Preparation method of mesoporous glass fiber

Abstract

This invention relates to the field of glass fiber technology and discloses a method for preparing mesoporous glass fibers. The method includes the following steps: Step 1: Spraying a pore-forming agent onto the surface of a glass sheet to form a pore-forming agent coating, obtaining a glass raw material; Step 2: Irradiating the glass raw material with a laser emitted from a laser emitter to form glass droplets; Step 3: Blowing the glass droplets with an airflow generated by an airflow blowing device to form glass fibers; Step 4: Immersing the glass fibers in an acid solution for acid treatment to obtain mesoporous glass fibers. This invention utilizes laser rapid heating to achieve a highly efficient process technology that melts glass while simultaneously forming fibers, maximizing material utilization and offering significant selectivity, flexibility, controllability, and targetability.

Description

Technical Field

[0001] This invention relates to the field of glass fiber technology, and more specifically to a method for preparing mesoporous glass fibers. Background Technology

[0002] Ultrafine glass fibers, through intertwining and three-dimensional matting, can form fiberglass wool felt with a multi-dimensional porous and fluffy structure. This material possesses excellent thermal insulation and sound absorption properties, making it a key material for thermal insulation and sound absorption / noise reduction in aerospace vehicles such as aircraft and rockets. The porous structure of the fiberglass wool felt is the core of its thermal insulation and sound absorption; increasing the porosity of the fiberglass wool felt can significantly reduce its thermal conductivity, allowing sound waves to be absorbed through multiple reflections within the fiber pore walls, thus improving sound insulation. Therefore, the development of high-performance thermal and sound-insulating ultrafine porous glass fibers has become a key research focus in the high-end aerospace field.

[0003] Patent application CN107558289B discloses a dry hot-pressed core material of high-strength, low-thermal-conductivity ultrafine glass fiber and its preparation method. The main technical concept involves uniformly mixing glass fiber raw materials and melting them into a transparent, impurity-free molten glass. The molten glass then flows through a perforator into a high-speed rotating centrifugal disc, from which ultrafine glass fibers are ejected. The temperature of the molten glass is 1040±10℃, and the temperature of the centrifugal disc is 950±10℃. By controlling the amount of each reactant and the production process conditions, ultrafine glass fibers with a diameter of 98% normally distributed between 2.4 and 4.5 μm, an aspect ratio of 1000 to 2500, and a porosity ≥85% are finally prepared. In this method, the molten glass needs to flow through a perforator into a high-speed rotating centrifugal disc before the ultrafine glass fibers are ejected.

[0004] Patent application CN107012585B discloses an ultrafine alkali-free glass fiber wool and its preparation method. The main technical approach involves uniformly mixing glass fiber raw materials and then calcining them in a furnace to melt a uniform, impurity-free, and transparent glass melt. The glass melt is then passed through a baffle to form a primary glass filament stream. This primary glass filament stream is then subjected to a secondary melting, blowing, and drawing process under high temperature and high-speed flame airflow to form ultrafine alkali-free glass fibers. By controlling the amount of each reactant and the production process conditions, ultrafine alkali-free glass fibers with 95% of their diameter normally distributed between 0.5 and 2 μm are finally produced. In this method, the glass melt needs to first form a primary glass filament stream through a baffle, followed by secondary melting, blowing, and drawing to form the ultrafine alkali-free glass fibers.

[0005] Patent application CN113307489A discloses a mesoporous glass fiber and its preparation method, as well as a graded porous fiber cotton and its preparation method. The main technical approach involves melting glass fiber raw materials into molten glass, which flows in streams into a centrifugal disc. Under high-speed rotation of the disc, the molten glass is uniformly concentrated on the sidewall and centrifuged through the sidewall pores to obtain glass fibers. The glass fibers and a pore-forming agent are then placed in a muffle furnace and heat-treated at 500-800℃ for 0.5-2 hours to obtain mesoporous glass fibers with a uniformly dispersed crystalline phase structure. By controlling the amount of each reactant and the production process conditions, mesoporous glass fibers with a diameter of 98% normally distributed between 0.3μm and 3μm are finally prepared. This method requires the molten glass to be spun out into ultrafine glass fibers via a high-speed rotating centrifugal disc, and the preparation of mesoporous fibers requires a muffle furnace. The pore-forming agent is used for heat treatment only after the glass fibers are formed, resulting in a complex process involving multiple pieces of equipment.

[0006] Existing technologies disclose the technical ideas for preparing glass fibers and mesoporous glass fibers, but they are energy-intensive, have long cycles, require a lot of equipment, and have complex processes. Summary of the Invention

[0007] The purpose of this invention is to overcome the problems of high energy consumption, long cycle, numerous equipment, and complex process flow in the preparation of mesoporous glass fibers in the existing technology, and to provide a method for preparing mesoporous glass fibers. A pore-forming agent is coated on the surface of a glass sheet to form a glass raw material. The glass raw material is rapidly melted by laser at high temperature, forming glass droplets. The pore-forming agent is uniformly dispersed in the glass droplets. Under high-speed airflow, the glass droplets are drawn and shaped into glass fibers by the airflow. Simultaneously, during the glass fiber forming process, the crystallization effect of the pore-forming agent is activated by temperature control of the high-speed airflow, forming an in-situ microcrystalline structure inside and on the surface of the glass fiber. Then, the glass fiber with the in-situ microcrystalline structure is immersed in an acid solution to achieve complete acid hydrolysis of the crystal phase structure, forming mesoporous glass fibers with a uniform pore structure.

[0008] To achieve the above objectives, the present invention provides a method for preparing mesoporous glass fibers, the method comprising the following steps:

[0009] Step 1: Spray the pore-forming agent onto the surface of the glass sheet to form a pore-forming agent coating, thus obtaining the glass raw material;

[0010] Step 2: Irradiate the glass material with a laser emitted from a laser emitter to form glass droplets;

[0011] Step 3: Use the airflow generated by the airflow jetting device to blow the molten glass droplets to form glass fibers;

[0012] Step 4: Immerse the glass fiber in an acid solution for acid treatment to obtain mesoporous glass fiber.

[0013] Preferably, the thickness of the glass sheet is 0.5-5 mm.

[0014] Preferably, the pore-forming agent is selected from one or more of nickel oxide, cerium oxide, barium oxide, and lanthanum oxide.

[0015] Preferably, the particle size of the pore-forming agent is 50-500 nm, and the thickness of the pore-forming agent coating is 5-300 μm.

[0016] Preferably, the wavelength of the laser is 8-12 μm and the spot size is 0.5-5 cm. 2 Power is 5-20kW / cm 2 .

[0017] Preferably, the viscosity of the glass droplet is 1g1.2-1g2 Pa·s.

[0018] Preferably, the angle between the airflow and the laser is 10-45°.

[0019] Preferably, the temperature of the airflow is 100-400℃ and the flow velocity is 20-100m / s.

[0020] Preferably, the concentration of the acid solution is 0.5-3 mol / L.

[0021] Preferably, the acid treatment conditions include: a temperature of 25-50°C and a time of 0.5-3 hours.

[0022] Preferably, the diameter of the mesoporous glass fiber is 1-10 μm, and the pore size of the mesoporous glass fiber is 20-120 nm.

[0023] Preferably, the glass sheet is one or more of silicate glass sheets, phosphate glass sheets, and borate glass sheets.

[0024] Preferably, the raw materials for preparing the silicate glass sheet include SiO2, B2O3, Al2O3, alkaline earth metal oxides and alkali metal oxides, and the molar ratio of SiO2, B2O3, Al2O3, alkaline earth metal oxides and alkali metal oxides is 1:0.02-0.29:0.02-0.43:0.1-1:0.01-0.57.

[0025] Preferably, the raw materials for preparing the phosphate glass sheet include P2O5, B2O3, Fe2O3, alkaline earth metal oxides and alkali metal oxides, and the molar ratio of P2O5, B2O3, Fe2O3, alkaline earth metal oxides and alkali metal oxides is 1:0.055-0.38:0.091-0.25:0.18-0.88:0.0091-0.25.

[0026] Preferably, the raw materials for preparing the borate glass sheet include B2O3, SiO2, Fe2O3, alkaline earth metal oxides and alkali metal oxides, and the molar ratio of B2O3, SiO2, Fe2O3, alkaline earth metal oxides and alkali metal oxides is 1:0.018-0.22:0.091-0.22:0.36-0.78:0.091-0.33.

[0027] Compared with the prior art, the above-mentioned technical solution of the present invention has the following advantages:

[0028] 1. This invention utilizes laser rapid heating to achieve a highly efficient process of melting glass at the edge and forming fibers at the edge. This avoids the long-term high-temperature requirements of the existing technology, which requires batch feeding of glass raw materials into the furnace for calcination and centrifugal drawing of molten glass. This greatly reduces the energy consumption required in the glass fiber forming process.

[0029] 2. This invention uses rare earth oxide pore-forming agents and high-temperature airflow blowing technology to crystallize the pore-forming agents during the fiber drawing process, forming a crystalline structure on the surface and inside of the fiber. This avoids the secondary heat treatment process of glass fiber and allows for the direct construction of mesoporous structures on glass fiber using acid treatment.

[0030] 3. This invention uses laser spot control to selectively melt the area of ​​the glass material to be melted, thereby maximizing the utilization of the material and exhibiting great selectivity, flexibility, controllability, and targetability. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of glass fiber laser forming technology.

[0032] Explanation of reference numerals in the attached figures

[0033] 1. Laser emitter; 2. Glass material; 3. Airflow blowing device; 4. Airflow; 5. Laser; 6. Glass fiber. Detailed Implementation

[0034] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0035] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0036] like Figure 1 As shown, the method for preparing mesoporous glass fibers according to the present invention includes the following steps:

[0037] Step 1: Spray the pore-forming agent onto the surface of the glass sheet to form a pore-forming agent coating, thus obtaining glass raw material 2;

[0038] Step 2: Irradiate the glass material 2 with laser 5 emitted by laser emitter 1 to form glass droplets;

[0039] Step 3: Use the airflow 4 generated by the airflow blowing device 3 to blow the glass droplets to form glass fibers 6;

[0040] Step 4: Immerse the glass fiber 6 in an acid solution for acid treatment to obtain mesoporous glass fiber.

[0041] In this invention, the glass sheet is one or more of silicate glass sheets, phosphate glass sheets, and borate glass sheets.

[0042] In this invention, the raw materials for preparing the silicate glass sheet include SiO2, B2O3, Al2O3, alkaline earth metal oxides and alkali metal oxides, and the molar ratio of SiO2, B2O3, Al2O3, alkaline earth metal oxides and alkali metal oxides is 1:0.02-0.29:0.02-0.43:0.1-1:0.01-0.57.

[0043] In a preferred embodiment, the molar ratio of SiO2, B2O3, Al2O3, alkaline earth metal oxide, and alkali metal oxide is 1:0.1-0.2:0.1-0.4:0.2-0.8:0.1-0.4; in a more preferred embodiment, the molar ratio of SiO2, B2O3, Al2O3, alkaline earth metal oxide, and alkali metal oxide is 1:0.1-0.15:0.1-0.3:0.4-0.8:0.1-0.3. Specifically, the molar ratio of SiO2, B2O3, Al2O3, and alkaline earth metal oxide can be 1:0.11:0.22:0.67:0.22, 1:0.12:0.15:0.5:0.15, or 1:0.14:0.2:0.7:0.25.

[0044] In this invention, the raw materials for preparing the phosphate glass sheet include P2O5, B2O3, Fe2O3, alkaline earth metal oxides and alkali metal oxides, and the molar ratio of P2O5, B2O3, Fe2O3, alkaline earth metal oxides and alkali metal oxides is 1:0.055-0.38:0.091-0.25:0.18-0.88:0.0091-0.25.

[0045] In a preferred embodiment, the molar ratio of P2O5, B2O3, Fe2O3, alkaline earth metal oxide, and alkali metal oxide is 1:0.1-0.3:0.1-0.2:0.2-0.8:0.05-0.25; in a further preferred embodiment, the molar ratio of P2O5, B2O3, Fe2O3, alkaline earth metal oxide, and alkali metal oxide is 1:0.15-0.25:0.1-0.15:0.3-0.7:0.1-0.2. Specifically, the molar ratio of P2O5, B2O3, Fe2O3, alkaline earth metal oxide, and alkali metal oxide can be 1:0.2:0.1:0.6:0.1, 1:0.18:0.13:0.4:0.15, or 1:0.23:0.15:0.5:0.2.

[0046] In this invention, the raw materials for preparing the borate glass sheet include B2O3, SiO2, Fe2O3, alkaline earth metal oxides and alkali metal oxides, and the molar ratio of B2O3, SiO2, Fe2O3, alkaline earth metal oxides and alkali metal oxides is 1:0.018-0.22:0.091-0.22:0.36-0.78:0.091-0.33.

[0047] In a preferred embodiment, the molar ratio of B₂O₃, SiO₂, Fe₂O₃, alkaline earth metal oxide, and alkali metal oxide is 1:0.05-0.15:0.05-0.15:0.4-0.7:0.1-0.3; in a further preferred embodiment, the molar ratio of B₂O₃, SiO₂, Fe₂O₃, alkaline earth metal oxide, and alkali metal oxide is 1:0.08-0.12:0.08-0.12:0.4-0.6:0.2-0.3. Specifically, the molar ratio of B₂O₃, SiO₂, Fe₂O₃, alkaline earth metal oxide, and alkali metal oxide can be 1:0.1:0.1:0.5:0.3, 1:0.09:0.09:0.4:0.2, or 1:0.11:0.11:0.6:0.25.

[0048] In this invention, the alkaline earth metal oxide can be CaO or MgO.

[0049] In this invention, the alkali metal oxide can be Na2O or K2O.

[0050] In this invention, the glass sheet is prepared by mixing glass raw material powder in a certain proportion, melting it into a liquid at a temperature of 1000-1400℃, keeping it at that temperature for 1-5 hours, and then pouring the liquid into a molding mold and pressing it into shape to obtain the glass sheet.

[0051] In this invention, the size of the glass sheet can be controlled by the forming mold, or it can be cut according to the size (length and width) required for laser processing after forming.

[0052] In this invention, the length and width dimensions of the glass sheet are selected according to the actual range of motion of the laser emitter 1.

[0053] In this invention, the thickness of the glass material 2 is 0.5-5mm. Specifically, the thickness of the glass material 2 can be 0.5mm, 1mm, 2mm, 3mm, 4mm, or 5mm.

[0054] In this invention, the pore-forming agent is a rare earth metal oxide, and the pore-forming agent is selected from one or more of nickel oxide (NiO), cerium oxide (CeO2), barium oxide (BaO) and lanthanum oxide (La2O3).

[0055] In this invention, the particle size of the pore-forming agent is 50-500 nm, and the thickness of the pore-forming agent coating is 5-300 μm. Specifically, the particle size of the pore-forming agent can be 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, or 500 nm; and the thickness of the pore-forming agent coating can be 5 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, or 300 μm.

[0056] In this invention, in step 1, the spraying method can be a conventional spraying method in the art. In one specific embodiment, the spraying method is electrostatic spraying.

[0057] In this invention, the pore-forming agent is nano-sized particles. The pore-forming agent particles are uniformly sprayed onto the surface of a glass sheet using an electrostatic spraying method to form a glass raw material 2. The glass raw material 2 includes a glass sheet and a pore-forming agent coating applied to the surface of the glass sheet.

[0058] In this invention, the working range is defined by the size of the glass material 2, and the parameters of the laser 5 and the blowing parameters of the airflow 4 are set accordingly.

[0059] In this invention, the wavelength of the laser 5 is 8-12 μm and the spot size is 0.5-5 cm. 2 Power is 5-20kW / cm 2Specifically, the wavelength of the laser 5 can be 8μm, 9μm, 10μm, 11μm, or 12μm; the spot size of the laser 5 can be 0.5cm. 2 1cm 2 2cm 2 4cm 2 or 5cm 2 The power of the laser 5 can be 5 kW / cm². 2 10kW / cm 2 15kW / cm 2 Or 20kW / cm 2 .

[0060] In this invention, the glass material 2 is placed horizontally, the laser emitter 1 is placed above the glass material 2, and the laser emitter 1 can move freely in the horizontal X and Y axis directions.

[0061] In this invention, any point X1Y1 is arbitrarily designated as the starting point on the glass material 2. The laser 5 irradiates the starting point X1Y1 of the glass material 2 and moves sequentially along the X-axis and Y-axis. First, it moves to X2Y1, then moves along the Y-axis to X2Y2, and then moves to X3Y2, X3Y3, etc., thus forming a reciprocating motion trajectory.

[0062] In this invention, the speed of the laser 5 moving along the X-axis and the Y-axis is 0.02-0.5 m / min. Specifically, the speed of the laser 5 moving along the X-axis and the Y-axis can be 0.02 m / min, 0.05 m / min, 0.1 m / min, 0.2 m / min, 0.3 m / min, 0.4 m / min, or 0.5 m / min.

[0063] In this invention, the laser 5 is parallel to the Z-axis direction.

[0064] In this invention, the distance between the laser emission port of the laser emitter 1 and the glass material 2 is 100-250mm. Specifically, the distance between the laser emission port of the laser emitter 1 and the glass material 2 can be 100mm, 150mm, 200mm, or 250mm.

[0065] In this invention, the laser 5 irradiates the surface of the glass material 2, causing the surface of the glass material 2 to rapidly heat up to 1000-1400°C, achieving complete melting of the glass material 2 and forming glass droplets. The pore-forming agent then mixes with the glass droplets. Specifically, the surface of the glass material 2 can be rapidly heated to 1000°C, 1100°C, 1200°C, 1300°C, or 1400°C.

[0066] In this invention, the viscosity of the glass droplet is 1g1.2-1g2 Pa·s. Specifically, the viscosity of the glass droplet can be 1g1.2 Pa·s, 1g1.3 Pa·s, 1g1.4 Pa·s, 1g1.5 Pa·s, 1g1.6 Pa·s, 1g1.7 Pa·s, 1g1.8 Pa·s, 1g1.9 Pa·s, or 1g2 Pa·s.

[0067] In this invention, an airflow jetting device 3 is designed above the glass raw material 2, and the airflow jetting device 3 is located between the glass raw material 2 and the laser emitter 1. Airflow 4 is ejected from the airflow jetting device 3, and the airflow 4 forms a certain angle with the laser 5.

[0068] In this invention, the angle between the airflow 4 and the laser 5 is 10-45°. Specifically, the angle between the airflow 4 and the laser 5 can be 10°, 15°, 20°, 25°, 30°, 35°, 40°, or 45°.

[0069] In a preferred embodiment, the temperature of the airflow 4 is 100-400℃, and the flow velocity of the airflow 4 is 20-100 m / s. Specifically, the temperature of the airflow 4 can be 100℃, 150℃, 200℃, 250℃, 300℃, 350℃, or 400℃; and the flow velocity of the airflow 4 can be 20 m / s, 30 m / s, 40 m / s, 50 m / s, 60 m / s, 70 m / s, 80 m / s, 90 m / s, or 100 m / s.

[0070] In this invention, the temperature of the airflow 4 is lower than the temperature of the glass droplet. The airflow 4 ejected from the airflow blowing device 3 is used to cool the glass droplet and stretch the glass droplet to form the glass fiber 6.

[0071] In this invention, a fiber collector is provided in the blowing direction of the airflow 4 to collect the glass fibers 6.

[0072] In this invention, the gas flow 4 is an inert gas flow. Specifically, the gas flow can be a dry compressed air flow, a nitrogen flow, an argon flow, or a helium flow.

[0073] In this invention, the nozzle of the airflow blowing device 3 is selected according to the size of the fiber melting zone, the shape of the light spot, and the fiber collection method.

[0074] In this invention, the nozzle can be a round nozzle or a flat nozzle, and can also be a single nozzle or multiple nozzles arranged side by side. The diameter of the round nozzle is 5-20mm; the distance between the two ends of the flat nozzle is 10-100mm, and the two ends of the flat nozzle are semi-circular structures with a diameter of 5-20mm; multiple nozzles arranged side by side refer to multiple round nozzles arranged side by side, with a spacing of 2-10mm between the multiple round nozzles, and the number of round nozzles is 3-10.

[0075] In this invention, the diameter of the circular opening can be 5mm, 10mm, 15mm or 20mm; the distance between the two ends of the flat opening can be 10mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm or 100mm; the diameter of the semicircle can be 5mm, 10mm, 15mm or 20mm; and the spacing between the plurality of circular openings can be 2mm, 4mm, 6mm, 8mm or 10mm.

[0076] In this invention, the concentration of the acid solution is 0.5-3 mol / L, and the acid treatment temperature is 25-50℃ for 0.5-3 h. Specifically, the concentration of the acid solution can be 0.5 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, or 3 mol / L; the acid treatment temperature can be 25℃, 30℃, 35℃, 40℃, 45℃, or 50℃; and the acid treatment time can be 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, or 3 h.

[0077] In this invention, the acid solution is an organic acid and / or an inorganic acid. Preferably, the acid solution is one or more of hydrochloric acid, nitric acid, and hydrofluoric acid.

[0078] In this invention, the collected glass fiber 6 is immersed in an acid solution, which can completely acid-dissolve the crystal phase structure in the glass fiber 6 and form a uniform pore structure.

[0079] The present invention will be described in detail below through examples, but the scope of protection of this method is not limited thereto. The fiber parameters of Examples 1 to 6 and Comparative Examples 1 to 2 are shown in Table 1.

[0080] Example 1

[0081] A silicate glass sheet is prepared using raw materials including SiO2, B2O3, Al2O3, CaO, and Na2O, with a molar ratio of 1:0.11:0.22:0.67:0.22. After uniform mixing, the raw materials are melted into a liquid at 1200℃ and held at that temperature for 2 hours. The liquid is then poured into a molding mold and integrally formed to obtain a glass sheet with an area of ​​250mm × 250mm and a thickness of 1mm. Next, barium oxide (BaO) with a particle size of 100nm is electrostatically sprayed onto the surface of the glass sheet, forming a 50μm thick pore-forming agent coating, thus obtaining glass raw material 2.

[0082] Next, laser 5 with a wavelength of 10.6 μm is emitted from laser emitter 1, and the spot size of laser 5 is 2 cm. 2 Power is 20kW / cm 2 The emission port of laser emitter 1 maintains a vertical distance of 100 mm from the glass material 2. The laser spot of laser 5 irradiates the surface of the glass material 2, and the laser spot of laser 5 reciprocates in the horizontal direction (XY axis direction) at a speed of 0.05 m / min. The glass material 2 in the spot area rapidly heats up to 1350℃ and begins to melt. After complete melting, the glass sheet and the pore-forming agent are mixed to form glass droplets. The viscosity of the glass droplets is 1g1.8 Pa·s.

[0083] Compressed nitrogen gas at a temperature of 400°C is sprayed from the air jet device 3. The angle between the compressed nitrogen gas and the laser 5 is 45°. The nozzle of the air jet device 3 is a round nozzle with a diameter of 20mm. The air jet device 3 sprays nitrogen gas flow into the glass droplet. The flow velocity of the nitrogen gas flow is 80m / s. The nitrogen gas flow stretches the glass droplet to form glass fibers with a microcrystalline structure and collects the glass fibers below the glass raw material 2.

[0084] The collected glass fibers were immersed in a 3 mol / L hydrochloric acid solution and soaked at 50°C for 2 hours to form mesoporous glass fibers with a porous structure. The diameter of the mesoporous glass fibers was 2.4-3.3 μm, the pore size was 20-50 nm, the strength was 2400 MPa, and the modulus was 75 GPa.

[0085] Example 2

[0086] Borate glass sheets are prepared using raw materials including B2O3, SiO2, Fe2O3, MgO, and Na2O, with a molar ratio of 1:0.1:0.1:0.5:0.3. After uniform mixing, the raw materials are melted into a liquid at 1200℃ and held at that temperature for 2 hours. The liquid is then poured into a molding die and integrally molded to obtain a glass sheet with an area of ​​250mm × 250mm and a thickness of 1mm. Next, barium oxide (BaO) with a particle size of 100nm is electrostatically sprayed onto the surface of the glass sheet, forming a 50μm thick pore-forming agent coating, thus obtaining glass raw material 2.

[0087] Next, a laser 5 with a wavelength of 10.6 μm is emitted from laser emitter 1, and the spot size of laser 5 is 2.5 cm. 2 Power is 15kW / cm 2 The emission port of laser emitter 1 maintains a vertical distance of 150 mm from the glass material 2. The laser spot of laser 5 irradiates the surface of the glass material 2, and the laser spot of laser 5 reciprocates in the horizontal direction (XY axis direction) at a speed of 0.1 m / min. The glass material 2 in the spot area rapidly heats up to 1200℃ and begins to melt. After complete melting, the glass sheet and the pore-forming agent are mixed to form glass droplets. The viscosity of the glass droplets is 1g1.5 Pa·s.

[0088] Compressed nitrogen gas at a temperature of 400°C is sprayed from the air jet device 3. The angle between the compressed nitrogen gas and the laser 5 is 45°. The nozzle of the air jet device 3 is a round nozzle with a diameter of 20mm. The air jet device 3 sprays nitrogen gas flow into the glass droplet. The flow rate of the nitrogen gas flow is 50m / s. The nitrogen gas flow stretches the glass droplet to form glass fibers with a microcrystalline structure and collects the glass fibers below the glass raw material 2.

[0089] The collected glass fibers were immersed in a 2 mol / L hydrochloric acid solution and soaked at 40°C for 1 hour to form mesoporous glass fibers with a porous structure. The diameter of the mesoporous glass fibers was 2.2-2.5 μm, the pore size was 40-75 nm, the strength was 1900 MPa, and the modulus was 56 GPa.

[0090] Example 3

[0091] Phosphate glass sheets are prepared using raw materials including P2O5, B2O3, Fe2O3, CaO, and Na2O, with a molar ratio of 1:0.2:0.1:0.6:0.1. After uniform mixing, the raw materials are melted into a liquid at 1200℃ and held at that temperature for 2 hours. The liquid is then poured into a molding die and integrally molded to obtain a glass sheet with an area of ​​200mm × 200mm and a thickness of 1.5mm. Next, barium oxide (BaO) with a particle size of 100nm is electrostatically sprayed onto the surface of the glass sheet to form a 100μm thick pore-forming agent coating, resulting in glass raw material 2.

[0092] Next, a laser 5 with a wavelength of 10.6 μm is emitted from laser emitter 1, and the spot size of laser 5 is 4 cm. 2 Power is 10kW / cm 2 The emission port of laser emitter 1 is kept at a vertical distance of 150 mm from the glass material 2. The laser spot of laser 5 irradiates the surface of the glass material 2, and the laser spot of laser 5 moves back and forth in the horizontal direction (XY axis direction) at a speed of 0.1 m / min. The glass material 2 in the spot area is rapidly heated to 1000℃ and begins to melt. After complete melting, the glass sheet and the pore-forming agent are mixed to form glass droplets. The viscosity of the glass droplets is 1g1.2 Pa·s.

[0093] Compressed nitrogen gas at a temperature of 350°C is sprayed from the air jet device 3. The angle between the compressed nitrogen gas and the laser 5 is 30°. The nozzle of the air jet device 3 is a flat nozzle with a diameter of 10 mm and a distance of 50 mm between the two semicircles at both ends. The air jet device 3 sprays nitrogen gas flow into the glass droplet. The flow velocity of the nitrogen gas flow is 80 m / s. The nitrogen gas flow stretches the glass droplet to form glass fibers with a microcrystalline structure and collects the glass fibers below the glass raw material 2.

[0094] The collected glass fibers were immersed in a 0.5 mol / L hydrochloric acid solution and soaked at 30°C for 1 hour to form mesoporous glass fibers with a porous structure. The diameter of the mesoporous glass fibers was 1.4-2.1 μm, the pore size was 70-95 nm, the strength was 1600 MPa, and the modulus was 44 GPa.

[0095] Example 4

[0096] The silicate glass sheet is prepared using raw materials including SiO2, B2O3, Al2O3, CaO, and Na2O, with a molar ratio of 1:0.11:0.22:0.67:0.22. After uniform mixing, the raw materials are melted into a liquid at 1200℃ and held at that temperature for 2 hours. The liquid is then poured into a molding die and integrally molded to obtain a glass sheet with an area of ​​250mm × 250mm and a thickness of 1mm. Cerium oxide (CeO2) with a particle size of 200nm is then electrostatically sprayed onto the surface of the glass sheet, forming a 150μm thick pore-forming agent coating, thus obtaining the raw glass material.

[0097] Next, laser 5 with a wavelength of 10.6 μm is emitted from laser emitter 1, and the spot size of laser 5 is 2 cm. 2 Power is 20kW / cm 2 The emission port of laser emitter 1 maintains a vertical distance of 100 mm from the glass material 2. The laser spot of laser 5 irradiates the surface of the glass material 2, and the laser spot of laser 5 reciprocates in the horizontal direction (XY axis direction) at a speed of 0.05 m / min. The glass material 2 in the spot area rapidly heats up to 1350℃ and begins to melt. After complete melting, the glass sheet and the pore-forming agent are mixed to form glass droplets. The viscosity of the glass droplets is 1g1.5 Pa·s.

[0098] Compressed argon gas at a temperature of 400°C is sprayed from the air jet device 3. The angle between the compressed argon gas and the laser 5 is 45°. The nozzle of the air jet device 3 is a round nozzle with a diameter of 10mm. The air jet device 3 sprays nitrogen gas flow into the glass droplet. The flow rate of the nitrogen gas flow is 80m / s. The nitrogen gas flow stretches the glass droplet to form glass fibers with a microcrystalline structure and collects the glass fibers below the glass raw material 2.

[0099] The collected glass fibers were immersed in a 3 mol / L hydrochloric acid solution and soaked at 50°C for 3 hours to form mesoporous glass fibers with a porous structure. The diameter of the mesoporous glass fibers was 2.1-2.9 μm, the pore size was 50-80 nm, the strength was 2100 MPa, and the modulus was 70 GPa.

[0100] Example 5

[0101] Borate glass sheets are prepared using raw materials including B2O3, SiO2, Fe2O3, MgO, and Na2O, with a molar ratio of 1:0.1:0.1:0.5:0.3. After uniform mixing, the raw materials are melted into a liquid at 1200℃ and held at that temperature for 2 hours. The liquid is then poured into a molding mold and integrally molded to obtain a glass sheet with an area of ​​250mm × 250mm and a thickness of 1mm. Cerium oxide (CeO2) with a particle size of 200nm is then electrostatically sprayed onto the surface of the glass sheet, forming a 150μm thick pore-forming agent coating, thus obtaining the raw glass material.

[0102] Next, laser 5 with a wavelength of 10.6 μm is emitted from laser emitter 1, and the spot size of laser 5 is 2 cm. 2 Power is 20kW / cm 2 The emission port of laser emitter 1 maintains a vertical distance of 100 mm from the glass material 2. The laser spot of laser 5 irradiates the surface of the glass material 2, and the laser spot of laser 5 reciprocates in the horizontal direction (XY axis direction) at a speed of 0.05 m / min. The glass material 2 in the spot area rapidly heats up to 1350℃ and begins to melt. After complete melting, the glass sheet and the pore-forming agent are mixed to form glass droplets. The viscosity of the glass droplets is 1g1.3 Pa·s.

[0103] Compressed argon gas at a temperature of 400°C is sprayed from the air jet device 3. The angle between the compressed argon gas and the laser 5 is 45°. The nozzle of the air jet device 3 is a round nozzle with a diameter of 10mm. The air jet device 3 sprays nitrogen gas flow into the glass droplet. The flow rate of the nitrogen gas flow is 80m / s. The nitrogen gas flow stretches the glass droplet to form glass fibers with a microcrystalline structure and collects the glass fibers below the glass raw material 2.

[0104] The collected glass fibers were immersed in a 2 mol / L hydrochloric acid solution and soaked at 40°C for 1 hour to form mesoporous glass fibers with a porous structure. The diameter of the mesoporous glass fibers was 1.9-2.1 μm, the pore size was 75-100 nm, the strength was 1700 MPa, and the modulus was 52 GPa.

[0105] Example 6

[0106] Phosphate glass sheets are prepared using raw materials including P2O5, B2O3, Fe2O3, CaO, and Na2O, with a molar ratio of 1:0.2:0.1:0.6:0.1. After uniform mixing, the raw materials are melted into a liquid at 1200℃ and held at that temperature for 2 hours. The liquid is then poured into a molding die and integrally molded to obtain a glass sheet with an area of ​​200mm × 200mm and a thickness of 1.5mm. Cerium oxide (CeO2) with a particle size of 200nm is then electrostatically sprayed onto the surface of the glass sheet as a pore-forming agent, forming a pore-forming agent coating with a thickness of 200μm, thus obtaining the raw glass material.

[0107] Next, laser 5 with a wavelength of 10.6 μm is emitted from laser emitter 1, and the spot size of laser 5 is 2 cm. 2 Power is 20kW / cm 2 The emission port of the laser emitter 1 is kept at a vertical distance of 100 mm from the glass material 2. The laser spot of the laser 5 irradiates the surface of the glass material 2, and the laser spot of the laser 5 moves back and forth in the horizontal direction (XY axis direction) at a speed of 0.05 m / min. The glass material 2 in the spot area is rapidly heated to 1350℃ and begins to melt. After complete melting, the glass sheet and the pore-forming agent are mixed to form glass droplets. The viscosity of the glass droplets is 1g1.2 Pa·s.

[0108] Compressed argon gas at a temperature of 350°C is sprayed from the air jet device 3. The angle between the compressed argon gas and the laser 5 is 30°. The nozzle of the air jet device 3 is a flat nozzle with a diameter of 10 mm and a distance of 50 mm between the two semicircles at both ends. The air jet device 3 sprays nitrogen gas into the glass droplets. The flow rate of the nitrogen gas is 80 m / s. The nitrogen gas stretches the glass droplets to form glass fibers with a microcrystalline structure and collects the glass fibers below the glass raw material 2.

[0109] The collected glass fibers were immersed in a 0.5 mol / L hydrochloric acid solution and soaked at 30°C for 1 hour to form mesoporous glass fibers with a porous structure. The diameter of the mesoporous glass fibers was 1.1-1.6 μm, the pore size was 90-120 nm, the strength was 1200 MPa, and the modulus was 41 GPa.

[0110] Comparative Example 1

[0111] The silicate glass sheet is prepared using raw materials including SiO2, B2O3, Al2O3, CaO, and Na2O, wherein the molar ratio of SiO2, B2O3, Al2O3, CaO, and Na2O is 1:0.11:0.22:0.67:0.22. After the above raw materials are mixed evenly, they are melted into a liquid at 1200℃ and kept at that temperature for 2 hours. The liquid is then poured into a molding mold and integrally formed to obtain a glass sheet with an area of ​​250mm×250mm and a thickness of 1mm.

[0112] Next, laser 5 with a wavelength of 10.6 μm is emitted from laser emitter 1, and the spot size of laser 5 is 2 cm. 2 Power is 20kW / cm 2 The emission port of laser emitter 1 maintains a vertical distance of 100 mm from the glass sheet. The laser spot of laser 5 irradiates the surface of the glass sheet, and the laser spot of laser 5 moves back and forth in the horizontal direction (XY axis direction) at a speed of 0.05 m / min. The glass sheet in the spot area rapidly heats up to 1350℃ and begins to melt. The viscosity of the glass droplet is 1g1.8 Pa·s.

[0113] Compressed nitrogen gas at a temperature of 400°C is sprayed from the air jet device 3. The angle between the compressed nitrogen gas and the laser 5 is 45°. The nozzle of the air jet device 3 is a round nozzle with a diameter of 20mm. The air jet device 3 sprays nitrogen gas flow into the glass droplets. The flow velocity of the nitrogen gas flow is 80m / s. The nitrogen gas flow stretches the glass droplets to form glass fibers with a microcrystalline structure, and collects them below the glass sheet to form homogeneous non-porous glass fibers. The diameter of the glass fibers is 2.81-4.1μm, the strength of the glass fibers is 2600MPa, and the modulus is 78GPa.

[0114] Comparative Example 2

[0115] The process uses silicate glass fiber raw materials, which include SiO2, B2O3, Al2O3, CaO, and Na2O, with a molar ratio of 1:0.11:0.22:0.67:0.22. After the raw materials are mixed evenly, they are fed into a kiln and calcined at 1200°C to melt into a liquid. The liquid then flows through a perforator at a flow rate of 50 kg / h into a high-speed rotating centrifugal disc at 950°C. At the same time, barium oxide (BaO) with a particle size of 100 nm is added to the glass melt and mixed. The mixture is then centrifuged and ejected from the perforator on the side wall of the centrifugal disc, and stretched into glass fibers under centrifugal force.

[0116] Glass fibers doped with barium oxide particles were heat-treated at 500℃ for 2 hours to obtain glass fibers with a uniformly dispersed crystalline phase structure. The collected glass fibers were then immersed in a 3 mol / L hydrochloric acid solution and soaked at 50℃ for 2 hours to form mesoporous glass fibers with a porous structure.

[0117] The mesoporous glass fiber has a diameter of 4.3-8.1 μm, a mesopore size of 20-100 nm, a strength of 2100 MPa, and a modulus of 68 GPa.

[0118] Table 1

[0119]

[0120] As can be seen from the test results in the table, the mesoporous glass fibers prepared in Examples 1 to 6 have smaller fiber diameter and mesopore diameter, higher fiber strength and lower fiber modulus.

[0121] Compared with Example 1, the glass fiber prepared in Example 1 did not undergo pore-forming agent coating design or acid immersion pore-forming process. Therefore, no mesopores were formed on the surface of the glass fiber, the fiber diameter was larger, and the fiber modulus was higher.

[0122] Compared with Example 1 and Comparative Example 2, although both Example 1 and Comparative Example 2 use pore-forming agents to achieve fiber crystallization and form a mesoporous structure through subsequent acid treatment, Comparative Example 2 uses a traditional ultrafine fiber centrifugal molding process, which has a long process flow, high temperature, and a larger range of fiber diameters compared with Example 1, and the fiber strength and modulus are relatively lower.

[0123] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method of making mesoporous glass fibers, characterized by, The method comprises the following steps: Step 1: Spraying a pore-forming agent on the surface of a glass sheet to form a pore-forming agent coating, thereby obtaining a glass raw material (2); Step 2: Irradiating the glass raw material (2) with laser light (5) emitted by a laser emitter (1) to form glass melt droplets; Step 3: Spraying the glass melt droplets with a gas stream (4) generated by a gas stream blowing device (3) to form glass fibers (6), wherein the temperature of the gas stream (4) is 100-400℃, and the gas stream (4) is used to activate the crystallization of the pore-forming agent during the spraying process, so as to form in-situ microcrystalline structures in the glass fibers; Step 4: Immersing the glass fibers (6) in an acid solution for acid treatment, thereby obtaining mesoporous glass fibers. The flow rate of the gas stream (4) is 20-100 m / s. The laser (5) has a wavelength of 8-12 μm, a spot of 0.5-5 cm 2 , and a power of 5-20 kW / cm 2； The included angle between the gas stream (4) and the laser light (5) is 10-45°. The viscosity of the glass melt droplets is lg1.2-lg2 Pa·s.

2. The method of making mesoporous glass fibers according to claim 1, wherein, The thickness of the glass raw material (2) is 0.5-5 mm.

3. The method of making mesoporous glass fibers according to claim 1, wherein, The pore-forming agent is selected from one or more of nickel oxide, cerium oxide, barium oxide, and lanthanum oxide.

4. The method of making mesoporous glass fibers according to claim 3, wherein, The particle size of the pore-forming agent is 50-500 nm, and the thickness of the pore-forming agent coating is 5-300 μm.

5. The method of making mesoporous glass fibers according to claim 1, wherein, The concentration of the acid solution is 0.5-3 mol / L.

6. The method of making mesoporous glass fibers according to claim 1, wherein, The acid treatment conditions include a temperature of 25-50℃ and a time of 0.5-3 h.

7. The method of making mesoporous glass fibers according to claim 1, wherein, The diameter of the mesoporous glass fibers is 1-10 μm, and the pore size of the mesopores of the mesoporous glass fibers is 20-120 nm.

8. The method of making mesoporous glass fibers according to claim 1, wherein, The glass sheet is one or more of a silicate glass sheet, a phosphate glass sheet, and a borate glass sheet.

9. The method of making mesoporous glass fibers according to claim 8, wherein, When the glass sheet comprises a silicate glass sheet, the raw materials for preparing the silicate glass sheet comprise SiO2, B2O3, Al2O3, alkaline earth metal oxides, and alkali metal oxides, and the molar ratio of the SiO2, B2O3, Al2O3, alkaline earth metal oxides, and alkali metal oxides is 1:0.02-0.29:0.02-0.43:0.1-1:0.01-0.

57.

10. The method of making mesoporous glass fibers according to claim 8, wherein, When the glass sheet comprises a phosphate glass sheet, the raw materials for preparing the phosphate glass sheet comprise P2O5, B2O3, Fe2O3, alkaline earth metal oxides, and alkali metal oxides, and the molar ratio of the P2O5, B2O3, Fe2O3, alkaline earth metal oxides, and alkali metal oxides is 1:0.055-0.38:0.091-0.25:0.18-0.88:0.0091-0.

25.

11. The method of making mesoporous glass fibers according to claim 8, wherein, When the glass sheet comprises a borate glass sheet, the raw materials for preparing the borate glass sheet comprise B2O3, SiO2, Fe2O3, alkaline earth metal oxides, and alkali metal oxides, and the molar ratio of the B2O3, SiO2, Fe2O3, alkaline earth metal oxides, and alkali metal oxides is 1:0.018-0.22:0.091-0.22:0.36-0.78:0.091-0.33.

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