CN102515744B - A kind of CaCu3Ti4O12 micro-nano fiber and its preparation method - Google Patents

Abstract

The invention discloses a CaCu3Ti4O12 micro nano sized fiber and its preparation method, which belongs to the inorganic material technical field. The CaCu3Ti4O12 micro nano sized fiber comprises the elements of Ca, Cu, Ti and O with the mol ratio of 13412, and the diameter is 200-300 nanometers. The preparation method comprises the following steps mixing anhydrous ethyl alcohol, calcium nitrate tetrahydrate and copper acetate monohydrate to obtain a solution A; mixing anhydrous ethanol, butyl titanate and a spinning auxiliary agent to obtain a solution B; slowly adding the solution B in the solution A, and using a static spinning technology to prepare the CaCu3Ti4O12 micro nano sized fiber. The method of the invention can effectively control the hydrolysis process of the raw materials by selecting and adjusting the ratio of raw materials and the spinning auxiliary agent, the obtained static spinning solution possesses spinnability, and the method of the invention provides the novel CaCu3Ti4O12 micro nano sized fiber. The preparation method has the advantages of simple process, mild condition, easy control and wide applicability.

Description

A kind of CaCu3Ti4O12 micro-nano fiber and its preparation method

technical field

The invention relates to an inorganic fiber material technology, in particular to a micro-nano ceramic fiber and a preparation method thereof.

Background technique

Materials with high dielectric constant can be used in the manufacture of small-volume capacitive devices, which provides a great possibility for the miniaturization of electronic devices, so it has a wide range of applications in the fields of micro-resonators, filters, mobile phones, etc., in Playing an increasingly important role in the microelectronics industry.

Subramanian et al. (M.A. Subramanian, Dong Li, et al. J. Solid State Chemistry, 2000, 151: 323-325) discovered CaCu with a perovskite-like structure in 2000 ₃ Ti ₄ o ₁₂ (abbreviated as CCTO) has a very high dielectric constant (generally greater than 10,000) in the temperature range of 100-500K, and in a wide temperature range, there is no structural phase transition and ferroelectric phase transition. Therefore, this The application of materials in the electronics industry has broad prospects.

One-dimensional micro-nano materials represented by fibers have special optical properties, electrical properties and spatial geometry, and are ideal materials for the development of new electronic transport properties, optical properties and mechanical properties. However, currently CaCu ₃ Ti ₄ o ₁₂ It is limited to the existing forms of ceramic sintered body, powder and film, and there is no information about CaCu ₃ Ti ₄ o ₁₂ The reports of micro-nano fibers limit their application in high-tech fields such as sensors.

Currently, the preparation of CaCu ₃ Ti ₄ o ₁₂ The sample methods are mainly solid sintering method, sol-gel method and pulsed laser deposition method. The solid sintering method prepares ultra-fine powders of each component by mechanical grinding, and then prepares dense microcrystalline ceramics by high-temperature solid-phase sintering; CaCu ₃ Ti ₄ o ₁₂ ceramics. The sol-gel method is an effective method for preparing uniform nano-ultrafine powder, which has the characteristics of high purity, molecular chemical uniformity of each component, controllable particle size, and simple equipment. Pulsed laser deposition can grow high-temperature superconducting thin films in situ, and has broad application prospects in the preparation of thin film materials and nanostructured materials. However, there are still many difficulties in preparing higher-quality nanomaterials, and due to the short research time, how to control the formation of nanostructures and the growth mechanism of nanostructures more easily and simply needs to be further explored. None of the above three methods can obtain CaCu ₃ Ti ₄ o ₁₂ micro-nano fibers.

In recent years, electrospinning technology has received widespread attention. It is a method of obtaining fibers through high-voltage static electricity. Its core is to make the charged spinning solution flow and deform in an electrostatic field. The body is cooled and solidified to obtain fibers. Electrospinning has distinct advantages over other methods. For example, the aspect ratio of the prepared fiber is very large, and the fiber length can reach the macro scale; the preparation conditions are mild, the speed is fast, the output is large, the application is wide, and the preparation process is very simple, which is a very effective and convenient method for preparing fibers. Prior to the present invention, a Chinese invention patent (CN102084044A) disclosed a method for producing inorganic nanofibers by electrospinning of a solution comprising metal or semimetal or non- metal alkoxides. The solution is stabilized by a chelating agent that prevents the hydrolysis of the alkoxylates, after homogenization the solution is mixed with a solution of poly(vinylpyrrolidone) in alcohol, and the resulting solution is delivered to an electrostatic field where continuous Electrospinning is performed, the result of which is the production of organic-inorganic nanofibers, which are then calcined outside the spinning equipment at a temperature of 500-1300°C in an air atmosphere. Chinese invention patent "A method for preparing alumina nanofibers by electrospinning" (CN 101982581A) dissolves the polymer in a solvent, and then adds aluminum acetylacetonate to the polymer solution to prepare a spinning solution, which is electrospun and sintering treatment to obtain alumina nanofibers. What above-mentioned technical scheme provides is to prepare the fiber of simple oxide, and CaCu ₃ Ti ₄ o ₁₂ Ceramics are composed of three metal elements in a fixed ratio. When titanium alkoxides and inorganic salts corresponding to calcium and copper are used as raw materials, the inorganic salts of calcium and copper contain crystal water and their own water absorption. , will lead to rapid hydrolysis and polymerization of metal alkoxylates, and even produce some gels, so that the viscosity of the spinning solution increases geometrically, far beyond the range that can be used for electrospinning. This phenomenon is very easy to occur in Before spinning, it brings difficulties to the electrospinning process, and even makes electrospinning impossible. Therefore, there is no CaCu ₃ Ti ₄ o ₁₂ The use of nanofibers, in the prior art, has not been seen about the electrospinning method to prepare CaCu ₃ Ti ₄ o ₁₂ Report on micro-nano fibers.

Contents of the invention

In order to overcome the deficiencies in the prior art, the object of the present invention is to provide a CaCu ₃ Ti ₄ o ₁₂ Micro-nano fibers, and a CaCu with simple process, mild conditions and wide application ₃ Ti ₄ o ₁₂ Preparation method of micro-nano fibers.

The technical solution adopted to realize the object of the invention is to provide a CaCu ₃ Ti ₄ o ₁₂ Micro-nano fiber, which includes elements Ca, Cu, Ti and O, and their molar ratio is 1:3:4:12; the diameter of the fiber is 200-300 nanometers.

a CaCu ₃ Ti ₄ o ₁₂ A preparation method for micro-nano fibers, comprising the steps of:

1. Under stirring conditions, by weight, add 100-200 parts of absolute ethanol, 1-5 parts of calcium nitrate tetrahydrate and 2-10 parts of copper acetate monohydrate into the reaction vessel. Under the condition of constant temperature reaction for 1 to 5 hours, the solution A is obtained;

2. Under stirring conditions, add 5-30 parts of polyvinylpyrrolidone, 100-200 parts of absolute ethanol, 3-15 parts of spinning aid and 3-15 parts of butyl titanate into the reaction vessel by weight , reacting at a constant temperature for 1 to 3 hours at a temperature of 20 to 50° C. to obtain a solution B;

3. Slowly add solution B to solution A under stirring conditions to obtain an electrospinning solution;

4. The fiber is obtained by electrospinning process;

5. Dry the fiber obtained by electrospinning at 50-70°C for 12-18 hours, then heat it to 900-1000°C at a heating rate of 5-10°C/min, and keep the temperature constant for 2-5 hours to obtain CaCu ₃ Ti ₄ o ₁₂ micro-nano fibers.

The spinning aid is one of acetic acid, tetramethylammonium hydroxide, or potassium hydroxide.

The electrospinning process uses a voltage of 15-30 kV, a curing distance of 5-15 cm, and the receiving device is aluminum foil.

Compared with the prior art, the present invention has the beneficial effect of providing a CaCu ₃ Ti ₄ o ₁₂ fiber, which is CaCu ₃ Ti ₄ o ₁₂ a new form of existence. The invention effectively controls the hydrolysis process of the raw materials by adjusting the ratio of the experimental raw materials, the addition mode and the spinning auxiliary agent, so that the electrospinning process can be carried out smoothly. The proposed preparation method has the characteristics of simple process, mild conditions, easy control and wide application.

Description of drawings

Fig. 1 is the CaCu that the embodiment of the present invention 1 provides ₃ Ti ₄ o ₁₂ SEM images of micro-nano fibers;

Fig. 2 is the CaCu that the embodiment of the present invention 1 provides ₃ Ti ₄ o ₁₂ XRD patterns of micro-nano fibers;

Fig. 3 is the CaCu that the embodiment of the present invention 5 provides ₃ Ti ₄ o ₁₂ SEM images of micro-nano fibers;

Fig. 4 is the CaCu that the embodiment of the present invention 5 provides ₃ Ti ₄ o ₁₂ XRD patterns of micro-nano fibers;

Fig. 5 is the CaCu that the embodiment of the present invention 8 provides ₃ Ti ₄ o ₁₂ SEM images of micro-nano fibers;

Fig. 6 is the CaCu that the embodiment of the present invention 8 provides ₃ Ti ₄ o ₁₂ XRD patterns of micro-nano fibers.

Detailed ways

The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Example 1

1. Under stirring conditions, add 10 ml of absolute ethanol, 1.04 g of calcium nitrate tetrahydrate and 2.63 g of copper acetate monohydrate into the reaction vessel, and react at a constant temperature of 30°C for 2 hours to obtain solution A;

2. Under stirring conditions, add 1.5 g of polyvinylpyrrolidone, 10 ml of absolute ethanol, 3 ml of acetic acid and 6 ml of butyl titanate into the reaction vessel, and react at a constant temperature of 30 ° C for 1 hour to obtain a solution B;

3. Under stirring conditions, all the solution B prepared in step 2 was slowly added dropwise to solution A at a rate of 100 ml per hour to obtain solution C;

4. Electrospinning solution C, the voltage used for electrospinning is 16.50 kV, the injection rate is 6.5 ml/hour, the curing distance is 12 cm, the receiving device is aluminum foil, and the electrospinning time is 3 hours. corresponding fibers;

5. Dry the fiber obtained by electrospinning at 60°C for 15 hours, then heat it to 900°C at a heating rate of 5°C/min, and keep the temperature constant for 3 hours to obtain a new type of CaCu ₃ Ti ₄ o ₁₂ fiber.

Referring to accompanying drawing 1 is the CaCu that embodiment 1 provides ₃ Ti ₄ o ₁₂ SEM image of the fiber, it can be seen that CaCu ₃ Ti ₄ o ₁₂ It exists in the form of fibers with a diameter of about 200-300 nanometers.

Referring to accompanying drawing 2 is present embodiment CaCu ₃ Ti ₄ o ₁₂ The XRD pattern of the fiber, from which it can be seen that the CaCu ₃ Ti ₄ o ₁₂ The structure of the fiber is pure CaCu ₃ Ti ₄ o ₁₂ Mutually.

Example 2

1. Under stirring conditions, add 15 ml of absolute ethanol, 1.04 g of calcium nitrate tetrahydrate and 2.63 g of copper acetate monohydrate into the reaction vessel, and react at a constant temperature of 45°C for 3 hours to obtain solution A;

2. Under stirring conditions, add 2.5 grams of polyvinylpyrrolidone, 15 milliliters of absolute ethanol, 1.5 grams of tetramethylammonium hydroxide and 6 milliliters of butyl titanate into the reaction vessel, and react at a constant temperature of 45°C for 3 Hour, obtain solution B;

3. Under stirring conditions, slowly add all the solution B prepared in step 2 to solution A at a rate of 200 ml per hour to obtain solution C;

4. Electrospinning solution C, the voltage used for electrospinning is 19.50 kV, the injection rate is 8.5 ml/hour, the curing distance is 15 cm, the receiving device is aluminum foil, and the electrospinning time is 2 hours. corresponding fibers;

5. Dry the fiber obtained by electrospinning at 70°C for 18 hours, then heat it to 950°C at a heating rate of 10°C/min, and keep the temperature constant for 5 hours to obtain a new type of CaCu ₃ Ti ₄ o ₁₂ fiber.

Example 3

1. Under stirring conditions, add 20 ml of absolute ethanol, 2.08 g of calcium nitrate tetrahydrate and 5.26 g of copper acetate monohydrate into the reaction vessel, and react at a constant temperature of 50° C. for 1 hour to obtain solution A;

2. Under stirring conditions, add 3 grams of polyvinylpyrrolidone, 20 milliliters of absolute ethanol, 3 grams of tetramethylammonium hydroxide and 12 milliliters of butyl titanate into the reaction vessel, and react at a constant temperature of 50 ° C for 1 Hour, obtain solution B;

3. Under stirring conditions, all the solution B prepared in step 2 was slowly added dropwise to solution A at a rate of 150 ml per hour to obtain solution C;

4. Electrospinning solution C, the voltage used for electrospinning is 23.50 kV, the injection rate is 9.5 ml/hour, the curing distance is 15 cm, the receiving device is aluminum foil, and the electrospinning time is 2 hours. corresponding fibers;

5. Dry the fiber obtained by electrospinning at 50°C for 12 hours, then heat it to 1000°C at a heating rate of 7°C/min, and keep the temperature constant for 2 hours to obtain a new type of CaCu ₃ Ti ₄ o ₁₂ fiber.

Example 4

1. Under stirring conditions, add 15 ml of absolute ethanol, 1.56 g of calcium nitrate tetrahydrate and 3.95 g of copper acetate monohydrate into the reaction vessel, and react at a constant temperature of 20°C for 1 hour to obtain solution A;

2. Under stirring conditions, add 1.9 grams of polyvinylpyrrolidone, 18 milliliters of absolute ethanol, 1 gram of potassium hydroxide and 9 milliliters of butyl titanate into the reaction vessel, and react at a constant temperature of 20 ° C for 1 hour to obtain Solution B;

3. Under stirring conditions, slowly add all the solution B prepared in step 2 to solution A at a rate of 200 ml per hour to obtain solution C;

4. Electrospinning solution C, the voltage used for electrospinning is 27.50 kV, the injection rate is 8.5 ml/hour, the curing distance is 12 cm, the receiving device is aluminum foil, and the electrospinning time is 2 hours. corresponding fibers;

5. Dry the fiber obtained by electrospinning at 70°C for 18 hours, then heat it to 1000°C at a heating rate of 9°C/min, and keep the temperature constant for 3 hours to obtain a new type of CaCu ₃ Ti ₄ o ₁₂ fiber.

Example 5

1. Under stirring conditions, add 20 ml of absolute ethanol, 1.56 g of calcium nitrate tetrahydrate and 3.95 g of copper acetate monohydrate into the reaction vessel, and react at a constant temperature of 50°C for 1 hour to obtain solution A;

2. Add 3 grams of polyvinylpyrrolidone, 20 milliliters of absolute ethanol, 1.5 grams of potassium hydroxide and 9 milliliters of butyl titanate into the reaction vessel under stirring conditions, and react at a constant temperature of 20°C for 3 hours to obtain Solution B;

3. Under stirring conditions, slowly add all the solution B prepared in step 2 to solution A at a rate of 200 ml per hour to obtain solution C;

4. Electrospinning the solution C, the voltage used for electrospinning is 30 kV, the injection rate is 10 ml/hour, the curing distance is 15 cm, the receiving device is aluminum foil, and the electrospinning time is 2 hours, the obtained corresponding fibers;

5. Dry the fiber obtained by electrospinning at 70°C for 18 hours, then heat it to 1000°C at a heating rate of 5°C/min, and keep the temperature constant for 3 hours to obtain a new type of CaCu ₃ Ti ₄ o ₁₂ fiber.

Referring to accompanying drawing 3 and 4 is the CaCu that present embodiment provides respectively ₃ Ti ₄ o ₁₂ The SEM image and XRD image of the fiber, it can be seen that CaCu ₃ Ti ₄ o ₁₂ Exists in fiber form and is pure CaCu ₃ Ti ₄ o ₁₂ phase with a diameter of about 200 to 300 nanometers.

Example 6

1. Under stirring conditions, add 20 ml of absolute ethanol, 1.56 g of calcium nitrate tetrahydrate and 3.95 g of copper acetate monohydrate into the reaction vessel, and react at a constant temperature of 20°C for 5 hours to obtain solution A;

2. Under stirring conditions, add 1.3 grams of polyvinylpyrrolidone, 20 milliliters of absolute ethanol, 0.5 grams of potassium hydroxide and 9 milliliters of butyl titanate into the reaction vessel, and react at a constant temperature of 20 ° C for 3 hours to obtain Solution B;

3. Under stirring conditions, slowly add all the solution B prepared in step 2 to solution A at a rate of 200 ml per hour to obtain solution C;

4. Electrospinning solution C, the voltage used for electrospinning is 15 kV, the injection rate is 1 ml/hour, the curing distance is 5 cm, the receiving device is aluminum foil, and the electrospinning time is 5 hours, and the obtained corresponding fibers;

5. Dry the fiber obtained by electrospinning at 50°C for 12 hours, then heat it to 900°C at a heating rate of 10°C/min, and keep the temperature constant for 5 hours to obtain a new type of CaCu ₃ Ti ₄ o ₁₂ fiber.

Example 7

1. Under stirring conditions, add 10 ml of absolute ethanol, 0.78 g of calcium nitrate tetrahydrate and 1.98 g of copper acetate monohydrate into the reaction vessel, and react at a constant temperature of 20°C for 5 hours to obtain solution A;

2. Under stirring conditions, add 0.5 g of polyvinylpyrrolidone, 10 ml of absolute ethanol, 0.8 ml of acetic acid and 4.5 ml of butyl titanate into the reaction vessel, and react at a constant temperature of 20 ° C for 3 hours to obtain solution B ;

3. Under stirring conditions, all the solution B prepared in step 2 was slowly added dropwise to solution A at a rate of 100 ml per hour to obtain solution C;

4. Electrospinning solution C, the voltage used for electrospinning is 15 kV, the injection rate is 2.3 ml/hour, the curing distance is 10 cm, the receiving device is aluminum foil, and the electrospinning time is 5 hours. corresponding fibers;

5. Dry the fiber obtained by electrospinning at 60°C for 12 hours, then heat it to 950°C at a heating rate of 5°C/min, and keep the temperature constant for 2 hours to obtain a new type of CaCu ₃ Ti ₄ o ₁₂ fiber.

Example 8

1. Under stirring conditions, add 20 ml of absolute ethanol, 2.08 g of calcium nitrate tetrahydrate and 5.26 g of copper acetate monohydrate into the reaction vessel, and react at a constant temperature of 30°C for 1 hour to obtain solution A;

2. Under stirring conditions, add 2.5 grams of polyvinylpyrrolidone, 15 milliliters of absolute ethanol, 1.5 grams of tetramethylammonium hydroxide and 12 milliliters of butyl titanate into the reaction vessel, and react at a constant temperature of 50 ° C for 1 Hour, obtain solution B;

3. Under stirring conditions, all the solution B prepared in step 2 was slowly added dropwise to solution A at a rate of 150 ml per hour to obtain solution C;

4. Electrospinning solution C, the voltage used for electrospinning is 23.50 kV, the injection rate is 9.5 ml/hour, the curing distance is 15 cm, the receiving device is aluminum foil, and the electrospinning time is 2 hours. corresponding fibers;

5. Dry the fiber obtained by electrospinning at 50°C for 12 hours, then heat it to 950°C at a heating rate of 5°C/min, and keep the temperature constant for 2 hours to obtain a new type of CaCu ₃ Ti ₄ o ₁₂ fiber.

Referring to accompanying drawing 5 and 6, it is the CaCu that present embodiment provides respectively ₃ Ti ₄ o ₁₂ The SEM image and XRD image of the fiber, it can be seen that CaCu ₃ Ti ₄ o ₁₂ Exists in fiber form and is pure CaCu ₃ Ti ₄ o ₁₂ phase with a diameter of about 200 to 300 nanometers.

Example 9

1. Under stirring conditions, add 18 ml of absolute ethanol, 1.04 g of calcium nitrate tetrahydrate and 2.63 g of copper acetate monohydrate into the reaction vessel, and react at a constant temperature of 35°C for 3 hours to obtain solution A;

2. Under stirring conditions, add 2.1 grams of polyvinylpyrrolidone, 18 milliliters of absolute ethanol, 1.8 grams of tetramethylammonium hydroxide and 6 milliliters of butyl titanate into the reaction vessel, and react at a constant temperature of 45°C for 3 Hour, obtain solution B;

3. Under stirring conditions, all the solution B prepared in step 2 was slowly added dropwise to solution A at a rate of 100 ml per hour to obtain solution C;

4. Electrospinning solution C, the voltage used for electrospinning is 22.50 kV, the injection rate is 7.5 ml/hour, the curing distance is 17 cm, the receiving device is aluminum foil, and the electrospinning time is 2 hours. corresponding fibers;

5. Dry the fiber obtained by electrospinning at 70°C for 18 hours, then heat it to 900°C at a heating rate of 10°C/min, and keep the temperature constant for 4 hours to obtain a new type of CaCu ₃ Ti ₄ o ₁₂ fiber.

Example 10

1. Under stirring conditions, add 13 ml of absolute ethanol, 1.04 g of calcium nitrate tetrahydrate and 2.63 g of copper acetate monohydrate into the reaction vessel, and react at a constant temperature of 45°C for 3 hours to obtain solution A;

2. Under stirring conditions, add 1.9 grams of polyvinylpyrrolidone, 13 milliliters of absolute ethanol, 1.1 grams of tetramethylammonium hydroxide and 6 milliliters of butyl titanate into the reaction vessel, and react at a constant temperature of 45°C for 3 Hour, obtain solution B;

3. Under stirring conditions, slowly add all the solution B prepared in step 2 to solution A at a rate of 200 ml per hour to obtain solution C;

4. Electrospinning solution C, the voltage used for electrospinning is 21.50 kV, the injection rate is 9.5 ml/hour, the curing distance is 16 cm, the receiving device is aluminum foil, and the electrospinning time is 2 hours. corresponding fibers;

5. Dry the fiber obtained by electrospinning at 65°C for 15 hours, then heat it to 950°C at a heating rate of 5°C/min, and keep the temperature constant for 4 hours to obtain a new type of CaCu ₃ Ti ₄ o ₁₂ fiber.

Claims (3)

1. CaCu ₃Ti ₄O ₁₂Micro-nano level fiber preparation method is characterized in that comprising the steps:

(1) under agitation condition, by weight, 100～200 parts of dehydrated alcohols, 1～5 part of calcium nitrate tetrahydrate and 2～10 part of one hydrated copper acetate are joined in the reaction vessel, isothermal reaction is 1～5 hour under 20～50 ℃ temperature condition, obtains solution A;

(2) under agitation condition, by weight, 5～30 parts of polyvinylpyrrolidones, 100～200 parts of dehydrated alcohols, 3～15 parts of spin finish aids and 3～15 parts of butyl (tetra) titanates are joined in the reaction vessel, and isothermal reaction is 1～3 hour under 20～50 ℃ temperature condition, obtains solution B;

(3) under agitation condition, solution B slowly is added drop-wise in the solution A, obtain electrostatic spinning solution;

(4) adopt electrostatic spinning process to obtain fiber;

(5) fiber that electrostatic spinning is obtained 50～70 ℃ dry 12～18 hours down, be heated to 900～1000 ℃ with 5～10 ℃/minute temperature rise rate again, and constant temperature 2～5 hours, obtain CaCu ₃Ti ₄O ₁₂Micro-nano level fiber, described CaCu ₃Ti ₄O ₁₂Micro-nano level fiber comprises Elements C a, Cu, Ti and O, and they are 1:3:4:12 in molar ratio; Fibre diameter is 200～300 nanometers.

2. CaCu according to claim 1 ₃Ti ₄O ₁₂Micro-nano level fiber preparation method is characterized in that: described spin finish aid is acetate, Tetramethylammonium hydroxide, or a kind of in the potassium hydroxide.

3. CaCu according to claim 1 ₃Ti ₄O ₁₂Micro-nano level fiber preparation method is characterized in that: electrostatic spinning process is 15～30 kilovolts of voltages, solidifies 5～15 centimetres of distances, and receiving trap is an aluminium foil.

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