A method for preparing a tooth enamel-like composite fiber

Abstract

The present application relates to a kind of microstructure and the preparation technology field of biomimetic composite similar to tooth enamel, specifically related to a kind of tooth enamel-like composite fiber and its preparation method.The present application obtains the micro cluster assembled by one-dimensional nanowire by hydrothermal technology, then by means of wet spinning technology, tooth enamel-like biomimetic composite fiber with multi-level structure is prepared.The specific method is (1) the preparation of micro cluster assembled by nanowire is realized using hydrothermal technology;(2) polymer is dissolved in water to obtain clear solution;(3) micro cluster is dispersed into organic solution, and uniform suspension is formed as spinning slurry;(4) wet spinning technology is used, and micro cluster is assembled into macroscopic tooth enamel-like composite fiber.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of microstructure and tooth enamel similar composite fiber preparation technical field, specifically to a kind of tooth enamel-like composite fiber and preparation method thereof. BACKGROUND

[0002] With the rapid development of intelligent fabric, public infrastructure, military equipment and bioengineering, higher requirements are put forward for the strength and toughness of fiber materials. However, the strength and toughness of materials are a pair of contradictory mechanical properties, which makes it impossible for traditional fiber manufacturing process to build strong and tough fiber materials. After hundreds of millions of years of evolution, living beings have been able to produce biological materials with excellent comprehensive mechanical properties, which is beyond the reach of existing engineering materials. Natural tooth enamel, as the hardest biological tissue in mammals, has multi-scale, multi-level micro-nano structure and amorphous interstitial phase, which can generate multiple mechanical dissipation mechanisms during loading process, thus showing excellent impact resistance. Therefore, by taking natural tooth enamel as a construction model, a tooth enamel-like multi-level structure and amorphous component are constructed in the composite fiber material, which is expected to obtain a high-strength and high-toughness tooth enamel-like composite fiber material.

[0003] So far, some tooth enamel-like composite materials based on inorganic structural units have been developed, such as graphene oxide (GO), carbon nanotube (CNT), gold nanowire (Au) and hydroxyapatite (HAP) based tooth enamel-like composite materials. However, due to the simulation of one or two levels in structure, the composite material cannot achieve high strength and high toughness at the same time. SUMMARY

[0004] The present application aims to overcome the shortcomings of existing preparation and assembly methods, and uses simple and green micro-cluster assembled by one-dimensional nanowire, organic polymer and the like as raw materials to prepare a tooth enamel-like composite fiber. A simple, pollution-free and macroscopic preparation method for preparing a tooth enamel-like composite fiber is provided. The present application uses hydrothermal technology to obtain micro-cluster assembled by one-dimensional nanowire, and then uses wet spinning technology to prepare tooth enamel-like composite material.

[0005] The tooth enamel-like composite fiber of the present application contains multi-level micro-nano structure ceramic micro-cluster reinforcing phase and organic polymer toughening phase in the multi-level tooth enamel-like structure material; the multi-level micro-nano structure ceramic micro-cluster is hydroxyapatite micro-cluster with aspect ratio (5-20 μm / 0.5-1.1 μm) of 20-40; and the organic polymer is polyvinyl alcohol and sodium alginate.

[0006] The tensile strength of the tooth-like enamel composite fiber is 178.8-196.3 MPa, the modulus can reach 15.2-18.6 GPa, and the fracture toughness is 31.6-46.3 MJ / m -3 .

[0007] The application also provides a preparation method of the tooth-like enamel composite fiber, comprising the following steps:

[0008] In the first step, sodium silicate nonahydrate is added into an aqueous solution, and stirred at 20-30 DEG C until completely dissolved, then sodium hydroxide and calcium nitrate tetrahydrate are added in sequence, and stirred at 20-30 DEG C until a uniform white suspension is formed and transferred to a high-temperature reaction kettle, and incubated at a specific temperature; the volume of the aqueous solution is 50-100 mL; the concentration of sodium silicate nonahydrate in the reaction system is 7.43-16.71 mg / mL; the concentration of sodium hydroxide in the reaction system is 3.22-9.66 mg / mL; the concentration of calcium nitrate tetrahydrate in the reaction system is 25.17-32.00 mg / mL; the temperature range is 180-240 DEG C; and the incubation time range is 5-26 h;

[0009] In the second step, the reaction product obtained in the first step is centrifuged and washed, then frozen and placed in a freeze dryer for vacuum drying at a low temperature of-50 DEG C to-90 DEG C for 24-48 h to remove the water in the sample, and finally a dry powder sample is obtained; wherein the centrifugal speed range is 5000-10000 r / min, the washing solvent is water, and the washing is performed 1-3 times;

[0010] In the third step, the dry powder in the second step is placed in a phosphate aqueous solution for hydrothermal conversion, and finally hydroxyapatite micrometer clusters are obtained; wherein the phosphate is sodium phosphate / dihydrogen sodium phosphate; the temperature range is 150-180 DEG C; and the incubation time range is 1.5-5.0 h;

[0011] In the fourth step, the reaction product obtained in the third step is centrifuged and washed, then frozen and placed in a freeze dryer for vacuum drying at a low temperature of-50 DEG C to-90 DEG C for 24-48 h to remove the water in the sample, and finally a dry powder sample is obtained; wherein the centrifugal speed range is 5000-10000 r / min, the washing solvent is water, and the washing is performed 1-3 times;

[0012] In the fifth step, the organic matter (polyvinyl alcohol and sodium alginate) is dissolved in water at 60-90 DEG C, and stirred to obtain a colorless and clear solution; wherein the organic polymer is water-soluble; and the mass ratio of polyvinyl alcohol to sodium alginate is 3:1 to 8:1;

[0013] The sixth step is to take the colorless and clear solution obtained in the fifth step, and add the micrometer cluster obtained in the fourth step, and stir at 20-30 DEG C until a uniform white suspension is formed; the concentration of the micrometer cluster in the colorless and clear polymer solution ranges from 0.01 g / mL to 0.03 g / mL;

[0014] The seventh step is to take the reaction product obtained in the sixth step by using a syringe with a range of 1-5 mL, and then perform wet spinning, inject the reaction product into an ethanol coagulation bath, stand for a period of time, draw the spun gel fiber out of the coagulation bath for collection and drying, and finally obtain a macroscopic composite fiber material; wherein the injection speed of the reaction product is 0.1-1 mL / min, the rotating speed of the rotating disc ranges from 10-45 r / min, the standing time is 30-60 s, and the drying temperature ranges from 60-80 DEG C.

[0015] Compared with the existing preparation method of the tooth enamel-like composite fiber, the present application has the following advantages:

[0016] 1. The raw materials used in the preparation process of the present application are simple and easy to obtain, have low cost, can be prepared in large quantities, are environment-friendly, and are easy to operate.

[0017] 2. The tooth enamel-like composite fiber prepared by the present application exhibits excellent mechanical properties: tensile strength of 178.8-196.3 MPa, modulus of 15.2-18.6 GPa, and fracture toughness of 31.6-46.3 MJ / m -3 , which meets the high-strength and high-toughness requirements of the composite fiber in engineering. DETAILED DESCRIPTION

[0018] Figure 1 It is a schematic diagram of the wet spinning process of the present application.

[0019] Figure 2 It is an optical photograph of the sample obtained by the present application.

[0020] Figure 3 It is a scanning electron microscope photograph of the hydroxyapatite micrometer cluster obtained in Example 1 of the present application.

[0021] Figure 4 It is a scanning electron microscope photograph of the tooth enamel-like composite fiber obtained in Example 1 of the present application.

[0022] Figure 5 It is the mechanical data of the tooth enamel-like composite fiber obtained in Example 1 of the present application.

[0023] Figure 6 It is a scanning electron microscope photograph of the tooth enamel-like composite fiber obtained in Example 2 of the present application.

[0024] Figure 7Mechanical data of the enamel-like composite fiber obtained in Example 2 of the present application.

[0025] Figure 8 Scanning electron microscope photograph of the enamel-like composite fiber obtained in Example 3 of the present application.

[0026] Figure 9 Mechanical data of the enamel-like composite fiber obtained in Example 3 of the present application. DETAILED DESCRIPTION

[0027] The preparation method of the enamel-like composite fiber will be specifically described below in combination with the drawings and examples. It should be understood that these examples are only used to illustrate the present application and do not limit the protection scope of the present application in any way.

[0028] Example 1

[0029] Preparation method of the enamel-like composite fiber based on hydroxyapatite microcluster and polyvinyl alcohol / sodium alginate directional assembly

[0030] In the first step, sodium silicate nonahydrate is added into an aqueous solution, stirred at 25°C until completely dissolved, and then sodium hydroxide and calcium nitrate tetrahydrate are added in sequence, stirred at 25°C until a uniform white suspension is formed and transferred to a high-temperature reaction kettle, and then incubated at a specific temperature; the volume of the aqueous solution is 100 mL; the concentration of the sodium silicate nonahydrate in the reaction system is 11.44 mg / mL; the concentration of the sodium hydroxide in the reaction system is 6.44 mg / mL; the concentration of the calcium nitrate tetrahydrate in the reaction system ranges from 29.74 mg / mL; the temperature ranges from 220°C; and the incubation time ranges from 24 h;

[0031] In the second step, the reaction product obtained in the first step is centrifuged and washed, and then frozen and placed in a freeze dryer for vacuum drying at a low temperature of -90°C for 48 h to remove the water in the sample, and finally a dry powder sample is obtained; wherein the centrifugal speed ranges from 8000 r / min, the washing solvent is water and ethanol, and the washing is performed for 3 times;

[0032] In the third step, the dry powder in the second step is placed in an aqueous phosphate solution for hydrothermal conversion, and finally hydroxyapatite microclusters are obtained; wherein the phosphate is sodium phosphate; the temperature ranges from 150°C; and the incubation time ranges from 1.5 h;

[0033] In the fourth step, the reaction product obtained in the third step is centrifuged and washed, and then frozen and placed in a freeze dryer for vacuum drying at a low temperature of -90°C for 48 h to remove the water in the sample, and finally a dry powder sample is obtained; wherein the centrifugal speed ranges from 8000 r / min, the washing solvent is water and ethanol, and the washing is performed for 3 times;

[0034] Fifth step, dissolving the organic matter in 6 mL water at 80℃, stirring to get a colorless clear solution; wherein the organic polymer is water-soluble; the organic matter is 240 mg polyvinyl alcohol and 40 mg sodium alginate;

[0035] Sixth step, taking the colorless clear solution obtained in the fifth step, adding the micron cluster obtained in the fourth step, stirring at 25℃ until a uniform white suspension is formed; the concentration of the micron cluster in the colorless clear polymer solution ranges from 0.017 g / mL;

[0036] Seventh step, using a syringe with a range of 1-5 mL to suck the reaction product obtained in the sixth step, then wet spinning (as shown in Figure 1 ), injecting the reactant into an ethanol coagulation bath, standing for a period of time, drawing the spun gel fiber out of the coagulation bath for collection and drying, and finally obtaining a macroscopic composite fiber material (as shown in Figure 2 ); wherein the syringe range is 2 mL, the injection speed of the reactant is 0.7 mL / min, the rotating speed of the rotating disc ranges from 30 r / min, the standing time is 60 s, and the drying temperature ranges from 60℃;

[0037] In the present application, transmission electron microscopy is used to characterize the hydroxyapatite micron cluster prepared in Example 1 (as shown in Figure 3 ), and the characterization finds that the micron cluster is composed of oriented nanowires. Scanning electron microscopy is used to characterize the enamel-like composite fiber prepared in Example 1 (referred to as CAHMBFS, see Figure 4 ), and the characterization finds that it has an enamel-like multi-level ordered structure. A universal tensile testing machine is used to test Example 1 (as shown in Figure 5 ), and the tensile speed is 0.5 mm / min, the tensile strength is 196.3 MPa, the modulus is 18.6 GPa, and the fracture toughness is 46.3 MJ m -3 .

[0038] Example 2

[0039] Preparation method of enamel-like composite fiber based on oriented assembly of hydroxyapatite micron cluster and polyvinyl alcohol

[0040] The first step, sodium silicate nonahydrate is added into an aqueous solution, stirring at 25°C until completely dissolved, sodium hydroxide and calcium nitrate tetrahydrate are added in turn, stirring at 25°C until a uniform white suspension is formed and transferred to a high-temperature reaction kettle, incubated at a specific temperature; the volume of the aqueous solution is 100 mL; the concentration of sodium silicate nonahydrate in the reaction system is 11.44 mg / mL; the concentration of sodium hydroxide in the reaction system is 6.44 mg / mL; the concentration of calcium nitrate tetrahydrate in the reaction system ranges from 29.74 mg / mL; the temperature ranges from 220°C; the incubation time ranges from 24 h;

[0041] The second step, the reaction product obtained in the first step is centrifuged and washed, then frozen and placed in a freeze dryer for vacuum drying at a low temperature of -90°C for 48 h to remove water in the sample, finally obtaining a dry powder sample; wherein the centrifugal speed ranges from 8000 r / min, the washing solvent is water and ethanol, and the washing is performed for 3 times;

[0042] The third step, the dry powder in the second step is placed in a sodium phosphate aqueous solution for hydrothermal conversion, the temperature ranges from 150°C, and the incubation time ranges from 1.5 h, finally obtaining hydroxyapatite micrometer clusters;

[0043] The fourth step, the reaction product obtained in the third step is centrifuged and washed, then frozen and placed in a freeze dryer for vacuum drying at a low temperature of -90°C for 48 h to remove water in the sample, finally obtaining a dry powder sample; wherein the centrifugal speed ranges from 8000 r / min, the washing solvent is water and ethanol, and the washing is performed for 3 times;

[0044] The fifth step, 240 mg of polyvinyl alcohol is dissolved in 6 mL of water in an 80° water bath, stirring to obtain a colorless clear solution;

[0045] The sixth step, the colorless clear solution obtained in the fifth step is taken, 0.1 g of hydroxyapatite micrometer clusters is added, stirring at a stirring rate of 300 revolutions per minute in a 30°C water bath for 48 h to form a uniform white suspension;

[0046] The seventh step, the reaction product obtained in the sixth step is taken by a syringe with a range of 1-5 mL, then wet spinning (as shown in Figure 1 ) is performed, the reactant is injected into an ethanol coagulation bath, left for a period of time, the spun gel fiber is drawn out of the coagulation bath for collection and drying, finally obtaining a macroscopic composite fiber material; wherein the syringe range is 2 mL, the injection speed of the reactant is 0.7 mL / min, the rotation speed of the rotating disc ranges from 30 r / min, the standing time is 60 s, and the drying temperature ranges from 60°C;

[0047] In the present application, the scanning electron microscope is used to characterize the tooth-like enamel composite fibers prepared in Example 2 (as shown in Figure 6 The characterization found that it has a tooth-like enamel multi-level ordered structure. The universal tensile testing machine is used to test Example 2 (as shown in Figure 7 The tensile strength is 180.1 MPa, the modulus is 15.5 GPa, and the fracture toughness is 30 MJ m -3 .

[0048] Example 3

[0049] Preparation method of tooth-like enamel composite fibers based on hydroxyapatite nanowires and polyvinyl alcohol / sodium alginate directional assembly

[0050] First step, 1.4g NaOH is dissolved in 15mL distilled water, and is added dropwise to a mixed solution containing 10.5mL oleic acid, 6mL ethanol and 13.5mL distilled water, and is stirred for 30 minutes. Subsequently, 0.333g CaCl2 is dissolved in 12mL distilled water and is added dropwise to the above solution, and is stirred vigorously for 30 minutes, and after ion exchange, calcium oleate is formed. Secondly, 0.936g NaH2PO4·2H2O is dissolved in 12mL distilled water and is added dropwise to the above solution, and is stirred for 30 minutes to form amorphous calcium phosphate. After that, the precursor suspension formed is transferred to a 100mL hydrothermal reactor, and is reacted at 180℃ for 18 hours.

[0051] Second step, the reaction product obtained in the first step is centrifuged and washed, and then is frozen and placed in a freeze dryer for vacuum drying at a low temperature of-90℃ for 48h to remove the water in the sample, and finally a dry powder sample is obtained; wherein the centrifugal speed is in the range of 8000r / min, the washing solvent is water and ethanol, and the washing is performed 3 times;

[0052] Third step, the organic matter is dissolved in 6mL water at 80℃, and a colorless clear solution is obtained by stirring; wherein the organic polymer is water-soluble; the organic matter is 240mg polyvinyl alcohol and 40mg sodium alginate;

[0053] Fourth step, the colorless clear solution obtained in the third step is taken, and the hydroxyapatite nanowires obtained in the second step are added, and are stirred at 25℃ until a uniform white suspension is formed; the concentration of the nanowires in the colorless clear polymer solution is in the range of 0.017g / mL;

[0054] Fifth step, the suspension obtained in the fourth step is taken by a syringe with a range of 1-5mL, and then wet spinning is performed (as shown in Figure 1The reaction is injected into an ethanol coagulation bath, the spun gel fiber is drawn out of the coagulation bath for collection and drying, and finally a macro composite fiber material is obtained; wherein the syringe range is 2 mL, the reaction injection speed is 0.7 mL / min, the rotating disc rotating speed range is 30 r / min, the standing time is 60 s, and the drying temperature range is 60 DEG C;

[0055] In the present application, the scanning electron microscope is used to characterize the tooth enamel-like composite fiber prepared in Example 3 (as shown in Figure 8 The characterization finds that it has a tooth enamel-like multi-level ordered structure. The universal tensile testing machine is used to test the Example 3 (as shown in Figure 9 The tensile speed is 0.5 mm / min, the tensile strength is 135.0 MPa, the modulus is 13.5 GPa, and the fracture toughness is 25.2 MJ / m -3 .

Claims

1. A method for preparing enamel-like composite fibers, characterized in that... Includes the following steps: The first step involves adding sodium silicate nonahydrate to an aqueous solution and stirring at 20–30°C until completely dissolved. Sodium hydroxide and calcium nitrate tetrahydrate are then added sequentially, and the mixture is stirred at 20–30°C until a uniform white suspension is formed. This suspension is then transferred to a high-temperature reactor and kept at a specific temperature. The volume of the aqueous solution is 50–100 mL; the concentration of sodium silicate nonahydrate in the reaction system is 7.43–16.71 mg / mL; the concentration of sodium hydroxide in the reaction system is 3.22–9.66 mg / mL; the concentration of calcium nitrate tetrahydrate in the reaction system is 25.17–32.00 mg / mL; the temperature range is 180–240°C; and the holding time ranges from 5 to 26 hours. The second step involves centrifuging and washing the reaction product obtained in the first step, then placing it in a freeze dryer and vacuum drying it at a low temperature of -50℃ to -90℃ for 24-48 hours to remove moisture from the sample, finally obtaining a dry powder sample; wherein the centrifugation speed range is 5000-10000 r / min, the washing solvent is water, and the washing is performed 1-3 times. The third step involves placing the dried powder from the second step into a phosphate aqueous solution for hydrothermal conversion, ultimately yielding hydroxyapatite micron clusters; wherein the phosphate is sodium phosphate or sodium dihydrogen phosphate; the temperature range is 150-180℃; and the holding time ranges from 1.5 to 5.0 h. The fourth step involves centrifuging and washing the reaction product obtained in the third step, then placing it in a freeze dryer and vacuum drying it at a low temperature of -50℃ to -90℃ for 24-48 hours to remove moisture from the sample, finally obtaining a dry powder sample; wherein the centrifugation speed range is 5000-10000 r / min, the washing solvent is water, and the washing is performed 1-3 times. Fifth step: Dissolve the organic compounds polyvinyl alcohol and sodium alginate in water at 60-90℃ and stir to obtain a colorless and clear solution; the mass ratio of polyvinyl alcohol to sodium alginate is 3:1 to 8:

1. Step 6: Take the colorless and clear solution obtained in Step 5, add the micron clusters obtained in Step 3, and stir at 20-30°C until a uniform white suspension is formed; the concentration of the micron clusters in the colorless and clear organic solution is in the range of 0.01 g / mL to 0.03 g / mL; Step 7: Using a syringe with a volume range of 1-5 mL, the reaction product obtained in step 6 is drawn up and then wet-spun. The reactant is injected into a coagulation bath containing ethanol, allowed to stand for a period of time, and the spun gel fibers are drawn out of the coagulation bath for collection and drying. Finally, inorganic / organic composite fiber material is obtained. The reaction injection rate is 0.1-1 mL / min, the turntable speed range is 10-45 r / min, the standing time is 30-60 s, and the drying temperature range is 60-80℃.

2. The method for preparing enamel-like composite fibers according to claim 1, characterized in that: The final product is an inorganic / organic composite material, with the mass ratio of organic matter to water being 1:

20.

3. The method for preparing enamel-like composite fibers according to claim 1, characterized in that: The concentration of polyvinyl alcohol in the spinning solution is 30-60 mg / mL, and the concentration of sodium alginate is 3.4-13.4 mg / mL.

4. The method for preparing enamel-like composite fibers according to claim 1, characterized in that: The concentration of polyvinyl alcohol in the spinning solution is 40 mg / mL, and the concentration of sodium alginate is 6.7 mg / mL.

5. The method for preparing enamel-like composite fibers according to claim 1, characterized in that: The hydroxyapatite microclusters consist of oriented one-dimensional nanowires with a length of 5–20 μm and a diameter of 0.5–1.1 μm.

6. The method for preparing enamel-like composite fibers according to claim 1, characterized in that: The concentration of hydroxyapatite microclusters in the spinning solution ranges from 0.01 g / mL to 0.025 g / mL.

7. The method for preparing enamel-like composite fibers according to claim 1, characterized in that: When performing wet spinning, the syringe has a volume range of 2 mL, an injection port diameter of 110 μm, and an injection rate of 0.1-1 mL / min.

8. The method for preparing enamel-like composite fibers according to claim 1, characterized in that: When wet spinning is performed, the rotational speed of the turntable is in the range of 10-45 r / min.

9. The method for preparing enamel-like composite fibers according to claim 1, characterized in that: When performing wet spinning, the coagulation bath is anhydrous ethanol.

10. The method for preparing enamel-like composite fibers according to claim 1, characterized in that: The spun gel fibers are drawn out of the coagulation bath for collection and drying.

11. The method for preparing enamel-like composite fibers according to claim 1, characterized in that: The hydroxyapatite microclusters in the tooth-like enamel composite fiber are arranged in an orderly manner along the c-axis of the fiber, with a diameter range of 20-30 μm.

12. The method for preparing enamel-like composite fibers according to claim 1, characterized in that: The enamel-like composite fiber described above has a multi-level structure similar to that of tooth enamel.

13. The method for preparing enamel-like composite fibers according to claim 1, characterized in that: The enamel-like composite fiber has a tensile strength of 178.8–196.3 MPa, a modulus of 15.2–18.6 GPa, and a fracture toughness of 31.6–46.3 MJ / m. -3 .

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