CN1234928C

CN1234928C - Preparing method for titanium dioxide fibre

Info

Publication number: CN1234928C
Application number: CN 200410024265
Authority: CN
Inventors: 刘和义; 许东; 包南; 赵相金; 侯宪钦; 王彦玲; 杜伟; 张光辉; 王新强; 吕孟凯; 袁多荣
Original assignee: Shandong University
Current assignee: Shandong University
Priority date: 2004-06-11
Filing date: 2004-06-11
Publication date: 2006-01-04
Anticipated expiration: 2024-06-11
Also published as: CN1584156A

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

(I) technical field

The invention relates to a preparation method of a functional semiconductor oxide fiber, in particular to a preparation method of a titanium dioxide fiber with photocatalysis and sterilization performances, belonging to the field of functional fiber materials.

(II) background of the invention

Due to the global energy crisis and the increasing weight of environmental pollution in the last century, the environmental problems are generally regarded by people. TiO 2₂、ZnO、GdS、WO₃、Fe₂O₃Semiconductor photocatalysis technologies are seen by many researchers as they can directly utilize light energy to solve the problem of environmental pollution.

Since Fujishima et al discovered that the titanium dioxide semiconductor electrode has a function of decomposing water in 1972, Cary et al successively reported that a titanium dioxide-water system can degrade various organic compounds which are difficult to degrade under ultraviolet light irradiation in 1976, and a method of treating water by using a titanium dioxide photocatalytic function has attracted much attention. Over 20 years, environmental workers in various countries have conducted extensive and intensive research in the field, and the photocatalytic oxidation process of titanium dioxide has become a research hotspot of the water deep purification treatment technology at home and abroad nowadays.

Among the various semiconductor oxides used for photocatalysis, titanium dioxide has proven to be the most effective photocatalyst. The titanium dioxide used as the green environment-friendly photocatalytic purifying agent has the characteristics of good chemical stability, abrasion resistance, low cost, safety, no toxicity and the like, so that the titanium dioxide has great application prospect in the fields of environmental protection, petrochemical industry and the like.

The basic principle of titanium dioxide photocatalysis is based on the energy band theory of N-type semiconductors. Semiconductors have a discontinuousband structure different from metals, and generally consist of a low-energy valence band filled with electrons and an empty high-energy conduction band, with a forbidden band between the valence band and the conduction band. When irradiated by photons having an energy equal to or greater than its forbidden bandwidth (also called the bandgap), electron-hole pairs are generated. Titanium dioxide is an N-type semiconductor metal oxide, has a forbidden band width of 3.26eV, and when it absorbs photons with a wavelength of 387.5nm or less, electrons in the valence band are excited to jump to the conduction band, forming negatively charged highly active electrons (e)^-) Generating a corresponding hole (h) in the valence band⁺) And the high-activity e is separated and migrated to different positions on the surface of the titanium dioxide under the action of an electric field^-Has strong reducing power, and can react with O in gas phase₂Reaction to form O^2-The free radicals can oxidize and decompose the gas organic matter adsorbed to the surface of titanium dioxide, and the photogenerated holes distributed on the surface have strong oxidizing (electron obtaining) capacity and can oxidize OH adsorbed on the surface of titanium dioxide^-And H₂The O molecules are oxidized to active OH radicals. OH free radical has strong oxidizing power, is known as the oxidant with the strongest reaction activity in water body, and can non-selectively oxidize organic sewage in waterThe dye and part of inorganic pollutants can oxidize a plurality of toxic, harmful and nondegradable organic matters into small organic molecules and finally degrade the small organic molecules into CO₂Water and corresponding inorganic ions, etc., to achieve complete mineralization. In addition, the oxidation potential of many organic substances is more negative than the valence band potential of titanium dioxide, and when the organic substances are adsorbed on the surface of titanium dioxide, the oxidation potential can also be h⁺And (4) oxidizing.

The crystal form and the grain size of the titanium dioxide have important influence on the photocatalytic activity of the titanium dioxide. Titanium dioxide has three crystal forms (phases): anatase phase (antatase), Rutile phase (Rutile) and brookite phase (Brookire). The titanium dioxide used as the photocatalyst has an anatase phase and a rutile phase, wherein the anatase phase has higher photocatalytic activity, and the rutile phase titanium dioxide adsorbs organic matters and O on the surface₂The capacity of the catalyst is not as good as that of the anatase phase, and the formed photoproduction electrons and holes are easy to recombine to cause the reduction of the catalytic activity. Studies have shown that mixtures of anatase phase and rutile phase of titanium dioxide (non-simple mixtures)Has high catalytic activity. Compared with large particles, the titanium dioxide crystal particles with the nanometer level have higher photocatalytic activity because the surface atomic number of the nanometer photocatalyst is rapidly increased along with the reduction of the size of the crystal particles, the absorption efficiency of light is improved, the density of photo-generated electron-hole pairs is increased, and simultaneously, because the surface active positions are increased, the titanium dioxide crystal particles are beneficial to organic matters and OH^-Thereby improving the reaction efficiency.

By adopting methods such as noble metal deposition, transition metal ion doping, semiconductor compounding, surface photosensitization and the like, an intermediate energy level can be introduced, the available spectral range of the titanium dioxide is expanded, or the recombination rate of photo-generated electron-hole pairs is reduced, the service life of photo-generated carriers is prolonged, and therefore the photocatalytic activity of the titanium dioxide is effectively improved. Research shows that noble metals or metal oxides such as Ag, Ir, Au, Ru, Pd and the like are deposited on the surface of the titanium dioxide which is a semiconductor material, or Fe is doped³⁺、Ru³⁺、Os³⁺、V⁵⁺、Cr³⁺、Co³⁺、Ni²⁺、Zn²⁺、Re⁴⁺、W⁶⁺、La³⁺Equal transition metal element ion (doping amount is less than 5wt percent) or SnO₂、WO₃、Al₂O₃、SiO₂、ZrO₂The photocatalytic activity and light absorption performance of titanium dioxide can be improved to different degrees by semiconductor compounding with different energy levels or organic dye sensitization.

At present, the titanium dioxide photocatalyst is mainly applied in the form of ultrafine powder, such as nanopowder, etc., and the catalyst particles are fixed on carriers such as glass, silicon wafers, optical fibers, hollow spheres, sand, etc. by a particle suspension system or by a loading method, or the titanium dioxide is made into a film and loaded on glass, ceramics, silica gel, activated carbon, polymeric membranes, zeolite, etc. to perform a liquid-phase or gas-phase photocatalytic reaction. The above application forms all have defects which are difficult to overcome, so that the photocatalytic technology based on titanium dioxide has a plurality of problems, and the industrial application is greatly restricted. For example, although the particle suspension system has high reaction efficiency, the separation and recovery of fine titanium dioxide powder are very difficult in the late stage of the reaction, and the catalyst loss is serious, thereby limiting the practical application thereof. Although the problem of loss can be avoided by using the immobilization technology, the specific surface area and the ultraviolet light utilization rate of the catalyst aregreatly reduced, the activity and the efficiency of the catalyst are seriously influenced, and the result is not ideal. Therefore, there is a need to develop an application form of titanium dioxide that can not only make full use of the catalytic activity of semiconductors, but also solve the problem of separation and recovery of catalysts, so that the photocatalytic function of titanium dioxide can be applied industrially in the most economical and simple manner. Titanium dioxide fibers are the best form of application for titanium dioxide to meet this need.

The titanium dioxide fiber is a ceramic fiber material with a polycrystalline structure, the diameter of the ceramic fiber material is generally between several microns and dozens of microns, the grain size is in a nanometer scale and is generally not more than 100nm, the length of the fiber can be in different magnitudes due to different preparation processes, generally, the fiber with the monofilament length of millimeter or centimeter is called short fiber, and the fiber with the monofilament length of more than one meter is called continuous fiber. The titanium dioxide fibers have high catalytic performance due to the nano-scale crystal grains, the large specific surface area and the large pore volume of suitable crystal phases (anatase phase or rutile phase or two-phase composite phase). Meanwhile, due to the shape characteristics and the fluffy structure of the fibers, the utilization efficiency of light is high, the fibers are very easy to fix or design a reactor, and the loss problem does not exist, so that the fiber is very convenient for practical application.

The titanium dioxide fiber has catalytic activity and can be directly used as a catalyst to catalyze various high-temperature chemical synthesis reactions, such as epoxidation reaction and the like. Meanwhile, the catalyst can be used As a carrier of the catalyst to load metals such As V, W, Al, As, Ni, Zr, Mo, Ru, Mg, Ca, Pt, Pd, Au, Ag and the like or oxides thereof, and is used for efficiently degrading harmful gases such As nitric oxide and the like in automobile exhaust. The titanium dioxide fiber can be applied to the treatment of industrial organic waste gas by utilizing the catalysis and/or photocatalytic activity of the titanium dioxide fiber, and can oxidize and degrade chlorine-containing organic matters, aromatic organic matters, alcohols, aldehydes, ketones, chain hydrocarbons, sulfur-containing organic matters, nitrogen-containing organic matters and the like in the waste gas; the product can also be used in air conditioners or other air purifiers to purify indoor air, decompose toxic and harmful gases such as formaldehyde and the like in rooms, sterilize and deodorize; the titanium dioxide cellucotton or the fabric thereof can be used in the mask to prepare an anti-virus mask which can kill pathogenic virus and bacteria, and the like.

By utilizing the photocatalytic activity, the titanium dioxide fiber can also be used for treating certain industrial wastewater. It can be used to make various reactors, to degrade the organic pollutant which is difficult to be biodegraded in waste water or to make it completely inorganic. The degradation process can be carried out at normal temperature and normal pressure, and can directly utilize solar ultraviolet light, and can also combine UV and O₃And the method forms an advanced oxidation process to carry out the reaction, and the problems of difficult separation and recovery and easy loss do not exist after the reaction.

The photocatalytic reaction of the titanium dioxide fiber can degrade various toxic and harmful organic matters in water, such as chlorine-containing organic matters, sulfur-containing organic matters, nitrogen-containing organic matters, aromatic hydrocarbons, cyanides, pesticides, petroleum, dyes, surfactants, herbicides, humus and other pollutants, as well as 'three-cause (carcinogenic, teratogenic and mutagenic) matters' and 'priority pollutants' in water, and has the advantages of killing various harmful bacteria such as escherichia coli and the like, along with good chemical and biological inertness, capability of ensuring the water quality to be safe, low in price, easy to obtain, no secondary pollution and the like, so the titanium dioxide fiber has a very attractive application prospect in the aspect of drinking water purification. Titanium dioxide fiber products have been developed by nippon department of china, ltd, for use in the field of drinking water treatment.

The titanium dioxide fiber can also be used as a high-temperature filter material, and the high-strength titanium dioxide fiber can also be applied to the fields of composite reinforced materials, electronic materials and the like. In addition, the titanium dioxide fiber can be further treated, and the hydrogen is prepared by utilizing sunlight irradiation and photocatalytic water decomposition, so that the conversion, storage and utilization of solar energy are realized.

Since the 80's of the 20 th century, several patents have been started relating to the production of titanium dioxide fibers, Japanese patent No.55003371, Japanese patent No.55136126, Japanese patent No.55136127, Japanese patent No.56017928, Japanese patent No.60046927, Japanese patent No.60259625, Japanese patent No.1073030, Japanese patent No.1246139, Japanese patent No.2164722 and the like, and the titanium dioxide fibers were almost produced by a titanate dealkalization method by melting M₂O·nTiO₂Where M is Na, K, Rb or Cs, and n is 1-5, obtaining fibrous titanate crystals, and acid-washing and dealkalizing to obtain titanium dioxide fibers. The KDC method (seaming-drafting-aging method) is one of the most widely used titanate dealkalization methods for preparing titanium dioxide fibers at home and abroad at present, and TiO isused₂And anhydrous K₂CO₃Grinding, mixing, drying, and sintering at 1000 deg.C for 100 hr to obtain K₂Ti₄O₉Removing K from the precursor fiber by acid washing⁺And (4) ionizing to obtain the hydrated titanium dioxide fiber. Although the titanium dioxide fiber obtained by adopting the titanate dealkalization method has a layered structure and higher photocatalytic activity, the obtained fiber length is only in the micrometer order, and the fiber is not called the titanium dioxide fiber in a strict sense, butIt should be called fibrous titanium dioxide, and therefore, it cannot replace the titanium dioxide fiber in the true sense, and meet the application requirements in many aspects.

Japanese patent No.2019569 and japanese patent No.4163317, etc. produce a titania fiber by the dipping method by dipping an organic filament in a titanium alkoxide solution, taking out after blotting, drying, calcining, and burning off the organic matter to obtain a titania fiber. The strength of the titanium dioxide fibers obtained by this method is low due to the high content of organic matter in the precursor fibers.

U.S. Pat. No.4166147, Japanese patent No. A62-223323, Japanese patent No.2000170039 and the like use a sol-gel method to prepare a titanium dioxide fiber, that is, a titanium alkoxide is used as a raw material, and a sol spinning solution is obtained through hydrolysis or acid hydrolysis and polycondensation reaction, and the titanium dioxide fiber is obtained through spinning and calcination. The method has the disadvantages that the reaction condition is difficult to control, and the sol spinning solution is unstable and is easy to spontaneously convert into gel to lose the spinning property.

In general, the above-mentioned methods have not produced titanium dioxide fibers having both high strength and good continuity, and the spinnability andstability of the prepared spinning solution are not satisfactory.

Japanese patent No.10325021, Japanese patent No.11005036, Japanese patent No.2000192336, Japanese patent No.2000218170, Japanese patent No.2000220038, U.S. patent in recent yearsNo.6162759, U.S. patent No.6086844, U.S. patent No.6191067, U.S. patent No.6409961 and the like, all of which use a titanium alkoxide such as tetraisopropyl titanate as a raw material, perform and control hydrolysis and polycondensation reactions of the titanium alkoxide by adding water and ethyl acetoacetate to an isopropanol solution thereof to produce a polymer precipitate, evaporate the isopropanol solvent and dry it through an oil bath to obtain a polymer powder, dissolve the powder in another organic solvent such as tetrahydrofuran, evaporate and concentrate it to obtain a spinning solution, spin and calcine it to obtain a continuous titanium dioxide fiber. By doping with SiO₂The method comprises maintaining anatase phase at 900 deg.C, obtaining high-strength titanium dioxide fiber with porous structure by high-pressure steam heat treatment, and using the fiber as catalyst carrier and loading vanadium oxideNO gas is dissolved, and satisfactory effect is obtained. Although the invention has a great progress compared with the prior art, the invention still has the problems of complex preparation process of the spinning solution, rigorous reaction conditions, expensive raw materials, long reaction time and the like.

Disclosure of the invention

The invention provides a novel method for preparing titanium dioxide fiber, aiming at the defects of the prior art.

The preparation method of the titanium dioxide fiber comprises the steps of synthesizing titanium acetylacetonate (titanium acetylacetonate polymer) as a precursor, respectively diluting titanium tetrachloride, distilled water, acetylacetone and triethylamine in stoichiometric ratio in methanol, mixing and reacting under the conditions of stirring and 0-25 ℃, synthesizing the titanium acetylacetonate in one step, removing a side reactant triethylamine hydrochloride by tetrahydrofuran, dissolving the titanium acetylacetonate in the methanol to prepare a spinning solution, centrifugally spinning to obtain precursor short fiber, obtaining continuous precursor long fiber by dry spinning, and sintering by adopting a high-pressure or normal-pressure steam heat treatment technology to obtain the titanium dioxide short fiber or continuous fiber with high porosity, high specific surface area and high strength.

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

synthesis of titanium polyacetylacetonate

The four liquid reagents are measured according to the proportion of titanium tetrachloride, distilled water, acetylacetone and triethylamine being 1 mol: 3mol to 6 mol: 1mol to 1.5 mol: 4mol, and are respectively diluted in four parts of methanol, wherein the dilution multiple of titanium tetrachloride is 3 times to 5 times, the dilution multiple of distilled water is 3 times to 5 times, the dilution multiple of acetylacetone is 2 times to 3 times, and the dilution multiple of triethylamine is 2 times to 3 times. Higher dilution factor is also possible, which is more favorable for the reaction result, but leads to a great increase in the amount of methanol, and it is appropriate to control the dilution factor within the above range in view of the production cost. Dropwise adding a methanol diluent of distilled water into a methanol diluent of titanium tetrachloride under stirring at 0-25 ℃, or dropwise adding the methanol diluent of titanium tetrachloride into the methanol diluent of distilled water, continuously stirring for 10-30 min after the dropwise addition to obtain a mixed diluent A, simultaneously directly and uniformly mixing acetylacetone and a methanol diluent of triethylamine to obtain a mixed diluent B, then dropwise adding the mixed diluent B into the mixed diluent A under stirring at 0-25 ℃ for reaction, or dropwise adding the mixed diluent A into the mixed diluent B for reaction, continuously stirring at room temperature for 1-24 h after the dropwise addition, then evaporating the solvent methanol in the reaction solution until the solvent is dry to obtain a yellow bonding substance, adding tetrahydrofuran according to the ratio of titanium tetrachloride to tetrahydrofuran of 1 mol: 1100-2200 ml, dissolving soluble substances, filtering to remove insoluble triethylamine hydrochloride white precipitate, evaporating solvent tetrahydrofuran in transparent filtrate until the solvent tetrahydrofuran is dried to obtain a titanium polyacetylacetonate precursor, wherein the reaction equation is as follows:

the purity of the above-mentioned reaction raw materials of titanium tetrachloride, acetylacetone, triethylamine and solvents of methanol, tetrahydrofuran, etc. can be industrial pure, or chemical pure, or analytical pure, which depends on the different requirements of application.

Secondly, preparing spinning solution

Dissolving the titanium polyacetylacetonate into methanol according to the proportion of 100g of the titanium polyacetylacetonate to 300ml to 600ml of the methanol, and doping SiO with the fibers according to the mass ratio of 0 percent to 15 percent₂The organic silicon reagent is added into the solution according to the proportion, the solution is concentrated by a method of evaporating the solvent, so that the viscosity of the solution reaches 5 Pa.s-100 Pa.s (20 ℃), and the transparent, uniform and stable spinning solution can be obtained.

The organic silicon reagent is silicate reagent which can be dissolved in methanol such as methyl orthosilicate, ethyl orthosilicate and the like.

The organosilicon reagent may also be added to the reaction solution during the synthesis of the titanium polyacetylacetonate.

Thirdly, spinning

The precursor short fiber can be obtained by adopting a centrifugal spinning method, and the continuous precursor long fiber can be obtained by adopting dry spinning.

The centrifugal wire throwing method comprises the following steps: injecting the spinning solution with the viscosity of 5 Pa.s-50 Pa.s into a centrifugal spinning disc, spinning the spinning solution from a spinning hole with the aperture of 0.1-0.5 mm at a high speed under the conditions that the temperature is 10-40 ℃, the relative humidity is 20-50% and the rotating speed of a centrifugal machine is 5000-15000 r/min, and collecting the spinning solution by a collecting device to obtain precursor short fibers which are randomly stacked and have the length of 2-90 cm.

The dry spinning method comprises the following steps: transferring the spinning solution with the viscosity of 50 Pa.s-100 Pa.s into a liquid material tank in a dry spinning device, defoaming for 5-10 min in vacuum, applying the pressure of 0.5-2.0 MPa to the spinning solution in a steel cylinder nitrogen or metering pump mode under the conditions that the temperature is 10-30 ℃ and the relative humidity is 20-80% to ensure that the spinning solution is sprayed out from a niobium-tantalum alloy spinning plate with the aperture of 0.06-0.15 mm, and obtaining the transparent and orderly continuous precursor long fiber with almost any length through drawing and drum filament collection.

Fourth, heat treatment

Placing precursor short fiber or continuous long fiber in a program control furnace, carrying out normal-pressure or high-pressure water vapor heat treatment at the temperature of 80-600 ℃, the treatment time is 5-24 h, the treatment pressure is 1-4 atm, then continuously heating the fiber to 700-1300 ℃ at the heating rate of 50-200 ℃/h, preserving the temperature at the highest temperature point for 5-10 h, and naturally cooling to obtain the single fiber with the tensile strength of 100 MPa-1.2 GPa, the diameter of 3-20μm, the continuous length of 1-50 cm or more than 1m and the BET specific surface area of 100m²/g～200m²G, pore volume 0.10cm³/g～0.30cm³The grain diameter is 5 nm-100 nm, and the crystal phase is anatase phase, rutile phase or two-phase coexistent titanium dioxide short fiber or continuous fiber.

SiO doped in titanium dioxide fiber₂The phase transition temperature of the titanium dioxide can be increased, so that the titanium dioxide in the anatase phase is kept at a higher sintering temperature. When the precursor fiber is subjected to heat treatment, titanium dioxide crystals with anatase phase appearing firstly at about 450 ℃ are gradually converted into rutile along with the increase of the heating temperatureAnd (4) phase(s). Not doped with SiO₂When the precursor fiber is subjected to heat treatment, the anatase phase is only kept to about 700 ℃, and only rutile phase titanium dioxide fiber can be obtained after 800 ℃. When SiO is doped₂Then, the anatase phase titanium dioxide can be kept to 900 ℃, the temperature of 1000 ℃ is kept for 0.5h, the anatase phase titanium dioxide in the fiber can still coexist with the rutile phase titanium dioxide, and the rutile phase titanium dioxide fiber is obtained after 1050 ℃.

By controlling the highest temperature of the heat treatment, the titanium dioxide fiber with the crystal phase of anatase phase, rutile phase or the coexistence of the anatase phase and the rutile phase can be obtained, which is mainly determined according to different application requirements.

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

(1) common chemical raw materials and a simple synthesis process are adopted to synthesize the titanium polyacetylacetonate precursor, harsh reaction conditions and complex reaction equipment are not needed in the reaction process, and solvents such as methanol and tetrahydrofuran, reactants triethylamine and the like required in the reaction can be recycled by adopting appropriate recovery and purification measures, so the synthesis cost is greatly reduced.

(2) The polyacetylacetonatitanium spinning solution is transparent and uniform, has good spinning performance and does not need to be doped with a spinning auxiliary agent; the performance is stable, and the precipitate and the coagulation are avoided; the method can be repeatedly used, and when the viscosity of the spinning solution is too high due to volatilization of the solvent methanol and even the spinning solution is dried, the spinning solution can be continuously used after being dissolved in the methanol.

(3) The precursor short fiber and the continuous precursor long fiber can be respectively and conveniently obtained by centrifugal spinning and dry spinning.

(4) The precursor fiber is pretreated by normal pressure or high pressure water vapor, so that the obtained titanium dioxide fiber has high porosity, high specific surface area and high strength.

(5) By doping with SiO₂And by controlling different maximum sintering temperatures, the titanium dioxide fiber with the crystal phase of anatase phase or the two phases of anatase phase and rutile phase coexisting and the grain size of nanometer scale can be easily obtained, and the photocatalytic activity of the fiber is very high.

(IV) description of the drawings

Fig. 1 is a photograph of a titanium dioxide staple fiber. Fig. 2 is a photograph of a titanium dioxide continuous fiber. Fig. 3 is a Scanning Electron Microscope (SEM) photograph of titanium dioxide fibers.

(V) detailed description of the preferred embodiments

Example 1: the preparation method of the titanium dioxide short fiber comprises the following steps:

(1) 40.0ml, 20.0ml, 37.3ml and 202.1ml of the four liquid reagents (analytically pure) are respectively measured according to the proportion of titanium tetrachloride to distilled water to acetylacetone to triethylamine being 1mol to 3mol to 1mol to 4mol, the four reagents are respectively diluted in four parts of methanol, 200.0ml, 100.0ml, 112.0ml and 606.5ml according to the relation that the dilution multiple of titanium tetrachloride is 5 times, the dilution multiple of distilled water is 5 times, the dilution multiple of acetylacetone is 3 times and the dilution multiple of triethylamine is 3 times, the methanol dilution of distilled water is dropwise added into the methanol dilution of titanium tetrachloride under the condition of stirring and 10 ℃, the stirring is continued for 20min after the dropwise addition to obtain mixed dilution A, the methanol dilution of acetylacetone and the methanol dilution of triethylamine are directly and uniformly mixed to obtain mixed dilution B, the mixed dilution B is dropwise added into the mixed dilution A under the condition of stirring and 10 ℃ to carry out the reaction, after dripping, continuing stirring for 1h at room temperature, then evaporating solvent methanol in the reaction solution until the solvent methanol is dried to obtain yellow bonding matter, adding 800.0ml tetrahydrofuran according to the proportion of titanium tetrachloride to tetrahydrofuran being 1mol to 2200ml to dissolve soluble matter, removing insoluble triethylamine hydrochloride white precipitate by suction filtration, then evaporating solvent tetrahydrofuran in transparent filtrate until the solvent tetrahydrofuran is dried to obtain the precursor of the titanium polyacetylacetonate, wherein the yield is 93%;

(2) the above-mentioned titanium polyacetylacetonate was dissolved in 200.0ml of methanol at a ratio of 100g to 300ml of titanium polyacetylacetonate to methanol, and the fiber was doped with SiO in an amount of 15% by mass₂17.5ml of tetraethyl orthosilicate are added and evaporatedConcentrating the solution by a solvent method to make the viscosity of the solution reach 5 Pa.s (20 ℃), and obtaining transparent, uniform and stable spinning solution;

(3) injecting the spinning solution into a centrifugal spinning disc, spinning the spinning solution out of a spinning hole with the aperture of 0.2mm at a high speed under the conditions that the temperature is 40 ℃, the relative humidity is 50% and the rotating speed of a centrifugal machine is 10000r/min, and collecting the spinning solution by a collecting device to obtain precursor short fibers which are stacked disorderly and have the length of 2-90 cm;

(4) the precursor short fiber is put in a program control furnace, normal pressure water vapor heat treatment is carried out at the temperature of 80-600 ℃, the treatment time is 24h, the temperature is kept at 600 ℃ for 10h, the natural temperature reduction is carried out, the tensile strength of the invention is obtained at 100 MPa-1.2 GPa,the diameter is 3-20 mu m, the monofilament length is 1-50 cm, and the BET specific surface area is 100m²/g～200m²G, pore volume 0.10cm³/g～0.30cm³The/g, the grain diameter is 5 nm-10 nm, and the crystal phase is anatase phase titanium dioxide short fiber.

Example 2: preparation method of titanium dioxide continuous fiber

As described in example 1, except that the viscosity of the spinning solution in step (2) is adjusted to 80Pa · s (20 ℃), the spinning solution in step (3) is used for obtaining continuous precursor fiber by the method of spinning, namely, the spinning solution is moved into a liquid material tank in a dry spinning device, vacuum deaeration is carried out for 10min, the pressure of 1.0MPa is applied to the spinning solution by a steel cylinder nitrogen mode under the conditions that the temperature is 10 ℃ and the relative humidity is 20%, the spinning solution is sprayed out from a niobium-tantalum alloy spinning plate with the aperture of 0.10mm, transparent and ordered continuous precursor long fiber with almost any length is obtained by drawing and drum filament collection, the continuous precursor fiber in step (4) is placed in a program control furnace, normal pressure water vapor heat treatment with the temperature of 80 ℃ to 600 ℃ is carried out, the treatment time is 24h, the temperature is kept at 600 ℃ for 10h, natural cooling is carried out, the tensile strength of 100MPa to 1.2GPa and the diameter of the invention is obtained, the continuous length of the monofilament is more than 1m, and the BET specific surface area is 100m²/g～200m²G, pore volume 0.10cm³/g～0.30cm³The grain diameter of the crystal grains is 5nm to 10nm, and the crystal phase is anatase phase titanium dioxide continuous fiber.

Example 3: preparation method of titanium dioxide short fiber

Asdescribed in example 1, except that the ratio of titanium tetrachloride, distilled water, acetylacetone and triethylamine in step (1) was changed to 1 mol: 4.5 mol: 1.3 mol: 4mol, namely 40.0ml, 30.0ml, 48.5ml and 202.1ml of each of the above four liquid reagents (analytical grade) were measured, and the four reagents were diluted in four portions of methanol, 160.0ml, 120.0ml, 121.3ml and 606.5ml, respectively, in accordance with the dilution factor of titanium tetrachloride of 4 times, the dilution factor of distilled water of 4 times, the dilution factor of acetylacetone of 2.5 times and the dilution factor of triethylamine of 3 times, under stirring and at 5 ℃, the methanol diluent of distilled water was added dropwise to the methanol diluent of titanium tetrachloride, stirring was continued for 15min after dropping, a mixed diluent A was obtained, and the methanol diluents of acetylacetone and triethylamine were directly mixed uniformly to obtain a mixed diluent B, then, under the conditions of stirring and 5 ℃, dropwise adding the mixed diluent B into the mixed diluent A for reaction, continuing stirring at room temperature for 12 hours after dropwise adding, then evaporating the solvent methanol in the reaction solution until the reaction solution is dried to obtain a yellow bonding material, adding 550.0ml of tetrahydrofuran according to the proportion of 1 mol: 1500ml of titanium tetrachloride to tetrahydrofuran to dissolve the soluble material, filtering to remove the insoluble triethylamine hydrochloride white precipitate, then evaporating the solvent tetrahydrofuran in the transparent filtrate to obtain a titanium polyacetylacetonate precursor with the yield of 95 percent, and replacing the proportion of the titanium polyacetylacetonate to the methanol in the step (2) with 100 g: 450ml, namely dissolving the titanium polyacetylacetonate into 300.0ml of methanol to prepare the spinning solution.

Example 4: preparation method of titanium dioxide continuous fiber

As described in example 2, except that the ratio of titanium tetrachloride, distilled water, acetylacetone and triethylamine in step (1) was changed to 1 mol: 4.5 mol: 1.3 mol: 4mol, namely 40.0ml, 30.0ml, 48.5ml and 202.1ml of each of the above four liquid reagents (analytical grade) were measured, and the four reagents were diluted in four portions of methanol, 160.0ml, 120.0ml, 121.3ml and 606.5ml, respectively, in accordance with the dilution factor of titanium tetrachloride of 4 times, the dilution factor of distilled water of 4 times, the dilution factor of acetylacetone of 2.5 times and the dilution factor of triethylamine of 3 times, under stirring and at 5 ℃, the methanol diluent of distilled water was added dropwise to the methanol diluent of titanium tetrachloride, stirring was continued for 15min after dropping, a mixed diluent A was obtained, and the methanol diluents of acetylacetone and triethylamine were directly mixed uniformly to obtain a mixed diluent B, then, under the conditions of stirring and 5 ℃, dropwise adding the mixed diluent B into the mixed diluent A for reaction, continuing stirring at room temperature for 12 hours after dropwise adding, then evaporating the solvent methanol in the reaction solution until the mixture is dried to obtain a yellow bonding material, adding 550.0ml of tetrahydrofuran according to the proportion of 1 mol: 1500ml of titanium tetrachloride to tetrahydrofuran to dissolve the soluble material, filtering to remove the insoluble triethylamine hydrochloride white precipitate, then evaporating the solvent tetrahydrofuran in the transparent filtrate until the mixture is dried to obtain a titanium polyacetylacetonate precursor with the yield of 95%, and replacing the proportion of the titanium polyacetylacetonate to the methanol in the step (2) with 100 g: 450ml, namely dissolving the titanium polyacetylacetonate into 300.0ml of methanol to prepare the spinning solution.

Example 5: preparation method of titanium dioxide short fiber

As described in example 1, except that the ratio of titanium tetrachloride, distilled water, acetylacetone and triethylamine in step (1) was changed to 1 mol: 6 mol: 1.5 mol: 4mol, namely 40.0ml, 56.0ml and 202.1ml of each of the above four liquid reagents (analytical reagents) were measured, and according to the relationship that the dilution factor of titanium tetrachloride was 3 times, the dilution factor of distilled water was 3 times, the dilution factor of acetylacetone was 2 times and the dilution factor of triethylamine was 3 times, the above four reagents were diluted in four parts of methanol, 120.0ml, 112.0ml and 606.5ml, respectively, under stirring and at 0 ℃, the methanol diluent of distilled water was added dropwise to the methanol solution of titanium tetrachloride, and after the dropwise addition, stirring was continued for 10min to obtain a mixed diluent A, and simultaneously the methanol diluents of acetylacetone and triethylamine were directly mixed uniformly to obtain a mixed diluent B, then, under the conditions of stirring and 0 ℃, dropwise adding the mixed diluent B into the mixed diluent A for reaction, continuing stirring at room temperature for 24 hours after dropwise adding, then evaporating the solvent methanol in the reaction solution until the mixture is dried to obtain a yellow bonding material, adding 400.0ml of tetrahydrofuran according to the proportion of 1 mol: 1100ml of titanium tetrachloride to tetrahydrofuran to dissolve the soluble material, filtering to remove the white precipitate of insoluble triethylamine hydrochloride, then evaporating the solvent tetrahydrofuran in the transparent filtrate until the mixture is dried to obtain a titanium polyacetylacetonate precursor with the yield of 96%, and replacing the proportion of the titanium polyacetylacetonate to the methanol in the step (2) with 100 g: 600ml, namely dissolving the titanium polyacetylacetonate into 400.0ml of methanol to prepare the spinning solution.

Example 6: preparation method of titanium dioxide continuous fiber

As described in example 2, except that the ratio of titanium tetrachloride, distilled water, acetylacetone and triethylamine in step (1) was changed to 1 mol: 6 mol: 1.5 mol: 4mol, namely 40.0ml, 56.0ml and 202.1ml of each of the above four liquid reagents (analytical reagents) were measured, and according to the relationship that the dilution factor of titanium tetrachloride was 3 times, the dilution factor of distilled water was 3 times, the dilution factor of acetylacetone was 2 times and the dilution factor of triethylamine was 3 times, the above four reagents were diluted in four parts of methanol, 120.0ml, 112.0ml and 606.5ml, respectively, under stirring and at 0 ℃, the methanol diluent of distilled water was added dropwise to the methanol solution of titanium tetrachloride, and after the dropwise addition, stirring was continued for 10min to obtain a mixed diluent A, and simultaneously the methanol diluents of acetylacetone and triethylamine were directly mixed uniformly to obtain a mixed diluent B, then, under the conditions of stirring and 0 ℃, dropwise adding the mixed diluent B into the mixed diluent A for reaction, continuing stirring at room temperature for 24 hours after dropwise adding, then evaporating the solvent methanol in the reaction solution until the mixture is dried to obtain a yellow bonding material, adding 400.0ml of tetrahydrofuran according to the proportion of 1 mol: 1100ml of titanium tetrachloride to tetrahydrofuran to dissolve the soluble material, filtering to remove the white precipitate of insoluble triethylamine hydrochloride, then evaporating the solvent tetrahydrofuran in the transparent filtrate until the mixture is dried to obtain a titanium polyacetylacetonate precursor with the yield of 96%, and replacing the proportion of the titanium polyacetylacetonate to the methanol in the step (2) with 100 g: 600ml, namely dissolving the titanium polyacetylacetonate into 400.0ml of methanol to prepare the spinning solution.

Example 7: preparation method of titanium dioxide short fiber

As described in example 1, except that the ratio of titanium tetrachloride, distilled water, acetylacetone and triethylamine in step (1) was changed to 1 mol: 4.5mo 1: 1.3 mol: 4mol, namely 40.0ml, 30.0ml, 48.5ml and 202.1ml of each of the above four liquid reagents (analytical grade) were measured, and the four reagents were diluted in four portions of methanol, 200.0ml, 150.0ml, 145.5ml and 606.5ml, respectively, in such a manner that the dilution factor of titanium tetrachloride was 5 times, the dilution factor of distilled water was 5 times, the dilution factor of acetylacetone was 3 times and the dilution factor of triethylamine was 3 times, the methanol diluent of distilled water was added to the methanol diluent of titanium tetrachloride under stirring at 20 ℃ and stirring was continued for 30min after completion of the dropwise addition, to obtain mixed diluent A, and the methanol diluent of acetylacetone and triethylamine was directly and uniformly mixed to obtain mixed diluent B, then, under the conditions of stirring and 20 ℃, dropwise adding the mixed diluent B into the mixed diluent A for reaction, continuing stirring at room temperature for 18 hours after dropwise adding, then evaporating the solvent methanol in the reaction solution, obtaining yellow sticky matter, adding 650.0ml of tetrahydrofuran according to the proportion of 1 mol: 1800ml of titanium tetrachloride to tetrahydrofuran, dissolving the soluble matter, filtering and removing the white precipitate of insoluble triethylamine hydrochloride by suction, and then evaporating the solvent tetrahydrofuran in the transparent filtrate until the solvent tetrahydrofuran is dried, thus obtaining the titanium polyacetylacetonate precursor.

Example 8: preparation method of titanium dioxide continuous fiber

As described in example 2, except that in step (1), the ratio of titanium tetrachloride, distilled water, acetylacetone and triethylamine was changed to 1 mol: 4.5 mol: 1.3 mol: 4mol, namely 40.0ml, 30.0ml, 48.5ml and 202.1ml of each of the above four liquid reagents (analytical reagents) were measured, and according to the relationship that the dilution factor of titanium tetrachloride was 5 times, the dilution factor of distilled water was 5 times, the dilution factor of acetylacetone was 3 times and the dilution factor of triethylamine was 3 times, the above four reagents were diluted in four parts of methanol, 200.0ml, 150.0ml, 145.5ml and 606.5ml, respectively, under the conditions of stirring and 20 ℃, the methanol diluent of distilled water was added to the methanol diluent of titanium tetrachloride, and after dropping, stirring was continued for 30min to obtain a mixed diluent A, and at the same time the methanol diluent of acetylacetone and triethylamine was directly mixed uniformly to obtain a mixed diluent B, then, under the conditions of stirring and 20 ℃, dropwise adding the mixed diluent B into the mixed diluent A for reaction, continuing stirring at room temperature for 18 hours after dropwise adding, then evaporating the solvent methanol in the reaction solution until the mixture is dried to obtain a yellow bonding material, adding 650.0ml of tetrahydrofuran according to the proportion of 1 mol: 1800ml of titanium tetrachloride to tetrahydrofuran to dissolve the soluble material, filtering to remove the white precipitate of insoluble triethylamine hydrochloride, and then evaporating the solvent tetrahydrofuran in the transparent filtrate until the solvent tetrahydrofuran is dried to obtain the titanium polyacetylacetonate precursor.

Example 9: preparation method of titanium dioxide short fiber

As described in example 1, exceptthat the ratio of titanium tetrachloride, distilled water, acetylacetone and triethylamine in step (1) was changed to 1 mol: 6 mol: 1.5 mol: 4mol, namely 40.0ml, 56.0ml and 202.1ml of each of the above four liquid reagents (analytical reagents) were measured, and according to the relationship that the dilution factor of titanium tetrachloride was 5 times, the dilution factor of distilled water was 5 times, the dilution factor of acetylacetone was 3 times and the dilution factor of triethylamine was 3 times, the four reagents were diluted in four parts of methanol, 200.0ml, 168.0ml and 606.5ml, respectively, and the methanol diluent of distilled water was added dropwise to the methanol solution of titanium tetrachloride under stirring at 25 ℃ and stirring for 30min after completion of the dropwise addition, to obtain a mixed diluent A, and the methanol diluent of acetylacetone and triethylamine was directly mixed uniformly to obtain a mixed diluent B, then, under the conditions of stirring and 25 ℃, dropwise adding the mixed diluent B into the mixed diluent A for reaction, continuing stirring at room temperature for 24 hours after dropwise adding, then evaporating the solvent methanol in the reaction solution until the solvent methanol is dried to obtain a yellow bonding material, adding 500.0ml of tetrahydrofuran according to the proportion of 1 mol: 1400ml of titanium tetrachloride to tetrahydrofuran to dissolve the soluble material, filtering to remove the insoluble triethylamine hydrochloride white precipitate, and then evaporating the solvent tetrahydrofuran in the transparent filtrate until the solvent tetrahydrofuran is dried to obtain the titanium polyacetylacetonate precursor.

Example 10: preparation method of titanium dioxide continuous fiber

As described in example 2, except that the ratio of titanium tetrachloride, distilled water, acetylacetone and triethylamine in step (1) was changed to 1 mol: 6 mol: 1.5 mol: 4mol, namely 40.0ml, 56.0ml and 202.1ml of each of the above four liquid reagents (analytical reagents) were measured, and according to the relationship that the dilution factor of titanium tetrachloride was 5 times, the dilution factor of distilled water was 5 times, the dilution factor of acetylacetone was 3 times and the dilution factor of triethylamine was 3 times, the four reagents were diluted in four parts of methanol, 200.0ml, 168.0ml and 606.5ml, respectively, under stirring and at 25 ℃, the methanol diluent of distilled water was added dropwise to the methanol solution of titanium tetrachloride, and after the dropwise addition, stirring was continued for 30min to obtain a mixed diluent A, and simultaneously the methanol diluent of acetylacetone and triethylamine was directly mixed uniformly to obtain a mixed diluent B, then, under the conditions of stirring and 25 ℃, dropwise adding the mixed diluent B into the mixed diluent A for reaction, continuing stirring at room temperature for 24 hours after dropwise adding, then evaporating the solvent methanol in the reaction solution until the solvent methanol is dried to obtain a yellow bonding material, adding 500.0ml of tetrahydrofuran according to the proportion of 1 mol: 1400ml of titanium tetrachloride to tetrahydrofuran to dissolve the soluble material, filtering to remove the insoluble triethylamine hydrochloride white precipitate, and then evaporating the solvent tetrahydrofuran in the transparent filtrate until the solvent tetrahydrofuran is dried to obtain the titanium polyacetylacetonate precursor.

Example 11: preparation method of titanium dioxide short fiber

As described in example 1, except that the dropwise addition of the methanol diluent of distilled water to the methanol diluent of titanium tetrachloride in step (1) was changed to the dropwise addition of the methanol diluent of titanium tetrachloride to the methanol diluent of distilled water, and the dropwise addition of the mixed diluent B to the mixed diluent a for reaction was changed to the dropwise addition of the mixed diluent a to the mixed diluent B for reaction.

Example 12: preparation method of titanium dioxide short fiber

As described in example 3, except that the dropwise addition of the methanol diluent of distilled water to the methanol diluent of titanium tetrachloride in step (1) was changed to the dropwise addition of the methanol diluent of titanium tetrachloride to the methanol diluent of distilled water, and the dropwise addition of the mixed diluent B to the mixed diluent a for reaction was changed to the dropwise addition of the mixed diluent a to the mixed diluent B for reaction.

Example 13: preparation method of titanium dioxide short fiber

As described in example 5, except that the dropwise addition of the methanol diluent of distilled water to the methanol diluent of titanium tetrachloride in step (1) was changed to the dropwise addition of the methanol diluent of titanium tetrachloride to the methanol diluent of distilled water, and the dropwise addition of the mixed diluent B to the mixed diluent a for reaction was changed to the dropwise addition of the mixed diluent a to the mixed diluent B for reaction.

Example 14: preparation method of titanium dioxide short fiber

As described in example 7, except that the dropwise addition of the methanol diluent of distilled water to the methanol diluent of titanium tetrachloride in step (1) was changed to the dropwise addition of the methanol diluent of titanium tetrachloride to the methanol diluent of distilled water, and the dropwise addition of the mixed diluent B to the mixed diluent a for reaction was changed to the dropwise addition of the mixed diluent a to the mixed diluent B for reaction.

Example 15: preparation method of titanium dioxide short fiber

As described in example 9, except that the dropwise addition of the methanol diluent of distilled water to the methanol diluent of titanium tetrachloride in step (1) was changed to the dropwise addition of the methanol diluent of titanium tetrachloride to the methanol diluent of distilled water, and the dropwise addition of the mixed diluent B to the mixed diluent a for reaction was changed to the dropwise addition of the mixed diluent a to the mixed diluent B for reaction.

Example 16: preparation method of titanium dioxide short fiber

As described in example 1, except that the purity of the reaction raw materials of titanium tetrachloride, acetylacetone, triethylamine and the solvents of methanol, tetrahydrofuran and the like used in step (1) was changed from analytical purity to industrial purity.

Example 17: preparation method of titanium dioxide short fiber

As described in example 1, except that the purity of the reaction raw materials of titanium tetrachloride, acetylacetone, triethylamine and the solvents of methanol, tetrahydrofuran and the like used in step (1) was changed from analytical purity to chemical purity.

Example 18: preparation method of titanium dioxide short fiber

As described in example 1, except that the step (2) was carried out in such a manner that the SiO was incorporated into the fiber in an amount of 10% by mass₂11.8ml of ethyl orthosilicate was added and the viscosity of the spinning dope was adjusted to 20 pas (20 ℃).

Example 19: preparation method of titanium dioxide continuous fiber

As described in example 2, except that the step (2) was carried out in such a manner that the SiO was incorporated into the fiber in an amount of 10% by mass₂11.8ml of ethyl orthosilicate was added and the viscosity of the spinning dope was adjusted to 60 pas (20 ℃).

Example 20: preparation method of titanium dioxide short fiber

As described in example 1, except that the step (2) was carried out in such a manner that the SiO was incorporated into the fiber in an amount of 5% by mass₂5.9ml of ethyl orthosilicate were added and the viscosity of the spinning dope was adjusted to 40 pas (20 ℃).

Example 21: preparation method of titanium dioxide continuous fiber

As described in example 2, except that the step (2) was carried out in such a manner that the SiO was incorporated into the fiber in an amount of 5% by mass₂5.9ml of ethyl orthosilicate are added and the viscosity of the spinning dope is adjusted to 100Pa.s (20 ℃).

Example 22: preparation method of titanium dioxide short fiber

As described in example 1, except that the step (2) was carried out in such a manner that the SiO was incorporated in the fiber in an amount of 0% by mass₂In a ratio of not incorporating any silicon-containing compound, and adjusting the viscosity of the spinning solution to 50 pas (20 ℃).

Example 23:

as described in example 2, except that the step (2) was carried out in such a manner that the SiO was incorporated in the fiber in an amount of 0% by mass₂In a proportion of not doping any silicon-containing compound, andthe viscosity of the spinning solution was adjusted to 50 pas (20 ℃ C.).

Example 24: preparation method of titanium dioxide short fiber

As described in example 1, except that the centrifugal spinning conditions in step (3) were changed to 30℃ C, 40% relative humidity, 5000r/min centrifuge rotation speed and 0.5mm spinning hole diameter.

Example 25: preparation method of titanium dioxide short fiber

As described in example 1, except that the centrifugal spinning conditions in step (3) were changed to 20 ℃ C, 30% relative humidity, 12000r/min centrifuge rotation speed, and 0.3mm spinning hole diameter.

Example 26: preparation method of titanium dioxide short fiber

As described in example 1, except that the centrifugal spinning conditions in step (3) were changed to 10 ℃ C, 20% relative humidity, 15000r/min centrifuge rotation speed, and 0.1mm spinning hole diameter.

Example 27: preparation method of titanium dioxide continuous fiber

As described in example 2, except that the conditions for dry spinning in step (3) were changed to 60 pas (20 ℃ C.) in the viscosity of the spinning dope, vacuum deaeration for 5min, 30 ℃ C., 80% in relative humidity, 0.5MPa in spinning pressure, and 0.06mm in spinning pore diameter.

Example 28: preparation method of titanium dioxide continuous fiber

As described in example 2, except that the conditions for the dry spinning in the step (3) were changed to 100 pas (20 ℃ C.) for the viscosity of the dope, and the vacuum deaeration was carried out for 10min at a temperature of 20 ℃ C., a relative humidity of 40%, a spinning pressure of 2.0MPa, and a spinning pore diameter of 0.15 mm.

Example 29: preparation method of titanium dioxide continuous fiber

As described in example 2, except that the conditions for the dry spinning in the step (3) were changed to 50 pas (20 ℃ C.) for the viscosity of the dope, and the vacuum deaeration was carried outfor 5min at a temperature of 25 ℃ C., a relative humidity of 60%, a spinning pressure of 1.2MPa, and a spinning pore diameter of 0.12 mm.

Example 30: preparation method of titanium dioxide short fiber

As described in example 1, except that the precursor short fiber is subjected to the steam heat treatment at 80 to 600 ℃ and 2atm in the step (4), the treatment time is 15 hours, and the temperature is kept at 600 ℃ for 8 hours, so as to obtain the titanium dioxide short fiber with the grain size of 5 to 10nm and the crystal phase of anatase phase.

Example 31: preparation method of titanium dioxide short fiber

As described in example 1, except that the precursor short fiber is subjected to the steam heat treatment at 80 to 600 ℃ and 3atm in the step (4), the treatment time is 10 hours, and the temperature is kept at 600 ℃ for 5 hours, so as to obtain the titanium dioxide short fiber with the grain size of 5 to 10nm and the crystal phase of anatase phase.

Example 32: preparation method of titanium dioxide short fiber

As described in example 1, except that the precursor short fiber is subjected to the steam heat treatment at 80 to 600 ℃ and 4atm in the step (4), the treatment time is 5 hours, and the temperature is kept at 600 ℃ for 2 hours, so as to obtain the titanium dioxide short fiber with the grain size of 5 to 10nm and the crystal phase of anatase phase.

Example 33: preparation method of titanium dioxide short fiber

As described in example 1, except that in step (4), the precursor short fiber is subjected to steam heat treatment at 80-600 ℃ and 1atm for 24h, and then the fiber is continuously heated to 700 ℃ at a heating rate of 50 ℃/h, and the temperature is kept at 700 ℃ for 8h, so as to obtain the titanium dioxide short fiber with the grain size of 10-20 nm and the crystal phase of anatase phase.

Example 34: preparation method of titanium dioxide short fiber

As described in example 1, except that in step (4), the precursor short fiber is subjected to a water vapor heat treatment at 80-600 ℃ and 2atm for 18h, and then the fiber is continuously heated to 800 ℃ at a heating rate of 80 ℃/h, and is kept at the temperature of 800 ℃ for 6h, so as to obtain the titanium dioxide short fiber with the grain size of 15-30 nm and the crystal phase of anatase phase.

Example 35: preparation method of titanium dioxide short fiber

As described in example 1, except that in step (4), the precursor short fiber is subjected to steam heat treatment at 80-600 ℃ and 1atm for 24h, and then the fiber is heated to 900 ℃ at a heating rate of 100 ℃/h, and is kept at 900 ℃ for 2h, so as to obtain the titanium dioxide short fiber with the grain size of 20-40 nm and the crystal phase of anatase phase.

Example 36: preparation method of titanium dioxide short fiber

As described in example 1, except that the precursor short fiber is subjected to the steam heat treatment at 80-600 ℃ and 3atm in the step (4), the treatment time is 10h, then the fiber is continuously burnt to 1000 ℃ at the heating rate of 120 ℃/h, and the temperature is kept at 1000 ℃ for 0.5h, so as to obtain the titanium dioxide short fiber with the grain size of 30-50 nm and the crystal phase of anatase phase and rutile phase coexisting.

Example 37: preparation method of titanium dioxide short fiber

As described in example 1, except that in step (4), the precursor short fiber is subjected to a steam heat treatment at 80-600 ℃ and 4atm for 5h, and then the fiber is burned to 1100 ℃ ata heating rate of 150 ℃/h, and the temperature is maintained at 1100 ℃ for 20min, so as to obtain the titanium dioxide short fiber with the grain size of 40-70 nm and the crystal phase of rutile phase.

Example 38: preparation method of titanium dioxide short fiber

As described in example 1, except that in step (4), the precursor short fiber is subjected to a steam heat treatment at 80-600 ℃ and 4atm for 5h, and then the fiber is heated to 1200 ℃ at a heating rate of 180 ℃/h, and the temperature is maintained at 1200 ℃ for 10min, so as to obtain the titanium dioxide short fiber with the grain size of 50-80 nm and the crystal phase of rutile phase.

Example 39: preparation method of titanium dioxide short fiber

As described in example 1, except that in step (4), the precursor short fiber is subjected to a steam heat treatment at 80-600 ℃ and 4atm for 5h, and then the fiber is heated to 1300 ℃ at a temperature rise rate of 200 ℃/h, and the temperature is maintained at 1300 ℃ for 5min, so as to obtain the titanium dioxide short fiber with the grain size of 70-100 nm and the crystal phase of rutile phase.

Example 40: preparation method of titanium dioxide continuous fiber

As described in example 2, except that the precursor short fiber is subjected to the steam heat treatment at 80-600 ℃ and 2atm in the step (4), the treatment time is 15h, and the heat preservation is carried out at 600 ℃ for 8h, so as to obtain the titanium dioxide continuous fiber with the grain size of 5-10 nm and the crystal phase of anatase phase.

Example 41: preparation method of titanium dioxide continuous fiber

As described in example 2, except that the precursor short fiber is subjected to the steam heat treatment at 80-600 ℃ and 3atm in the step (4), the treatment time is 10h, and the heat preservation is carried out at 600 ℃ for 5h, so as to obtain the titanium dioxide continuous fiber with the grain size of 5-10 nm and the crystal phase of anatase phase.

Example 42: preparation method of titanium dioxide continuous fiber

As described in example 2, except that the precursor short fiber is subjected to the steam heat treatment at 80-600 ℃ and 4atm in the step (4), the treatment time is 5h, and the heat preservation is carried out at 600 ℃ for 2h, so as to obtain the titanium dioxide continuous fiber with the grain size of 5-10 nm and the crystal phase of anatase phase.

Example 43: preparation method of titanium dioxide continuous fiber

As described in example 2, except that in the step (4), the precursor short fiber is subjected to the steam heat treatment at 80-600 ℃ and 1atm for 24h, and then the fiber is continuously burnt to 700 ℃ at the heating rate of 50 ℃/h, and the temperature is kept at 700 ℃ for 8h, so that the titanium dioxide continuous fiber with the grain size of 10-20 nm and the crystal phase of anatase phase is obtained.

Example 44: preparation method of titanium dioxide continuous fiber

As described in example 2, except that in step (4), the precursor short fiber is subjected to steam heat treatment at 80-600 ℃ and 2atm for 18h, and then the fiber is continuously heated to 800 ℃ at a heating rate of 80 ℃/h, and is kept at 800 ℃ for 6h, so as to obtain the titanium dioxide continuous fiber with the grain size of 15-30 nm and the crystalline phase of anatase phase.

Example 45: preparation method of titanium dioxide continuous fiber

As described in example 2, except that in the step (4), the precursor short fiber is subjected to the steam heat treatment at 80-600 ℃ and 1atm for 24h, and then the fiber is continuously heated to 900 ℃ at the heating rate of 100 ℃/h, and the temperature is kept at 900 ℃ for 2h, so that the titanium dioxide continuous fiber with the grain size of 20-40 nm and the crystal phase of anatase phase is obtained.

Example 46: preparation method of titanium dioxide continuous fiber

As described in example 2, except that in the step (4), the precursor short fiber is subjected to the steam heat treatment at 80-600 ℃ and 3atm for 10h, and then the fiber is continuously burnt to 1000 ℃ at the heating rate of 120 ℃/h, and the temperature is kept at 1000 ℃ for 0.5h, so as to obtain the titanium dioxide continuous fiber with the grain size of 30-50 nm and the crystal phase of anatase phase and rutile phase coexisting.

Example 47: preparation method of titanium dioxide continuous fiber

As described in example 2, except that in step (4), the precursor short fiber is subjected to a steam heat treatment at 80-600 ℃ and 4atm for 5h, and then the fiber is continuously heated to 1100 ℃ at a heating rate of 150 ℃/h, and the temperature is maintained at 1100 ℃ for 20min, so as to obtain the titanium dioxide continuous fiber with the grain size of 40-70 nm and the crystal phase of rutile phase.

Example 48: preparation method of titanium dioxide continuous fiber

As described in example 2, except that in step (4), the precursor short fiber is subjected to a steam heat treatment at 80-600 ℃ and 4atm for 5h, and then the fiber is continuously heated to 1200 ℃ at a heating rate of 180 ℃/h, and the temperature is maintained at 1200 ℃ for 10min, so as to obtain the titanium dioxide continuous fiber with the grain size of 50-80 nm and the crystal phase of rutile phase.

Example 49: preparation method of titanium dioxide continuous fiber

As described in example 2, except that in step (4), the precursor short fiber is subjected to a steam heat treatment at 80-600 ℃ and 4atm for 5h, and then the fiber is heated to 1300 ℃ at a heating rate of 200 ℃/h, and the temperature is maintained at 1300 ℃ for 5min, so as to obtain the titanium dioxide continuous fiber with the grain size of 70-100 nm and the crystal phase of rutile phase.

Example 50: preparation method of titanium dioxide short fiber

As described in example 1, except that no silicon-containing compound is doped in step (2), the precursor short fiber is subjected to steam heat treatment at 80-600 ℃ and 1atm in step (4) for 24h, then the fiber is continuously burned to 700 ℃ at a heating rate of 50 ℃/h, and the temperature is kept at 700 ℃ for 8h, so as to obtain the titanium dioxide short fiber with the grain size of 10-20 nm and the crystal phase of anatase phase and rutile phase coexisting.

Example 51: preparation method of titanium dioxide continuous fiber

As described in example 2, except that no silicon-containing compound is doped in step (2), the precursor short fiber is subjected to steam heat treatment at 80-600 ℃ and 2atm in step (4) for 18h, then the fiber is continuously heated to 700 ℃ at a heating rate of 50 ℃/h, and the temperature is kept at 700 ℃ for 8h, so as to obtain the titanium dioxide continuous fiber with the grain size of 10-20 nm and the crystal phase of anatase phase and rutile phase coexisting.

Example 52: preparation method of titanium dioxide short fiber

As described in example 1, except that no silicon-containing compound is doped in step (2), the precursor short fiber is subjected to steam heat treatment at 80-600 ℃ and 1atm in step (4) for 24h, and then the fiber is continuously burned to 800 ℃ at the temperature rise speed of 80 ℃/h and is kept at 800 ℃ for 6h, so as to obtain the titanium dioxide short fiber with the grain diameter of 15-30 nm and the crystal phase of rutile phase.

Example 53: preparation method of titanium dioxide continuous fiber

As described in example 2, except that no silicon-containing compound is doped in step (2), the precursor short fiber is subjected to steam heat treatment at 80-600 ℃ and 2atm in step (4) for 18h, and then the fiber is continuously heated to 800 ℃ at a heating rate of 80 ℃/h and is kept at 800 ℃ for 6h, so that the titanium dioxide continuous fiber with the grain size of 15-30 nm and the crystal phase of rutile phase is obtained.

Example 54: preparation method of titanium dioxide short fiber

As described in example 1, except that in the step (4), the precursor short fiber is subjected to steam heat treatment at 80-600 ℃ and 4atm for 8h, and then the fiber is heated to 900 ℃ at a heating rate of 150 ℃/h, and is kept at 900 ℃ for 3h, so as to obtain the titanium dioxide short fiber with the grain size of 40-50 nm, the crystalline phase of anatase phase and rutile phase coexisting and mainly anatase phase.

Example 55: preparation method of titanium dioxide continuous fiber

As described in example 2, except that in the step (4), the precursor short fiber is subjected to the steam heat treatment at 80-600 ℃ and 4atm for 10h, and then the fiber is heated to 900 ℃ at a heating rate of 200 ℃/h, and is kept at 900 ℃ for 8h, so as to obtain the titanium dioxide short fiber with the grain size of 50-60 nm, the crystal phase of which is two phases of anatase phase and rutile phase coexisting and is mainly rutile phase.

Claims

1. A process for preparing titanium dioxide fibre includes such steps as synthesizing titanium polyacetylacetonate as precursor, diluting titanium tetrachloride, distilled water, acetylacetone and triethylamine in methanol, mixing at 0-25 deg.C while stirring, reaction, one-step synthesizing titanium polyacetylacetonate, removing by-product triethylamine hydrochloride by tetrahydrofuran, dissolving titanium polyacetylacetonate in methanol to obtain spinning liquid, centrifugal spinning to obtain short precursor fibre, dry spinning to obtain long continuous precursor fibre, and high-pressure or ordinary-pressure steam heat treating.

2. The method for preparing titanium dioxide fiber according to claim 1, wherein the specific steps of synthesizing the titanium polyacetylacetonate are as follows:

the four liquid reagents are measured according to the proportion of titanium tetrachloride, distilled water, acetylacetone and triethylamine being 1 mol: 3 mol-6 mol: 1 mol-1.5 mol: 4mol, and are respectively diluted in four parts of methanol, wherein the dilution multiple of titanium tetrachloride is 3 times-5 times, the dilution multiple of distilled water is 3 times-5 times, the dilution multiple of acetylacetone is 2 times-3 times, and the dilution multiple of triethylamine is 2 times-3 times, the methanol dilution of distilled water is dropwise added into the methanol dilution of titanium tetrachloride under the condition of stirring and 0 ℃ to 25 ℃, the methanol dilution of titanium tetrachloride can also be dropwise added into the methanol dilution of distilled water, the mixture is continuously stirred for 10min to 30min after the dropwise addition, a mixed dilution A is obtained, the methanol dilution of acetylacetone and the methanol dilution of triethylamine are directly and uniformly mixed, a mixed dilution B is obtained, then under the condition of stirring and 0 ℃ to 25 ℃, dropwise adding the mixed diluent B into the mixed diluent A to react, or dropwise adding the mixed diluent A into the mixed diluent B to react, continuing to stir at room temperature for 1-24 h after dropwise adding, then evaporating solvent methanol in the reaction solution to dryness to obtain yellow sticky matter, adding tetrahydrofuran according to the proportion of titanium tetrachloride to tetrahydrofuran being 1 mol: 1100-2200 ml to dissolve soluble matter, filtering by suction to remove insoluble triethylamine hydrochloride white precipitate, then evaporating solvent tetrahydrofuran in transparent filtrate to dryness to obtain a titanium polyacetylacetonate precursor, wherein the reaction equation is as follows:

3. the method for preparing titanium dioxide fiber according to claim 1, wherein the spinning dope is prepared by the following steps:

dissolving the titanium polyacetylacetonate into methanol according to the proportion of 100g of the titanium polyacetylacetonate to 300ml to 600ml of the methanol, and doping SiO with the fibers according to the mass ratio of 0 percent to 15 percent₂The organic silicon reagent is added into the solution according to the proportion, the solution is concentrated by a method of evaporating the solvent, so that the viscosity of the solution reaches 5 Pa.s-100 Pa.s at the temperature of 20 ℃, and transparent, uniform and stable spinning solution is obtained; the organic silicon reagent is a silicate reagent.

4. Such asThe process for producing a titanium dioxide fiber according to claim 1, wherein the titanium polyacetylacetonate is synthesized by adding 0 to 15% by mass of SiO to the fiber₂The silicate reagent is added to the reaction solution in the ratio of (A) to (B).

5. The method for preparing titanium dioxide fiber according to claim 3 or 4, wherein the silicate reagent is methyl orthosilicate or ethyl orthosilicate.

6. The method for preparing titanium dioxide fiber according to claim 1, wherein the centrifugal spinning method comprises the steps of: injecting the spinning solution with the viscosity of 5 Pa.s-50 Pa.s into a centrifugal spinning disc, spinning the spinning solution from a spinning hole with the aperture of 0.1-0.5 mm at a high speed under the conditions that the temperature is 10-40 ℃, the relative humidity is 20-50% and the rotating speed of a centrifugal machine is 5000-15000 r/min, and collecting the spinning solution by a collecting device to obtain precursor short fibers which are randomly stacked and have the length of 2-90 cm.

7. The method for producing a titanium dioxide fiber according to claim 1, characterized in that the dry spinning step is: transferring the spinning solution with the viscosity of 50 Pa.s-100 Pa.s into a liquid material tank in a method spinning device, defoaming for 5-10 min in vacuum, applying the pressure of 0.5-2.0 MPa to the spinning solution in a mode of a steel cylinder nitrogen or a metering pump under the conditions that the temperature is 10-30 ℃ and the relative humidity is 20-80% to ensure that the spinning solution is sprayed out from a niobium-tantalum alloy spinning plate with the aperture of 0.06-0.15 mm, and obtaining the transparent and orderly continuous precursor long fiber through drawing and drum filament collection.

8. The method for producing a titanium dioxide fiber according to claim 1, characterized in that the heat treatment is carried out by the steps of:

the precursor short fiber or continuous long fiber is placed in a program control furnace to carry out normal-pressure or high-pressure water vapor heat treatment at the temperature of 80-600 ℃, the treatment time is 5-24 h, the treatment pressure is 1-4 atm, then the fiber can be continuously heated to 700-1300 ℃ at the heating rate of 50-200 ℃/h, the temperature is kept at the highest temperature point for 5 min-10 h, the temperature is naturally reduced, and the crystalline phase is anatase phase, rutile phase or two-phase coexistent titanium dioxide short fiber or continuous fiber.