Rare earth bioprotein fiber, preparation method and application thereof

Abstract

The present invention relates to the field of biotechnology, and in particular to rare earth bioprotein fibers, their preparation methods, and applications. The bioprotein fibers described herein are synthesized using a direct doping method using rare earth nanoparticles and silk fibroin as raw materials. Test results demonstrate that the bioprotein fibers exhibit both high photothermal efficiency and mechanical properties, providing a novel strategy for the development of new, high-performance photothermal fibers. These fibers can be widely used in the preparation of specialized outdoor thermal insulation equipment for extreme environments.

Description

Technical Field

[0001] The present invention relates to the field of biotechnology, in particular to rare earth biological protein fiber, a preparation method and application thereof. Background Art

[0002] Fiber materials play a vital role in the national economy and people's livelihood. In today's world of increasing resource and energy scarcity and frequent extreme weather events, biofibers with high mechanical properties and thermal management capabilities represent a future development trend, with significant implications for protecting personal health and national equipment safety.

[0003] Current photothermal fibers can be categorized as either active or passive. Passive thermal regulation achieves thermal regulation without relying on external energy, relying solely on the body's own heat production and dissipation. Active thermal regulation uses external energy input to assist in heating or cooling the body. However, these scenarios still require electrical power, making them difficult to apply under extreme conditions. Currently, research on fiber materials and thermal storage devices that directly utilize sunlight for efficient photothermal conversion remains limited. For example, photothermal fibers have been prepared and woven using materials such as silk fibroin and polydopamine (PDA) composite fibers and carbon fiber@MXene. However, the photothermal fibers used in these studies have poor mechanical properties, below 200 MPa, and a photothermal efficiency of only approximately 30%. Therefore, the development of high-performance rare earth biofibers with broad-spectrum photothermal conversion capabilities could provide new material support for the development of thermal storage and insulation equipment for extreme conditions. Summary of the Invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide rare earth bioprotein fiber, its preparation method and application.

[0005] The present invention provides biological protein fibers, the raw materials of which include rare earth nanoparticles and silk fibroin;

[0006] The rare earth nanoparticles are NaNdF4 modified with Teng's blue or Bruce's blue;

[0007] The mass ratio of the rare earth photothermal nanoparticles to the silk fibroin is (0.1-1.5): (10-20);

[0008] In the present invention, the rare earth photothermal nanoparticles are NaNdF4 modified with Teng's blue or Bruce's blue; Fe 2+ With [Fe(CN)6] 4- Reaction, forming a dark blue precipitate, which is Prussian blue; Fe 2+ With [Fe(CN)6] 3-The reaction produces a dark blue color, Teng's blue; the two products exhibit similar colors (blue) and contain exactly the same chemical elements and chemical formulas. X-ray, magnetic susceptibility, photoelectron spectroscopy, and Mössbauer spectroscopy measurements show that the two have the same or substantially the same properties. In the present invention, the two can be used interchangeably. In the actual reaction, potassium ferrocyanide K4Fe(CN)6 contains the ferrocyanide complex ion [Fe(CN)6] 4- , and Fe 2+ The blue product obtained by the reaction is Prussian blue; potassium ferrocyanide K3Fe(CN)6 contains ferrocyanide complex ion [Fe(CN)6] 3− , and Fe 2+ The blue product obtained by the reaction is Teng's blue. In a specific embodiment of the present invention, potassium ferrocyanide is used to carry out the reaction to obtain Teng's blue.

[0009] Furthermore, the mass ratio of the rare earth nanoparticles to the silk fibroin is (0.1-1.5):(10-20); furthermore, (0.5-1.5):15.

[0010] In the present invention, the mass ratio of rare earth nanoparticles to silk fibroin is (0.1~1.5):(10~20); in a specific embodiment of the present invention, the mass ratio of rare earth nanoparticles to silk fibroin can be 0.5:15; it can also be 1:15; it can also be 1.5:15; experimental results show that when the mass ratio of rare earth nanoparticles to silk fibroin is 1:15, it has high photothermal efficiency and high mechanical strength at the same time, wherein the photothermal efficiency can reach 56%, and the mechanical strength can reach 512±27 MPa.

[0011] The rare earth nanoparticles have a particle size of 180nm to 220nm and a cluster-like morphology;

[0012] The rare earth nanoparticles are NaNdF4 modified with Teng's blue.

[0013] In the present invention, the silk fibroin can be homemade or purchased, and the present invention is not limited to this; further, in a specific embodiment of the present invention, the silk fibroin is obtained by degumming silk, which is a conventional technical means adopted by those skilled in the art; further, specifically, the preparation steps of the silk fibroin are: cutting tussah silkworm pupae into pieces, immersing them in a 0.5wt% sodium carbonate solution at a ratio of 10g / L, boiling for 30 minutes, washing and drying, to obtain degummed silk, which is the silk fibroin described in the present invention.

[0014] In the present invention, the photothermal protein fibers described herein can be prepared by direct doping of the nanoparticles obtained by direct Tengger's Blue modification with silk fibroin, or by in-situ Tengger's Blue modification of unmodified NaNdF4 during the spinning process. This is not a limitation of the present invention. Experimental results indicate that the performance of photothermal protein fibers prepared using the direct doping method is slightly superior to that obtained using the in-situ modification method.

[0015] The present invention provides a method for preparing the biological protein fiber, which comprises the following steps:

[0016] The rare earth nanoparticles and silk fibroin are wet-spun in the presence of a cosolvent and an organic acid to prepare the bioprotein fiber.

[0017] The co-solvents include CaCl2 and LaCl3.

[0018] The mass concentration ratio of the rare earth nanoparticles, silk fibroin, CaCl2 and LaCl3 is (0.1~1.5): (10~20): 2:2; more specifically, in an embodiment of the present invention, the mass concentration ratio of the rare earth nanoparticles, silk fibroin, CaCl2 and LaCl3 is (0.1~1.5): 15: 2:2; more specifically, the mass concentration ratio of the rare earth nanoparticles, silk fibroin, CaCl2 and LaCl3 is 0.5:15:2:2 or 1:15:2:2 or 1.5:15:2:2; experimental results show that when the mass ratio of rare earth nanoparticles and silk fibroin is 1:15, it has high photothermal efficiency and high mechanical strength at the same time, wherein the photothermal efficiency can reach 56% and the mechanical strength can reach 512±27 MPa.

[0019] The organic acid is formic acid.

[0020] The wet spinning extrusion speed is 10-40 μL / min;

[0021] The coagulation liquid for wet spinning is a mixture of ethanol and water, wherein the ethanol content is 30vt% to 70vt%.

[0022] In the present invention, CaCl2‌ helps silk fibroin dissolve in a specific solvent to form a uniform solution during the dissolution and regeneration process of silk fibroin, which is very important for the subsequent spinning step; LaCl3‌ and CaCl2 work synergistically to promote the dissolution of silk fibroin in the solvent, and may also affect the molecular structure and arrangement of silk fibroin, thereby affecting the performance of the final fiber; formic acid, as an organic acid, may help adjust the pH value of the solution, thereby affecting the solubility and molecular structure of silk fibroin. Therefore, CaCl2, LaCl3 and formic acid work together in the process of silk fibroin spinning to affect the spinning effect.

[0023] The wet spinning step further includes a stretching step, wherein the stretched length is 0% to 600% of the original filament length.

[0024] Furthermore, in the present invention, the method for preparing the rare earth nanoparticles comprises the following steps:

[0025] Step 1: mixing neodymium salt in a mixed solvent of oleic acid and octadecene, and then reacting with a sodium source and a fluorine source to obtain NaNdF4;

[0026] Step 2: mixing the NaNdF4 and NOBF4, centrifuging, collecting the precipitate, and modifying the precipitate with citric acid to obtain NaNdF4@CA;

[0027] Step 3: The NaNdF4@CA reacts with cyanide in the presence of FeSO4 and citric acid to obtain the rare earth nanoparticles.

[0028] Further,

[0029] In step 1,

[0030] The neodymium salt includes at least one of NdCl3, Nd(NO3)3, Nd(CH3CO2)3, Nd(TFA)3 or Nd(ACAC)3; specifically, the neodymium salt is NdCl3;

[0031] The sodium source includes at least one of sodium oleate, NaF, NaTFA or NaOA; specifically, the sodium source is sodium oleate;

[0032] The fluorine source includes any one of NH4F or NaF; specifically, the fluorine source is NH4F;

[0033] In the mixed solvent of oleic acid and octadecene, the volume ratio of oleic acid to octadecene is 3:7;

[0034] The molar ratio of the neodymium salt, the sodium source, and the fluorine source is: (0.5-1.5): (3-4): (1-1.5); specifically, 1:3.3:1.25. In a specific embodiment of the present invention, NdCl3 is dissolved in oleic acid and octadecene to a final concentration of 1 mmol, and then NH4F and sodium oleate are added to achieve a NH4F concentration of 3.3 mmol and a sodium oleate concentration of 1.25 mmol after addition.

[0035] The conditions of the first reaction are: heating to 110°C in vacuum and then heating to 310°C under N2 protection and maintaining for 40 min;

[0036] The precipitation reagent is anhydrous ethanol;

[0037] The method further comprises a first washing step after the precipitation; the reagent for the first washing comprises ethanol and / or cyclohexane, and specifically, washing is performed using ethanol and cyclohexane in sequence.

[0038] In step 2,

[0039] The mass ratio of NaNdF4 to NOBF4 is (25~30):(3~8). Specifically, in a specific embodiment of the present invention, the mass ratio of NaNdF4 to NOBF4 is 27.273:(3.6~7.27), and 1 mL of N,N-dimethylformamide (DMF) solution containing 40~80 mg / mL NOBF4 is added to 10 mL of n-hexane solution containing 300 mg NaNdF4; more specifically, in a specific embodiment of the present invention, the mass concentration ratio of NaNdF4 to NOBF4 is 27.273:5.455, and 1 mL of N,N-dimethylformamide (DMF) solution containing 60 mg / mL NOBF4 is added to 10 mL of n-hexane solution containing 300 mg NaNdF4.

[0040] The conditions for the citric acid modification are immersing in a citric acid solution and ultrasonicating for 30 minutes;

[0041] The concentration of the citric acid solution is 50% to 64.3%. In a specific embodiment of the present invention, it is a saturated citric acid solution with a specific concentration of 64.3%.

[0042] In step 3,

[0043] The mass ratio of the NaNdF4@CA, FeSO4, citric acid and K3Fe(CN)6 is (0.01~0.1):(3~4):(4~5.5):(7.5~9); in a specific embodiment of the present invention, the mass ratio of the NaNdF4@CA, FeSO4, citric acid and K3Fe(CN)6 is 0.06:3.8:4.803:8.225; 1 mL of 60 mg / L NaNdF4@CA solution is added to 50 mL of water, 5 mL of an aqueous solution of FeSO4 and CA is added, and then 5 mL of an aqueous solution of K3Fe(CN)6 (potassium ferrocyanide) with the same concentration as FeSO4 is added. The concentrations of FeSO4 and CA before addition are preferably 5 mM FeSO4 and 0.09M CA.

[0044] The cyanide is potassium ferrocyanide and / or potassium ferrocyanide; if the cyanide is potassium ferrocyanide, the rare earth nanoparticles are NaNdF4 modified with Teng's blue; if the cyanide is potassium ferrocyanide, the rare earth nanoparticles are NaNdF4 modified with Bruce's blue; in a specific embodiment of the present invention, the cyanide is potassium ferrocyanide.

[0045] After the reaction with cyanide, the process further includes the steps of centrifugation and washing, wherein the washing solution is a mixture of water and acetone, wherein the content of acetone is 30vt% to 70vt%, specifically, the content of acetone is 50vt%.

[0046] In the present invention, the mixed solution can be extruded into a coagulation solution for spinning and then post-stretched, with the stretching length being 0% to 600% of the original filament length, to obtain the bioprotein fiber of the present invention.

[0047] The present invention optimizes the preparation method of the biological protein fiber. In a specific embodiment of the present invention, the biological protein fiber is prepared by an in-situ modification method and a direct doping method. Experimental results show that the biological protein fiber obtained by the direct doping method has higher strength, better toughness and modulus, and better photothermal efficiency.

[0048] In other specific embodiments of the present invention, the mass ratio of silk fibroin to rare earth nanoparticles is optimized. In specific embodiments of the present invention, the mass ratio of silk fibroin to rare earth nanoparticles can be 15:0.5; 15:1; or 15:1.5. Experimental results show that when the mass ratio of silk fibroin to rare earth nanoparticles is 15:1, the photothermal efficiency is the highest and the mechanical strength is high, wherein the photothermal efficiency can reach 56% and the mechanical strength can reach 512±27MPa.

[0049] This invention primarily utilizes silk fibroin structural assembly for fiber formation. The introduction of inorganic nanoparticles (the rare earth nanoparticles in this invention are inorganic nanoparticles) typically interferes with protein structural assembly, leading to reduced performance, particularly during in-situ synthesis. By manipulating the process, this invention achieves synergistic mechanical and photothermal performance. In specific embodiments of the invention, adjustments are made to the bioprotein fiber preparation method, and the corresponding rare earth nanoparticle preparation method is also adaptively modified. Furthermore, adjustments are made to the doping concentrations of the rare earth nanoparticles and silk fibroin to produce the bioprotein fiber of this invention, exhibiting both photothermal and mechanical properties.

[0050] The present invention provides a photothermal nanocomposite material, which comprises at least one of the bioprotein fibers of the present invention and / or the bioprotein fibers prepared by the preparation method of the present invention and a matrix thereof.

[0051] Furthermore, the substrate includes cloth, resin, rubber, ceramic and / or metal.

[0052] In the present invention, the bioprotein fiber has the characteristics of excellent mechanical stability and easy regeneration processing, making it a preferred hot material for wearable products. At the same time, the bioprotein fiber of the present invention can be used in the biomedical field for the development of biomimetic structures, such as membranes, gels, and scaffolds; the bioprotein fiber of the present invention can also be processed into thin films, gels and other materials, and through modification and functionalization, it can be applied to optoelectronic devices and biological imaging and other fields.

[0053] In the present invention, the photothermal nanocomposite material includes but is not limited to textile materials, equipment, cables and / or coatings.

[0054] The present invention provides applications of at least one of the following A) to C) in the fields of electrical and / or optical conductors, smart wearables, and / or medical bionics:

[0055] A), the biological protein fiber of the present invention;

[0056] B) biological protein fiber prepared by the preparation method of the present invention;

[0057] C) The photothermal nanocomposite material of the present invention.

[0058] Specifically, in a specific embodiment of the present invention, it is used in the field of smart wearables for bioheat storage.

[0059] The present invention uses rare earth nanoparticles and silk fibroin as raw materials and utilizes a direct doping method to synthesize the bioprotein fiber described in the present invention. Experimental results show that the bioprotein fiber described in the present invention has both high photothermal efficiency and mechanical properties, providing a new strategy for the development of new high-performance photothermal fibers, and can be widely used in the preparation of special outdoor thermal insulation equipment for extreme environments.

[0060] The method for heat preservation and / or heat conduction is to use at least one of the following a) to c) for heat preservation and / or heat conduction:

[0061] a) The biological protein fiber of the present invention;

[0062] b) Bioprotein fiber prepared by the preparation method of the present invention;

[0063] c) The photothermal nanocomposite material of the present invention.

[0064] The present invention uses rare earth nanoparticles and silk fibroin as raw materials and utilizes a direct doping method to synthesize the bioprotein fiber described in the present invention. Experimental results show that the bioprotein fiber described in the present invention has both high photothermal efficiency and mechanical properties, providing a new strategy for the development of new high-performance photothermal fibers, and can be widely used in the preparation of special outdoor thermal insulation equipment for extreme environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 TEM image of the rare earth photothermal nanoparticles obtained in Example 1, scale: 50 nm;

[0066] Figure 2 2 is a graph showing the tensile mechanical properties of the fiber obtained by post-stretching treatment in Example 2;

[0067] Figure 3 1 is a graph showing the tensile mechanical properties of the fiber obtained by post-stretching treatment in Example 3;

[0068] Figure 4 2 is a graph showing the photothermal performance of the fiber obtained by post-drawing treatment in Example 2;

[0069] Figure 5 2 shows the light and thermal performance curve of the fiber obtained by post-drawing treatment in Example 3. DETAILED DESCRIPTION

[0070] The present invention provides rare earth bioprotein fibers, preparation methods, and applications thereof. Those skilled in the art can refer to the contents herein and appropriately modify the process parameters to achieve the desired results. It should be noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in the present invention. The methods and applications of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately alter and combine the methods and applications herein without departing from the content, spirit, and scope of the present invention to implement and apply the technology of the present invention.

[0071] In the present invention, the preparation steps of silk fibroin are as follows: chopping tussah pupae, immersing them in a 0.5 wt% sodium carbonate solution at a ratio of 10 g / L, boiling for 30 minutes, washing and drying, and obtaining degummed silk.

[0072] The biological protein fiber described in the present invention is a rare earth protein fiber prepared with both mechanical properties and photothermal properties. The present invention uses the special light response properties of rare earth elements to achieve the engineered preparation of rare earth high-strength and high-toughness biological fibers with photothermal functions. The fiber can achieve efficient photothermal conversion under sunlight, promoting the high-value application of rare earth resources.

[0073] At the same time, innovative methods have been developed to combine Prussian blue or Tönnenberg blue-coated NaNdF4 photothermal molecules with fibers, and innovative in-situ photothermal molecular synthesis techniques have been developed. While the introduction of inorganic nanoparticles typically interferes with protein assembly and reduces performance, the in-situ synthesis process, in particular, achieves synergistic mechanical and photothermal performance through process control.

[0074] Traditional inorganic composite strategies often significantly reduce the mechanical properties of fibers. The strategy provided by the present invention can maintain the mechanical properties of fibers while also achieving excellent photothermal conversion characteristics. The present invention effectively assembles rare earth photothermal nanoparticles with protein / biomacromolecule systems to achieve compatibility between mechanical properties and photothermal efficiency, thereby obtaining a photothermal protein fiber material with high mechanical properties and high photothermal efficiency. The photothermal protein fiber has excellent mechanical properties, wearable comfort, and biodegradability, and has important application value in the field of specialty clothing, providing a new strategy for the development of a new generation of rare earth biomaterials.

[0075] The test materials used in the present invention are all common commercial products and can be purchased on the market. The present invention is further described below with reference to the following examples:

[0076] Example 1 Preparation of rare earth photothermal nanoparticles

[0077] Dissolve 1 mmol of NdCl₃ in 20 mL of oleic acid and octadecene (3 / 7 v / v). Add NH₄F and sodium oleate while stirring, preferably in amounts of 3.3 mmol and 1.25 mmol, respectively. Evacuate the mixture and raise the temperature to 110°C. Then, under nitrogen, heat to 310°C and maintain for 40 minutes. Cool to room temperature, add ethanol for precipitation, centrifuge, and wash with ethanol and cyclohexane, respectively. Disperse the product in cyclohexane or n-hexane.

[0078] To a 10 mL hexane solution containing 300 mg of NaNdF4, add 1 mL of a N,N-dimethylformamide (DMF) solution containing NOBF4 (preferably 60 mg / mL NOBF4). Centrifuge the mixture, then add 5 mL of a saturated citric acid (CA) solution (64.3%) to the precipitate. Ultrasonicate for 30 minutes to obtain NaNdF4@CA nanoparticles.

[0079] 1 mL of a 60 mg / L NaNdF4@CA solution was added to 50 mL of water, followed by 5 mL of an aqueous solution of FeSO4 and CA. Subsequently, 5 mL of an aqueous solution of K3Fe(CN)6 (potassium ferrocyanide) with the same concentration as the FeSO4 was added. The FeSO4 and CA concentrations were preferably 5 mM FeSO4 and 0.09 M CA. The mixture was centrifuged and washed with a water / acetone mixture (50% acetone), and the product was dispersed in water. Transmission electron microscopy revealed uniformly distributed, cluster-like nanoparticles approximately 200 nm in size. Figure 1 As shown; the centrifugal speed of the present invention is 6000rpm.

[0080] Example 2 Preparation of 0.5% NaNdF4@TB rare earth photothermal biofiber by direct doping

[0081] A formic acid solution of silk fibroin and NaNdF4@TB is prepared. The silk fibroin concentration is preferably 15wt%, and the NaNdF4@TB concentration is preferably 0.5wt%. The silk fibroin is dissolved in a spinning solution, and the spinning solution contains CaCl2 and LaCl3, each preferably at a concentration of 2wt%. The protein solution is extruded into a coagulation bath for wet spinning, and the fibers are collected. The extrusion speed is preferably 15μL / min. The coagulation bath is a mixed solution of ethanol and water, and the ethanol ratio is preferably 50%. A high-performance rare earth photothermal biofiber is obtained. The collected fibers are post-stretched to obtain rare earth photothermal biofibers with good mechanical properties, wherein the post-stretching degree is preferably 600% of the original fiber length.

[0082] Example 3 Preparation of 1% NaNdF4@TB rare earth photothermal biofiber by direct doping

[0083] A formic acid solution of silk fibroin and NaNdF4@TB is prepared. The silk fibroin concentration is preferably 15wt%, the NaNdF4@TB concentration is preferably 1wt%, and the spinning solution contains CaCl2 and LaCl3, both of which are preferably 2wt%. The protein solution is extruded into a coagulation bath for wet spinning, and the fibers are collected. The extrusion speed is preferably 15μL / min. The coagulation bath is a mixed solution of ethanol and water, and the ethanol ratio is preferably 50%. A high-performance rare earth photothermal biofiber is obtained. The collected fibers are post-stretched to obtain rare earth photothermal biofibers with good mechanical properties, wherein the post-stretching degree is preferably 600% of the original fiber length.

[0084] Example 4 Preparation of 1.5% NaNdF4@TB rare earth photothermal biofiber by direct doping

[0085] A formic acid solution of silk fibroin and NaNdF4@TB is prepared. The silk fibroin concentration is preferably 15wt%, the NaNdF4@TB concentration is preferably 1.5wt%, and CaCl2 and LaCl3 are dissolved in the spinning solution, and their concentrations are preferably 2wt%. The protein solution is extruded into a coagulation bath for wet spinning, and the fibers are collected. The extrusion speed is preferably 15μL / min. The coagulation bath is a mixed solution of ethanol and water, and the ethanol ratio is preferably 50%. A high-performance rare earth photothermal biofiber is obtained. The collected fibers are post-stretched to obtain rare earth photothermal biofibers with good mechanical properties, wherein the post-stretching degree is preferably 600% of the original fiber length.

[0086] Example 5 Preparation of rare earth photothermal biofibers by in-situ modification during spinning

[0087] A formic acid solution of silk fibroin is prepared. The silk fibroin concentration is preferably 15 wt%. NdCl3 and FeCl2 are dissolved in the spinning solution, with the NdCl3 mass fraction preferably being 2% and the FeCl2 concentration preferably being 1%. K3Fe(CN)6 is added to a coagulation bath. Preferably, the K3Fe(CN)6 mass fraction is 1%. The protein solution is extruded into a coagulation bath for wet spinning, and fibers are collected. The extrusion rate is preferably 15 μL / min. The coagulation bath is a mixed solution of ethanol and water, with the ethanol ratio preferably being 50%. A high-performance rare earth photothermal biofiber is obtained. The collected fibers are post-stretched to obtain rare earth photothermal biofibers with excellent mechanical properties. The post-stretching degree is preferably 600% of the original fiber length.

[0088] Example 6 Testing of Fiber Mechanical Strength and Fiber Photothermal Properties

[0089] The specific test method is as follows: take 8mm of fiber that has been stretched and placed for 24 hours, use Textchno single fiber tensile tester, set the test length to 5mm, clamp the fiber, and stretch it at a speed of 10 mm / min to obtain the tensile value; the fiber diameter is measured by microscope, and the tensile strength is obtained by the ratio of tensile force to fiber cross-sectional area. The tensile curve is obtained by processing with origin software, such as Figures 2 and 3 As shown ( Figure 2 and Figure 3 (In the figure, different curves represent the results of multiple repetitions of the same experiment). It can be seen that the breaking strength of the fibers prepared in Examples 2 and 3 both reached approximately 500 MPa (Table 1), which can meet the application requirements of equipment thermal storage and clothing fabric preparation.

[0090] Take 20 single fibers and twist them into a bundle. Then test the photothermal performance under the light of a xenon lamp equipped with a solar spectrum filter. The light intensity used is measured by an optical power meter to be 0.1W / cm 2 The temperature change of the fiber under light is tested using a FLIR infrared thermal imaging camera, and the temperature change curve over time is recorded, such as Figures 4 and 5 The results show that the photothermal efficiency of the fibers prepared in Examples 2 to 5 is greater than 40%, which can meet the needs of outdoor active heating and equipment insulation (Table 1).

[0091] Table 1. Test results of fiber mechanical strength and fiber optical and thermal properties

[0092]

[0093] Example 7 Comparison with other fibers

[0094] The RSF / MoO2NPs hybrid fiber with a content of 0.04 wt% has the best breaking strength and elongation, which are 311.62±10.52 MPa and 153.81±6.21%, respectively (Guo Jianjun. Research on photothermal nanoparticle functionalized silk fibroin composites [D]. Jiangsu University of Science and Technology, 2022. DOI: 10.27171 / d.cnki.ghdcc.2022.000448.).

[0095] RSF-PDA composite fiber has a strength of 246 MPa and a photothermal efficiency of 33% (Chen, Wei. , et al. "Polydopamine-Induced Multilevel Engineering of Regenerated Silk Fibroin Fiberfor Photothermal Conversion." Small (Weinheim an der Bergstrasse, Germany)18.11(2022):e2107196).

[0096] The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. Bioprotein fiber, characterized in that: including rare earth nanoparticles and silk fibroin; The preparation method of the rare earth nanoparticles comprises the following steps: Step 1: mixing neodymium salt in a mixed solvent of oleic acid and octadecene, and then reacting with a sodium source and a fluorine source for a first reaction and then precipitating to obtain NaNdF4; Step 2: The NaNdF4 and NOBF4 are mixed and centrifuged to collect the precipitate, and the precipitate is modified with citric acid to obtain NaNdF4@CA; Step 3: The NaNdF4@CA and FeSO4 react with cyanide in the presence of citric acid to obtain the rare earth nanoparticles; The cyanide is potassium ferrocyanide and / or potassium ferrocyanide; if the cyanide is potassium ferrocyanide, the rare earth nanoparticles are NaNdF4 modified with Teng's blue; if the cyanide is potassium ferrocyanide, the rare earth nanoparticles are NaNdF4 modified with Bruce's blue; The mass ratio of the rare earth nanoparticles to the silk fibroin is (0.1-1.5): (10-20).

2. The bioprotein fiber according to claim 1, characterized in that The mass ratio of the rare earth nanoparticles to the silk fibroin is (0.5-1.5):

15.

3. The bioprotein fiber according to claim 1, wherein the particle size of the rare earth nanoparticles is 180 nm to 220 nm.

4. The method for preparing the bioprotein fiber according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: wet spinning the rare earth nanoparticles and silk fibroin in the presence of a cosolvent and an organic acid to obtain the bioprotein fiber.

5. The preparation method according to claim 4, characterized in that The co-solvents include CaCl2 and LaCl3.

6. The preparation method according to claim 4 or 5, characterized in that The mass ratio of the rare earth nanoparticles, silk fibroin, CaCl2 and LaCl3 is (0.1-1.5): (10-20): 2:

2.

7. Photothermal nanocomposite material, characterized in that: The invention comprises at least one of the biological protein fibers according to any one of claims 1 to 3 and / or the biological protein fibers prepared by the preparation method according to any one of claims 4 to 6, and a matrix thereof.

8. The photothermal nanocomposite material according to claim 7, characterized in that: The substrate includes cloth, resin, rubber, ceramic and / or metal.

9. Application of at least one of the following items A) to C) in the fields of electrical and / or optical conductors, smart wearables, and / or medical bionics: A), the biological protein fiber according to any one of claims 1 to 3; B) The biological protein fiber prepared by the preparation method according to any one of claims 4 to 6; C) The photothermal nanocomposite material according to claim 7 or 8.

10. A method for heat preservation and / or heat conduction, characterized in that: Use at least one of the following a) to c) for heat preservation and / or heat conduction: a), the biological protein fiber according to any one of claims 1 to 3; b) The biological protein fiber prepared by the preparation method according to any one of claims 4 to 6; c) The photothermal nanocomposite material according to claim 7 or 8.

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