Hollow glass microspheres based on laser surface microcrystallization and a method for preparing the same

Abstract

The application discloses hollow glass microspheres based on laser surface microcrystallization and a preparation method thereof, and belongs to the technical field of functional material preparation. The method comprises the following steps: S1, spreading hollow glass microspheres in a single layer and in dispersion on a substrate; S2, under a protective atmosphere, scanning and irradiating the surface of the spread hollow glass microspheres by using a pulsed laser, and repeating the operation for 2-4 times to obtain hollow glass microspheres with a microcrystalline layer on the surface. The microcrystalline layer is induced on the surface of the microspheres by the laser, the compressive strength, wear resistance and interface bonding force of the microspheres with the substrate are significantly improved, and meanwhile, the structure of the microspheres is kept complete. The process is clean and controllable, and is easy to realize large-scale production.

Description

Technical Field

[0001] This invention belongs to the field of functional material preparation technology, specifically, it relates to a hollow glass microsphere based on laser surface microcrystallization and its preparation method. Background Technology

[0002] Hollow glass microspheres, as a lightweight, high-strength, and excellent heat and sound insulation inorganic non-metallic material, have been widely used in composite materials such as plastics, rubber, coatings, and building materials. Their main functions include reducing product weight, increasing rigidity, and improving sound and heat insulation performance.

[0003] However, the smooth surface and high chemical inertness of traditional hollow glass microspheres result in weak interfacial bonding between them and the polymer matrix, easily leading to stress concentration points in the composite material and reducing its impact strength, tensile strength, and other mechanical properties. Furthermore, their limited surface hardness makes them prone to wear during processing or long-term use, affecting the material's durability. In terms of chemical stability, the tolerance of traditional hollow glass microspheres to harsh environments such as strong acids and alkalis needs further improvement.

[0004] Currently, common surface modification methods for addressing the problem of insufficient bonding between hollow glass microspheres and the substrate mainly include: chemical coupling agent treatment, which can improve interfacial compatibility to some extent, but the effect is limited and may introduce organic impurities, affecting the performance of the material under high-temperature environments; plasma treatment, which involves complex equipment, high cost, and insufficient uniformity and stability, making it difficult to achieve large-scale continuous production; and acid-base etching, which involves violent reactions that easily damage the thin-walled structure of the microspheres, leading to a significant decrease in their strength or even breakage, and failing to achieve effective modification while maintaining the integrity of the microspheres.

[0005] Therefore, developing a surface modification method that can significantly improve the interfacial bonding force between hollow glass microspheres and the matrix without damaging their bulk structure and basic properties, and that is characterized by controllable process, high efficiency and environmental protection, has become an urgent technical problem to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a hollow glass microsphere based on laser surface microcrystallization and its preparation method.

[0007] The objective of this invention can be achieved through the following technical solutions: A method for preparing hollow glass microspheres based on laser surface microcrystallization includes the following steps: S1: Hollow glass microspheres are spread in a single layer and dispersed on the substrate; S2: The surface of the spread hollow glass microspheres is scanned and irradiated with a pulsed laser, and the process is repeated 2-4 times to obtain hollow glass microspheres with a microcrystalline layer on the surface.

[0008] In a more optimized manner, the hollow glass microspheres contain a nucleating agent; the nucleating agent includes one or more of TiO2, P2O5, or ZrO2.

[0009] Ideally, the substrate is a high-purity quartz glass plate, a graphite plate, or an alumina ceramic plate.

[0010] Ideally, the pulsed laser is one of a nanosecond laser, a picosecond laser, or a femtosecond laser.

[0011] In a more optimized manner, the process parameters of the pulsed laser are as follows: the laser wavelength is one of 355nm, 532nm, 1064nm, and 10.6μm; the laser power is 5-15W; the pulse frequency is 20-100kHz; and the scanning speed is 100-1000mm / s.

[0012] Ideally, the thickness of the microcrystalline layer is 50-500 nm.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes laser-induced surface heating on hollow glass microspheres to instantly raise the surface temperature and form a glass melt. Since glass is a poor conductor of heat, the glass melt contacts the cool glass substrate below to form crystal nuclei. Due to the rapid cooling, the crystals do not have time to grow, thus generating a microcrystalline layer bonded to the substrate. This microcrystalline layer, acting as a reinforcing phase, can effectively bear and disperse external loads, thereby significantly improving the compressive strength of the hollow glass microspheres themselves. Secondly, the microcrystalline layer significantly increases surface roughness and chemical activity, enabling stronger physical and chemical bonding between the microspheres and matrix materials such as polymers and rubber. This substantially enhances the interfacial bonding force, thereby improving the overall mechanical properties of the composite material. Furthermore, laser processing, being an instantaneous, localized, and precise energy application, allows for controlled surface modification of the hollow glass microspheres while fully preserving their original lightweight, high-strength, spherical structure and thermal and sound insulation properties, thus avoiding damage to the thin-walled structure. Finally, this method requires no chemical reagents and produces no pollutants, making the process clean and environmentally friendly. Furthermore, the parameters are precisely controllable, highly repeatable, and easy to integrate into automated equipment, providing a reliable way to achieve efficient, stable, and large-scale continuous production. Attached Figure Description

[0014] The invention will now be further described with reference to the accompanying drawings.

[0015] Figure 1This is a comparison image of hollow glass microspheres and laser-surfaced microcrystallized hollow glass microspheres in the embodiments. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0017] The hollow glass microspheres in the following examples and comparative examples comprise the following components by mass percentage: SiO2: 70%, B2O3: 10%, CaO: 5%, TiO2: 8%, TiN: 5%, Na2O: 1%, and calcium carbonate: 1%.

[0018] Example 1: A method for preparing hollow glass microspheres based on laser surface microcrystallization, comprising the following steps: S1: Hollow glass microspheres containing TiO2 nucleating agent, with DO3=8μm, D50=20μm, and D97=40μm, are spread in a single layer and dispersed on the substrate; S2: Under a nitrogen atmosphere, the surface of the spread hollow glass microspheres is scanned and irradiated using a pulsed laser. The hollow glass microsphere powder is rolled, and this process is repeated twice to obtain hollow glass microspheres with a microcrystalline layer on the surface (see schematic diagram). Figure 1 As shown); The substrate is a graphite plate; the pulsed laser is a nanosecond laser; the laser power is 15W; the pulse frequency is 100kHz; the scanning speed is 100mm / s; the laser wavelength is 10.6μm; and the microcrystalline layer thickness is 500nm.

[0019] Example 2: A method for preparing hollow glass microspheres based on laser surface microcrystallization, comprising the following steps: S1: Hollow glass microspheres containing TiO2 nucleating agent, with DO3=8μm, D50=20μm, and D97=40μm, are spread in a single layer and dispersed on the substrate; S2: Under a nitrogen atmosphere, the surface of the spread hollow glass microspheres is scanned and irradiated using a pulsed laser. The hollow glass microsphere powder is rolled, and this process is repeated twice to obtain hollow glass microspheres with a microcrystalline layer on the surface (see schematic diagram). Figure 1 As shown); The substrate is a graphite plate; the pulsed laser is a nanosecond laser; the laser power is 5W; the pulse frequency is 20kHz; the scanning speed is 1000mm / s; the laser wavelength is 355nm; and the microcrystalline layer thickness is 50nm.

[0020] Example 3: A method for preparing hollow glass microspheres based on laser surface microcrystallization, comprising the following steps: S1: Hollow glass microspheres containing TiO2 nucleating agent, with DO3=8μm, D50=20μm, and D97=40μm, are spread in a single layer and dispersed on the substrate; S2: Under a nitrogen atmosphere, the surface of the spread hollow glass microspheres is scanned and irradiated using a pulsed laser. The hollow glass microsphere powder is rolled, and this process is repeated twice to obtain hollow glass microspheres with a microcrystalline layer on the surface (see schematic diagram). Figure 1 As shown); The substrate is a graphite plate; the pulsed laser is a nanosecond laser; the laser power is 10W; the pulse frequency is 80kHz; the scanning speed is 500mm / s; the laser wavelength is 1064nm; and the microcrystalline layer thickness is 200nm.

[0021] Comparative Example 1: Hollow glass microspheres without surface microcrystallization.

[0022] Testing and experimentation: Corrosion resistance and compressive strength tests were conducted on the hollow glass microspheres before and after treatment. The data are shown in the table below. Conclusion: The experimental results show that the hollow glass microspheres based on laser surface microcrystallization described in this invention exhibit significant improvements in corrosion resistance and compressive strength. After laser surface microcrystallization treatment, the mass loss of the microspheres in acidic and alkaline environments is significantly reduced, and their acid and alkali resistance is superior to that of untreated hollow glass microspheres. Simultaneously, their compressive strength increases to 105-110 MPa under a 20% breakage rate, significantly higher than the 80 MPa of Comparative Example 1. This indicates that laser surface microcrystallization treatment not only effectively enhances the mechanical properties of hollow glass microspheres but also significantly improves their chemical stability. Furthermore, this treatment method is clean and controllable, and can optimize surface properties without damaging the microsphere structure, demonstrating promising application prospects and widespread application value.

[0023] In the description of this specification, references to terms such as "an embodiment," "example," and "specific example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0024] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing hollow glass microspheres based on laser surface microcrystallization, characterized in that... , Includes the following steps: S1: Hollow glass microspheres are spread in a single layer and dispersed on the substrate; S2: Under a protective atmosphere, the surface of the spread hollow glass microspheres is scanned and irradiated with a pulsed laser. This process is repeated 2-4 times to obtain hollow glass microspheres with a microcrystalline layer on the surface.

2. The method for preparing hollow glass microspheres based on laser surface microcrystallization according to claim 1, characterized in that... The hollow glass microspheres contain a nucleating agent; the nucleating agent includes one or more of TiO2, P2O5 or ZrO2.

3. The method for preparing hollow glass microspheres based on laser surface microcrystallization according to claim 1, characterized in that... The substrate is a high-purity quartz glass plate, graphite plate, or alumina ceramic plate.

4. The method for preparing hollow glass microspheres based on laser surface microcrystallization according to claim 1, characterized in that... The pulsed laser is one of a nanosecond laser, a picosecond laser, or a femtosecond laser.

5. The method for preparing hollow glass microspheres based on laser surface microcrystallization according to claim 1, characterized in that... The process parameters of the pulsed laser are as follows: the laser wavelength is one of 355nm, 532nm, 1064nm, and 10.6μm; the laser power is 5-15W; the pulse frequency is 20-100kHz; and the scanning speed is 100-1000mm / s.

6. The method for preparing hollow glass microspheres based on laser surface microcrystallization according to claim 1, characterized in that... The thickness of the microcrystalline layer is 50-500 nm.

7. Hollow glass microspheres obtained by the method for preparing hollow glass microspheres based on laser surface microcrystallization according to any one of claims 1-6.

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