Visible light response inorganic-polymer composite ferroelectric material and preparation method thereof

Abstract

The application provides a visible light response inorganic-polymer composite ferroelectric material and a preparation method thereof. The preparation method comprises the following steps: A) mixing an inorganic ferroelectric material, a polymer and a solvent to obtain an electrostatic spinning solution; and B) electrostatic spinning the electrostatic spinning solution to obtain a composite ferroelectric fiber membrane material; wherein the inorganic ferroelectric material is an ABO2 series ferroelectric phase material. The inorganic ferroelectric material, the polymer and the solvent are mixed first, and then the hydrogen bond or chelation between the oxygen atoms of the ABO2 series ferroelectric phase and the polymer chains can be utilized to obtain a uniformly dispersed mixed solution. Then, the electrostatic spinning is performed to obtain the composite ferroelectric fiber membrane material. In the electrostatic spinning process, there is a certain pre-polarization effect, and the effect of the ferroelectric composite material is achieved. The preparation method can greatly simplify the process, and the response can be realized under visible light conditions, the antibacterial rate is improved, and the skin repair is promoted.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of composite materials, in particular to a visible light responsive inorganic-polymer composite ferroelectric material and a preparation method thereof. BACKGROUND

[0002] Skin is the largest organ of the human body and the first line of defense against infectious pathogens. However, it is also the most vulnerable to injuries such as electric shock, burns, scalds, frostbite, sunburn, and complications of chronic diseases. Currently, animal skin (such as pig skin) is used in clinical treatment to replace skin for treating various wounds. However, exogenous skin undoubtedly causes a series of immune rejection reactions. In the face of various hazards, it is a research hotspot to achieve active wound treatment by designing wound dressings and characterizing the dynamic process of wound healing.

[0003] Wound regeneration is divided into four consecutive processes, namely hemostasis, inflammation, proliferation, and remodeling. Promoting wound repair is mainly intervened through the following three aspects: ① preventing wound infection; ② shortening the inflammation stage; and ③ promoting skin regeneration, nerve regeneration, and blood vessel regeneration. In terms of preventing wound infection, the most common bacteria causing wound infection is Staphylococcus aureus, so the antibacterial effect of wound dressings on Staphylococcus aureus is of great concern.

[0004] Ferroelectric materials have piezoelectric, pyroelectric, inverse piezoelectric, nonlinear optical, ferroelectric photovoltaic, and other properties, and have received extensive attention in the biomedical field in recent years. Due to their ability to generate electrical, mechanical, and optical signals through interactions with force, heat, electricity, and light, ferroelectric materials show unique advantages in biological sensing, acoustic tweezers, biological imaging, therapy, tissue engineering, and stimulating biological functions. Studies have also shown that ferroelectricity may play an important role in cellular processes or have an impact on biological molecules.

[0005] Current studies have shown that ferroelectric materials can achieve antibacterial effects through the production of reactive oxygen species (ROS) or electrostatic interactions, and the electrical stimulation generated by ferroelectric materials can reduce edema around the electrode; stimulate granulation tissue growth; increase blood flow, fibroblast proliferation, and collagen production; induce epidermal cell migration; and promote epithelial growth and organization. Because ferroelectric materials can prevent wound infection through antibacterial effects, and can also regulate cell proliferation and differentiation through electrical stimulation, they have a very promising application prospect in the field of skin wound repair.

[0006] However, inorganic ferroelectric materials are not suitable for biomedical applications due to their brittleness and fragility, while polymer materials are flexible and biocompatible, so preparing inorganic / polymer composite ferroelectric materials is an excellent solution to apply ferroelectric materials to biomedical applications.

[0007] The prior art 202211206420.6 discloses an antibacterial dressing based on ferroelectric materials and a preparation method and use thereof, which is prepared from a ferroelectric polymer, ferroelectric ceramic particles and an inorganic pore-forming agent; the composite material is subjected to high-temperature treatment, corona polarization treatment and acid treatment in sequence; or corona polarization treatment, high-temperature treatment and acid treatment in sequence. Experiments show that the prepared antibacterial dressing has the ability to promote the regeneration of infected tissues and the anti-infection effect in vivo.

[0008] However, the sample preparation process of the above prior art is relatively complex, and after obtaining a uniformly dispersed mixed solution, it needs to go through steps such as casting into a film, drying, annealing, acid soaking, washing, drying and corona polarization. Moreover, its antibacterial effect is poor and it does not have visible light response characteristics. SUMMARY

[0009] Therefore, the present application provides an inorganic-polymer composite ferroelectric material with visible light response and a preparation method thereof. The preparation method of the present application can greatly simplify the process, and can realize response under visible light conditions, improve the antibacterial rate and promote skin repair, and greatly simplify the application conditions for visible light, without the need for external light source.

[0010] The present application provides a preparation method of an inorganic-polymer composite ferroelectric material with visible light response, comprising the following steps:

[0011] A) mixing an inorganic ferroelectric material, a polymer and a solvent to obtain an electrospinning solution;

[0012] B) electrospinning the electrospinning solution to obtain a composite ferroelectric fiber film material;

[0013] wherein,

[0014] The inorganic ferroelectric material is an ABO2 series ferroelectric phase material.

[0015] Preferably, the inorganic ferroelectric material is selected from at least one of CuBO2, AgBO2, CuAlO2, AgAlO2, AuAlO2, CuGaO2, AgGaO2, NaFeO2, KFeO2, RbFeO2, CuFeO2, AgFeO2, AuFeO2, LiBiO2, NaPO2, AgBiO2, LiRE1O2, NaRE2O2, KRE3O2, RbRE4O2, CsRE5O2, CuRE6O2, AgRE7O2, AuRE8O2;

[0016] wherein,

[0017] RE1is selected from Y, Ce, Pr, Nd, Eu, Gd, Tb, Dy, or Lu;

[0018] RE2is selected from Sc, Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Tm, Yb, or Lu;

[0019] RE3is selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, or Lu;

[0020] RE4is selected from Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, or Lu;

[0021] RE5is selected from Y, Ce, Nd, Sm, Tb, Dy, Er, Tm, Yb, or Lu;

[0022] RE6is selected from Y, Pr, Nd, Eu, Dy, Ho, Er, Tm, Yb, or Lu;

[0023] RE7is selected from Sc, La, Gd, Tb, Dy, Ho, Er, Tm, Yb, or Lu;

[0024] RE8is selected from Sc, Ho, Er, Tm, Yb, or Lu.

[0025] Preferably, the inorganic ferroelectric material has a particle size of 200-800 nm.

[0026] Preferably, the polymer is selected from at least one of polylactic acid, a copolymer of polylactic acid, polyvinylidene fluoride, a copolymer of polyvinylidene fluoride, polyurethane, polycarbonate, a copolymer of polycarbonate, polycaprolactone, a copolymer of polycaprolactone, polyvinyl alcohol, a copolymer of polyvinyl alcohol, polymethyl methacrylate, and a copolymer of polymethyl methacrylate.

[0027] Preferably, the solvent comprises at least one of hexafluoroisopropanol, N,N-dimethylformamide, dichloromethane, and tetrahydrofuran.

[0028] Preferably, the mass ratio of the inorganic ferroelectric material to the polymer is 1:(5-100);

[0029] The total mass of the inorganic ferroelectric material and the polymer in the electrospinning solution accounts for 1%-20% of the mass of the electrospinning solution.

[0030] Preferably, the electrospinning conditions are as follows: voltage 6-7 kV, receiving distance between the needle and the receiver 10-12 cm, solution flow rate 0.4-0.8 mL / h, temperature 20-25 °C, and humidity 30%-40%.

[0031] Preferably, in step A), the mixing is stirring mixing.

[0032] The stirring mixing conditions are as follows: rotation speed 50-500 rpm and time 3-24 h.

[0033] Preferably, in step B), drying is further performed after electrospinning.

[0034] The thickness of the composite ferroelectric fiber membrane material is 30-200 μm.

[0035] The application also provides a visible light responsive inorganic-polymer composite ferroelectric material prepared by the preparation method.

[0036] The preparation method provided by the application first mixes certain inorganic ferroelectric material, polymer, and solvent, and then performs electrospinning on the mixture to obtain a composite ferroelectric fiber membrane material. During the electrospinning process, there is a certain pre-polarization effect, and the effect of the ferroelectric composite material is achieved. The preparation method can simplify the process, realize the regulation of the composite material at the nanoscale, and achieve the polarization effect while preparing the sample, without the need for subsequent polarization processes. In the prior art, after obtaining the mixture, the following steps need to be performed: casting into a film, drying, annealing, soaking in an acid solution, washing, drying, and corona polarization. In the application, only electrospinning and drying need to be performed after obtaining the mixture, which greatly simplifies the process flow. Meanwhile, in terms of product performance, the specific ABO2 narrow-band-gap inorganic ferroelectric material and the polymer are used in the application, which can achieve response under visible light conditions, catalyze H2O to generate ROS to play an antibacterial role, greatly improve the antibacterial rate on the basis of the prior art, greatly simplify the application conditions for visible light, and do not need to provide an external light source.

[0037] The experimental results show that the prepared composite ferroelectric material has the maximum open circuit voltage of more than 1.3 V in the piezoelectric performance test; the antibacterial rate under visible light is obviously improved and reaches more than 88% in the antibacterial test; the survival rate of mice reaches 100% in the skin breakage infection experiment, and the average wound healing rate reaches more than 80% at the 7th day, more than 90% at the 10th day and 100% at the 14th day. The above results prove that the ferroelectric composite material has excellent piezoelectric performance, visible light responsiveness and antibacterial property, and promotes the skin repair effect. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by the provided drawings without creative labor for those skilled in the art.

[0039] Figure 1 Fig. 1 is an SEM image of the sample in Example 1; wherein, Figure 1 (a) is an SEM image of the control sample (PLLA group), Figure 1 (b) is an SEM image of the experimental sample (PLLA / CGO group);

[0040] Figure 2 Fig. 3 is an effect diagram of the antibacterial test in Example 1;

[0041] Figure 3 Fig. 4 is a test effect diagram of the skin breakage infection experiment in Example 1. DETAILED DESCRIPTION

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application.

[0043] In this document, the technical features described in an open manner include both the closed technical solutions consisting of listed features and the open technical solutions containing listed features.

[0044] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0045] In this text, when referring to a numerical interval, unless otherwise specified, the numerical interval is considered to be continuous and includes the minimum and maximum values of the range, as well as every value between such minimum and maximum values. Further, when the range refers to integers, every integer between the minimum and maximum values of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein are to be understood as including any and all sub-ranges subsumed therein.

[0046] In this text, when referring to a numerical interval, unless otherwise specified, the numerical interval is considered to be continuous and includes the minimum and maximum values of the range, as well as every value between such minimum and maximum values. Further, when the range refers to integers, every integer between the minimum and maximum values of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein are to be understood as including any and all sub-ranges subsumed therein.

[0047] In this text, when referring to a numerical interval, unless otherwise specified, the numerical interval is considered to be continuous and includes the minimum and maximum values of the range, as well as every value between such minimum and maximum values. Further, when the range refers to integers, every integer between the minimum and maximum values of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein are to be understood as including any and all sub-ranges subsumed therein.

[0048] The present application provides a preparation method of a visible light responsive inorganic-polymer composite ferroelectric material, comprising the following steps:

[0049] A) mixing an inorganic ferroelectric material, a polymer and a solvent to obtain an electrospinning solution;

[0050] B) electrospinning the electrospinning solution to obtain a composite ferroelectric fiber membrane material;

[0051] wherein,

[0052] The inorganic ferroelectric material is an ABO2 series ferroelectric phase material.

[0053] [About step A]:

[0054] A) mixing an inorganic ferroelectric material, a polymer and a solvent to obtain an electrospinning solution.

[0055] In the present application, the inorganic ferroelectric material is an ABO2 series ferroelectric phase material.

[0056] In the present application, preferably, the inorganic ferroelectric material is selected from at least one of CuBO2, AgBO2, CuAlO2, AgAlO2, AuAlO2, CuGaO2, AgGaO2, NaFeO2, KFeO2, RbFeO2, CuFeO2, AgFeO2, AuFeO2, LiBiO2, NaPO2, AgBiO2, LiRE1O2, NaRE2O2, KRE3O2, RbRE4O2, CsRE5O2, CuRE6O2, AgRE7O2, AuRE8O2; wherein RE1 is selected from Y, Ce, Pr, Nd, Eu, Gd, Tb, Dy or Lu; RE2 is selected from Sc, Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Tm, Yb or Lu; RE3 is selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu; RE4 is selected from Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu; RE5 is selected from Y, Ce, Nd, Sm, Tb, Dy, Er, Tm, Yb or Lu; RE6 is selected from Y, Pr, Nd, Eu, Dy, Ho, Er, Tm, Yb or Lu; RE7 is selected from Sc, La, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu; and RE8 is selected from Sc, Ho, Er, Tm, Yb or Lu; wherein in CuBO2 and AgBO2, B is boron.

[0057] The present application adopts the above-mentioned ABO2 series ferroelectric phase material, which has a non-centrosymmetric derivative wurtzite structure (Pna21) to ensure the ferroelectric property, and the polarization intensity is between 40-195 μC / cm 2 ; and at the same time, has the characteristics of narrow band gap, and the band gap is adjustable in the range of 1.0-3.1 eV, can realize full spectrum absorption, and is convenient for responding under visible light conditions, greatly simplifying the application conditions. In the present application, most preferably, the inorganic ferroelectric material is at least one of CuGaO2 (abbreviation CGO, copper gallium oxide), AgGaO2 (abbreviation AGO, silver gallium oxide), CuFeO2 (abbreviation CFO, copper iron oxide) and AgFeO2 (abbreviation AFO, silver iron oxide).

[0058] In the present application, the inorganic ferroelectric material is a nanomaterial, and the particle size is preferably 200-800 nm.

[0059] In the present application, the polymer is preferably at least one of polylactic acid, a copolymer of polylactic acid, polyvinylidene fluoride, a copolymer of polyvinylidene fluoride, polyurethane, polycarbonate, a copolymer of polycarbonate, polycaprolactone, a copolymer of polycaprolactone, polyvinyl alcohol, a copolymer of polyvinyl alcohol, polymethyl methacrylate and a copolymer of polymethyl methacrylate. The present application uses the above-mentioned polymer in combination with inorganic ferroelectric materials, which can be polarized under a strong electric field, and the polarization effect is realized at the same time as the sample is prepared, without the need for an additional separate polarization process, simplifying the process. The above-mentioned inorganic ferroelectric materials and polymers are combined, which can respond under visible light conditions, catalyze H2O to generate ROS to play an antibacterial role, greatly improving the antibacterial rate on the basis of the prior art. Moreover, the use of visible light greatly simplifies the application conditions, without the need for an external light source.

[0060] In the present application, the weight average molecular weight of the polymer is preferably 40,000-80,000, and can be 40,000, 50,000, 60,000, 70,000 or 80,000.

[0061] In the present application, the mass ratio of the inorganic ferroelectric material to the polymer is preferably 1:(5-100), and can be 1:5, 1:6.7, 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, 1:55, 1:60, 1:65, 1:70, 1:75, 1:80, 1:85, 1:90, 1:95 or 1:100.

[0062] In the present application, the solvent preferably includes at least one of hexafluoroisopropanol (HFIP), N,N-dimethylformamide (DMF), dichloromethane (DCM) and tetrahydrofuran. The above-mentioned solvent can dissolve the ferroelectric polymer and meet the film preparation requirements.

[0063] In the present application, the amount of the solvent is preferably such that the mass ratio of the total mass of the inorganic ferroelectric material and the polymer in the electrospinning solution is 1%-20%, and can be 1%, 5%, 6%, 7%, 8%, 9%, 10%, 15% or 20%.

[0064] In the present application, the mixing method of the inorganic ferroelectric material, the polymer and the solvent is preferably stirring mixing. In the present application, the stirring mixing conditions are preferably a rotation speed of 50-500 rpm and a time of 3-24 h. More preferably, the rotation speed is 80-100 rpm. After the above-mentioned mixing, the polymer is completely dissolved, and the inorganic ferroelectric material is uniformly dispersed in the polymer solution, thereby obtaining an electrospinning solution.

[0065] [About step B]:

[0066] B) electrospinning the electrospinning solution to obtain a composite ferroelectric fiber film material.

[0067] In the present application, the electrospinning conditions are preferably as follows: voltage 6-7 kV, receiving distance between needle and receiver 10-12 cm, solution flow rate 0.4-0.8 mL / h, temperature 20-25℃, humidity 30%-40%. Specifically, the voltage can be 6.0 kV, 6.5 kV, or 7.0 kV. Specifically, the receiving distance can be 10 cm, 11 cm, or 12 cm. Specifically, the solution flow rate can be 0.4 mL / h, 0.5 mL / h, 0.6 mL / h, 0.7 mL / h, or 0.8 mL / h. Specifically, the temperature can be 20℃, 21℃, 22℃, 23℃, 24℃, or 25℃. Specifically, the humidity (i.e. relative humidity) can be 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, or 40%. The receiver can be a flat plate receiver or a roller receiver. Specifically, the roller receiver has a rotation speed of 50-200 r / min, which can be 50 r / min, 100 r / min, 150 r / min, or 200 r / min.

[0068] In the present application, the thickness of the fiber membrane obtained by electrospinning is preferably 30-200 μm, more preferably 60-100 μm, and specifically can be 60 μm, 70 μm, 80 μm, 90 μm, or 100 μm.

[0069] In the present application, after the above electrospinning, drying is preferably performed. In the present application, the drying is vacuum drying or ordinary drying (i.e. non-vacuum drying in a conventional oven). The conditions for vacuum drying are preferably as follows: temperature 20-25℃, time 6-12 h. The conditions for ordinary drying are preferably as follows: temperature 50-70℃, time 6-12 h. After the above drying, residual solvent is removed, thereby obtaining a composite ferroelectric fiber membrane material.

[0070] The present application utilizes the multifunctionality of inorganic ferroelectric materials, such as piezoelectricity, thermoelectricity, nonlinear optics, and ferroelectric photovoltaic characteristics, as well as the flexibility and biocompatibility of polymer materials. An inorganic / polymer composite ferroelectric material is prepared by electrospinning, so that it has multi-source responsiveness characteristics such as force, light, and electricity, and achieves the goals of antibiosis and promotion of skin repair.

[0071] The present application also provides a composite ferroelectric fiber membrane material prepared by the preparation method described in the above technical solution.

[0072] The present application also provides the use of the composite ferroelectric fiber membrane material described in the above technical solution in the preparation of an antibacterial material.

[0073] The present application also provides the use of the composite ferroelectric fiber membrane material described in the above technical solution in the preparation of a repair-promoting material.

[0074] The application further provides application of the composite ferroelectric fiber membrane material in the technical scheme to antibiosis / repair promotion under multi-source response.

[0075] The preparation method provided by the application mixes certain inorganic ferroelectric material, polymer and solvent, uses the hydrogen bond or chelation between the oxygen atoms of the ABO2 series ferroelectric phase and the polymer chain, and the solution mixing can obtain a uniformly dispersed mixed solution. Then electrospinning is performed on the mixed solution, so as to obtain the composite ferroelectric fiber membrane material. In the electrospinning process, there is a certain pre-polarization effect, and the effect of the ferroelectric composite material is achieved. The preparation method can simplify the process, realize the regulation of the composite material at the nanoscale, and realize the polarization effect while preparing the sample, without the subsequent polarization process. In the prior art, after obtaining the mixed solution, the following steps need to be performed: casting into a film, drying, annealing, soaking in an acid solution, washing, drying and corona polarization. In the application, after obtaining the mixed solution, only electrospinning and drying need to be performed, so that the process flow is greatly simplified. Meanwhile, in terms of product performance, the specific ABO2 narrow-band-gap inorganic ferroelectric material and the polymer are matched, the response under visible light can be realized, H2O is catalyzed to generate ROS to play an antibacterial role, and the antibacterial rate is greatly improved on the basis of the prior art. The use of visible light greatly simplifies the application conditions, and an external light source is not needed.

[0076] The experimental results show that the composite ferroelectric material prepared by the application has a maximum open-circuit voltage of more than 1.3 V in the piezoelectric performance test, the antibacterial rate under visible light is obviously improved and reaches more than 88% in the antibacterial test, the survival rate of mice reaches 100% in the skin damage infection experiment, the average wound healing rate reaches more than 80% at the 7th day, more than 90% at the 10th day and 100% at the 14th day. The above results prove that the ferroelectric composite material has excellent piezoelectric performance, visible light responsiveness and antibacterial property, and can promote skin repair.

[0077] In order to further understand the application, the preferred embodiments of the application are described below in combination with examples, but it should be understood that the description is only for further illustrating the features and advantages of the application, and is not a limitation on the claims of the application.

[0078] Example 1

[0079] 1. Raw materials: copper gallium oxide (CuGaO2, CGO), particle size 300-600 nm; left-handed polylactic acid (PLLA), brand revode110, molecular weight 5w; hexafluoroisopropanol (HFIP).

[0080] 2. Preparation of samples

[0081] A) CGO and PLLA (CGO: PLLA mass ratio = 1:10) were weighed into a sample bottle, solvent HFIP (7% of the mass of CGO and PLLA and 7% of the total system mass) was added, a magnetic stirrer was placed in the sample bottle, the sample bottle was placed on a magnetic stirrer, and stirring was carried out at 100 rpm for 10 h. PLLA was completely dissolved and CGO was uniformly dispersed in the polymer solution to obtain an electrospinning solution.

[0082] B) The electrospinning solution was sucked into a 10 mL syringe, a spinning needle was connected, and the electrospinning device was placed on a flat plate receiver. The electrospinning conditions were as follows: voltage 6.5 kV, receiving distance between the needle and the receiver 11 cm, solution flow rate 0.6 mL / h, temperature 25°C, and humidity 35%. The obtained fiber film had a thickness of 80 μm. Then, the obtained fiber film was placed in an oven and dried at 60°C for 10 h to remove residual solvent to obtain a composite ferroelectric fiber film material (denoted as the PLLA / CGO group).

[0083] Preparation of a control sample:

[0084] The above steps A) to B) were implemented, except that no CGO was added in step A). Finally, a fiber film material was obtained (denoted as the PLLA group).

[0085] 3. Product testing

[0086] (1) SEM characterization

[0087] The control sample (PLLA group) and the experimental sample (PLLA / CGO group) were respectively characterized by scanning electron microscopy, and the results are shown in Figure 1 , wherein, Figure 1 (a) is the SEM image of the control sample (PLLA group), Figure 1 (b) is the SEM image of the experimental sample (PLLA / CGO group). It can be seen that the PLLA and PLLA / CGO fibers are uniformly distributed, and CGO is uniformly distributed in the PLLA fibers.

[0088] (2) Piezoelectric property testing

[0089] The piezoelectric performance is affected by the polarization of the material, so the fiber film is pre-polarized before testing the piezoelectric performance. The polarization is performed by using two copper foils with an area smaller than that of the fiber film, which are attached to the two sides of the fiber film. Two wires are attached to the two copper foils, one of which is connected to the ground, and the other of which is connected to a voltage of 35V. The polarization is performed for 2min at a temperature of 25℃. After polarization, polyimide (PI) tape is attached to the two sides of the fiber film to cover the copper foils, and the preparation of the fiber film sample to be tested is completed. The fiber film sample to be tested is tightly attached to the vertical sample stage, and a linear motor is used to apply a constant frequency and constant amount of force to the fiber film. The two wires on the sample are connected to the electrochemical workstation to measure the open-circuit voltage signal generated by the fiber film in response to the force.

[0090] The results show that the highest open-circuit voltage of the experimental sample (PLLA / CGO group) can reach 5V, while the highest open-circuit voltage of the control sample (PLLA group) is only 1V. It is proved that the piezoelectric performance of the experimental sample (PLLA / CGO group) is significantly improved compared with the control sample (PLLA group), which further proves that the CGO particles are successfully loaded in the PLLA, and the compatibility between PLLA and CGO is good, which can complete the conduction of electrons and exhibit excellent piezoelectric performance. The improvement of piezoelectricity is beneficial to the electric stimulation of cells, which promotes skin repair (as described in the background art: the electric stimulation generated by the ferroelectric material can reduce edema around the electrode; stimulate granular tissue growth; increase blood flow, fibroblast proliferation and collagen production; induce epidermal cell migration; promote epithelial growth and tissue formation to shorten inflammation and promote skin regeneration), and the surface charging of the material caused by piezoelectricity is also beneficial to the antibacterial performance.

[0091] (3) Antibacterial test

[0092] The PLLA group fiber film and the PLLA / CGO group fiber film were co-cultured with Staphylococcus aureus, and two conditions of light avoidance (DARK) and indoor LED lamp irradiation (LIGHT) were set. After 24h, the bacterial growth activity and structural changes were detected, and the antibacterial rate was analyzed. At the same time, the blank without film was used as a blank control group (CONTROL group).

[0093] The results are as follows Figure 2As shown, it can be seen that the PLLA / CGO ferroelectric composite fiber film can achieve an antibacterial rate of 50% under dark conditions, and can achieve an antibacterial rate of more than 90% under visible light irradiation, and the antibacterial properties under the two conditions are obviously improved compared with the CONTROL group and the PLLA group. At the same time, the antibacterial rate of the PLLA / CGO ferroelectric composite fiber film of the application is further significantly improved under visible light irradiation compared with dark conditions, proving that the composite ferroelectric material of the application has high responsiveness to visible light. Moreover, the SEM image of the bacteria shows that the structure of the bacteria under the action of the composite ferroelectric fiber film changes obviously, and holes appear in the bacterial cell membrane, proving that the composite ferroelectric fiber film catalytically produces ROS to act on the bacterial cell membrane to cause its death, thereby achieving high-efficiency antibacterial effect.

[0094] (4) Skin breakage infection experiment

[0095] The mice were adaptively fed for 7 days, anesthetized with pentobarbital with a concentration of 1%, and injected with a dose of 50 mg / kg. After the mice were shaved, a circular full-thickness skin wound (Φ10 mm) was prepared on the back of each mouse, and then 20 μL of Staphylococcus aureus solution (10 7 CFU / mL) was evenly applied to the wound area twice, and a gas-impermeable plastic film was fixed. After 24 h, it was observed whether the model was successfully constructed (success sign: pus was observed at the wound site). After the model was successfully constructed, the ferroelectric fiber composite film was added to the wound for treatment, and a 3M Tegaderm transparent and breathable dressing was used for fixation. The blank group (CONTROL group) was consistent with the control conditions and the experimental group except that no material was placed. The change in the wound diameter of the mice was recorded daily, and the recording was recorded to the 14th day.

[0096] The results are shown in Figure 3 and Table 1.

[0097] Table 1: Test effect of skin breakage infection experiment

[0098]

[0099] As can be seen from the test results, the blank group and the PLLA group can be seen to have obvious purulent infection in the first four days, and the composite ferroelectric material PLLA / CGO group has a clean wound without pus. On the 10th day, the wound of the mouse in the composite ferroelectric material PLLA / CGO group has healed, while the blank group and the PLLA group still have obvious wounds.

[0100] The mice were killed after 14 days of treatment. The wound area tissue was fixed with paraformaldehyde, and HE staining and Masson staining were used to observe the histopathological changes; immunofluorescence was used to detect the expression of CD31 in the tissue. The HE staining results showed that more inflammatory cells appeared in the blank group and the PLLA group, and the inflammatory cells in the ferroelectric composite material group were significantly less, indicating that the ferroelectric composite material can significantly inhibit the inflammatory process during wound repair and thus promote wound repair; the Masson staining results showed that obvious fibrous deposition appeared in the wound tissues of the three groups, and fibrous deposition can promote wound healing, while in the composite ferroelectric material group, the surface muscle fibers were repaired completely, while in the blank group and the PLLA group, there were still defects, indicating that the wound repair effect of the composite ferroelectric material group was the best; the CD31 staining results showed that the CD31 staining in the composite ferroelectric material group was significantly more than that in the other two groups, indicating that the composite ferroelectric material can promote angiogenesis in the wound site, thereby accelerating the wound repair process.

[0101] Examples 2-35

[0102] According to the method of Example 1, except that the types and proportions of raw materials were adjusted, see Table 2.

[0103] Table 2: Types and proportions of raw materials in Examples 2-35

[0104]

[0105] Examples 2-35 were tested according to the test method in Example 1, and the results are shown in Table 3. The test results of Example 1 are also summarized in Table 3.

[0106] Table 3: Test results of Examples 1-35

[0107]

[0108] It can be seen that the composite ferroelectric material prepared in the present application has a maximum open circuit voltage of more than 1.3V in the piezoelectric performance test; the antibacterial rate under visible light is significantly improved, reaching more than 88%; in the skin damage infection experiment, the survival rate of mice reaches 100%, and the average wound healing rate reaches more than 80% on the 7th day, more than 90% on the 10th day, and 100% on the 14th day. The above results prove that the ferroelectric composite material of the present application has excellent piezoelectric performance, visible light responsiveness and antibacterial properties, and promotes skin repair effect.

[0109] The principles and implementations of the present application are described herein with specific examples, and the above descriptions of the examples are only used to help understand the method of the present application and its core ideas, including the best mode, and also enable any person skilled in the art to practice the present application, including manufacturing and using any device or system, and implementing any combined method. It should be noted that, for those skilled in the art, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application. The scope of patent protection of the present application is defined by the claims, and can include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to the literal expressions of the claims, or if they include equivalent structural elements that are not substantially different from the literal expressions of the claims, then these other embodiments should also be included within the scope of the claims.

Claims

1. A method for preparing a visible light-responsive inorganic-polymer composite ferroelectric material, characterized in that, Includes the following steps: A) Inorganic ferroelectric materials, polymers and solvents are mixed to obtain an electrospinning solution; B) Electrospinning the electrospinning solution to obtain a composite ferroelectric fiber membrane material; in, The inorganic ferroelectric material is selected from at least one of CuBO2, AgBO2, CuAlO2, AgAlO2, AuAlO2, CuGaO2, AgGaO2, NaFeO2, KFeO2, RbFeO2, CuFeO2, AgFeO2, AuFeO2, LiBiO2, NaPO2, AgBiO2, LiRE1O2, NaRE2O2, KRE3O2, RbRE4O2, CsRE5O2, CuRE6O2, AgRE7O2, and AuRE8O2. in, The RE1 in the LiRE1O2 is selected from Y, Ce, Pr, Nd, Eu, Gd, Tb, Dy or Lu; The RE2 in NaRE2O2 is selected from Sc, Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Tm, Yb or Lu; The RE3 in KRE3O2 is selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu; The RE4 in RbRE4O2 is selected from Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu; The RE5 in CsRE5O2 is selected from Y, Ce, Nd, Sm, Tb, Dy, Er, Tm, Yb or Lu; The RE6 in CuRE6O2 is selected from Y, Pr, Nd, Eu, Dy, Ho, Er, Tm, Yb or Lu; The RE7 in AgRE7O2 is selected from Sc, La, Gd, Tb, Dy, Ho, Er, Tm, Yb or Lu; The RE8 in AuRE8O2 is selected from Sc, Ho, Er, Tm, Yb or Lu.

2. The preparation method according to claim 1, characterized in that, The particle size of the inorganic ferroelectric material is 200–800 nm.

3. The preparation method according to claim 1, characterized in that, The polymer is selected from at least one of polylactic acid, copolymers of polylactic acid, polyvinylidene fluoride, copolymers of polyvinylidene fluoride, polyurethane, polycarbonate, copolymers of polycarbonate, polycaprolactone, copolymers of polycaprolactone, polyvinyl alcohol, copolymers of polyvinyl alcohol, polymethyl methacrylate, and copolymers of polymethyl methacrylate.

4. The preparation method according to claim 1, characterized in that, The solvent includes at least one of hexafluoroisopropanol, N,N-dimethylformamide, dichloromethane, and tetrahydrofuran.

5. The preparation method according to claim 1, characterized in that, The mass ratio of the inorganic ferroelectric material to the polymer is 1:(5-100); The total mass of the inorganic ferroelectric material and the polymer accounts for 1% to 20% of the mass of the electrospinning solution.

6. The preparation method according to claim 1, characterized in that, The conditions for electrospinning are: voltage 6-7 kV, receiving distance between needle and receiver 10-12 cm, solution flow rate 0.4-0.8 mL / h, temperature 20-25 °C, and humidity 30%-40%.

7. The preparation method according to claim 1, characterized in that, In step A), the mixing is a stirring mixture; The mixing conditions are: 50-500 rpm for 3-24 hours.

8. The preparation method according to claim 1, characterized in that, In step B), drying is also performed after electrospinning; The thickness of the composite ferroelectric fiber membrane material is 30–200 μm.

9. A visible light-responsive inorganic-polymer composite ferroelectric material prepared by the preparation method according to any one of claims 1 to 8.

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