Photochromic fiber material and preparation method thereof
By embedding DASAs photochromic compounds into the fiber through electrospinning technology, the problems of slow color change rate, poor stability and uneven dispersion of traditional photochromic fiber materials are solved, realizing efficient and reversible color change and fiber integration, thus improving the application performance of the fiber.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-25
- Publication Date
- 2026-03-31
AI Technical Summary
Traditional photochromic fiber materials suffer from slow color-changing rates, poor cycle stability, uneven dispersion of color-changing agents, and easy shedding, which limits their application in the fiber field.
Photochromic DASAs compounds are directly embedded into the fiber using electrospinning technology, and efficient and reversible color changes are achieved by visible light driving the process. The electrospinning solution is prepared by mixing DASAs precursor solution and PVDF precursor solution to form photochromic fibers.
It achieves color change within 10 seconds under visible light, and the color is reversible, solving the problems of uneven dispersion and easy shedding of color-changing agents, and improving the mechanical properties of fibers and production efficiency.
Smart Images
Figure CN121760087A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of functional materials technology, specifically relating to a photochromic fiber material and its preparation method. Background Technology
[0002] Photochromic fibers, as an important branch of smart textiles, have broad application prospects in fields such as military camouflage, information anti-counterfeiting, and wearable devices. However, traditional materials generally rely on ultraviolet light triggering, resulting in slow color-changing rates and poor cycle stability. For example, inorganic materials (such as WO3) require proton or hydrogen atom implantation mechanisms, leading to insufficient color-changing sensitivity; while organic materials (such as spiropyran), although reversible, often require high-temperature and high-pressure dyeing or graft polymerization processes, resulting in deterioration of fiber mechanical properties and high production costs. Furthermore, existing photochromic fibers are mostly functionalized through physical mixing or surface coating, which suffers from uneven dispersion of the color-changing agent and easy shedding, limiting their practical applications.
[0003] In recent years, donor-acceptor Steinhaus adducts (DASAs) have become a research hotspot due to their advantages such as visible light response and rapid reversible color change. This material can achieve color switching through photoisomerization under mild synthesis conditions, but its color-changing performance is easily degraded in solid matrices due to molecular stacking. This defect greatly limits its breakthrough applications in the fiber field.
[0004] In view of this, the present invention is hereby proposed. Summary of the Invention
[0005] The purpose of this invention is to overcome the shortcomings of the prior art and to propose a photochromic fiber material and its preparation method.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing photochromic fibers, comprising the following steps: Step 1: Preparation of DASA precursors: Furfural is added dropwise to a pre-prepared electron acceptor solution, heated and stirred, and then filtered to obtain DASA precursors; Step 2, Preparation of DASAs: The DASAs precursor obtained in Step 1 is added to dichloromethane to prepare a DASAs precursor solution. An electron donor material is added to the DASAs precursor solution, and the reaction is carried out in the dark at 25℃~35℃ for 2h~6h. After the reaction is completed, the DASAs are obtained by purification. Step 3: Preparation of PVDF precursor solution: Mix DMF and PVDF particles in a set ratio and place them in a beaker. Seal the beaker and stir to obtain PVDF precursor solution. Step 4: Preparation of electrospinning solution: Mix the DASAs prepared in step 2 and the PVDF precursor solution prepared in step 3 according to the set ratio and stir to obtain the electrospinning solution. Step 5: Preparation of photochromic fiber: The electrospinning solution obtained in step 4 is used to prepare fiber through electrospinning equipment, and the target photochromic fiber is obtained after drying treatment.
[0007] Furthermore, in step 1, the preparation process of the electron acceptor solution is as follows: 8 mmol to 12 mmol of electron acceptor material is placed in a round-bottom flask, and then 40 ml to 60 ml of deionized water is added. The mixture is sonicated until the electron acceptor material is completely dissolved to obtain the electron acceptor solution. The electron acceptor material is 1,3-dimethylbarbituric acid or 2,2-dimethyl-1,3-dioxane-4,6-dione.
[0008] Furthermore, in step 1, 8 mmol to 12 mmol of furfural is added to the electron acceptor solution, and after heating and stirring at 60 to 80°C for 2 to 6 hours, a precipitate appears in the electron acceptor solution. After filtration, the collected precipitate is the DASA precursor.
[0009] Furthermore, in step 2, the process of preparing the DASAs precursor is as follows: the DASAs precursor obtained in step 1 is added to dichloromethane and sonicated for 2 min to 6 min to fully dissolve the DASAs precursor, resulting in a DASAs precursor solution with a concentration of 30 uM to 60 uM.
[0010] Furthermore, in step 2, 8-10 mmol of electron donor material is added to the DASA precursor solution, wherein the electron donor material is indoline or N-propylaniline, and the purification is performed by silica gel column chromatography.
[0011] Furthermore, in step 3, the DMF and PVDF particles are mixed at a mass ratio of 7.5~8.5:1.5~2.5, and then stirred at a heating temperature of 60-80℃ for 0.5h-2h, followed by static stirring at room temperature for 0.5h-2h to obtain a PVDF precursor solution.
[0012] Furthermore, the DASAs prepared in step 2 and the PVDF precursor solution prepared in step 3 are mixed in a mass ratio of 2-3:7-8 and stirred at room temperature for 2-4 hours to obtain an electrospinning solution.
[0013] Furthermore, in step 5, the fiber drying process is as follows: the fiber prepared by the electrospinning equipment is placed in an oven and dried at 30℃~60℃ for 6h~12h.
[0014] Furthermore, the operating parameters of the electrospinning equipment in step 5 are as follows: voltage 15kV~30kV, feed speed 0.52ml / h~2ml / h, receiving distance 10cm~20cm, and receiving plate rotation speed 100rad / s~400rad / s.
[0015] Secondly, a photochromic fiber, which is a photochromic fiber prepared based on the above-mentioned method for preparing photochromic fibers.
[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) The photochromic fiber proposed in this invention is prepared by electrospinning of DASAs photochromic compounds. The photochromic fiber can achieve high-efficiency color change under the drive of visible light, and complete the color change within 10s. Moreover, the process is reversible and the fiber color is restored after the visible light is removed.
[0017] (2) In this invention, the photochromic material is directly embedded inside the fiber, making the fiber and the photochromic material a whole, which solves the problems of uneven dispersion of the color-changing agent, easy shedding, and high-efficiency loading of DASAs molecules in the solid matrix of existing photochromic fibers. Attached Figure Description
[0018] The accompanying drawings are incorporated in and form part of this specification, and together with the description serve to explain the principles of the invention.
[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 This is a flowchart of the preparation method of the present invention; Figure 2 The synthetic route diagram for the DASAs prepared in this invention is shown. Figure 3 This is a schematic diagram of an electrospinning device; Figure 4 The diagram shows the ultraviolet-visible absorption spectrum curve and color change of the DASAs solution prepared in this invention after visible light irradiation. Detailed Implementation
[0021] Exemplary embodiments will now be described in detail. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples consistent with some aspects of the invention as detailed in the appended claims.
[0022] Example 1 Please see Figures 1-4 This invention provides a method for preparing photochromic fibers, comprising the following steps: Step 1: Preparation of electron acceptor solution Place 8 mmol of 2,2-dimethyl-1,3-dioxane-4,6-dione in a round-bottom flask, add 40 ml of deionized water, and sonicate until the 2,2-dimethyl-1,3-dioxane-4,6-dione is completely dissolved to obtain an electron acceptor solution.
[0023] Step 2: Preparation of DASA precursors 8 mmol of furfural was slowly added dropwise to the electron acceptor solution. After heating and stirring at 60°C for 2 hours, a yellow precipitate appeared in the electron acceptor solution. After filtration, the collected yellow precipitate was the DASAs-1 precursor.
[0024] Step 3: Preparation of DASAs The DASA precursor was added to dichloromethane and sonicated for 2 min to fully dissolve it, thus preparing a 30 μM DASA precursor solution. Then, 9 mmol of indoline was added to the solution, and the reaction was carried out at 35 °C in the dark for 4 h. After the reaction was completed, the product was purified by silica gel column chromatography to obtain the final product DASAs. The silica gel column chromatography method described herein is existing technology and is not described in detail in this paper.
[0025] Step 4: Preparation of PVDF precursor solution DMF (N,N-dimethylformamide) and PVDF (polyvinylidene fluoride) particles were mixed in a mass ratio of 7.5:2.5 and placed in a beaker. After sealing the beaker, the mixture was magnetically heated and stirred at 60°C for 0.5 h. The mixture was then left to stand at room temperature for 0.5 h to obtain a PVDF precursor solution.
[0026] Step 5: Preparation of electrospinning solution The solutions prepared in steps 3 and 4 were mixed in a mass ratio of 3:7 and stirred at room temperature for 2 hours to obtain an electrospinning solution.
[0027] Step 6: Preparation of photochromic fibers The electrospinning solution prepared in step 5 was used to prepare photochromic fibers through an electrospinning device. The humidity was controlled at 65±5%. The electrospinning parameters were set as follows: voltage 15kV, feed speed 0.52ml / h, receiving distance 10cm, and receiving plate rotation speed 100rad / s.
[0028] Step 7: Drying treatment The photochromic fibers prepared in step 6 were placed in an oven and dried at 60°C for 6 hours.
[0029] Example 2 Step 1: Preparation of electron acceptor solution Place 10 mmol of 2,2-dimethyl-1,3-dioxane-4,6-dione in a round-bottom flask, add 50 ml of deionized water, and sonicate until the 2,2-dimethyl-1,3-dioxane-4,6-dione is completely dissolved to obtain an electron acceptor solution.
[0030] Step 2: Preparation of DASA precursors 10 mmol of furfural was slowly added dropwise to the electron acceptor solution. After heating and stirring at 75°C for 4 hours, a yellow precipitate appeared in the electron acceptor solution. After filtration, the collected yellow precipitate was the precursor of DASAs.
[0031] Step 3: Preparation of DASAs The DASA precursor was added to dichloromethane and sonicated for 4 min to fully dissolve it, thus preparing a 40 μM DASA precursor solution. Then, 9 mmol of indoline was added to the solution, and the reaction was carried out at 35 °C in the dark for 4 h. After the reaction was completed, the product was purified by silica gel column chromatography to obtain the final product DASA. The silica gel column chromatography method described herein is existing technology and is not described in detail in this paper.
[0032] Step 4: Preparation of PVDF precursor solution DMF (N,N-dimethylformamide) and PVDF (polyvinylidene fluoride) particles were mixed in a mass ratio of 8:2 and placed in a beaker. The beaker was sealed and then magnetically heated and stirred at 70°C for 1 hour. The mixture was then left to stand at room temperature for 2 hours to obtain a PVDF precursor solution.
[0033] Step 5: Preparation of electrospinning solution The solutions prepared in steps 3 and 4 were mixed at a mass ratio of 2.5:7.5 and stirred at room temperature for 3 hours to obtain the electrospinning solution.
[0034] Step 6: Preparation of photochromic fibers The electrospinning solution prepared in step 5 was used to prepare photochromic fibers through an electrospinning device. The humidity was controlled at 65±5%. The electrospinning parameters were set as follows: voltage 20kV, feed speed 1ml / h, receiving distance 15cm, and receiving plate rotation speed 200rad / s.
[0035] Step 7: Drying treatment The photochromic fibers prepared in step 6 were placed in an oven and dried at 50°C for 8 hours.
[0036] Example 3 Step 1: Preparation of electron acceptor solution 12 mmol of 1,3-dimethylbarbituric acid was placed in a round-bottom flask, 60 ml of deionized water was added, and the mixture was sonicated until 2,2-dimethyl-1,3-dioxane-4,6-dione was completely dissolved to obtain an electron acceptor solution.
[0037] Step 2: Preparation of DASA precursors 12 mmol of furfural was slowly added dropwise to the electron acceptor solution. After heating and stirring at 80°C for 6 hours, a yellow precipitate appeared in the electron acceptor solution. After filtration, the collected yellow precipitate was the precursor of DASAs.
[0038] Step 3: Preparation of DASAs The DASA precursor was added to dichloromethane to prepare a 40 μM DASA precursor solution. The solution was sonicated for 6 min to fully dissolve the DASA precursor. Then, 9 mmol of indoline was added to the solution and the reaction was carried out at 35 °C in the dark for 4 h. After the reaction was completed, the solution was purified by silica gel column chromatography to obtain the final product DASAs. The silica gel column chromatography method described herein is existing technology and is not described in detail in this paper.
[0039] Step 4: Preparation of PVDF precursor solution DMF (N,N-dimethylformamide) and PVDF (polyvinylidene fluoride) particles were mixed in a mass ratio of 8.5:1.5 and placed in a beaker. The beaker was sealed and then magnetically heated and stirred at 80°C for 2 hours. The mixture was then left to stand at room temperature for 2 hours to obtain a PVDF precursor solution.
[0040] Step 5: Preparation of electrospinning solution The solutions prepared in steps 3 and 4 were mixed at a mass ratio of 2:8 and stirred at room temperature for 4 hours to obtain the electrospinning solution.
[0041] Step 6: Preparation of photochromic fibers The electrospinning solution prepared in step 5 was used to prepare photochromic fibers through an electrospinning device. The humidity was controlled at 65±5%. The electrospinning parameters were set as follows: voltage 30kV, feed speed 2ml / h, receiving distance 20cm, and receiving plate rotation speed 400rad / s.
[0042] Step 7: Drying treatment The photochromic fibers prepared in step 6 were placed in an oven and dried at 30°C for 12 hours.
[0043] Example 4 Step 1: Preparation of electron acceptor solution Place 8 mmol of 1,3-dimethylbarbituric acid in a round-bottom flask, add 40 ml of deionized water, and sonicate until 2,2-dimethyl-1,3-dioxane-4,6-dione is completely dissolved to obtain an electron acceptor solution.
[0044] Step 2: Preparation of DASA precursors 8 mmol of furfural was slowly added dropwise to the electron acceptor solution. After heating and stirring at 60°C for 2 hours, a yellow precipitate appeared in the electron acceptor solution. After filtration, the collected yellow precipitate was the DASAs-1 precursor.
[0045] Step 3: Preparation of DASAs The DASA precursor was added to dichloromethane and sonicated for 2 min to fully dissolve the DASA precursor, thus preparing a 30 μM DASA precursor solution. Then, 9 mmol of N-propylaniline was added to the solution, and the reaction was carried out at 35 °C in the dark for 4 h. After the reaction was completed, the product was purified by silica gel column chromatography to obtain the final product DASA. The silica gel column chromatography method described herein is existing technology and is not described in detail in this paper.
[0046] Step 4: Preparation of PVDF precursor solution DMF (N,N-dimethylformamide) and PVDF (polyvinylidene fluoride) particles were mixed in a mass ratio of 7.5:2.5 and placed in a beaker. After sealing the beaker, the mixture was magnetically heated and stirred at 60°C for 0.5 h. The mixture was then left to stand at room temperature for 0.5 h to obtain a PVDF precursor solution.
[0047] Step 5: Preparation of electrospinning solution The solutions prepared in steps 3 and 4 were mixed in a mass ratio of 3:7 and stirred at room temperature for 2 hours to obtain an electrospinning solution.
[0048] Step 6: Preparation of photochromic fibers The electrospinning solution prepared in step 5 was used to prepare photochromic fibers through an electrospinning device. The humidity was controlled at 65±5%. The electrospinning parameters were set as follows: voltage 15kV, feed speed 0.52ml / h, receiving distance 10cm, and receiving plate rotation speed 100rad / s.
[0049] Step 7: Drying treatment The photochromic fibers prepared in step 6 were placed in an oven and dried at 30°C for 12 hours.
[0050] like Figure 4 As shown, the DASAs solution prepared by this invention changes from purple to colorless after being irradiated with visible light. Its photochromic excitation band is 560nm, and it can be excited by green light to achieve the transformation from a colored state to a colorless state.
[0051] The photochromic fiber prepared by this invention is composed of PVDF and DASAs, wherein PVDF is the outer layer of the fiber and DASAs is the inner core. This photochromic fiber can achieve high-efficiency color change under the drive of visible light, and complete the color change within 10 seconds. Moreover, the process is reversible, and the fiber color is restored after the visible light is removed.
[0052] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention.
[0053] It should be understood that the present invention is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of the present invention is limited only by the appended claims.
Claims
1. A method for preparing a photochromic fiber, characterized by, The method comprises the following steps: Step 1, preparation of DASAs precursor: furaldehyde is added dropwise into a prepared electron acceptor solution, heated and stirred, and after filtration, a DASAs precursor is obtained; Step 2, preparation of DASAs: the DASAs precursor obtained in step 1 is added into dichloromethane to prepare a DASAs precursor solution, an electron donor material is added into the DASAs precursor solution, and reaction is carried out at 25-35 DEG C in the dark for 2-6 hours, and after reaction is completed, purification is carried out to obtain DASAs; Step 3, preparation of PVDF precursor solution: DMF and PVDF particles are mixed in a beaker in a set proportion, the beaker is sealed and stirred to obtain a PVDF precursor solution; Step 4, preparation of electrospinning solution: the DASAs prepared in step 2 and the PVDF precursor solution prepared in step 3 are mixed in a set proportion and stirred to obtain an electrospinning solution; Step 5, preparation of photochromic fiber: the electrospinning solution obtained in step 4 is prepared into a fiber through an electrospinning device, and after drying treatment, a target photochromic fiber is obtained.
2. The method for preparing the photochromic fiber according to claim 1, characterized in that, In step 1, the preparation process of the electron acceptor solution is as follows: 8-12 mmol of electron acceptor material is placed in a round-bottom flask, 40-60 ml of deionized water is added, and ultrasonic treatment is carried out until the electron acceptor material is completely dissolved to obtain an electron acceptor solution. The electron acceptor material is 1,3-dimethylbarbituric acid or 2,2-dimethyl-1,3-dioxane-4,6-dione.
3. A method of preparing a photochromic fiber according to claim 1 or 2, characterized in that, In step 1, 8-12 mmol of furaldehyde is added into the electron acceptor solution, heated and stirred at 60-80 DEG C for 2-6 hours, and after that, a precipitate appears in the electron acceptor solution, and after filtration, the collected precipitate is the DASAs precursor.
4. The method for preparing photochromic fibers according to claim 1, characterized in that, In step 2, the preparation process of the DASAs precursor solution is as follows: the DASAs precursor obtained in step 1 is added into dichloromethane, and ultrasonic treatment is carried out for 2-6 minutes to fully dissolve the DASAs precursor to obtain a DASAs precursor solution with a concentration of 30-60 uM.
5. The method for preparing photochromic fibers according to claim 1, characterized in that, In step 2, 8-10 mmol of electron donor material is added into the DASAs precursor solution, the electron donor material is indoline or N-propyl aniline, and the purification is carried out by silica gel column chromatography.
6. The method of claim 1, wherein the photochromic fiber is prepared by the steps of: In step 3, the DMF and PVDF particles are mixed in a mass ratio of 7.5-8.5:1.5-2.5, then stirred at a heating temperature of 60-80 DEG C for 0.5-2 hours, and then stirred at room temperature for 0.5-2 hours to obtain a PVDF precursor solution.
7. The method for preparing photochromic fibers according to claim 1, characterized in that, The DASAs prepared in step 2 and the PVDF precursor solution prepared in step 3 are mixed in a mass ratio of 2-3:7-8, and stirred at room temperature for 2-4 hours to obtain an electrospinning solution.
8. The method for preparing photochromic fibers according to claim 1, characterized in that, In step 5, the process of drying the fiber is as follows: the fiber prepared by the electrospinning device is placed in an oven and dried at 30-60 DEG C for 6-12 hours.
9. The method for preparing photochromic fibers according to claim 1, characterized in that, The electrospinning equipment operating parameters in step 5 are: voltage 15kv~30kv, propelling speed 0.52ml / h~2ml / h, receiving distance 10cm~20cm, and the rotating speed of the receiving plate is 100rad / s~400rad / s.
10. A photochromic fiber characterized by, The photochromic fiber prepared by the preparation method according to any one of claims 1~9.