Method for preparing mullite porous hollow microspheres by electrostatic spinning technology
By employing coaxial electrospinning technology and high-temperature calcination, the preparation challenges of porous and hollow mullite microspheres have been solved, enabling controllable preparation and performance improvement of porous core-shell structures, which are suitable for photocatalysis and aerospace applications.
Patent Information
- Application Number
- CN202512029506.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-03-20
AI Technical Summary
Existing technologies cannot simultaneously prepare mullite microspheres with porous and hollow structures, and existing methods suffer from problems such as shell rupture, uneven pore structure distribution, and impurity residue.
Using coaxial electrospinning technology, different polymer solutions were added to the inner and outer channels of the coaxial needle, and the spinning process parameters and environmental humidity were adjusted to prepare porous core-shell mullite precursor microspheres. The mullite porous hollow microspheres were then formed by curing, crosslinking and high-temperature calcination.
The controllable fabrication of porous core-shell structures has been achieved, forming a uniform internal interconnected pore or bubble structure, resulting in low-density, lightweight, and high-temperature resistant mullite porous hollow microspheres suitable for photocatalysis and aerospace applications.
Smart Images
Figure CN121698671A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of mullite material preparation, and more particularly to a method for preparing porous hollow mullite microspheres using electrospinning technology. Background Technology
[0002] To date, mullite microspheres are mostly prepared through high-temperature sintering, a simple process but with poor performance that cannot meet the demands of high-end applications. Single hollow mullite microspheres are often prepared using a template method, but the template removal process is complex, prone to shell cracking, and difficult to control shell thickness and cavity size. Single porous mullite microspheres are mostly prepared using pore-forming agents, but the amount of pore-forming agent is difficult to control, resulting in uneven pore structure distribution and easy residue of impurities. Methods for preparing mullite microspheres with both porous and hollow structures are extremely rare.
[0003] Therefore, providing a mullite microsphere that simultaneously possesses both porous and hollow structures is a problem that urgently needs to be solved. Summary of the Invention
[0004] This invention provides a method for preparing porous hollow mullite microspheres using electrospinning technology. Utilizing coaxial electrospinning technology, spinning solutions containing one or more different polymers are added to two spinning channels, one inside and one outside the coaxial needle. By adjusting the spinning process parameters and the humidity of the spinning environment, porous core-shell structured mullite precursor microspheres with controllable inner and outer diameters and pore size distribution can be prepared. Further curing, crosslinking, and high-temperature calcination are then performed to eliminate the inner matrix of the microspheres, resulting in porous hollow mullite microspheres.
[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: This invention provides a method for preparing porous hollow mullite microspheres using electrospinning technology, comprising the following steps: The inner polymer is mixed with the first solvent to obtain an inner polymer solution; the mullite precursor is mixed with the second solvent to obtain an outer polymer solution. The inner polymer solution and the outer polymer solution were electrospun using coaxial electrospinning technology to obtain porous core-shell structured precursor microspheres. The porous core-shell structure precursor microspheres were subjected to curing heat treatment to obtain cured and crosslinked porous core-shell structure precursor microspheres. The solidified and cross-linked porous core-shell structure precursor microspheres were calcined to obtain mullite porous hollow microspheres. The humidity of the electrospinning is 30-60%.
[0006] In some specific embodiments, the inner layer polymer includes at least one selected from polyvinyl alcohol, polyvinylpyrrolidone, polyethylene oxide, polyurethane, polylactic acid, polymethyl methacrylate, and polycaprolactone.
[0007] In some specific embodiments, the mullite precursor includes a silicon source and an aluminum source.
[0008] In some specific embodiments, the silicon source includes at least one of tetraethyl orthosilicate, tetrapropyl orthosilicate, and tetrabutyl orthosilicate.
[0009] In some specific embodiments, the aluminum source includes at least one of aluminum sec-butoxide, aluminum tert-butoxide, polyaluminosiloxane, aluminum chloride, aluminum isopropoxide, and aluminum nitrate.
[0010] In some specific embodiments, the concentration of the outer polymer solution is 4wt% to 12wt%.
[0011] In some specific embodiments, the concentration of the inner polymer solution is 1wt% to 20wt%.
[0012] In some specific embodiments, the electrospinning conditions are as follows: spinning voltage is 15~20kV, distance from the spinneret to the receiving plate is 10~23cm, temperature is 25~30℃, humidity is 30~60%, internal feed speed is 0.01~0.02mL / min, and external feed speed is 0.01~0.02mL / min.
[0013] In some specific embodiments, the particle size of the porous core-shell structure precursor microspheres is 1~10μm.
[0014] In some specific embodiments, the curing heat treatment temperature is 200~400℃, the curing heat treatment time is 1~6h, and the atmosphere of the heat curing treatment is air or oxygen.
[0015] In some specific embodiments, the calcination conditions are as follows: heating rate of 5~15℃ / min, temperature of 1100~1400℃, isothermal time of 2~6h, and atmosphere of air or oxygen.
[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) The method for preparing porous hollow mullite microspheres of the present invention employs coaxial electrospinning technology, using an outer layer polymer solution as the outer spinning solution and an inner layer polymer solution as the inner spinning solution. Porous core-shell structure precursor microspheres are obtained through electrospinning at a humidity of 30-60%. The porous core-shell structure precursor microspheres are then cured, cross-linked, and calcined at high temperature to eliminate the inner matrix of the microspheres, thus obtaining porous hollow mullite microspheres. Specifically, electrospinning is performed at a humidity of 30-60%. Within this humidity range, solvent evaporation is slow, and the polymer molecular chains inside the jet gradually aggregate. When the polymer concentration reaches a critical value, the homogeneous spinning solution undergoes liquid-liquid phase separation, splitting into a solid precursor phase and a solvent phase. As the jet further stretches and solidifies, the solid precursor phase gradually forms the framework of the microspheres, while the solvent phase leaves pores during subsequent evaporation. High humidity enhances this process, as water molecules in the air diffuse into the jet, mixing with the solvent to form a more volatile mixed phase, accelerating solvent removal and simultaneously increasing the volume and connectivity of the pores. The resulting pores, formed through liquid-liquid phase separation, are mostly interconnected internal pores or bubble structures with a relatively uniform pore size distribution, yielding porous core-shell structured precursor microspheres. Further curing and calcination cause the precursor core polymer to decompose at high temperatures, transforming into smaller molecules, while the shell polymer transforms into mullite, thus forming hollow mullite microspheres.
[0017] (2) This invention uses electrospinning technology to prepare mullite microspheres that combine porous and hollow structures, providing a new method for the preparation of porous hollow mullite microspheres. These porous hollow mullite microspheres have the characteristics of low density, light weight and high temperature resistance, and have strong development prospects in photocatalysis and aerospace fields.
[0018] (3) The electrospinning technology described in this invention can meet the requirements of milder experimental conditions and shorter time consumption. Attached Figure Description
[0019] The above and other objects, features, and advantages of the invention will be apparent from the following description of preferred embodiments illustrating the gist of the invention and its use, and the accompanying drawings, in which: Figure 1 Scanning electron microscope image of the porous core-shell structured mullite precursor microspheres in Example 1; Figure 2 Scanning electron microscope image of the porous core-shell structured mullite precursor microspheres in Example 2; Figure 3 The image shows the characterization of the porous hollow mullite microspheres in Example 1; where (a) is a scanning electron microscope image of the hollow mullite microspheres and (b) is a transmission electron microscope image of the hollow mullite microspheres. Figure 4The image shows a scanning electron microscope image of the core-shell structured mullite precursor microspheres in Comparative Example 1. Detailed Implementation
[0020] The present invention will be described below through specific embodiments. Those skilled in the art will understand that the specific embodiments described below are for illustrative purposes only and do not limit the scope of the invention in any way. Furthermore, in the following embodiments, unless otherwise specified, the reagents and equipment used are commercially available. If specific processing conditions and methods are not explicitly described in the following embodiments, conditions and methods known in the art can be used for processing.
[0021] This invention provides a method for preparing porous hollow mullite microspheres using electrospinning technology, comprising the following steps: The inner polymer is mixed with the first solvent to obtain an inner polymer solution; the mullite precursor is mixed with the second solvent to obtain an outer polymer solution. The inner polymer solution and the outer polymer solution were electrospun using coaxial electrospinning technology to obtain porous core-shell structured precursor microspheres. The porous core-shell structure precursor microspheres were subjected to curing heat treatment to obtain cured and crosslinked porous core-shell structure precursor microspheres. The solidified and cross-linked porous core-shell structure precursor microspheres were calcined to obtain mullite porous hollow microspheres. The humidity of the electrospinning process is 30-60%. As an example, the humidity can be 30%, 35%, 40%, 45%, 50%, 55%, and 60%, etc.
[0022] In this invention, when the humidity is too low, the solvent evaporates quickly, the jet solidifies rapidly, the phase separation is insufficient, and it is difficult to form a porous structure; when the humidity is moderate (30%~60%), the phase separation rate matches the solidification rate, and a uniform porous structure can be formed; when the humidity is too high, the solvent evaporates too slowly, the jet is prone to adhesion, and the pores will collapse due to excessive expansion, resulting in a deterioration of the microsphere morphology.
[0023] In this invention, coaxial electrospinning technology is used. Inner polymer solution and outer polymer solution are added to the inner and outer channels of the coaxial spinning needle, respectively. By adjusting the spinning process parameters and the humidity of the spinning environment, porous core-shell structured mullite precursor microspheres with controllable inner and outer diameters and pore size distribution can be prepared. After curing, crosslinking and high-temperature calcination, the inner matrix of the microspheres is eliminated, and porous hollow mullite microspheres are obtained.
[0024] In some embodiments, the inner layer polymer includes, but is not limited to, at least one of polyvinyl alcohol, polyvinylpyrrolidone, polyethylene oxide, polyurethane, polylactic acid, polymethyl methacrylate, and polycaprolactone.
[0025] In some embodiments, the mullite precursor includes a silicon source and an aluminum source.
[0026] In some embodiments, the silicon source includes, but is not limited to, at least one of tetraethyl orthosilicate, tetrapropyl orthosilicate, and tetrabutyl orthosilicate.
[0027] In some embodiments, the aluminum source includes, but is not limited to, at least one of aluminum sec-butoxide, aluminum tert-butoxide, polyaluminosiloxane, aluminum chloride, aluminum isopropoxide, and aluminum nitrate.
[0028] In some embodiments, the concentration of the outer polymer solution is 4 wt% to 12 wt%. As an example, the concentration of the outer polymer solution can be 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, and 12 wt%, etc.
[0029] In some embodiments, the concentration of the inner layer polymer solution is 1 wt% to 20 wt%. As an example, the concentration of the inner layer polymer solution can be 1 wt%, 2 wt%, 4 wt%, 5 wt%, 8 wt%, 10 wt%, 12 wt%, 15 wt%, 18 wt%, and 20 wt%, etc.
[0030] In some embodiments, the first solvent is a highly volatile solvent at room temperature corresponding to the inner layer polymer, and the first solvent is preferably at least one of N,N-dimethylformamide (DMF), chloroform, and tetrahydrofuran.
[0031] In some embodiments, the second solvent is a highly volatile solvent at room temperature corresponding to the outer polymer, and the second solvent is preferably at least one of water, ethanol, isopropanol, n-butanol and acetic acid.
[0032] In some embodiments, the electrospinning conditions are as follows: spinning voltage is 15~20kV, distance from spinneret to receiving plate is 10~23cm, temperature is 25~30℃, inner feed speed is 0.01~0.02mL / min, and outer feed speed is 0.01~0.02mL / min. As an example, the spinning voltage can be 15kV, 16kV, 17kV, 18kV, 19kV, and 20kV, etc.; the distance from the spinneret to the receiving plate can be 10cm, 12cm, 15cm, 18cm, 20cm, 22cm, and 23cm, etc.; the temperature can be 25℃, 26℃, 27℃, 28℃, 29℃, and 30℃, etc.; the internal propulsion speed can be 0.01mL / min, 0.012mL / min, 0.014mL / min, 0.015mL / min, 0.018mL / min, and 0.02mL / min, etc.; and the external propulsion speed can be 0.01mL / min, 0.012mL / min, 0.014mL / min, 0.015mL / min, 0.018mL / min, and 0.02mL / min, etc.
[0033] In this invention, excessive propulsion speed and temperature can easily clog the needle; excessively low propulsion speed, excessively high or low voltage can easily cause the microsphere morphology to collapse, making it difficult to form a complete microsphere morphology; if the temperature is too low, solvent evaporation is difficult, making it difficult to form a porous structure, and the precursor microspheres collected on the receiving plate are prone to collapse after all the solvent has evaporated.
[0034] In this invention, the electrospinning time is not specifically limited. In some embodiments, the electrospraying time during electrospinning can be 2-3 hours.
[0035] In some embodiments, the particle size of the porous core-shell structured precursor microspheres is 1~10 μm. As an example, the particle size of the precursor microspheres can be 1 μm, 2 μm, 4 μm, 5 μm, 6 μm, 8 μm, and 10 μm, etc.
[0036] In this invention, by controlling the particle size of the porous core-shell structure precursor microspheres, it is beneficial to form a porous core-shell structure. If the particle size is too large or too small, it is not conducive to the formation of core-shell structure microspheres.
[0037] In some embodiments, the precursor microspheres further include a drying process prior to the curing heat treatment.
[0038] In some embodiments, the curing heat treatment temperature is 200~400℃, the curing heat treatment time is 1~6h, and the atmosphere for the heat curing treatment is air or oxygen. As an example, the curing heat treatment temperature can be 200℃, 250℃, 300℃, 350℃, and 400℃, etc., and the curing heat treatment time can be 1h, 2h, 3h, 4h, 5h, and 6h, etc.
[0039] In some embodiments, the calcination conditions are as follows: heating rate of 5~15℃ / min, temperature of 1100~1400℃, isothermal time of 2~6h, and atmosphere of air or oxygen. As examples, the heating rate can be 5℃ / min, 8℃ / min, 10℃ / min, 12℃ / min, and 15℃ / min, etc.; the temperature can be 1100℃, 1150℃, 1200℃, 1250℃, 1300℃, 1350℃, and 1400℃, etc.; and the isothermal time can be 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, and 6h, etc.
[0040] In this invention, controlling the calcination conditions within the aforementioned range helps to ultimately form porous hollow mullite microspheres. If the calcination temperature is too low, the mullite formation temperature will not be reached; if the temperature is too high, over-sintering will damage the original microsphere morphology, making the microspheres prone to breakage.
[0041] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments. The embodiments of this application are only examples, and all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0042] Example 1 A method for preparing mullite porous hollow microspheres using electrospinning technology includes the following steps: Tetrabutyl orthosilicate and aluminum sec-butoxide were dissolved in a mixed solvent of water and ethanol (3:5, m / m) to obtain an outer polymer solution; wherein the concentration of tetrabutyl orthosilicate was 4 wt% and the concentration of aluminum sec-butoxide was 8 wt%. Polyvinylpyrrolidone was dissolved in a mixed solvent of N,N-dimethylformamide and chloroform (2:8, v / v) to obtain an inner polymer solution; wherein the concentration of polyvinylpyrrolidone was 6 wt%. The outer polymer solution and inner polymer solution obtained above were added to the coaxial propulsion injector for electrospinning, with the outer polymer solution serving as the outer spinning solution and the inner polymer solution serving as the inner spinning solution. Coaxial electrospinning was performed under the following conditions: the distance from the spinneret to the receiving plate was 15 cm, the voltage was 18 kV, the inner propulsion rate was 0.018 mL / min, the outer propulsion rate was 0.018 mL / min, the temperature was 25 °C, and the humidity was 52%. Electrospinning was carried out continuously and stably for 3 h to obtain porous core-shell structured mullite precursor microspheres with a particle size of 3.6 μm. The microspheres were then placed in a forced-air drying oven and dried at 80 °C for 2 h. In an air atmosphere, the dried porous core-shell structure mullite precursor microspheres are cured and heat-treated at 280℃ for 3 hours, and then calcined at high temperature in an air atmosphere at a rate of 10℃ / min to 1300℃, held for 3 hours, and then naturally cooled to room temperature to obtain porous hollow mullite microspheres.
[0043] Figure 1 This is a scanning electron microscope image of the porous core-shell structured mullite precursor microspheres from Example 1. Figure 1 It can be seen that the prepared mullite precursor microspheres have a distinct porous structure.
[0044] Figure 3 The images show the characterization of the porous hollow mullite microspheres in Example 1; where (a) is a scanning electron microscope image of the hollow mullite microspheres, and (b) is a transmission electron microscope image of the hollow mullite microspheres. Figure 3 It can be seen that the prepared mullite microspheres have obvious porous and hollow structures.
[0045] Example 2 A method for preparing mullite porous hollow microspheres using electrospinning technology includes the following steps: Tetraethyl orthosilicate and aluminum tert-butoxide were dissolved in a mixed solvent of water and ethanol (1:2, m / m) to obtain an outer polymer solution; wherein the concentration of tetraethyl orthosilicate was 3 wt% and the concentration of aluminum tert-butoxide was 6 wt%. Polyurethane was dissolved in a mixed solvent of N,N-dimethylformamide and chloroform (2:8, v / v) to obtain an inner polymer solution; wherein the concentration of polyurethane was 5 wt%. The outer polymer solution and inner polymer solution obtained above were added to the coaxial propulsion injector for electrospinning, with the outer polymer solution serving as the outer spinning solution and the inner polymer solution serving as the inner spinning solution. Coaxial electrospinning was performed under the following conditions: the distance from the spinneret to the receiving plate was 15 cm, the voltage was 18 kV, the inner propulsion rate was 0.018 mL / min, the outer propulsion rate was 0.018 mL / min, the temperature was 25 °C, and the humidity was 40%. Electrospinning was carried out continuously and stably for 3 h to obtain porous core-shell structured mullite precursor microspheres with a particle size of 4.1 μm. Then, they were placed in a forced-air drying oven and dried at 80 °C for 2 h. In an air atmosphere, the dried porous core-shell structured mullite precursor microspheres are cured and heat-treated at 320℃ for 3 hours, and then calcined at high temperature in an air atmosphere at a rate of 10℃ / min to 1400℃, held for 3 hours, and then naturally cooled to room temperature to obtain porous hollow mullite microspheres.
[0046] Figure 2 This is a scanning electron microscope image of the porous core-shell structured mullite precursor microspheres from Example 2. Figure 2It can be seen that the prepared mullite precursor microspheres have a distinct porous structure.
[0047] Example 3 A method for preparing mullite porous hollow microspheres using electrospinning technology includes the following steps: Tetrapropyl orthosilicate and aluminum nitrate nonahydrate were dissolved in a mixed solvent of water and ethanol (3:5, m / m) to obtain an outer polymer solution; wherein the concentration of tetrapropyl orthosilicate was 3 wt% and the concentration of aluminum nitrate nonahydrate was 7 wt%. Polylactic acid was dissolved in a mixed solvent of N,N-dimethylformamide and chloroform (2:8, v / v) to obtain an inner polymer solution; wherein the concentration of polylactic acid was 7 wt%. The outer and inner polymer solutions obtained above were added to an electrospinning coaxial propulsion injector, with the outer polymer solution serving as the outer spinning solution and the inner polymer solution serving as the inner spinning solution. Coaxial electrospinning was performed under the following conditions: a distance of 15 cm between the spinneret and the receiving plate, a voltage of 18 kV, an inner propulsion rate of 0.018 mL / min, an outer propulsion rate of 0.018 mL / min, a temperature of 25 °C, and a humidity of 45%. Electrospinning was carried out continuously and stably for 3 hours to obtain porous core-shell structured mullite precursor microspheres with a particle size of 3.4 μm. The microspheres were then dried in a forced-air drying oven at 80 °C for 2 hours. In an air atmosphere, the dried porous core-shell structure mullite precursor microspheres are cured and heat-treated at 350℃ for 2 hours, and then calcined at high temperature in an air atmosphere at a rate of 10℃ / min to 1200℃, held for 3 hours, and then naturally cooled to room temperature to obtain porous hollow mullite microspheres.
[0048] Comparative Example 1 A method for preparing mullite porous hollow microspheres using electrospinning technology includes the following steps: Tetrabutyl orthosilicate and aluminum sec-butoxide were dissolved in a mixed solvent of water and ethanol (3:5, m / m) to obtain an outer polymer solution; wherein the concentration of tetrabutyl orthosilicate was 4 wt% and the concentration of aluminum sec-butoxide was 8 wt%. Polyvinylpyrrolidone was dissolved in a mixed solvent of N,N-dimethylformamide and chloroform (2:8, v / v) to obtain an inner polymer solution; wherein the concentration of polyvinylpyrrolidone was 6 wt%. The outer polymer solution and inner polymer solution obtained above were added to the coaxial propulsion injector for electrospinning, with the outer polymer solution serving as the outer spinning solution and the inner polymer solution serving as the inner spinning solution. Coaxial electrospinning was carried out under the following conditions: the distance from the spinneret to the receiving plate was 15 cm, the voltage was 18 kV, the inner propulsion rate was 0.018 mL / min, the outer propulsion rate was 0.018 mL / min, the temperature was 25 °C, and the humidity was 20%. Electrospinning was carried out continuously and stably for 3 h to obtain porous core-shell structured mullite precursor microspheres with a particle size of 3.4 μm. The microspheres were then placed in a forced-air drying oven and dried at 80 °C for 2 h. In an air atmosphere, the dried porous core-shell structure mullite precursor microspheres are cured and heat-treated at 280℃ for 3 hours, and then calcined at high temperature in an air atmosphere at a rate of 10℃ / min to 1300℃, held for 3 hours, and then naturally cooled to room temperature to obtain porous hollow mullite microspheres.
[0049] Figure 4 This is a scanning electron microscope image of the core-shell structured mullite precursor microspheres in Comparative Example 1. Figure 4 It can be seen that the prepared mullite precursor microspheres clearly exhibit a non-porous structure.
[0050] In summary, the embodiments of the present invention provide a method for preparing porous core-shell structure precursor microspheres with controllable diameter and pore size distribution by using coaxial electrospinning and adjusting the humidity of the spinning environment, and obtaining low-density, lightweight, and high-temperature resistant porous mullite hollow microspheres by high-temperature calcination.
[0051] Although preferred embodiments of the invention have been shown and described, it is conceivable that those skilled in the art can devise various modifications to the invention within the spirit and scope of the appended claims.
Claims
1. A method for preparing mullite porous hollow microspheres using electrospinning technology, characterized in that, Includes the following steps: The inner polymer is mixed with the first solvent to obtain an inner polymer solution; the mullite precursor is mixed with the second solvent to obtain an outer polymer solution. The inner polymer solution and the outer polymer solution were electrospun using coaxial electrospinning technology to obtain porous core-shell structured precursor microspheres. The porous core-shell structure precursor microspheres were subjected to curing heat treatment to obtain cured and crosslinked porous core-shell structure precursor microspheres. The solidified and cross-linked porous core-shell structure precursor microspheres were calcined to obtain mullite porous hollow microspheres. The humidity of the electrospinning is 30-60%.
2. The method for preparing mullite porous hollow microspheres using electrospinning technology according to claim 1, characterized in that, The inner layer polymer includes at least one of polyvinyl alcohol, polyvinylpyrrolidone, polyethylene oxide, polyurethane, polylactic acid, polymethyl methacrylate, and polycaprolactone.
3. The method for preparing mullite porous hollow microspheres using electrospinning technology according to claim 1, characterized in that, The mullite precursor includes a silicon source and an aluminum source; The silicon source includes at least one of tetraethyl orthosilicate, tetrapropyl orthosilicate, and tetrabutyl orthosilicate. The aluminum source includes at least one of aluminum sec-butoxide, aluminum tert-butoxide, polyaluminosiloxane, aluminum chloride, aluminum isopropoxide, and aluminum nitrate.
4. The method for preparing mullite porous hollow microspheres using electrospinning technology according to claim 1, characterized in that, The concentration of the outer polymer solution is 4wt% to 12wt%.
5. The method for preparing mullite porous hollow microspheres using electrospinning technology according to claim 1, characterized in that, The concentration of the inner polymer solution is 1wt% to 20wt%.
6. The method for preparing mullite porous hollow microspheres using electrospinning technology according to claim 1, characterized in that, The electrospinning conditions are as follows: spinning voltage is 15~20kV, distance from spinneret to receiving plate is 10~23cm, temperature is 25~30℃, inner feed speed is 0.01~0.02mL / min, and outer feed speed is 0.01~0.02mL / min.
7. The method for preparing mullite porous hollow microspheres using electrospinning technology according to claim 1, characterized in that, The porous core-shell structure precursor microspheres have a particle size of 1~10 μm.
8. The method for preparing mullite porous hollow microspheres using electrospinning technology according to claim 1, characterized in that, The curing heat treatment temperature is 200~400℃, the curing heat treatment time is 1~6h, and the atmosphere of the heat curing treatment is air or oxygen.
9. The method for preparing mullite porous hollow microspheres using electrospinning technology according to claim 1, characterized in that, The calcination conditions are as follows: heating rate of 5~15℃ / min, temperature of 1100~1400℃, holding time of 2~6h, and atmosphere of air or oxygen.