphate salts.

[0018] Optionally, alkylbenzene sulfonates include at least one of C10 to C16 sodium alkylbenzene sulfonate.

[0019] Optionally, alkyl naphthalene sulfonates include sodium dibutylnaphthalene sulfonate.

[0020] Optionally, phenolic polyether phosphate salts include nonylphenol polyoxyethylene ether phosphate.

[0021] In conjunction with the first aspect, in some possible embodiments, the nonionic surfactant includes at least one of polyether-modified polydimethylsiloxane, Span 20, cetearyl alcohol polyether-10, nonylphenol polyether-10, castor oil polyoxyethylene ether, or Tween.

[0022] In the above-described process, the cationic surfactant containing aromatic groups can generate non-covalent interactions such as electrostatics and hydrogen bonding with anionic or nonionic surfactants, thereby producing a solubilizing effect and enabling the spinning solution to form a stable homogeneous system. Furthermore, the aromatic groups in the two ionic surfactants can increase the steric hindrance between them, appropriately weakening their binding tightness and thus avoiding the probability of precipitation during surfactant blending. In addition, due to charge neutralization and hydrogen bonding, the charge in the spinning solution is reduced, resulting in a lower conductivity of the blended surfactant spinning solution compared to the single surfactant system. This avoids a significant increase in solvent residue within the nanofiber membrane during electrospinning, which is caused by excessively rapid jet acceleration, reduced jet stretching time, and incomplete solvent evaporation.

[0023] In conjunction with the first aspect, in some possible embodiments, the mixed polymeric material includes at least two of polycaprolactone (PCL), polylactic acid, polylactic acid-glycolic acid copolymer, polyglycolic acid, polyvinyl butyral, polyethylene glycol, polyethylene oxide, polyvinyl alcohol, or chitosan.

[0024] Optionally, the mixed polymer material includes two polymer materials in a ratio of 1:1 to 9.

[0025] In the above process, the blending of two or more polymer materials can compensate for the shortcomings of the properties of a single polymer material and improve the quality of the nanofiber membrane.

[0026] In conjunction with the first aspect, in some possible embodiments, the mixed solvent includes a first solvent and a second solvent; the first solvent includes at least one of ethyl acetate, propyl acetate, butyl acetate, formic acid, n-heptane, dimethyl sulfoxide, butanol, n-propanol, isopropanol, or N,N'-dimethylformamide; and the second solvent includes at least one of acetic acid, acetone, or ethanol.

[0027] In conjunction with the first aspect, in some possible implementations, the mass ratio of the first solvent to the second solvent is 1 to 7:1.

[0028] In the above process, a first solvent such as ethyl acetate with high solubility is mixed with a second solvent with low toxicity. This allows the mixed solvent to have good solubility while also reducing its toxicity, thereby improving the safety of the prepared nanofiber membrane.

[0029] In a second aspect, an example of this application provides a method for preparing a nanofiber membrane, wherein in-situ electrospinning is performed at a target receiving location using the spinning solution provided in the first aspect.

[0030] Optionally, the target receiving location may include the surface of human skin.

[0031] In the above-described process, in-situ electrospinning is performed at target receiving sites such as the human skin surface using the spinning solution provided in the first aspect, directly forming a nanofiber membrane at these sites. Furthermore, because the spinning solution contains 0.05wt%–1wt% of a cationic surfactant containing aromatic groups and 0.05wt%–1wt% of an anionic surfactant containing aromatic groups, or 0.05wt%–1wt% of a nonionic surfactant with HLB>8, this combination of surfactants not only improves the solubility of the spinning solution, allowing various polymer materials to be uniformly dispersed in the solution to form a stable homogeneous system, reducing the probability of phase separation and the likelihood of generating bicontinuous phase fibers with uneven diameter distribution, but also improves the morphological uniformity of the nanofiber membrane. Additionally, while improving spinning efficiency, it reduces the amount of solvent residue in the nanofiber membrane directly deposited at target receiving sites such as the human skin surface, reducing the impact of solvents on human health and improving the safety of the prepared nanofiber membrane.

[0032] In a third aspect, an example of this application provides a nanofiber membrane prepared according to the preparation method provided in the second aspect.

[0033] In the above-described process, the nanofiber membrane prepared according to the method provided in the second aspect has a uniform nanofiber diameter distribution and is formed in situ at the target receiving site, such as the surface of human skin. This avoids structural damage to the nanofiber membrane during transfer, thus preventing it from affecting its performance. Furthermore, the nanofiber membrane has a low solvent residue, exhibiting good safety. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0035] Figure 1 This is a SEM image of the nanofiber membrane provided in Example 1 of this application;

[0036] Figure 2 SEM image of the nanofiber membrane provided in Comparative Example 1 of this application;

[0037] Figure 3 This is a SEM image of the nanofiber membrane provided in Comparative Example 2 of this application. Detailed Implementation

[0038] The embodiments of this application will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of this application. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0039] Electrospinning is an advanced technology that uses a high-voltage electric field to create a jet of spinning solution, which then evaporates, solidifies, and stretches into nanofibers, ultimately depositing them at the target receiving site to form a nanofiber film. Nanofiber films prepared by electrospinning have a nanofiber structure similar to the natural extracellular matrix, mimicking the natural cell growth environment and having wide applications in the medical field. In-situ (or portable) electrospinning, using a handheld electrospinning device, utilizes a high-voltage electrostatic field to achieve in-situ deposition of nanofiber films at target receiving sites such as the human skin surface, integrating the preparation and application processes.

[0040] Currently, electrospinning solutions typically include two or more polymer materials to compensate for the limitations of a single polymer material. To reduce the toxicity of the spinning solution, a low-toxicity solvent is usually added. However, the addition of a low-toxicity solvent can lead to uneven dispersion of the multiple polymer materials, resulting in phase separation. This can cause uneven morphology in the prepared nanofiber membrane, affecting its performance.

[0041] Furthermore, when in-situ electrospinning technology is applied to the medical field, nanofiber films are deposited directly on the surface of human skin. However, nanofiber films deposited directly on the surface of human skin usually retain a large amount of solvent, which may harm human health and has low safety.

[0042] Therefore, the first aspect of this application provides a spinning solution comprising 20 wt% to 50 wt% of a mixed polymer material, 0.05 wt% to 1 wt% of a cationic surfactant, 0.05 wt% to 1 wt% of a first surfactant, and 50 wt% to 80 wt% of a mixed solvent. The first surfactant is selected from anionic surfactants or nonionic surfactants; both anionic and cationic surfactants contain aromatic groups, and the nonionic surfactant has an HLB > 8.

[0043] By compounding 0.05wt%–1wt% of a cationic surfactant containing aromatic groups with 0.05wt%–1wt% of an anionic surfactant containing aromatic groups, the two surfactants can generate non-covalent interactions such as electrostatics and hydrogen bonding, resulting in a solubilizing effect. This allows various polymer materials to be uniformly dispersed in the spinning solution, forming a stable homogeneous system. During electrospinning, this reduces the probability of forming bicontinuous phase fibers with uneven diameter distribution, thereby improving the morphological uniformity of the nanofiber membrane. Furthermore, the aromatic groups of the anionic and cationic surfactants can increase the steric hindrance between the two, appropriately weakening their compactness and thus reducing the probability of precipitation during compounding.

[0044] Compared to the combination of cationic and anionic surfactants containing aromatic groups in this application, traditional anionic and cationic surfactants without aromatic groups have too high a tightness and generate strong electrostatic interactions. Therefore, precipitation is easily generated during the compounding process, resulting in the loss of the compounding effect.

[0045] By compounding 0.05wt%–1wt% of a cationic surfactant containing aromatic groups with 0.05wt%–1wt% of a nonionic surfactant with HLB>8, non-covalent interactions such as electrostatics and hydrogen bonding can be generated, which can improve the solubilization effect of the spinning solution. Furthermore, the more polar nonionic surfactant with hydrophilic groups can increase its tightness with the cationic surfactant, enhancing the compounding effect and reducing the probability of phase separation in various polymer materials. In electrospinning, this can reduce the probability of generating bicontinuous phase fibers with uneven diameter distribution, thereby improving the morphological uniformity of the nanofiber membrane.

[0046] The degree of hydrophilicity or lipophilicity of a surfactant can be determined by its HLB value. A higher HLB value indicates stronger hydrophilicity, meaning stronger polarity of the hydrophilic groups; conversely, a lower HLB value indicates stronger lipophilicity. When traditional nonionic surfactants with HLB < 8 are combined with cationic surfactants, although hydrogen bonding exists, this bonding relies on the polarization effect of the nonionic surfactant in water. Therefore, the bonding is not very strong, resulting in poor mixing and low solubilization of the spinning solution. Phase separation is also likely to occur, and during electrospinning, bicontinuous phase fibers with uneven diameter distribution are easily generated, which in turn affects the morphological uniformity of the nanofiber membrane.

[0047] In addition, this application utilizes two specific surfactants to create a compound, which can generate charge neutralization and hydrogen bonding, thereby reducing the charge in the compound surfactant system. This results in a lower conductivity of the compound surfactant system compared to the single surfactant system. During electrospinning, this avoids the phenomenon that the amount of solvent residue in the nanofiber membrane would increase significantly due to excessively fast jet acceleration, reduced jet stretching time, and incomplete solvent evaporation.

[0048] In this application, "wt%" refers to a mass percentage. For example, "50wt% to 80wt% mixed solvent" means that the mass of the mixed solvent accounts for 50% to 80% of the total mass of the spinning solution. Similarly, "0.05wt% to 1wt% cationic surfactant" means that the mass of the cationic surfactant accounts for 0.05% to 1% of the total mass of the spinning solution; "0.05wt% to 1wt% first surfactant" means that the mass of the first surfactant accounts for 0.05% to 1% of the total mass of the spinning solution; and "20wt% to 50wt% mixed polymer material" means that the mass of the mixed polymer material accounts for 20% to 50% of the total mass of the spinning solution.

[0049] In some embodiments, the percentage of the mass of the mixed solvent to the total mass of the spinning solution can be one of 50%, 60%, 70%, or 80%, or any combination thereof.

[0050] For example, the mass percentage of the mixed solvent to the total mass of the spinning solution can be 55% to 75%; or, the mass percentage of the mixed solvent to the total mass of the spinning solution can be 60% to 70%.

[0051] In some embodiments, the percentage of the cationic surfactant by mass of the total mass of the spinning solution can be one or a range between any two of 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, or 1%.

[0052] In some embodiments, the mass percentage of the cationic surfactant in the total mass of the spinning solution may be 0.05% to 0.5%.

[0053] In some embodiments, the percentage of the mass of the first surfactant to the total mass of the spinning solution can be one or a range between any two of 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, or 1%.

[0054] In some embodiments, the mass percentage of the first surfactant in the total mass of the spinning solution may be 0.5% to 1%.

[0055] In some embodiments, the sum of the mass of the cationic surfactant and the first surfactant may account for 0.1% to 1.05% of the total mass of the spinning solution.

[0056] In some embodiments, the percentage of the mass of the mixed polymer material to the total mass of the spinning solution can be one of 20%, 30%, 40%, or 50%, or any combination thereof.

[0057] In some embodiments, the percentage of the mixed polymer material in the total mass of the spinning solution may be 20% to 40%; or, the percentage of the mixed polymer material in the total mass of the spinning solution may be 30% to 40%.

[0058] In some embodiments, the spinning solution comprises 20 wt% to 49 wt% of a mixed polymer material, 0.05 wt% to 0.5 wt% of a cationic surfactant, 0.5 wt% to 1 wt% of a first surfactant, and 50 wt% to 79 wt% of a mixed solvent.

[0059] "Mixed polymer materials" refers to the mixing of multiple different types of polymer materials.

[0060] In some embodiments, the mixed polymeric material includes at least two of polycaprolactone, polylactic acid, polylactic acid-glycolic acid copolymer, polyglycolic acid, polyvinyl butyral, polyethylene glycol, polyethylene oxide, polyvinyl alcohol, or chitosan.

[0061] For example, a mixed polymeric material may include two polymeric materials. For instance, a mixed polymeric material may include polycaprolactone and polyvinyl butyral.

[0062] Furthermore, in some embodiments, the mass ratio of the two polymer materials is 1:1 to 9.

[0063] For example, the mass ratio of the two polymer materials can be one of 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8 or 1:9 or any range between two of them.

[0064] "Mixed solvent" refers to a mixed solvent in which two or more different solvents are mixed together to form a uniformly dispersed phase.

[0065] In some embodiments, the mixed solvent comprises a first solvent with higher solubility and a second solvent with lower toxicity. By mixing the second solvent with lower toxicity with the first solvent with higher solubility, it is possible to increase the solubility of the mixed solvent system while reducing its toxicity.

[0066] In some embodiments, the first solvent includes at least one of ethyl acetate, propyl acetate, butyl acetate, formic acid, n-heptane, dimethyl sulfoxide, butanol, n-propanol, isopropanol, or N,N'-dimethylformamide.

[0067] In some embodiments, the second solvent includes at least one of acetic acid, acetone, or ethanol.

[0068] For example, the mixed solvents include ethyl acetate and ethanol.

[0069] In some embodiments, the mass ratio of the first solvent to the second solvent is 1 to 7:1.

[0070] The mass ratio of the first solvent to the second solvent is 1 to 7:1. This can further reduce the toxicity of the mixed solvent, and under the combined action of the two surfactants, it can dissolve a variety of polymer materials in the mixed solvent to form a stable homogeneous system.

[0071] For example, the mass ratio of the first solvent and the second solvent can be one of 1:1, 2:1, 3:1, 4:1, 5:1, 6:1 or 7:1 or any range between the two.

[0072] For example, the mass ratio of the first solvent to the second solvent can be 7:1.

[0073] Cationic surfactants contain aromatic groups. In some embodiments, cationic surfactants include at least one of oteninidine dihydrochloride, hexadecyl bromopyridine, dodecyl pyridine chloride, dodecyl benzyl dimethyl ammonium chloride, dodecyl benzyl dimethyl ammonium chloride, or hexadecyl benzyl dimethyl ammonium chloride.

[0074] For example, the cationic surfactant may be at least one of alkylpyridines such as oteninidine dihydrochloride, hexadecyl bromopyridine, dodecyl pyridine chloride, or dodecyl benzyl dimethyl ammonium chloride.

[0075] For example, the cationic surfactant may be at least one of benzyl quaternary ammonium salts such as dodecyl benzyl dimethyl ammonium chloride or hexadecyl benzyl dimethyl ammonium chloride.

[0076] In some embodiments, the first surfactant may be an anionic surfactant containing aromatic groups.

[0077] By combining anionic surfactants containing aromatic groups with cationic surfactants containing similar aromatic groups, a solubilizing effect can be achieved, reducing the likelihood of phase separation in the spinning solution. Furthermore, when the two surfactants are combined, the charge content within the combined surfactant system decreases due to charge neutralization and hydrogen bonding, resulting in a lower conductivity of the combined surfactant system compared to the single surfactant system. During electrospinning, this reduces the jet velocity and prolongs the jet stretching time, allowing for sufficient solvent evaporation. This reduces the amount of residual solvent deposited in the nanofiber membrane at target receiving sites such as human skin, thus improving the safety of the nanofiber membrane.

[0078] In some embodiments, the anionic surfactant includes at least one of alkylbenzene sulfonates, alkylnaphthalene sulfonates, or phenolic polyether phosphate salts.

[0079] For example, the anionic surfactant includes at least one of sodium decaalkylbenzene sulfonate, sodium undecylbenzene sulfonate, sodium dodecylbenzene sulfonate, sodium tridecylbenzene sulfonate, sodium tetradecylbenzene sulfonate, sodium pentadecylbenzene sulfonate, or sodium hexadecylbenzene sulfonate.

[0080] For example, anionic surfactants include sodium dibutylnaphthalene sulfonate.

[0081] For example, anionic surfactants include nonylphenol polyoxyethylene ether phosphate.

[0082] In some embodiments, the first surfactant may be a nonionic surfactant with an HLB greater than 8. Nonionic surfactants with an HLB greater than 8 have strong polarity, which can increase the tightness between them and cationic surfactants, increase the solubilization effect of the spinning solution, reduce the probability of phase separation in the spinning solution, and improve the morphological uniformity of the prepared nanofiber membrane.

[0083] In some embodiments, the nonionic surfactant may include at least one of polyether-modified polydimethylsiloxane, Span 20, cetearyl alcohol polyether-10, nonylphenol polyether-10, castor oil polyoxyethylene ether, or Tween.

[0084] For example, nonionic surfactants may include Tween 20, Tween 40, Tween 60, Tween 80 or Tween 85, etc.

[0085] In addition to the above-mentioned components, functional active substances can be selectively added to the spinning solution according to the intended use of the nanofiber membrane. For example, a small amount of antibacterial component can be added to the spinning solution to prepare an antibacterial nanofiber membrane via in-situ electrospinning.

[0086] In a second aspect, this application also provides a nanofiber membrane prepared by the following method:

[0087] Using the spinning solution provided in the first aspect of the present application, in-situ electrospinning is performed at the target receiving location, such as the surface of human skin, to prepare a nanofiber membrane.

[0088] Using the spinning solution provided in this application, in-situ electrospinning can be performed at target receiving sites such as the human skin surface to directly form nanofiber membranes. This avoids structural damage to the nanofiber membrane during transfer, which would affect its performance. Furthermore, since the spinning solution includes 0.05wt%–1wt% of a cationic surfactant containing aromatic groups and 0.05wt%–1wt% of anionic surfactant containing aromatic groups or 0.05wt%–1wt% of a nonionic surfactant with HLB>8, this combination of surfactants not only improves the solubility of the spinning solution, allowing various polymer materials to be uniformly dispersed in the spinning solution to form a stable homogeneous system and reducing the probability of phase separation, but also reduces the likelihood of generating bicontinuous phase fibers with uneven diameter distribution during electrospinning, improving the morphological uniformity of the nanofiber membrane. It also improves spinning efficiency while reducing the amount of solvent residue in the nanofiber membrane directly deposited at target receiving sites such as the human skin surface, thus reducing the impact of solvents on human health.

[0089] Furthermore, in some embodiments, the spinning parameters include a spinning voltage of 10–25 kV and a spinning solution flow rate of 0.01–1 mL / min.

[0090] The nanofiber membrane of this application will be further described in detail below with reference to the embodiments.

[0091] Example 1

[0092] Example 1 provides a nanofiber membrane, the preparation method of which includes:

[0093] (1) 68.74 wt% ethyl acetate and 9.82 wt% ethanol were mixed as a mixed solvent, and the total mass fraction of the mixed solvent was 78.56 wt%.

[0094] (2) Weigh 4.15 wt% of polyvinyl butyral (Mw = 90,000-120,000) and 16.24 wt% of polycaprolactone (Mw = 80,000) as mixed polymer materials, add them to the mixed solvent obtained in step (1), and heat and stir at 40°C until completely dissolved to obtain a blended spinning solution. The total mass fraction of the mixed polymer materials is 20.39 wt%.

[0095] (3) Add 0.05 wt% of oteninidine dihydrochloride and 1 wt% of polyether-modified polydimethylsiloxane (HLB value = 10.5) to the blended spinning solution obtained in step (2), stir at room temperature until a homogeneous solution is formed, and then let it stand at room temperature for 1 day to obtain the spinning solution. The specific composition of the spinning solution is shown in Table 1.

[0096] (4) Add the spinning solution obtained in step (3) into the syringe, place the syringe into the in-situ electrospinning device, turn on the switch, push the syringe, and prepare the nanofiber membrane at the target receiving position. The spinning parameters include: a spinning voltage of 20 kV and a spinning solution flow rate of 0.05 mL / min.

[0097] Example 2

[0098] Example 2 provides a nanofiber membrane, which differs from Example 1 in that:

[0099] In step (3), 0.05 wt% of oteninidine dihydrochloride and 1 wt% of Span 20 (HLB value = 8.5) were added to the blended spinning solution obtained in step (2). The mixture was stirred at room temperature until a homogeneous solution was formed, and then allowed to stand at room temperature for 1 day to obtain the spinning solution. The specific composition of the spinning solution is shown in Table 1.

[0100] Example 3

[0101] Example 3 provides a nanofiber membrane, which differs from Example 1 in that:

[0102] In step (3), 0.05 wt% of oteninidine dihydrochloride and 1 wt% of sodium dodecylbenzenesulfonate were added to the blended spinning solution obtained in step (2), and stirred at room temperature until a homogeneous solution was formed. Then, the solution was allowed to stand at room temperature for 1 day to obtain the spinning solution. The specific composition of the spinning solution is shown in Table 1.

[0103] Example 4

[0104] Example 4 provides a nanofiber membrane, which differs from Example 1 in that:

[0105] In step (1), 34.88 wt% ethyl acetate and 31.22 wt% acetic acid are mixed as a mixed solvent, and the total mass fraction of the mixed solvent is 66.10 wt%.

[0106] In step (2), 15.55 wt% of chitosan (Mw = 30,000) and 17.30 wt% of polycaprolactone (Mw = 80,000) were weighed as mixed polymer materials and added to the mixed solvent obtained in step (1). The mixture was heated and stirred at 40°C until completely dissolved to obtain a blended spinning solution. The total mass fraction of the mixed polymer materials was 32.85 wt%.

[0107] Comparative Example 1

[0108] Comparative Example 1 provides a nanofiber membrane, which differs from Example 1 in that:

[0109] Without step (3), the spinning solution does not contain surfactants. That is, in step (1), the total mass fraction of the mixed solvent is 78.56 wt%, and the total mass fraction of the mixed polymer material is 21.44 wt%. The specific composition of the spinning solution is shown in Table 1.

[0110] Comparative Example 2

[0111] Comparative Example 2 provides a nanofiber membrane, which differs from Example 1 in that:

[0112] In step (3), 1.05 wt% of oteninidine dihydrochloride was added to the blended spinning solution obtained in step (2), and the mixture was stirred at room temperature until a homogeneous solution was formed. The solution was then allowed to stand at room temperature for one day to obtain the blended spinning solution. That is, the spinning solution does not contain the first surfactant. The specific composition of the spinning solution is shown in Table 1.

[0113] Comparative Example 3

[0114] Comparative Example 3 provides a nanofiber membrane, which differs from Example 1 in that:

[0115] In step (3), 0.05 wt% of ostinidine dihydrochloride and 1 wt% of mono-fatty acid glycerides (HLB value = 3.6) were added to the blend spinning solution obtained in step (2). The mixture was stirred at room temperature until a homogeneous solution was formed, and then allowed to stand at room temperature for 1 day to obtain the spinning solution. The specific composition of the spinning solution is shown in Table 1.

[0116] Comparative Example 4

[0117] Comparative Example 4 provides a nanofiber membrane, which differs from Example 1 in that:

[0118] In step (3), 0.05 wt% octinidine dihydrochloride and 1 wt% sodium dodecyl sulfate were added to the blended spinning solution obtained in step (2), and stirred at room temperature until a homogeneous solution was formed. Then, the solution was allowed to stand at room temperature for 1 day to obtain the spinning solution. The specific composition of the spinning solution is shown in Table 1.

[0119] Table 1

[0120]

[0121]

[0122] Test case

[0123] Solvent residue tests were performed on the nanofiber membranes provided in Examples 1-4 and Comparative Examples 1-4. Morphology analysis was performed on the nanofiber membranes provided in Examples 1, Comparative Examples 1 and 2. Conductivity tests were performed on the compound surfactants provided in Examples 1-4 and Comparative Examples 1-4. The test methods are as follows:

[0124] (1) Solvent Residue Test

[0125] Gas chromatography was used to test the solvent residue of the nanofiber membranes provided in Examples 1-4 and Comparative Examples 1-4. The experimental results are shown in Table 2 (the residual amount of ethyl acetate should be less than 1000 ppm).

[0126] (2) Conductivity test

[0127] The conductivity of the spinning solutions prepared in Examples 1-4 and Comparative Examples 1-4 was tested using a conductivity meter. The experimental results are shown in Table 2.

[0128] The test results for conductivity and solvent residue are shown in Table 2. The SEM image of the nanofiber membrane provided in Example 1 is shown below. Figure 1 As shown, the SEM image of the nanofiber membrane provided in Comparative Example 1 is as follows. Figure 2 As shown, the SEM image of the nanofiber membrane provided in Comparative Example 2 is as follows. Figure 3 As shown.

[0129] Table 2

[0130]

[0131]

[0132] Results analysis:

[0133] Combination Figure 1 , Figure 2 Compared with Table 2, Comparative Example 1 did not add surfactants. Although only a small amount of ethyl acetate remained in the nanofiber membrane after electrospinning, the preparation efficiency was low, and phase separation occurred in the spinning solution. Figure 2 As shown, the prepared nanofiber membrane has an uneven diameter distribution and a rough fiber surface. In contrast, the nanofiber membrane provided in Example 1, while having a lower ethyl acetate content, exhibits... Figure 1 As shown, the nanofiber diameter distribution in the nanofiber membrane is more uniform. This illustrates that the embodiments of this application, through the compounding of two specific surfactants, can promote the formation of a stable homogeneous system in the spinning solution, thereby improving the morphological uniformity of the nanofiber membrane.

[0134] Table 2 compares Examples 1-3 and Comparative Example 2. Comparative Example 2, with the addition of a single cationic surfactant, resulted in nanofiber membranes with a higher residual content of ethyl acetate. Furthermore, a comparison was made... Figure 1 and Figure 3 It can be seen that, Figure 1 The diameter distribution of medium-sized nanofibers relative to Figure 3 The diameter distribution of the nanofibers is more uniform. This indicates that the present application utilizes a cationic surfactant containing aromatic groups to compound with the first surfactant, which can reduce the probability of phase separation in the spinning solution and improve the morphological uniformity and safety of the nanofiber membrane.

[0135] Table 2 shows that, comparing Examples 1, 2, and 3, in Comparative Example 3, the nanofiber membrane obtained by compounding a nonionic surfactant with HLB=3.6 and a cationic surfactant containing aromatic groups contained 19955.74 ppm of ethyl acetate. In Examples 1 and 2, the nanofiber membranes obtained by compounding a nonionic surfactant with HLB>8 and a cationic surfactant containing aromatic groups contained only no more than 868.18 ppm of ethyl acetate. The residual amount of ethyl acetate in Comparative Example 3 is much greater than that in Examples 1 and 2, indicating that the present application's use of a nonionic surfactant with HLB>8 and a cationic surfactant containing aromatic groups can reduce the residual amount of ethyl acetate solvent in the nanofiber membrane and improve the safety of the nanofiber membrane.

[0136] Table 2 shows that, comparing Example 3 and Comparative Example 4, the nanofiber membrane of Comparative Example 4 contains 10490.31 ppm of ethyl acetate, while the nanofiber membrane of Example 3 contains 818.48 ppm of ethyl acetate. The solvent residue in Comparative Example 4 is significantly higher than that in Example 3. This indicates that the present application utilizes a combination of a cationic surfactant containing aromatic groups and an anionic surfactant containing aromatic groups. Compared to using a combination of cationic and anionic surfactants without aromatic groups, this reduces the solvent residue in the nanofiber membrane and improves its safety.

[0137] In summary, this application utilizes a combination of cationic surfactants containing aromatic groups and anionic surfactants containing aromatic groups, or a combination of cationic surfactants containing aromatic groups and nonionic surfactants with HLB>8, to improve the solubility of the spinning solution, reduce the probability of phase separation, and further improve the morphological uniformity of the nanofiber membrane. It can also reduce the amount of residual solvent in the nanofiber membrane, thereby improving its safety.

[0138] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A spinning solution, characterized in that, It comprises 20wt% to 50wt% of a mixed polymer material, 0.05wt% to 1wt% of a cationic surfactant, 0.05wt% to 1wt% of a first surfactant, and 50wt% to 80wt% of a mixed solvent; wherein the first surfactant is selected from anionic surfactants or nonionic surfactants, both the anionic surfactant and the cationic surfactant contain aromatic groups, and the nonionic surfactant has an HLB > 8.

2. The spinning solution according to claim 1, characterized in that, The sum of the mass of the cationic surfactant and the first surfactant accounts for 0.1% to 1.05% of the total mass of the spinning solution; Optionally, the spinning solution includes 0.05 wt% to 0.5 wt% of the cationic surfactant; Optionally, the spinning solution includes 0.5 wt% to 1 wt% of the first surfactant.

3. The spinning solution according to claim 1, characterized in that, The cationic surfactant includes at least one of alkylpyridines or benzyl quaternary ammonium salts; Optionally, the alkylpyridine class includes at least one of oxytinididine dihydrochloride, hexadecyl bromopyridine, or dodecyl pyridine chloride; Optionally, the benzyl quaternary ammonium salt includes at least one of dodecylbenzyl dimethyl ammonium chloride or hexadecylbenzyl dimethyl ammonium chloride.

4. The spinning solution according to claim 1, characterized in that, The anionic surfactant includes at least one of alkylbenzene sulfonates, alkylnaphthalene sulfonates, or phenolic polyether phosphate salts; Optionally, the sodium alkylbenzene sulfonate salt includes at least one of C10 to C16 sodium alkylbenzene sulfonate; Optionally, the alkyl naphthalene sulfonates include sodium dibutylnaphthalene sulfonate; Optionally, the phenolic polyether phosphate salts include nonylphenol polyoxyethylene ether phosphate.

5. The spinning solution according to claim 1, characterized in that, The nonionic surfactant includes at least one of polyether-modified polydimethylsiloxane, Span 20, cetearyl alcohol polyether-10, nonylphenol polyether-10, castor oil polyoxyethylene ether, or Tween.

6. The spinning solution according to any one of claims 1 to 5, characterized in that, The mixed polymer material includes at least two of the following: polycaprolactone, polylactic acid, polylactic acid-glycolic acid copolymer, polyglycolic acid, polyvinyl butyral, polyethylene glycol, polyethylene oxide, polyvinyl alcohol, or chitosan. Optionally, the mixed polymer material includes two polymer materials in a ratio of 1:1 to 9.

7. The spinning solution according to claim 6, characterized in that, The mixed solvent includes a first solvent and a second solvent; the first solvent includes at least one of ethyl acetate, propyl acetate, butyl acetate, formic acid, n-heptane, dimethyl sulfoxide, butanol, n-propanol, isopropanol, or N,N'-dimethylformamide; the second solvent includes at least one of acetic acid, acetone, or ethanol.

8. The spinning solution according to claim 7, characterized in that, The mass ratio of the first solvent to the second solvent is 1 to 7:

1.

9. A method for preparing a nanofiber membrane, characterized in that, At the target receiving position, in-situ electrospinning is performed using the spinning solution described in any one of claims 1 to 8; Optionally, the target receiving location may include the surface of human skin.

10. A nanofiber membrane, characterized in that, It is prepared according to the preparation method described in claim 9.

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