CN1234928C - Preparing method for titanium dioxide fibre - Google Patents

Abstract

The present invention relates to a preparation method for titanium dioxide fibre, which belongs to the technical field of functional fibre material. Polyacetylacetone titanium is synthesized as a precursor; titanium tetrachloride, distilled water, acetylacetone and triethylamine are respectively diluted in methanol according to stoichiometric proportion, mixed under the condition of 0 DEG C to 25 DEG C by stirring and react to synthesize the polyacetylacetone titanium in one step; tetrahydrofuran is used for removing the secondary reactant of triethylammonium chloride; the polyacetylacetone titanium is dissolved in a spinning solution prepared by methanol; filaments are centrifugally swung to obtain short fiber of the precursor; continuous long fibre of the precursor is obtained by dry spinning; the titanium dioxide fibre is sintered by using a high-pressure steam heat treatment technique or a normal-pressure steam heat treatment technique. The tensile strength of the present invention is from 100MPa to 1.2GPa, the diameters are from 3 mu m to 20 mu m, the continuous length of a single filament is from 1cm to 50cm or larger than 1m, and the particle diameters of crystal particles are from 5 nm to 100 nm; the titanium dioxide fibre is titanium dioxide short fibre or titanium dioxide continuous fibre with the crystal phase of an anatase phase or a rutile phase or the anatase phase and the rutile phase which are coexistent.

Description

Preparation method of titanium dioxide fiber

(1) Technical field

The invention relates to a method for preparing functional semiconductor oxide fibers, in particular to a method for preparing titanium dioxide fibers with photocatalytic and bactericidal properties, and belongs to the field of functional fiber materials.

(2) Background technology

Due to the global energy crisis and the increasing environmental pollution in the last century, environmental issues have received widespread attention. Semiconductor photocatalytic technologies such as TiO ₂ , ZnO, GdS, WO ₃ , and Fe ₂ O ₃ are favored by many researchers because they can directly use light energy to solve environmental pollution problems.

Since Fujishima et al. discovered in 1972 that illuminated titanium dioxide semiconductor electrodes have the function of splitting water, especially in 1976, Cary et al. successively reported that titanium dioxide-water systems can degrade various refractory organic compounds under ultraviolet light irradiation. Methods for water treatment have attracted widespread attention. For more than 20 years, environmental workers from various countries have conducted extensive and in-depth research in this field, and the photocatalytic oxidation process of titanium dioxide has become a research hotspot in advanced water purification treatment technology at home and abroad.

Among various semiconductor oxides used in photocatalysis, titanium dioxide has been proved to be one of the most effective photocatalysts. As a green and environment-friendly photocatalytic purifying agent, titanium dioxide has good chemical stability, wear resistance, low cost, safety and non-toxicity, etc., which makes it show great application prospects in the fields of environmental protection and petrochemical industry.

The basic principle of titanium dioxide photocatalysis is based on the energy band theory of N-type semiconductors. Semiconductors have a discontinuous energy band structure different from metals, generally consisting of a low-energy valence band filled with electrons and an empty high-energy conduction band, and there is a forbidden band between the valence band and the conduction band. When irradiated by photons with energies equal to or greater than its forbidden band width (also called band gap), electron-hole pairs will be generated. Titanium dioxide is an N-type semiconductor metal oxide with a forbidden band width of 3.26eV. When it absorbs photons with a wavelength less than or equal to 387.5nm, the electrons in the valence band are excited to jump to the conduction band, forming a negatively charged highly active Electrons (e ^- ), generate corresponding holes (h ⁺ ) on the valence band, and separate and migrate to different positions on the surface of titanium dioxide under the action of an electric field. The highly active e ^- has a strong reducing ability and can be combined with the gas phase The O ₂ in the reaction generates O ^2- free radicals, which realize the oxidative decomposition of the gaseous organic matter adsorbed on the surface of titanium dioxide, while the photogenerated holes distributed on the surface have a strong oxidation (gaining electrons) ability, which can be adsorbed on the titanium dioxide The OH ^- and H ₂ O molecules on the surface are oxidized to active OH radicals. OH free radical has a strong oxidizing ability and has been recognized as the most reactive oxidant in water. It can non-selectively oxidize organic pollutants and some inorganic pollutants in water, and can degrade many toxic, harmful and difficult to degrade. The organic matter is oxidized into small organic molecules, which can be finally degraded into harmless substances such as CO ₂ , water and corresponding inorganic ions to achieve complete mineralization. In addition, the oxidation potential of many organic substances is more negative than the valence band potential of titanium dioxide. When such organic substances are adsorbed on the surface of titanium dioxide, they can also be directly oxidized by h ⁺ .

The crystal form and grain size of titanium dioxide have an important influence on the photocatalytic activity of titanium dioxide. There are three crystal forms (phases) of titanium dioxide: Anatase, Rutile and Brookire. As a photocatalyst, titanium dioxide has anatase phase and rutile phase, and the anatase phase has higher photocatalytic activity, and the ability of the rutile phase to adsorb organic matter and _O2 on the surface of titanium dioxide is not as good as that of the anatase phase, and the photogenerated electrons and holes formed are easy Compounding leads to a decrease in catalytic activity. Studies have shown that the mixture (non-simple mixture) of anatase phase and rutile phase titanium dioxide has higher catalytic activity. Compared with large particles, the photocatalytic activity of nanoscale titanium dioxide grains is higher, because as the grain size decreases, the number of surface atoms of nanoscale photocatalysts increases rapidly, the absorption efficiency of light increases, and the photogenerated The density of electron-hole pairs increases, and at the same time, due to the increase of surface active sites, it is beneficial to the adsorption of organic matter and ^OH- , thereby improving the reaction efficiency.

Using methods such as noble metal deposition, transition metal ion doping, semiconductor recombination, and surface photosensitization, intermediate energy levels can be introduced to expand the available spectral range of titanium dioxide, or reduce the recombination rate of photogenerated electron-hole pairs, and prolong the photogenerated charge. life, thereby effectively improving the photocatalytic activity of titanium dioxide. Studies have shown that by depositing Ag, Ir, Au, Ru, Pd and other noble metals or metal oxides on the surface of semiconductor material titanium dioxide, or doping Fe ³⁺ , Ru ³⁺ , Os ³⁺ , V ⁵⁺ , Cr ³⁺ , Co ³⁺ , Ni ²⁺ , Zn ²⁺ , Re ⁴⁺ , W ⁶⁺ , La ³⁺ and other transition metal element ions (doped <5wt%), or with SnO ₂ , WO ₃ , Al ₂ O ₃ , The compounding of SiO ₂ , ZrO ₂ and other semiconductors with different energy levels, or the sensitization of organic dyes can improve the photocatalytic activity and light absorption performance of titanium dioxide to varying degrees.

At present, the practical application form of titanium dioxide photocatalyst is mainly ultrafine powder, such as nano powder, etc., through the particle suspension system, or through the method of loading, the catalyst particles are fixed on glass, silicon wafer, optical fiber, hollow ball and sand etc., or make titanium dioxide into a thin film, and attach it to glass, ceramics, silica gel, activated carbon, polymer membrane and zeolite, etc., to carry out photocatalytic reaction in liquid or gas phase. The above application forms all have insurmountable defects, which lead to many problems in the photocatalytic technology based on titanium dioxide, and the industrial application is greatly restricted. For example, although the particle suspension system has high reaction efficiency, it is very difficult to separate and recover titanium dioxide fine powder in the later stage of the reaction, and the loss of catalyst is serious, which limits its practical application. Although the use of immobilization technology can avoid the problem of loss, it will greatly reduce the specific surface area of the catalyst and the utilization rate of ultraviolet light, seriously affecting the activity and efficiency of the catalyst, and the result is not ideal. Therefore, it is necessary to develop an application form of titanium dioxide that can not only make full use of the catalytic activity of the semiconductor, but also solve the problem of separation and recovery of the catalyst, so that the photocatalytic function of titanium dioxide can be realized as soon as possible in the most economical and convenient way. industrial applications. Titanium dioxide fiber is the best application form of titanium dioxide for this requirement.

Titanium dioxide fiber is a ceramic fiber material with a polycrystalline structure. Its diameter is generally between a few to tens of microns, and the grain size is in the nanometer scale, generally not greater than 100nm. The length of the fiber can be in the range due to different preparation processes. Different orders of magnitude, generally, fibers with a monofilament length of millimeter or centimeter are called short fibers, while fibers with a monofilament length of more than one meter are called continuous fibers. Titanium dioxide fiber has nanoscale crystal grains, suitable crystal phase (anatase phase or rutile phase or two-phase composite phase), large specific surface area and pore volume, so it has high catalytic performance. At the same time, due to the shape characteristics and fluffy structure of the fiber, the utilization efficiency of light is high, it is also very easy to fix it or design a reactor, and there is no loss problem, so it is very convenient for practical application.

Titanium dioxide fiber itself has catalytic activity and can be directly used as a catalyst to catalyze a variety of high-temperature chemical synthesis reactions, such as epoxidation reactions. At the same time, it can be used as a catalyst carrier to load V, W, Al, As, Ni, Zr, Mo, Ru, Mg, Ca, Pt, Pd, Au, Ag and other metals or their oxides to efficiently degrade automobiles. Harmful gases such as nitric oxide in the exhaust. Utilizing the catalytic and/or photocatalytic activity of titanium dioxide fibers, it can be applied to the treatment of industrial organic waste gas, and oxidatively degrades chlorine-containing organic compounds, aromatic organic compounds, alcohols, aldehydes, ketones, chain hydrocarbons, and sulfur-containing, Contains organic matter such as nitrogen; it can also be used in air conditioners or other air purifiers to purify indoor air, decompose toxic and harmful gases such as formaldehyde in the living room, and sterilize and deodorize; titanium dioxide fiber cotton or its fabric can also be used for masks Among them, it is made into a gas mask that can kill pathogenic virus bacteria, and so on.

Taking advantage of its photocatalytic activity, titanium dioxide fibers can also be used in some industrial wastewater treatment. Various forms of reactors can be conveniently made by using it to degrade organic pollutants that are difficult to biodegrade in wastewater or completely inorganicize them. The degradation process can be carried out at normal temperature and pressure, and can directly use solar ultraviolet light, or combine UV and O ₃ methods to form an advanced oxidation process for reaction. After the reaction, there is no problem of difficult separation and recovery, and easy loss.

Due to the photocatalytic reaction of titanium dioxide fiber, it can non-selectively degrade various toxic and harmful organic substances in water, such as chlorine-containing organic substances, sulfur-containing organic substances, nitrogen-containing organic substances, aromatic hydrocarbons, cyanides, pesticides, petroleum, dyes, surfactants, Pollutants such as herbicides and humus, as well as "three causes (carcinogenic, teratogenic, mutagenic) substances" and "priority pollutants" in water, have a killing effect on various harmful bacteria such as E. coli, and have good The chemical and biological inertness of titanium dioxide can ensure the safety of water quality and the advantages of cheap and easy to obtain, no secondary pollution, etc. Therefore, titanium dioxide fiber has a very attractive application prospect in drinking water purification. Nihon Kobe Kosan Co., Ltd. has developed titanium dioxide fiber products for drinking water treatment.

Titanium dioxide fibers can also be used as high-temperature filter materials, and high-strength titanium dioxide fibers can also be used in composite reinforcement materials and electronic materials. In addition, through further processing of titanium dioxide fibers, sunlight can be used to photocatalytically decompose water to produce hydrogen, so as to realize the conversion, storage and utilization of solar energy.

Since the 1980s, several patents have begun to involve the preparation method of titanium dioxide fibers, namely Japanese Patent No. 55003371, Japanese Patent No. 55136126, Japanese Patent No. 55136127, Japanese Patent No. 56017928, and Japanese Patent No. 60046927 , Japanese Patent No. 60259625, Japanese Patent No. 1073030, Japanese Patent No. 1246139, Japanese Patent No. 2164722, etc., almost all use the titanate dealkalization method to prepare titanium dioxide fibers, that is, by melting M ₂ O·nTiO ₂ , where M is Na, K, Rb, Cs, n=1-5, to obtain fibrous titanate crystals, and to obtain titanium dioxide fibers by acid elution. The Knealing-Drying-Calcination method (Knealing-Drying-Calcination method) is one of the most widely used titanate dealkalization methods for preparing titanium dioxide fibers at home and abroad. TiO ₂ and anhydrous K ₂ CO ₃ are ground and mixed, dried and melted at a constant temperature of 1000°C The K ₂ Ti ₄ O ₉ precursor fiber was obtained by sintering for 100 hours, and then the K ⁺ ions were eluted by acid washing to obtain the hydrated titanium dioxide fiber. Although the titanium dioxide fiber obtained by the titanate dealkalization method has a layered structure and high photocatalytic activity, the length of the obtained fiber is only on the order of microns. Strictly speaking, it should not be called titanium dioxide fiber, but should be called It is fibrous titanium dioxide, so it cannot replace the real titanium dioxide fiber and meet the application requirements in many aspects.

Japanese Patent No. 2019569 and Japanese Patent No. 4163317, etc., adopt the impregnation method to prepare titanium dioxide fibers, that is, immerse the organic silk in the titanium alkoxide solution, take it out and dry it after absorbing enough, calcinate, and burn off the organic matter to obtain titanium dioxide fibers. Because the content of organic matter in the precursor fiber is too high, the strength of the titanium dioxide fiber obtained by this method is very low.

U.S. Patent No. 4166147, Japanese Patent No. A62-223323 and Japanese Patent No. 2000170039 use the sol-gel method to prepare titanium dioxide fibers, that is, use titanium alkoxide as raw material, undergo hydrolysis or acidolysis and polycondensation reaction, and obtain Sol spinning solution, spinning and calcining to obtain titanium dioxide fibers. The disadvantage of this method is that the reaction conditions are difficult to control, and the sol spinning solution is unstable, and it is easy to spontaneously transform into a gel and lose spinnability.

Generally speaking, the above methods fail to prepare titanium dioxide fibers with high strength and good continuity at the same time, and the spinnability and stability of the prepared spinning solution are not ideal.

In recent years, Japanese Patent No.10325021, Japanese Patent No.11005036, Japanese Patent No.2000192336, Japanese Patent No.2000218170, Japanese Patent No.2000220038, US Patent No.6162759, US Patent No.6086844, US Patent No.6191067 And U.S. Patent No.6409961 etc., all adopt titanium alkoxide as raw material such as tetraisopropyl titanate, carry out and control the hydrolysis and polycondensation of titanium alkoxide by adding water and ethyl acetoacetate to its isopropanol solution React to form a polymer precipitate, evaporate the isopropanol solvent and dry in an oil bath to obtain a polymer powder, dissolve the powder in another organic solvent such as tetrahydrofuran, evaporate and concentrate to obtain a spinning solution, spin, and calcinate to obtain Continuous titanium dioxide fibers. Using the method of doping _SiO2 , keeping the anatase phase to 900 ° C, using high-pressure steam heat treatment to obtain high-strength titanium dioxide fibers with a porous structure, and using the fibers as a catalyst carrier, supporting vanadium oxide to decompose NO gas, and obtaining a satisfactory effect. Although this invention has made great progress compared with the previous technology, there are still problems such as complicated spinning solution preparation process, harsh reaction conditions, expensive raw materials, and long reaction time.

(3) Contents of the invention

The invention aims at the deficiencies of the prior art and provides a new method for preparing titanium dioxide fibers.

The preparation method of the titanium dioxide fiber of the present invention is, synthesize polyacetylacetonate titanium (acetylacetonate titanium polymer) as precursor, dilute titanium tetrachloride, distilled water, acetylacetone and triethylamine of stoichiometric ratio respectively in methanol In the process of mixing and reacting under the conditions of stirring and 0℃～25℃, one-step synthesis of titanium polyacetylacetonate, removing triethylamine hydrochloride as a by-product with tetrahydrofuran, dissolving titanium polyacetylacetonate in methanol to prepare spinning solution, and centrifuging Short precursor fibers are obtained by spin spinning, continuous long precursor fibers are obtained by dry spinning, and high-pressure or normal-pressure steam heat treatment technology is used for sintering to obtain titanium dioxide short fibers or continuous fibers with high porosity, high specific surface area, and high strength. .

The preparation method of titanium dioxide fiber of the present invention is described more specifically below:

1. Synthesis of titanium polyacetylacetonate

Measure the above four liquid reagents according to the ratio of titanium tetrachloride: distilled water: acetylacetone: triethylamine=1mol: 3mol～6mol: 1mol～1.5mol: 4mol, and dilute them in four parts of methanol respectively. The dilution factor of titanium dioxide is 3 to 5 times, that of distilled water is 3 to 5 times, that of acetylacetone is 2 to 3 times, and that of triethylamine is 2 to 3 times. A higher dilution factor is also possible. A higher dilution factor is more beneficial to the reaction result, but it will greatly increase the amount of methanol used. Considering the production cost, it is more appropriate to control the dilution factor within the above range. Under the condition of stirring and 0 ℃ ~ 25 ℃, add the distilled water methanol dilution to the methanol diluent of titanium tetrachloride drop by drop, or add the methanol diluent of titanium tetrachloride to the methanol diluent of distilled water drop by drop. solution, continue to stir for 10min to 30min after dripping to obtain mixed diluent A, and at the same time directly mix the methanol diluent of acetylacetone and triethylamine to obtain mixed diluent B. Next, add the mixed diluent B dropwise to the mixed diluent A for reaction, or add the mixed diluent A dropwise to the mixed diluent B for reaction, and continue to stir at room temperature for 1h to 24h after dropping. Subsequently, the solvent methanol in the reaction solution was evaporated to dryness to obtain a yellow sticky substance, and tetrahydrofuran was added according to the ratio of titanium tetrachloride: tetrahydrofuran = 1mol: 1100ml to 2200ml to dissolve the soluble matter, and the insoluble trihydrochloride was removed by suction filtration. Ethylamine white precipitates, evaporates the solvent tetrahydrofuran in the transparent filtrate then, to dryness, promptly obtains polyacetylacetonate titanium precursor, and reaction equation is:

The purity of the reagents such as titanium tetrachloride, acetylacetone, triethylamine and solvent methanol, tetrahydrofuran can be industrially pure, chemically pure, or analytically pure, which mainly depends on different application requirements.

2. Preparation of spinning solution

According to the ratio of titanium polyacetylacetonate: methanol=100g: 300ml～600ml, the above-mentioned titanium polyacetylacetonate is dissolved in methanol, and according to the amount of _SiO2 that is 0%～15% by mass ratio in the fiber, Proportionally mixed with organic silicon reagent, the solution is concentrated by evaporating the solvent, so that the viscosity reaches 5Pa·s～100Pa·s (20°C), and a transparent, uniform and stable spinning solution can be obtained.

The above-mentioned organosilicon reagents are methanol-soluble silicate reagents such as methyl orthosilicate and ethyl orthosilicate.

The above organosilicon reagent can also be added to the reaction solution when synthesizing titanium polyacetylacetonate.

3. Spinning

Short precursor fibers can be obtained by centrifugal spinning, and continuous long precursor fibers can be obtained by dry spinning.

The steps of the centrifugal spinning method are: inject the spinning solution with a viscosity of 5Pa·s～50Pa·s into the centrifugal spinning disc, at a temperature of 10°C～40°C, a relative humidity of 20%～50%, and a centrifuge speed of Under the condition of 5000r/min～15000r/min, the spinning liquid is thrown out at high speed from the spinning holes with a diameter of 0.1mm～0.5mm, and collected by the collecting device to obtain disorderly accumulated precursors with a length of 2cm～90cm. short body fibers.

The steps of dry spinning are: move the spinning solution with a viscosity of 50Pa·s to 100Pa·s into the liquid material tank in the dry spinning device, vacuum defoaming for 5min to 10min, at a temperature of 10°C to 30°C and Under the condition of a relative humidity of 20% to 80%, use cylinder nitrogen or a metering pump to apply a pressure of 0.5MPa to 2.0MPa on the spinning solution to make it spin from a niobium-tantalum alloy spinning plate with a hole diameter of 0.06mm to 0.15mm Spraying, drawing and drum collection, the length can be almost any length, transparent, orderly continuous precursor long fiber.

4. Heat treatment

Place short precursor fibers or continuous long fibers in a program-controlled furnace, and perform heat treatment with normal pressure or high pressure steam at 80°C to 600°C for 5h to 24h at a pressure of 1atm to 4atm, and then continue to heat at 50°C/ h～200℃/h heating rate, burn the fiber to 700℃～1300℃, keep it warm at the highest temperature point for 5min～10h, cool down naturally, obtain the tensile strength of the present invention 100MPa～1.2GPa, diameter 3μm～20μm, Monofilament continuous length 1cm～50cm or >1m, BET specific surface area 100m ² /g～200m ² /g, pore volume 0.10cm ³ /g～0.30cm ³ /g, grain size 5nm～100nm, crystal phase is sharp Titanium ore phase, or rutile phase, or titanium dioxide short fibers or continuous fibers with two phases coexisting.

The addition of SiO ₂ into the titanium dioxide fiber can increase the phase transition temperature of titanium dioxide, so that the anatase phase of titanium dioxide can be kept at a higher sintering temperature. When heat-treating the precursor fiber, titanium dioxide crystals in the anatase phase will first appear at around 450 °C, and gradually transform into the rutile phase as the heating temperature increases. When the precursor fiber without SiO ₂ is heat-treated, the anatase phase can only be maintained up to about 700 °C, and after 800 °C, only the titanium dioxide fiber of the rutile phase can be obtained. When _SiO2 is added, the anatase phase titanium dioxide can be kept at 900°C, and the anatase phase titanium dioxide in the fiber can still coexist with the rutile phase titanium dioxide at 1000°C for 0.5h, and the rutile phase titanium dioxide can be obtained after 1050°C fiber.

By controlling the maximum temperature of heat treatment, it is possible to obtain titanium dioxide fibers whose crystal phase is anatase phase, rutile phase, or coexistence of anatase phase and rutile phase, which mainly depends on different application requirements.

Compared with the prior art, the present invention has the following excellent effects:

(1) The polyacetylacetonate titanium precursor is synthesized by using common chemical raw materials and a simple synthesis process. The reaction process does not require harsh reaction conditions and complicated reaction equipment. The solvent methanol and tetrahydrofuran required in the reaction and the reactant triethyl Amines can be reused by taking appropriate recovery and purification measures, so the synthesis cost is greatly reduced.

(2) The polyacetylacetonate-titanium spinning solution is transparent and uniform, with good spinning performance, no need to add spinning aids; stable performance, no precipitation, no condensation; reusable, when the spinning solution is caused by the volatilization of solvent methanol If the viscosity is too high or even dry, it can be dissolved in methanol and can still be used continuously.

(3) Short precursor fibers and continuous precursor long fibers can be conveniently obtained by centrifugal spinning and dry spinning, respectively.

(4) Pretreatment of the precursor fiber with normal pressure or high pressure steam can make the obtained titanium dioxide fiber have high porosity, high specific surface area and high strength.

(5) By adding SiO ₂ and controlling different maximum sintering temperatures, it is easy to obtain crystal phases that are anatase phase, or anatase phase and rutile phase coexist, and the crystal grain size is nanoscale. Titanium dioxide fibers have high photocatalytic activity.

(4) Description of drawings

Figure 1 is a photograph of short titanium dioxide fibers. Figure 2 is a photo of titanium dioxide continuous fiber. Figure 3 is a scanning electron microscope (SEM) photograph of titanium dioxide fibers.

(5) Specific implementation methods

Embodiment 1: the preparation method of titanium dioxide short fiber, the steps are as follows:

(1) According to the ratio of titanium tetrachloride: distilled water: acetylacetone: triethylamine=1mol: 3mol: 1mol: 4mol, measure 40.0ml, 20.0ml, 37.3ml and 40.0ml of the above four liquid reagents (analytical pure) respectively. 202.1ml, and according to the relationship that the dilution factor of titanium tetrachloride is 5 times, the dilution factor of distilled water is 5 times, the dilution factor of acetylacetone is 3 times, and the dilution factor of triethylamine is 3 times. Reagents were diluted in 200.0ml, 100.0ml, 112.0ml and 606.5ml of four parts of methanol, under the condition of stirring and 10°C, the methanol dilution of distilled water was added dropwise to the methanol dilution of titanium tetrachloride, and the dropwise Then continue to stir for 20 minutes to obtain the mixed diluent A, and at the same time directly mix the methanol diluents of acetylacetone and triethylamine to obtain the mixed diluent B, and then add the mixed diluent B dropwise under the condition of stirring and 10°C React in the mixed diluent A, continue to stir at room temperature for 1h after dropping, then evaporate the solvent methanol in the reaction solution to dryness, and obtain a yellow sticky substance, according to the formula of titanium tetrachloride: tetrahydrofuran = 1mol: 2200ml Proportionally add 800.0ml tetrahydrofuran to dissolve the soluble matter, remove the insoluble triethylamine hydrochloride white precipitate by suction filtration, then evaporate the solvent tetrahydrofuran in the transparent filtrate to dryness, and obtain the titanium polyacetylacetonate precursor. 93%;

(2) According to the ratio of titanium polyacetylacetonate: methyl alcohol=100g: 300ml, the above-mentioned titanium polyacetylacetonate is dissolved in 200.0ml methanol, and according to the amount of _SiO2 which is 15% by mass ratio in the fiber. Proportionally mixed with 17.5ml tetraethyl orthosilicate, and concentrated the solution by evaporating the solvent to make the viscosity reach 5Pa s (20°C), and a transparent, uniform and stable spinning solution can be obtained;

(3) The above-mentioned spinning solution is injected into the centrifugal spinning disk, and at a temperature of 40° C., a relative humidity of 50%, and a centrifuge speed of 10000 r/min, the spinning solution is injected from a spinning hole with a diameter of 0.2 mm. Throwing out at a high speed, collecting the filaments through the collection device, and obtaining short precursor fibers with a length of 2 cm to 90 cm that are piled up disorderly;

(4) Put the above-mentioned short precursor fiber in a program-controlled furnace, carry out heat treatment with water vapor under normal pressure at 80°C to 600°C for 24 hours, keep warm at 600°C for 10 hours, and cool down naturally to obtain the tensile strength of the present invention of 100MPa ～1.2GPa, diameter 3μm～20μm, monofilament length 1cm～50cm, BET specific surface area 100m ² /g～200m ² /g, pore volume 0.10cm ³ /g～0.30cm ³ /g, grain size 5nm～10nm , the crystal phase is titanium dioxide short fiber of anatase phase.

Embodiment 2: the preparation method of titanium dioxide continuous fiber

As described in Example 1, the difference is that the viscosity of the spinning solution in step (2) is adjusted to 80 Pa·s (20°C), and the continuous precursor fiber is obtained by spinning in step (3). The silk liquid is moved into the liquid material tank in the dry spinning device, vacuum defoamed for 10 minutes, and the temperature is 10 °C and the relative humidity is 20%, and the pressure of 1.0 MPa is applied to the spinning liquid by means of cylinder nitrogen, so that It is sprayed from a niobium-tantalum alloy spinning plate with a hole diameter of 0.10 mm, and is drawn and drum-wrapped to obtain transparent and orderly continuous precursor long fibers with almost arbitrary lengths. In step (4), the continuous The precursor fiber is placed in a program-controlled furnace, subjected to 80°C-600°C atmospheric pressure water vapor heat treatment for 24 hours, and kept at 600°C for 10 hours, and naturally cooled to obtain the tensile strength of the present invention 100MPa-1.2GPa, diameter 3μm ~20μm, single filament continuous length >1m, BET specific surface area 100m ² /g ~ 200m ² /g, pore volume 0.10cm ³ /g ~ 0.30cm ³ /g, grain size 5nm ~ 10nm, crystal phase is anatase Titanium dioxide continuous fibers in mineral phase.

Embodiment 3: the preparation method of titanium dioxide short fiber

As described in Example 1, the difference is that the ratio of titanium tetrachloride: distilled water: acetylacetone: triethylamine in step (1) is changed to 1mol: 4.5mol: 1.3mol: 4mol, that is, measure the above four kinds of Liquid reagents (analytical pure) are 40.0ml, 30.0ml, 48.5ml and 202.1ml, and the dilution factor of titanium tetrachloride is 4 times, the dilution factor of distilled water is 4 times, and the dilution factor of acetylacetone is 2.5 times. The dilution factor of ethylamine is 3 times. Dilute each of the above four reagents into four parts of methanol of 160.0ml, 120.0ml, 121.3ml and 606.5ml respectively. Add dropwise to the methanol dilution of titanium tetrachloride, continue to stir for 15 minutes after the drop is complete, to obtain a mixed dilution A, and at the same time directly mix the methanol dilutions of acetylacetone and triethylamine to obtain a mixed dilution B, then Under the condition of stirring and 5°C, add the mixed diluent B dropwise to the mixed diluent A for reaction, continue to stir at room temperature for 12 hours after the drop, and then evaporate the solvent methanol in the reaction solution to dryness to obtain a yellow color Caking matter, add 550.0ml tetrahydrofuran according to the ratio of titanium tetrachloride: tetrahydrofuran=1mol: 1500ml, make soluble matter dissolve, remove insoluble triethylamine hydrochloride white precipitate by suction filtration, evaporate the solvent tetrahydrofuran in the transparent filtrate then, As for obtaining the titanium polyacetylacetonate precursor, its yield rate is 95%, and the ratio of titanium polyacetylacetonate: methanol in step (2) is changed to 100g: 450ml, and the above-mentioned titanium polyacetylacetonate is dissolved in 300.0 ml methanol to prepare the spinning solution.

Embodiment 4: the preparation method of titania continuous fiber

As described in Example 2, the difference is that the ratio of titanium tetrachloride: distilled water: acetylacetone: triethylamine in step (1) is changed to 1mol: 4.5mol: 1.3mol: 4mol, that is, the above four kinds are measured respectively Liquid reagents (analytical pure) are 40.0ml, 30.0ml, 48.5ml and 202.1ml, and the dilution factor of titanium tetrachloride is 4 times, the dilution factor of distilled water is 4 times, and the dilution factor of acetylacetone is 2.5 times. The dilution factor of ethylamine is 3 times. Dilute each of the above four reagents into four parts of methanol of 160.0ml, 120.0ml, 121.3ml and 606.5ml respectively. Add dropwise to the methanol dilution of titanium tetrachloride, continue to stir for 15 minutes after the drop is complete, to obtain a mixed dilution A, and at the same time directly mix the methanol dilutions of acetylacetone and triethylamine to obtain a mixed dilution B, then Under the condition of stirring and 5°C, add the mixed diluent B dropwise to the mixed diluent A for reaction, continue to stir at room temperature for 12 hours after the drop, and then evaporate the solvent methanol in the reaction solution to dryness to obtain a yellow color Caking matter, add 550.0ml tetrahydrofuran according to the ratio of titanium tetrachloride: tetrahydrofuran=1mol: 1500ml, make soluble matter dissolve, remove insoluble triethylamine hydrochloride white precipitate by suction filtration, evaporate the solvent tetrahydrofuran in the transparent filtrate then, To dryness, obtain the polyacetylacetonate titanium precursor, its productive rate is 95%, and in the step (2) polyacetylacetonate titanium: the ratio of methyl alcohol is changed into 100g: 450ml, is about to above-mentioned polyacetylacetonate titanium dissolves in 300.0ml methanol to prepare spinning solution.

Embodiment 5: the preparation method of titanium dioxide short fiber

As described in Example 1, the difference is that the ratio of titanium tetrachloride: distilled water: acetylacetone: triethylamine in step (1) is changed to 1mol: 6mol: 1.5mol: 4mol, that is, measure the above four liquids respectively The reagents (analytical pure) are 40.0ml, 40.0ml, 56.0ml and 202.1ml each, and the dilution factor of titanium tetrachloride is 3 times, the dilution factor of distilled water is 3 times, the dilution factor of acetylacetone is 2 times, and the dilution factor of triethyl acetone is 2 times. The dilution factor of the amine is 3 times. Dilute each of the above four reagents into four parts of methanol of 120.0ml, 120.0ml, 112.0ml and 606.5ml respectively. Under the condition of stirring and 0℃, dilute the distilled water methanol dilution Add it dropwise in the methanol dilution of titanium tetrachloride, continue to stir for 10 minutes after the drop is completed, and obtain a mixed dilution A, and simultaneously directly mix the methanol dilutions of acetylacetone and triethylamine to obtain a mixed dilution B, and then in Under the condition of stirring and 0°C, add the mixed diluent B dropwise to the mixed diluent A for reaction, continue to stir at room temperature for 24 hours after the drop, then distill off the solvent methanol in the reaction solution to dryness to obtain a yellow viscous Concrete, add 400.0ml tetrahydrofuran according to the ratio of titanium tetrachloride: tetrahydrofuran=1mol: 1100ml, make soluble matter dissolve, remove the insoluble triethylamine hydrochloride white precipitate by suction filtration, evaporate the solvent tetrahydrofuran in the transparent filtrate then, to Dry, obtain titanium polyacetylacetonate precursor, its productive rate is 96%, and the ratio of titanium polyacetylacetonate in step (2): methanol is changed to 100g: 600ml, is about to dissolve above-mentioned titanium polyacetylacetonate into 400.0 ml methanol to prepare the spinning solution.

Embodiment 6: the preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that the ratio of titanium tetrachloride: distilled water: acetylacetone: triethylamine in step (1) is changed to 1mol: 6mol: 1.5mol: 4mol, that is, measure the above four liquids respectively The reagents (analytical pure) are 40.0ml, 40.0ml, 56.0ml and 202.1ml each, and the dilution factor of titanium tetrachloride is 3 times, the dilution factor of distilled water is 3 times, the dilution factor of acetylacetone is 2 times, and the dilution factor of triethyl acetone is 2 times. The dilution factor of the amine is 3 times. Dilute each of the above four reagents into four parts of methanol of 120.0ml, 120.0ml, 112.0ml and 606.5ml respectively. Under the condition of stirring and 0℃, dilute the distilled water methanol dilution Add it dropwise in the methanol dilution of titanium tetrachloride, continue to stir for 10 minutes after the drop is completed, and obtain a mixed dilution A, and simultaneously directly mix the methanol dilutions of acetylacetone and triethylamine to obtain a mixed dilution B, and then in Under the condition of stirring and 0°C, add the mixed diluent B dropwise to the mixed diluent A for reaction, continue to stir at room temperature for 24 hours after the drop, then distill off the solvent methanol in the reaction solution to dryness to obtain a yellow viscous Concrete, add 400.0ml tetrahydrofuran according to the ratio of titanium tetrachloride: tetrahydrofuran=1mol: 1100ml, make soluble matter dissolve, remove the insoluble triethylamine hydrochloride white precipitate by suction filtration, evaporate the solvent tetrahydrofuran in the transparent filtrate then, to Dry, obtain titanium polyacetylacetonate precursor, its productive rate is 96%, and the ratio of titanium polyacetylacetonate in step (2): methanol is changed to 100g: 600ml, is about to dissolve above-mentioned titanium polyacetylacetonate into 400.0 ml methanol to prepare the spinning solution.

Embodiment 7: the preparation method of titanium dioxide short fiber

As described in Example 1, the difference is that the ratio of titanium tetrachloride: distilled water: acetylacetone: triethylamine in step (1) is changed to 1mol: 4.5mol: 1.3mol: 4mol, that is, the above four kinds are measured respectively Liquid reagents (analytical pure) are 40.0ml, 30.0ml, 48.5ml and 202.1ml, and the dilution factor of titanium tetrachloride is 5 times, the dilution factor of distilled water is 5 times, and the dilution factor of acetylacetone is 3 times. The dilution factor of ethylamine is 3 times. Dilute each of the above four reagents into 200.0ml, 150.0ml, 145.5ml and 606.5ml of four parts of methanol respectively, and dilute the methanol dilution of distilled water under the condition of stirring and 20°C Add dropwise to the methanol dilution of titanium tetrachloride, continue to stir for 30 minutes after the drop, to obtain a mixed dilution A, and at the same time directly mix the methanol dilutions of acetylacetone and triethylamine to obtain a mixed dilution B, then Under the conditions of stirring and 20°C, the mixed diluent B was added dropwise to the mixed diluent A for reaction. After the drop was completed, the stirring was continued at room temperature for 18 hours, and then the solvent methanol in the reaction liquid was evaporated to obtain a yellow viscous Concrete, add 650.0ml tetrahydrofuran according to the ratio of titanium tetrachloride: tetrahydrofuran=1mol: 1800ml, make soluble matter dissolve, remove the insoluble triethylamine hydrochloride white precipitate by suction filtration, evaporate the solvent tetrahydrofuran in the transparent filtrate then, to dry to obtain a titanium polyacetylacetonate precursor.

Embodiment 8: the preparation method of titania continuous fiber

As described in Example 2, the difference is that the ratio of titanium tetrachloride: distilled water: acetylacetone: triethylamine in step (1) is changed to 1mol: 4.5mol: 1.3mol: 4mol, that is, the above four kinds are measured respectively Liquid reagents (analytical pure) are 40.0ml, 30.0ml, 48.5ml and 202.1ml, and the dilution factor of titanium tetrachloride is 5 times, the dilution factor of distilled water is 5 times, and the dilution factor of acetylacetone is 3 times. The dilution factor of ethylamine is 3 times. Dilute each of the above four reagents into 200.0ml, 150.0ml, 145.5ml and 606.5ml of four parts of methanol respectively, and dilute the methanol dilution of distilled water under the condition of stirring and 20°C Add dropwise to the methanol dilution of titanium tetrachloride, continue to stir for 30 minutes after the drop, to obtain a mixed dilution A, and at the same time directly mix the methanol dilutions of acetylacetone and triethylamine to obtain a mixed dilution B, then Under the condition of stirring and 20°C, add the mixed diluent B dropwise to the mixed diluent A for reaction, continue to stir at room temperature for 18 hours after the drop, then distill off the solvent methanol in the reaction liquid to dryness, and obtain a yellow color Caking matter, add 650.0ml tetrahydrofuran according to the ratio of titanium tetrachloride: tetrahydrofuran=1mol: 1800ml, make soluble matter dissolve, remove the insoluble triethylamine hydrochloride white precipitate by suction filtration, then evaporate the solvent tetrahydrofuran in the transparent filtrate, to dryness to obtain a titanium polyacetylacetonate precursor.

Embodiment 9: the preparation method of titanium dioxide short fiber

As described in Example 1, the difference is that the ratio of titanium tetrachloride: distilled water: acetylacetone: triethylamine in step (1) is changed to 1mol: 6mol: 1.5mol: 4mol, that is, measure the above four liquids respectively The reagents (analytical pure) are 40.0ml, 40.0ml, 56.0ml and 202.1ml each, and the dilution factor of titanium tetrachloride is 5 times, the dilution factor of distilled water is 5 times, the dilution factor of acetylacetone is 3 times, and the dilution factor of triethyl acetone is 3 times. The dilution factor of the amine is 3 times. Dilute each of the above four reagents into four parts of methanol of 200.0ml, 200.0ml, 168.0ml and 606.5ml respectively. Under the condition of stirring and 25℃, dilute the distilled water methanol dilution Add it dropwise in the methanol dilution of titanium tetrachloride, continue to stir for 30 minutes after the drop is complete, and obtain a mixed dilution A, and simultaneously directly mix the methanol dilutions of acetylacetone and triethylamine to obtain a mixed dilution B, and then Under the condition of stirring and 25°C, add the mixed diluent B dropwise to the mixed diluent A for reaction, continue to stir at room temperature for 24 hours after dropping, then evaporate the solvent methanol in the reaction solution to dryness, and obtain a yellow viscous Concrete, add 500.0ml tetrahydrofuran according to the ratio of titanium tetrachloride: tetrahydrofuran=1mol: 1400ml, make soluble matter dissolve, remove the insoluble triethylamine hydrochloride white precipitate by suction filtration, evaporate the solvent tetrahydrofuran in the transparent filtrate then, to dry to obtain a titanium polyacetylacetonate precursor.

Embodiment 10: the preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that the ratio of titanium tetrachloride: distilled water: acetylacetone: triethylamine in step (1) is changed to 1mol: 6mol: 1.5mol: 4mol, that is, measure the above four liquids respectively The reagents (analytical pure) are 40.0ml, 40.0ml, 56.0ml and 202.1ml each, and the dilution factor of titanium tetrachloride is 5 times, the dilution factor of distilled water is 5 times, the dilution factor of acetylacetone is 3 times, and the dilution factor of triethyl acetone is 3 times. The dilution ratio of the amine is 3 times. Dilute each of the above four reagents into 200.0ml, 200.0ml, 168.0ml and 606.5ml of four parts of methanol respectively. Under the condition of stirring and 25°C, dilute the methanol dilution of distilled water one by one. Add it dropwise in the methanol dilution of titanium tetrachloride, continue to stir for 30 minutes after the drop is complete, and obtain a mixed dilution A, and simultaneously directly mix the methanol dilutions of acetylacetone and triethylamine to obtain a mixed dilution B, and then Under the condition of stirring and 25°C, add the mixed diluent B dropwise to the mixed diluent A for reaction, continue to stir at room temperature for 24 hours after dropping, then evaporate the solvent methanol in the reaction solution to dryness, and obtain a yellow viscous Concrete, add 500.0ml tetrahydrofuran according to the ratio of titanium tetrachloride: tetrahydrofuran=1mol: 1400ml, make soluble matter dissolve, remove the insoluble triethylamine hydrochloride white precipitate by suction filtration, evaporate the solvent tetrahydrofuran in the transparent filtrate then, to dry to obtain a titanium polyacetylacetonate precursor.

Embodiment 11: the preparation method of titanium dioxide short fiber

As described in Example 1, the difference is that in step (1), the methanol dilution of distilled water is added dropwise to the methanol dilution of titanium tetrachloride and the methanol dilution of titanium tetrachloride is added dropwise. Add the mixed diluent B dropwise to the mixed diluent A to react in the distilled methanol diluent, instead add the mixed diluent A dropwise to the mixed diluent B to react.

Embodiment 12: the preparation method of titanium dioxide short fiber

As described in Example 3, the difference is that in step (1), the methanol dilution of distilled water is added dropwise to the methanol dilution of titanium tetrachloride and the methanol dilution of titanium tetrachloride is added dropwise. Add the mixed diluent B dropwise to the mixed diluent A to react in the distilled methanol diluent, instead add the mixed diluent A dropwise to the mixed diluent B to react.

Embodiment 13: the preparation method of titanium dioxide short fiber

As described in Example 5, the difference is that in step (1), the methanol dilution of distilled water is added dropwise to the methanol dilution of titanium tetrachloride and the methanol dilution of titanium tetrachloride is added dropwise. Add the mixed diluent B dropwise to the mixed diluent A to react in the distilled methanol diluent, instead add the mixed diluent A dropwise to the mixed diluent B to react.

Embodiment 14: the preparation method of titanium dioxide short fiber

As described in Example 7, the difference is that in step (1), the methanol dilution of distilled water is added dropwise to the methanol dilution of titanium tetrachloride and the methanol dilution of titanium tetrachloride is added dropwise. Add the mixed diluent B dropwise to the mixed diluent A to react in the distilled methanol diluent, instead add the mixed diluent A dropwise to the mixed diluent B to react.

Embodiment 15: the preparation method of titanium dioxide short fiber

As described in Example 9, the difference is that in step (1), the methanol dilution of distilled water is added dropwise to the methanol dilution of titanium tetrachloride and the methanol dilution of titanium tetrachloride is added dropwise. Add the mixed diluent B dropwise to the mixed diluent A to react in the distilled methanol diluent, instead add the mixed diluent A dropwise to the mixed diluent B to react.

Embodiment 16: the preparation method of titanium dioxide short fiber

As described in Example 1, the difference is that the purity of reagents such as titanium tetrachloride, acetylacetone, triethylamine and solvent methanol, tetrahydrofuran used in the step (1) is changed from analytical pure to industrial pure.

Embodiment 17: the preparation method of titanium dioxide short fiber

As described in Example 1, the difference is that the purity of reagents such as titanium tetrachloride, acetylacetone, triethylamine and solvent methanol, tetrahydrofuran used in the step (1) is changed from analytical pure to chemical pure.

Embodiment 18: the preparation method of titanium dioxide short fiber

As described in Example 1, the difference is that in the step (2) according to the equivalent of blending in the fiber, the mass ratio is 10% SiO The ratio is mixed with _11.8ml tetraethyl orthosilicate, and the spinning solution The viscosity was adjusted to 20Pa·s (20°C).

Embodiment 19: the preparation method of titania continuous fiber

As described in Example 2, the difference is that in step (2) according to the SiO that is equivalent to blending in the fiber with a mass ratio of 10% _11.8ml of tetraethyl orthosilicate is mixed in, and the spinning solution The viscosity is adjusted to 60Pa · s (20 ℃).

Embodiment 20: the preparation method of titanium dioxide short fiber

As described in Example 1, the difference is that in the step (2) according to the equivalent of blending in the fiber, the mass ratio is 5% SiO ₂ The ratio is mixed with 5.9ml tetraethyl orthosilicate, and the spinning solution The viscosity is adjusted to 40Pa · s (20 ℃).

Example 21: Preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that in the step (2) according to the equivalent in the fiber, the mass ratio is 5% SiO ₂ mixed with 5.9ml tetraethyl orthosilicate, and the spinning solution The viscosity is adjusted to 100Pa.s (20 ℃).

Embodiment 22: the preparation method of titanium dioxide short fiber

As described in Example 1, the difference is that in step (2) according to the proportion of _SiO2 that is 0% by mass in the fiber, no silicon-containing compound is added, and the viscosity of the spinning solution Adjust to 50Pa·s (20°C).

Example 23:

As described in Example 2, the difference is that in step (2) according to the proportion of _SiO2 that is 0% by mass ratio in the fiber, do not mix any silicon-containing compound, and adjust the viscosity of the spinning solution Adjust to 50Pa·s (20°C).

Embodiment 24: the preparation method of titanium dioxide short fiber

As described in Example 1, the difference is that the centrifugal spinning conditions in step (3) are changed to a temperature of 30° C., a relative humidity of 40%, a centrifuge speed of 5000 r/min, and a spinning hole diameter of 0.5 mm.

Embodiment 25: the preparation method of titanium dioxide short fiber

As described in Example 1, the difference is that the centrifugal spinning conditions in step (3) are changed to a temperature of 20° C., a relative humidity of 30%, a centrifuge speed of 12000 r/min, and a spinning hole diameter of 0.3 mm.

Embodiment 26: the preparation method of titanium dioxide short fiber

As described in Example 1, the difference is that the centrifugal spinning conditions in step (3) are changed to a temperature of 10° C., a relative humidity of 20%, a centrifuge speed of 15000 r/min, and a spinning hole diameter of 0.1 mm.

Example 27: Preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that the dry spinning conditions in step (3) are changed to a spinning solution viscosity of 60 Pa s (20°C), vacuum defoaming for 5min, a temperature of 30°C, and a relative humidity of 80%. , spinning pressure 0.5MPa, spinning aperture 0.06mm.

Example 28: Preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that the dry spinning conditions in step (3) are changed to a spinning solution viscosity of 100Pa·s (20°C), vacuum defoaming for 10min, a temperature of 20°C, and a relative humidity of 40%. , spinning pressure 2.0MPa, spinning aperture 0.15mm.

Example 29: Preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that the dry spinning conditions in step (3) are changed to a spinning solution viscosity of 50 Pa s (20°C), vacuum defoaming for 5min, a temperature of 25°C, and a relative humidity of 60%. , spinning pressure 1.2MPa, spinning aperture 0.12mm.

Example 30: Preparation method of short titanium dioxide fibers

As described in Example 1, the difference is that in step (4), the short precursor fiber is subjected to 80°C to 600°C, 2atm water vapor heat treatment for 15 hours, and is kept at 600°C for 8 hours to obtain the grain size 5nm ~ 10nm, short titanium dioxide fibers whose crystal phase is anatase phase.

Example 31: Preparation method of titanium dioxide short fibers

As described in Example 1, the difference is that in step (4), the short precursor fiber is subjected to 80°C to 600°C, 3atm water vapor heat treatment for 10 hours, and kept at 600°C for 5 hours to obtain the grain size 5nm ~ 10nm, short titanium dioxide fibers whose crystal phase is anatase phase.

Example 32: Preparation method of titanium dioxide short fibers

As described in Example 1, the difference is that in step (4), the short precursor fibers are subjected to 80°C to 600°C, 4atm water vapor heat treatment for 5h, and kept at 600°C for 2h to obtain the grain size 5nm ~ 10nm, short titanium dioxide fibers whose crystal phase is anatase phase.

Example 33: Preparation method of titanium dioxide short fibers

As described in Example 1, the difference is that in step (4), the short precursor fiber is subjected to 80°C-600°C, 1atm water vapor heat treatment for 24 hours, and then continues to heat up at a rate of 50°C/h. The fibers are fired to 700°C and kept at 700°C for 8 hours to obtain titanium dioxide short fibers with a grain size of 10nm-20nm and an anatase phase.

Example 34: Preparation method of titanium dioxide short fibers

As described in Example 1, the difference is that in step (4), the short precursor fibers are subjected to 80°C to 600°C, 2atm water vapor heat treatment for 18 hours, and then continue to heat up at a rate of 80°C/h. The fibers are fired to 800°C and kept at 800°C for 6 hours to obtain titanium dioxide short fibers with a grain size of 15nm-30nm and an anatase crystal phase.

Example 35: Preparation method of short titanium dioxide fibers

As described in Example 1, the difference is that in step (4), the short precursor fiber is subjected to 80°C to 600°C, 1atm water vapor heat treatment for 24 hours, and then continues to heat up at a rate of 100°C/h. The fibers are fired to 900°C and kept at 900°C for 2 hours to obtain titanium dioxide short fibers with a grain size of 20nm to 40nm and a crystal phase of anatase phase.

Example 36: Preparation method of titanium dioxide short fibers

As described in Example 1, the difference is that in step (4), the short precursor fiber is subjected to 80°C to 600°C, 3atm water vapor heat treatment for 10 hours, and then continues to heat up at a rate of 120°C/h. The fibers are fired to 1000°C and kept at 1000°C for 0.5h to obtain titanium dioxide short fibers with a grain size of 30nm to 50nm and crystal phases of anatase phase and rutile phase coexisting.

Example 37: Preparation method of titanium dioxide short fibers

As described in Example 1, the difference is that in step (4), the short precursor fiber is subjected to 80°C to 600°C, 4atm water vapor heat treatment for 5 hours, and then continues to heat up at a rate of 150°C/h. The fibers are fired to 1100°C and kept at 1100°C for 20 minutes to obtain titanium dioxide short fibers with a grain size of 40nm to 70nm and a crystal phase of rutile.

Example 38: Preparation method of titanium dioxide short fibers

As described in Example 1, the difference is that in step (4), the short precursor fiber is subjected to 80°C to 600°C, 4atm steam heat treatment for 5 hours, and then continues to heat up at a rate of 180°C/h. The fibers are fired to 1200°C and kept at 1200°C for 10 minutes to obtain titanium dioxide short fibers with a grain size of 50nm to 80nm and a crystal phase of rutile phase.

Example 39: Preparation method of titanium dioxide short fibers

As described in Example 1, the difference is that in step (4), the short precursor fiber is subjected to 80°C to 600°C, 4atm water vapor heat treatment for 5 hours, and then continues to heat up at a rate of 200°C/h. The fibers are fired to 1300°C and kept at 1300°C for 5 minutes to obtain titanium dioxide short fibers with a grain size of 70nm to 100nm and a crystal phase of rutile.

Example 40: Preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that in step (4), the short precursor fibers are subjected to 80°C to 600°C, 2atm water vapor heat treatment for 15 hours, and kept at 600°C for 8 hours to obtain the grain size 5nm ~ 10nm, titanium dioxide continuous fiber whose crystal phase is anatase phase.

Example 41: Preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that in step (4), the short precursor fibers are subjected to 80°C to 600°C, 3atm water vapor heat treatment for 10 hours, and kept at 600°C for 5 hours to obtain the grain size 5nm ~ 10nm, titanium dioxide continuous fiber whose crystal phase is anatase phase.

Example 42: Preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that in step (4), the short precursor fiber is subjected to 80°C to 600°C, 4atm water vapor heat treatment for 5h, and kept at 600°C for 2h to obtain the grain size 5nm ~ 10nm, titanium dioxide continuous fiber whose crystal phase is anatase phase.

Example 43: Preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that in step (4), the short precursor fiber is subjected to 80°C to 600°C, 1atm water vapor heat treatment for 24 hours, and then continues to heat up at a rate of 50°C/h. The fibers were fired to 700°C and kept at 700°C for 8 hours to obtain continuous titanium dioxide fibers with a grain size of 10nm to 20nm and an anatase crystal phase.

Example 44: Preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that in step (4), the short precursor fiber is subjected to 80°C to 600°C, 2atm water vapor heat treatment for 18 hours, and then continues to heat up at a rate of 80°C/h. The fibers are fired to 800°C and kept at 800°C for 6 hours to obtain continuous titanium dioxide fibers with a grain size of 15nm to 30nm and an anatase crystal phase.

Example 45: Preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that in step (4), the short precursor fiber is subjected to 80°C to 600°C, 1atm water vapor heat treatment for 24 hours, and then continues to heat up at a rate of 100°C/h. The fibers are fired to 900°C and kept at 900°C for 2 hours to obtain continuous titanium dioxide fibers with a grain size of 20nm to 40nm and an anatase crystal phase.

Example 46: Preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that in step (4), the short precursor fiber is subjected to 80°C to 600°C, 3atm water vapor heat treatment for 10 hours, and then continues to heat up at a rate of 120°C/h. The fiber is fired to 1000°C and kept at 1000°C for 0.5h to obtain a continuous titanium dioxide fiber with a grain size of 30nm to 50nm and an anatase phase and a rutile phase coexisting in the crystal phase.

Example 47: Preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that in step (4), the short precursor fiber is subjected to 80°C to 600°C, 4atm water vapor heat treatment for 5 hours, and then continues to heat up at a rate of 150°C/h. The fiber is fired to 1100°C and kept at 1100°C for 20 minutes to obtain a continuous titanium dioxide fiber with a grain size of 40nm to 70nm and a crystal phase of rutile.

Example 48: Preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that in step (4), the short precursor fiber is subjected to 80°C to 600°C, 4atm water vapor heat treatment for 5 hours, and then continues to heat up at a rate of 180°C/h. The fiber is fired to 1200°C and kept at 1200°C for 10 minutes to obtain a continuous titanium dioxide fiber with a grain size of 50nm to 80nm and a crystal phase of rutile.

Example 49: Preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that in step (4), the short precursor fiber is subjected to 80°C to 600°C, 4atm water vapor heat treatment for 5 hours, and then continues to heat up at a rate of 200°C/h. The fibers are fired to 1300°C and kept at 1300°C for 5 minutes to obtain continuous titanium dioxide fibers with a grain size of 70nm to 100nm and a crystal phase of rutile.

Example 50: Preparation method of titanium dioxide short fibers

As described in Example 1, the difference is that no silicon-containing compound is added in step (2), and in step (4), the short precursor fiber is subjected to 80 ° C to 600 ° C, 1 atm water vapor heat treatment, and the treatment time is 24 hours , and then continue to burn the fiber to 700°C at a heating rate of 50°C/h, and keep it at 700°C for 8 hours to obtain a titanium dioxide with a grain size of 10nm to 20nm and a crystal phase of anatase phase and rutile phase. short fibre.

Example 51: Preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that step (2) is not mixed with any silicon-containing compound, and in step (4), the short precursor fiber is subjected to 80 ° C to 600 ° C, 2 atm water vapor heat treatment, and the treatment time is 18 hours. , and then continue to burn the fiber to 700°C at a heating rate of 50°C/h, and keep it at 700°C for 8 hours to obtain a titanium dioxide with a grain size of 10nm to 20nm and a crystal phase of anatase phase and rutile phase. continuous fiber.

Example 52: Preparation method of short titanium dioxide fibers

As described in Example 1, the difference is that no silicon-containing compound is added in step (2), and in step (4), the short precursor fiber is subjected to 80 ° C to 600 ° C, 1 atm water vapor heat treatment, and the treatment time is 24 hours , and then continue to burn the fiber to 800°C at a heating rate of 80°C/h, and keep it at 800°C for 6 hours to obtain titanium dioxide short fibers with a grain size of 15nm to 30nm and a crystal phase of rutile.

Example 53: Preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that step (2) is not mixed with any silicon-containing compound, and in step (4), the short precursor fiber is subjected to 80 ° C to 600 ° C, 2 atm water vapor heat treatment, and the treatment time is 18 hours. , and then continue to burn the fiber to 800°C at a heating rate of 80°C/h, and keep it at 800°C for 6 hours to obtain continuous titanium dioxide fibers with a grain size of 15nm to 30nm and a crystal phase of rutile.

Example 54: Preparation method of titanium dioxide short fibers

As described in Example 1, the difference is that in step (4), the short precursor fibers are subjected to 80°C to 600°C, 4atm water vapor heat treatment for 8 hours, and then continue to heat up at a rate of 150°C/h. The fiber is fired to 900°C and kept at 900°C for 3 hours to obtain short titanium dioxide fibers with a grain size of 40nm-50nm, anatase phase and rutile phase coexisting, mainly anatase phase.

Example 55: Preparation method of titanium dioxide continuous fiber

As described in Example 2, the difference is that in step (4), the short precursor fiber is subjected to 80°C to 600°C, 4atm water vapor heat treatment for 10 hours, and then continues to heat up at a rate of 200°C/h. The fibers are fired to 900°C and kept at 900°C for 8 hours to obtain short titanium dioxide fibers with a grain size of 50nm to 60nm, an anatase phase and a rutile phase coexisting in the crystal phase, mainly rutile phase.

Claims (8)

1. The preparation method of titanium dioxide fiber is characterized in that the synthesis of titanium polyacetylacetonate is used as a precursor, and stoichiometric titanium tetrachloride, distilled water, acetylacetone and triethylamine are respectively diluted in methanol, and stirred and heated at 0 ° C. Mix and react at ~25°C to synthesize titanium polyacetylacetonate in one step, remove triethylamine hydrochloride as a by-product with tetrahydrofuran, dissolve titanium polyacetylacetonate in methanol to prepare spinning solution, and spin spinning to obtain precursor short fibers , dry spinning to obtain continuous precursor long fibers, and use high-pressure or normal-pressure steam heat treatment technology to sinter to obtain titanium dioxide short fibers or continuous fibers. 2, the preparation method of titanium dioxide fiber as claimed in claim 1 is characterized in that the specific steps of synthesizing titanium polyacetylacetonate are as follows: Measure the above four liquid reagents according to the ratio of titanium tetrachloride: distilled water: acetylacetone: triethylamine=1mol: 3mol～6mol: 1mol～1.5mol: 4mol, and dilute them in four parts of methanol respectively. The dilution factor of titanium dioxide is 3 times to 5 times, the dilution factor of distilled water is 3 times to 5 times, the dilution factor of acetylacetone is 2 times to 3 times, and the dilution factor of triethylamine is 2 times to 3 times. And under the condition of 0℃～25℃, add the methanol diluent of distilled water to the methanol diluent of titanium tetrachloride dropwise, or add the methanol diluent of titanium tetrachloride dropwise to the methanol diluent of distilled water After dropping, continue to stir for 10min to 30min to obtain a mixed diluent A, and at the same time directly mix the methanol diluents of acetylacetone and triethylamine to obtain a mixed diluent B, and then stir at 0°C to 25°C, Add the mixed diluent B dropwise to the mixed diluent A for reaction, or add the mixed diluent A dropwise to the mixed diluent B for reaction, continue to stir at room temperature for 1h to 24h after dropping, then evaporate Remove the solvent methanol in the reaction solution until dry to obtain a yellow sticky substance, add tetrahydrofuran according to the ratio of titanium tetrachloride: tetrahydrofuran = 1mol: 1100ml ~ 2200ml, dissolve the soluble matter, remove the insoluble triethylamine hydrochloride by suction filtration White precipitate, then evaporate the solvent tetrahydrofuran in the transparent filtrate, to dryness, promptly obtain polyacetylacetonate titanium precursor, reaction equation is: 3. The preparation method of titanium dioxide fiber as claimed in claim 1, characterized in that the specific steps of preparing the spinning solution are as follows: According to the ratio of titanium polyacetylacetonate: methanol=100g: 300ml～600ml, the above-mentioned titanium polyacetylacetonate is dissolved in methanol, and according to the amount of _SiO2 that is 0%～15% by mass ratio in the fiber, The organic silicon reagent is mixed in proportion, and the solution is concentrated by evaporating the solvent, so that the viscosity at 20°C reaches 5Pa·s～100Pa·s, and a transparent, uniform and stable spinning solution is obtained; the organic silicon reagent is silicate reagent. 4. The preparation method of titanium dioxide fiber as claimed in claim 1, characterized in that when synthesizing titanium polyacetylacetonate, silicon is mixed into the fiber in a proportion equivalent to _SiO2 with a mass ratio of 0% to 15%. ester reagents into the reaction solution. 5. The method for preparing titanium dioxide fibers according to claim 3 or 4, characterized in that the silicate reagent is methyl orthosilicate or ethyl orthosilicate. 6. The preparation method of titanium dioxide fiber according to claim 1, characterized in that the step of the centrifugal spinning method is: inject the spinning solution with a viscosity of 5Pa·s～50Pa·s into the centrifugal spinning disc, Under the conditions of 10℃～40℃, relative humidity of 20%～50%, and centrifuge speed of 5000r/min～15000r/min, the spinning solution is thrown out at high speed from the spinning hole with a diameter of 0.1mm～0.5mm. , collected by a collecting device to obtain short precursor fibers with a length of 2 cm to 90 cm that are piled up in disorder. 7. The method for preparing titanium dioxide fibers as claimed in claim 1, characterized in that the step of dry spinning is: transferring the spinning solution with a viscosity of 50 Pa·s to 100 Pa·s into the method spinning device Liquid material tank, vacuum defoaming for 5min~10min, under the condition of temperature 10℃~30℃ and relative humidity 20%~80%, apply 0.5MPa~2.0MPa to the spinning solution by means of cylinder nitrogen or metering pump The pressure is so that it is ejected from the niobium-tantalum alloy spinning plate with a hole diameter of 0.06mm to 0.15mm, and is drawn and collected by a drum to obtain transparent and orderly continuous precursor long fibers. 8. The method for preparing titanium dioxide fibers according to claim 1, characterized in that the steps of heat treatment are as follows: Place short precursor fibers or continuous long fibers in a program-controlled furnace, and perform heat treatment with normal pressure or high pressure steam at 80°C to 600°C for 5h to 24h at a pressure of 1atm to 4atm, and then continue to heat at 50°C/ h～200℃/h heating rate, burn the fiber to 700℃～1300℃, keep it warm at the highest temperature point for 5min～10h, cool down naturally, the crystal phase is anatase phase, rutile phase, or two phases coexist Titanium dioxide short or continuous fibers.

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