A cadmium carbonate-collagen nanofiber and a preparation method and application thereof

Abstract

The present application relates to a kind of cadmium carbonate-collagen nanofiber and its preparation method and application, the cadmium carbonate-collagen nanofiber is obtained by the ordered dense growth of cadmium carbonate nanoparticles in collagen fiber inside, the cadmium carbonate nanoparticles are arranged in the direction of collagen fiber long axis, form directional structure.The cadmium carbonate-collagen nanofiber of the present application has ordered directional structure, improves ion transmission efficiency, has high memristor performance, has good application prospect in the field of memristor.

Description

Technical Field

[0001] This invention belongs to the field of nanotechnology for materials and surface science, specifically relating to a cadmium carbonate-collagen nanofiber, its preparation method, and its application. Background Technology

[0002] Memristors, as nonlinear resistors, possess unique memristor characteristics that enable data storage, computation, and encryption, making them one of the most promising candidates for next-generation non-volatile memory devices. Currently, various inorganic and organic materials are used as memristor materials. However, inorganic memristors are insensitive to changes in voltage and current; while polymer or metal composite memristors exhibit poor resistance switching performance. Developing inorganic-organic composite-based memristors that combine the advantages of both approaches holds promise for solving this problem. Research indicates that the structure of the material also significantly impacts the performance of memristor devices. Regular ion channels or ordered structures facilitate ion / atom migration, thereby improving memristor performance to some extent. Therefore, developing inorganic-organic composite materials with ordered ion channels is a key challenge in improving memristor performance. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a cadmium carbonate-collagen nanofiber, its preparation method and application. In the cadmium carbonate-collagen nanofiber, cadmium carbonate nanoparticles are arranged in an orderly and compact manner along the long axis of the collagen fiber to form an oriented structure. As a memristor functional layer, it is conducive to rapid ion transport and has high memristor performance.

[0004] This invention provides a cadmium carbonate-collagen nanofiber, which is obtained by the orderly and dense growth of cadmium carbonate nanoparticles inside collagen fibers. The cadmium carbonate nanoparticles are oriented along the long axis of the collagen fibers to form an oriented structure.

[0005] According to the above scheme, the cadmium carbonate nanoparticles have a particle size of 20-40 nm, and the cadmium carbonate-collagen nanofibers have a diameter of 200-600 nm.

[0006] This invention also includes a method for preparing the above-mentioned cadmium carbonate-collagen nanofibers, the specific steps of which are as follows:

[0007] 1) Dissolve cadmium chloride and 4-hydroxyethylpiperazine ethanesulfonic acid in water to obtain solution A;

[0008] 2) Dissolve sodium carbonate and sodium chloride in water to obtain a mixed solution of sodium carbonate and sodium chloride. Prepare an aqueous solution of polyacrylamide hydrochloride. Then add the obtained aqueous solution of polyacrylamide hydrochloride to the mixed solution of sodium carbonate and sodium chloride to obtain solution B.

[0009] 3) The solution A obtained in step 1) is slowly added dropwise to the solution B obtained in step 2) using a peristaltic pump to obtain a mineralization solution. The frozen sectioned tendon slices are immersed in the mineralization solution for mineralization, and then post-processed to obtain single cadmium carbonate-collagen nanofibers.

[0010] According to the above scheme, the concentration of cadmium chloride in solution A in step 1) is 20-60 mM (mmol / L), and the molar ratio of cadmium chloride to 4-hydroxyethylpiperazine ethanesulfonic acid is 1-2:1.

[0011] According to the above scheme, in step 2), the concentration of sodium carbonate in the mixed solution of sodium carbonate and sodium chloride is 20-60 mM, and the molar ratio of sodium carbonate to sodium chloride is 1-3:15.

[0012] According to the above scheme, the molecular weight of polyacrylamide hydrochloride in step 2) is 120,000-200,000, the concentration of the aqueous solution of polyacrylamide hydrochloride is 200-800 μg / mL, and the mass ratio of sodium carbonate in the mixed solution of sodium carbonate and sodium chloride to the mass of polyacrylamide hydrochloride in the aqueous solution of polyacrylamide hydrochloride is 150-2000:1.

[0013] According to the above scheme, in step 3), the molar ratio of cadmium chloride in solution A to sodium carbonate in solution B is 1:1-3.

[0014] According to the above scheme, the peristaltic pump operates at a speed of 30 rpm in step 3).

[0015] According to the above scheme, the mineralization temperature in step 3) is 25-37℃, and the mineralization time is 3-24h.

[0016] The present invention also includes the application of the above-mentioned cadmium carbonate-collagen nanofibers in the preparation of memristors.

[0017] The present invention further provides a memristor prepared using the above-mentioned cadmium carbonate-collagen nanofibers, wherein the memristor uses cadmium carbonate-collagen nanofibers as the memristor functional layer.

[0018] This invention also includes a method for fabricating the aforementioned memristor, the specific steps of which are as follows: two electrodes (such as silver electrodes with silicon dioxide as the substrate) are arranged alternately, and the cadmium carbonate-collagen nanofibers are adhered to a flexible polydimethylsiloxane film with a thickness of 2-5 mm. The nanofibers are then transferred and overlapped onto the two electrodes to obtain the memristor. This fabrication process can be achieved at room temperature and pressure, simplifying the nanowire transfer steps and reducing energy consumption.

[0019] In this invention, cadmium carbonate, a functional inorganic material that is easy to form precursors, is selected and subjected to collagen mineralization at 37°C. The confined space inside the collagen fibers causes mineral particles to grow in an oriented manner inside, forming a directional structure, which accelerates ion transport efficiency and forms a high-performance single nanowire memristor device.

[0020] The beneficial effects of this invention are as follows: 1. The cadmium carbonate-collagen nanofibers of this invention have an ordered directional structure, which improves ion transport efficiency and has high memristor performance, and has good application prospects in the field of memristors; 2. This invention uses biological matrix collagen fibers as a template to prepare single cadmium carbonate mineralized collagen fibers through intra-collagen mineralization. The reaction conditions are mild and the preparation process is simple, making it easy to industrialize. Attached Figure Description

[0021] Figure 1 This is a SEM image of the cadmium carbonate mineralized collagen fibers prepared in Example 1 of the present invention.

[0022] Figure 2 The image shows the XRD pattern of the cadmium carbonate mineralized collagen fibers prepared in Example 1.

[0023] Figure 3 TEM images of fragments at different mineralization stages taken from a single cadmium carbonate mineralized collagen fiber prepared in Example 1.

[0024] Figure 4 An optical photograph of the memristor device prepared in Example 1;

[0025] Figure 5 The first voltage-current curve of the memristor device prepared in Example 1 is shown.

[0026] Figure 6 The diagram shows the dual threshold switching curve of the memristor device prepared in Example 1.

[0027] Figure 7 This is a test result of the memristor device prepared in Example 1 under multiple pulse cycles.

[0028] Figure 8 SEM image of cadmium carbonate-collagen nanofibers prepared in Comparative Example 1.

[0029] Figure 9 SEM image of the cadmium carbonate-collagen nanofibers prepared in Comparative Example 2.

[0030] Figure 10 An optical photograph of the memristor device fabricated in Comparative Example 2;

[0031] Figure 11 The image shows the XRD pattern of the cadmium carbonate-collagen nanofibers prepared in Comparative Example 2.

[0032] Figure 12 The current-voltage curve of the memristor device prepared in Comparative Example 2 is shown. Detailed Implementation

[0033] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below using embodiments and in conjunction with the accompanying drawings.

[0034] Example 1

[0035] A cadmium carbonate-collagen nanofiber is prepared by the following method:

[0036] 1) Dissolve cadmium chloride and 4-hydroxyethylpiperazine ethanesulfonic acid in water to obtain 25 mL of solution A. The concentration of cadmium chloride in solution A is 20 mM, and the concentration of 4-hydroxyethylpiperazine ethanesulfonic acid is 20 mM.

[0037] 2) Dissolve sodium carbonate and sodium chloride in water to obtain 25 mL of a mixed solution of sodium carbonate and sodium chloride. The concentration of sodium carbonate in the mixed solution is 20 mM and the concentration of sodium chloride is 300 mM. Prepare an aqueous solution of polyacrylamide hydrochloride (purchased from Thermo Fisher Scientific, Mw = 120000-200000) with a concentration of 800 μg / mL. Take 400 μL and add it to the mixed solution of sodium carbonate and sodium chloride to obtain solution B.

[0038] 3) Use a peristaltic pump to slowly add solution A to solution B dropwise at a speed of 30 rpm. After the addition is complete, stir the resulting mixture on a magnetic stirrer for 10 minutes to obtain a mineralized solution.

[0039] 4) After freezing the turkey leg tendon (freezing at -25℃ for 10 min) and slicing it, a 100 μm thick tendon slice was obtained. The slice was then immersed in a mineralization solution and placed in a 37℃ oven for static mineralization for 9 h. After mineralization, the slice was removed, rinsed in deionized water, dried at room temperature, and the fibers were separated on a transfer stage using a tungsten needle to obtain a single cadmium carbonate mineralized collagen fiber.

[0040] The memristor is prepared based on the above-mentioned cadmium carbonate mineralized collagen fiber. The specific method is as follows: two silver electrodes with silicon dioxide as the substrate are arranged alternately with a spacing of 2 μm. A single cadmium carbonate mineralized collagen fiber prepared in this embodiment is adhered to a flexible polydimethylsiloxane film with a thickness of 5 mm. The fiber is then transferred and overlapped on the two silver electrodes to obtain the memristor device.

[0041] Figure 1The images show SEM images of the cadmium carbonate mineralized collagen fibers prepared in this embodiment. a is an SEM image of the tendon sheet after mineralization, b is an SEM image of a single cadmium carbonate mineralized collagen fiber, and c is an SEM image of the cross-section of a single cadmium carbonate mineralized collagen fiber. It can be seen that the mineralized collagen fibers are evenly distributed, and the mineralization of a single collagen fiber is clearly observed to be full, with a diameter of about 400 nm. The fracture surface indicates that its interior is filled with cadmium carbonate nanoparticles with a particle size of about 40 nm.

[0042] Figure 2 The XRD pattern of the cadmium carbonate mineralized collagen fibers prepared in this embodiment shows diffraction peaks at angles of 23.5°, 30.3°, and 32.9° that correspond to the standard PDF card (PDF#42-1342) for cadmium carbonate.

[0043] Figure 3 These are TEM images of fragments at different mineralization stages taken from a single cadmium carbonate mineralized collagen fiber prepared in this embodiment. a (left) shows a single collagen fiber fragment in the early stage of mineralization, and a (right) shows its SAED image. b (left) shows a fragment of the same single collagen fiber in the fully mineralized stage, and b (right) shows its SAED image. The comparison shows that when mineralization is incomplete, the diffraction spots are more disordered, proving that it has a disordered structure; when fully mineralized, the diffraction spots prove that the internal crystals grow in a directional manner.

[0044] An optical photograph showing the transfer of a single cadmium carbonate mineralized collagen fiber to a silver electrode during the memristor fabrication process in this embodiment is shown below. Figure 4 A single cadmium carbonate mineralized collagen fiber is connected between the two silver electrodes.

[0045] Figure 5 The image shows the voltage-current curve of the memristor device prepared in this embodiment when it is first applied. The memristor device is initially insulated. When the voltage rises to about 3.3V, the resistance changes abruptly, and the memristor device instantly changes from a low conductivity state to a high conductivity state. When the applied voltage drops to near zero, the device spontaneously returns to a low conductivity state, which has the typical formation process of "memristor".

[0046] Figure 6 The diagram shows the dual threshold switching curve of the memristor device fabricated in this embodiment. After a typical fabrication process, only a threshold voltage of 1.5V is required to switch the device to a high-conductivity state. Applying positive and negative voltages to the device produces similar hysteresis loops, indicating the presence of a threshold switching effect.

[0047] Figure 7 The image shows the multiple pulse cycle test results of the memristor device prepared in this embodiment. After multiple stimulation pulses, the memristor operates stably with a consistent current output. Its relaxation time is also very stable during repeated tests, indicating that the memristor device exhibits excellent short-term memristor performance.

[0048] Comparative Example 1

[0049] A cadmium carbonate-collagen nanofiber is prepared in a manner similar to that of Example 1, except that polyacrylamide hydrochloride aqueous solution is not added to solution B.

[0050] Figure 8 The image shows a SEM image of the cadmium carbonate-collagen nanofibers prepared in this comparative example. As can be seen from the image, the irregularly shaped large cadmium carbonate crystals are deposited only on the surface of the collagen fiber matrix and cannot penetrate into the collagen fiber interior for mineralization.

[0051] Comparative Example 2

[0052] A non-oriented cadmium carbonate-collagen nanofiber is prepared by the following method:

[0053] 1) Strontium chloride and 4-hydroxyethylpiperazine ethanesulfonic acid were dissolved in water to obtain 25 mL of solution A, in which the concentration of strontium chloride was 20 mM and the concentration of 4-hydroxyethylpiperazine ethanesulfonic acid was 20 mM;

[0054] 2) Dissolve sodium carbonate and sodium chloride in water to obtain 25 mL of a mixed solution of sodium carbonate and sodium chloride. The concentration of sodium carbonate in the mixed solution is 20 mM and the concentration of sodium chloride is 300 mM. Prepare an aqueous solution of polyacrylamide hydrochloride (purchased from Thermo Fisher Scientific, Mw = 120000-200000) with a concentration of 800 μg / mL. Take 400 μL and add it to the mixed solution of sodium carbonate and sodium chloride to obtain solution B.

[0055] 3) Using a peristaltic pump, slowly add solution A dropwise to 25 mL of solution B at a speed of 30 rpm. After the addition is complete, stir the resulting mixture on a magnetic stirrer for 10 min to obtain a mineralized solution.

[0056] 4) The frozen-sliced ​​tendon slices (prepared in the same way as in Example 1) were immersed in the mineralization solution and then placed in an oven at 37°C for 9 hours to mineralize. After mineralization, the slices were taken out and rinsed in deionized water to obtain strontium carbonate mineralized tendon slices.

[0057] 5) Place the strontium carbonate mineralized tendon sheet into 20 mL of cadmium chloride solution (concentration 30 mM) and let it stand for 30 min. Rinse it in deionized water, dry it at room temperature, and separate the fibers on the transfer stage with a tungsten needle to obtain single non-oriented cadmium carbonate-collagen nanofibers.

[0058] Using the non-oriented cadmium carbonate-collagen nanofibers prepared in this comparative example as the memristor functional layer, memristor devices were prepared using the same method as in Example 1.

[0059] Figure 9The SEM image of the cadmium carbonate-collagen nanofibers prepared in step 5) of this comparative example shows that a large number of crystalline particles are mineralized on the outside of a single collagen fiber, and the particles grow randomly oriented on the surface.

[0060] Optical photographs showing the transfer of a single cadmium carbonate mineralized collagen fiber onto a silver electrode during the comparative memristor fabrication process are shown below. Figure 10 A single cadmium carbonate mineralized collagen fiber is connected between the two silver electrodes.

[0061] Figure 11 The XRD pattern of the non-oriented cadmium carbonate-collagen nanofibers prepared for this comparative example shows diffraction peaks at angles of 23.5°, 30.3°, and 32.9° that correspond to the standard PDF card (PDF#42-1342) of cadmium carbonate, proving that strontium carbonate in the collagen fibers is completely replaced by cadmium carbonate.

[0062] Figure 12 The image shows the memristor performance test results of the memristor device prepared in this comparative example. No obvious hysteresis loop was observed in the five cycles of testing on this sample, indicating that the unoriented cadmium carbonate particles do not have memristor performance.

Claims

1. A method for preparing cadmium carbonate-collagen nanofiber, wherein cadmium carbonate nanoparticles are grown in order and densely inside collagen fiber, the cadmium carbonate nanoparticles are arranged in the direction of the long axis of the collagen fiber, forming a directional structure, the particle size of the cadmium carbonate nanoparticles is 20-40 nm, and the diameter of the cadmium carbonate-collagen nanofiber is 200-600 nm, characterized in that, The specific steps are as follows: ​ 1) Dissolve cadmium chloride and 4-hydroxyethylpiperazine ethanesulfonic acid in water to obtain solution A; 2) Dissolve sodium carbonate and sodium chloride in water to obtain a mixed solution of sodium carbonate and sodium chloride, and then prepare a polyacrylamide hydrochloride aqueous solution, and then add the polyacrylamide hydrochloride aqueous solution to the mixed solution of sodium carbonate and sodium chloride to obtain solution B; 3) Slowly add solution A obtained in step 1) to solution B obtained in step 2) using a peristaltic pump to obtain a mineralization solution, and then immerse the tendon slice treated by freezing sectioning in the mineralization solution for mineralization, and then obtain single cadmium carbonate-collagen nanofiber after processing.

2. The method for preparing a cadmium carbonate-collagen nanofiber according to claim 1, characterized by, The concentration of cadmium chloride in solution A in step 1) is 20-60 mM, and the molar ratio of cadmium chloride to 4-hydroxyethylpiperazine ethanesulfonic acid is 1-2:

1.

3. The method of claim 1, wherein the method is characterized by, In step 2), the concentration of sodium carbonate in solution B is 20-60 mM, and the molar ratio of sodium carbonate to sodium chloride is 1-3:

15. In step 2), the molecular weight of the polyacrylamide hydrochloride is 120,000-200,000, the concentration of the polyacrylamide hydrochloride aqueous solution is 200-800 μg / mL, and the mass ratio of sodium carbonate in the mixed solution of sodium carbonate and sodium chloride to the mass of polyacrylamide hydrochloride in the polyacrylamide hydrochloride aqueous solution is 150-2000:

1.

4. The method of claim 1, wherein the method is characterized by, In step 3), the molar ratio of cadmium chloride in solution A to sodium carbonate in solution B is 1:1-3.

5. The method of claim 1, wherein the method is characterized by, In step 3), the working speed of the peristaltic pump is 30 rpm, and the mineralization temperature is 25-37°C, and the mineralization time is 3-24 h.

6. The application of cadmium carbonate-collagen nanofiber prepared by the preparation method of any one of claims 1-5 in the preparation of a memristor.

7. A memristor prepared by using the cadmium carbonate-collagen nanofiber prepared by the preparation method according to any one of claims 1 to 5, characterized in that, The memristor uses the cadmium carbonate-collagen nanofiber prepared by the preparation method of any one of claims 1-5 as a memristor functional layer.

8. A method of making the memristor of claim 7, wherein, The specific steps are as follows: two electrodes are arranged in a staggered manner, a flexible polydimethylsiloxane film with a thickness of 2-5 mm is used to adhere the cadmium carbonate-collagen nanofiber prepared by the preparation method of any one of claims 1-5, and the cadmium carbonate-collagen nanofiber is transferred and overlapped on the two electrodes to obtain a memristor.

Images