Modified nanometer rare earth oxide composite, and preparation method and application thereof

Abstract

This invention proposes a modified nano-rare earth oxide composite, its preparation method, and its application, belonging to the field of polishing materials technology. Porous hollow cerium oxide / lanthanum oxide nanospheres are prepared, then loaded with formaldehyde-melamine organic resin, with a ZrO2 / SiO2 / Al2O3 composite embedded on the surface. After calcination, carbon nanotubes are deposited via chemical vapor deposition, followed by carbon quantum dot deposition. The surface is then modified with 1H,1H,2H,2H-perfluorodecyltrimethoxysilane and long-chain alkylsilanes to obtain the modified nano-rare earth oxide composite. This composite exhibits good suspension in polishing fluids, is not prone to aggregation, and possesses chemical inertness and conductivity. It does not undergo unnecessary chemical reactions with the polished material during polishing. Furthermore, it reduces static electricity generation and the addition of organic matter to the polishing fluid, avoiding cleaning difficulties. The production cost is low, making it easy to implement industrially and showing broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of polishing materials technology, specifically to a modified nano-rare earth oxide composite, its preparation method, and its application. Background Technology

[0002] High-generation, large-size display glass substrates are a key basic material in the display industry. Generally, 8.5-generation lines and above are considered high-generation lines, characterized by their larger glass substrate sizes, meeting the production needs of ultra-large-size LCD TVs. For example, 8.5-generation and 10.5-generation glass substrates are mainly used to manufacture 55-inch, 65-inch, and 75-inch large-size LCD TV panels. Precision polishing is a crucial processing technology that plays a vital role in improving the surface quality and precision of the glass substrate.

[0003] Polishing processes include:

[0004] 1. Chemical Mechanical Polishing (CMP): Combining the effects of chemical etching and mechanical grinding, CMP uses a chemical polishing solution to react with the glass surface, generating easily removable products. At the same time, the mechanical grinding action of the polishing pad removes minute defects, resulting in a highly uniform and smooth surface. It is widely used in display manufacturing, semiconductor manufacturing and other fields.

[0005] 2. Multi-step polishing process: For example, the glass substrate is first rough polished to remove larger unevenness and scratches; then fine polishing is performed to further improve the surface flatness and smoothness; finally, final polishing can be performed by reducing the particle size of polishing powder and reducing the polishing hardness, etc., to slowly polish, reduce the glass erosion rate, deal with submicron level defects on the glass surface, and form a smoother surface.

[0006] 3. Other polishing methods: These include rotary polishing, vibratory polishing, and centrifugal polishing. Rotary polishing can apply polishing force evenly, improving polishing efficiency and effect, and is suitable for mass production; vibratory polishing is suitable for processing surfaces with complex shapes and geometric features; centrifugal polishing uses centrifugal force generated by high-speed rotation to achieve efficient surface polishing and is also suitable for mass production.

[0007] Polishing materials include rare earth oxide powders, such as cerium oxide polishing powder and silicon dioxide polishing powder. Different polishing powders have different particle sizes and chemical properties, and are suitable for different polishing stages and glass substrate materials. For example, when polishing quartz glass substrates, cerium oxide particles can be used as the main component of the polishing slurry, utilizing its chemical reaction with the glass surface and mechanical grinding action to remove the protruding parts of the glass surface.

[0008] However, during the preparation of nano-rare earth oxides, when nano-rare earth oxide particles precipitate in an aqueous solution system, agglomeration is prone to occur, affecting the polishing effect. At the same time, traditional polishing solutions require the addition of various organic substances to improve the stability and monodispersity of the polishing solution, which also brings the problem of cleaning difficulties. Summary of the Invention

[0009] The purpose of this invention is to propose a modified nano-rare earth oxide composite, its preparation method, and its application. It can be well suspended in polishing liquid, is not prone to agglomeration, has chemical inertness and conductivity, and will not undergo unnecessary chemical reactions with the polished material during the polishing process. At the same time, it reduces static electricity generation and reduces the addition of organic matter in the polishing liquid, avoiding cleaning difficulties. Moreover, it has low production cost, is easy to realize industrial application, and has broad application prospects.

[0010] The technical solution of this invention is implemented as follows:

[0011] This invention provides a method for preparing modified nano-rare earth oxide composites, comprising the following steps:

[0012] S1. Preparation of porous hollow cerium oxide / lanthanum oxide nanospheres: Cerium nitrate and lanthanum nitrate were dissolved in a mixed solution of water and ethylene glycol, acetic acid was added dropwise, the mixture was stirred and mixed, polyvinylpyrrolidone and a pore-forming agent were added, the reaction was stirred, hydrothermal reaction was carried out, centrifuged, washed, dried and calcined to obtain porous hollow cerium oxide / lanthanum oxide nanospheres.

[0013] S2. Organic resin loading and modification: Porous hollow cerium oxide / lanthanum oxide nanospheres were added to formaldehyde solution, melamine was added, the pH of the solution was adjusted, the reaction was stirred, the product was added to Tris-HCl solution, tannic acid was added, the reaction was heated and stirred, centrifuged, washed, and dried to obtain modified nanospheres.

[0014] S3. Embedding of ZrO2 / SiO2 / Al2O3 composite: Modified nanospheres were added to ethanol, along with zirconium citrate, aluminum isopropoxide, tetraethyl orthosilicate, and water. The pH of the solution was adjusted, the reaction was stirred, centrifuged, washed, and dried to obtain embedded modified nanospheres.

[0015] S4. Chemical vapor deposition of carbon nanotubes: Carbon nanotube-deposited embedded modified nanospheres were prepared by calcining the embedded modified nanospheres under inert gas protection.

[0016] S5. Deposition of carbon quantum dots: Carbon nanotubes were deposited and embedded in modified nanospheres, citric acid and urea were added to water, hydrothermal reaction was carried out, centrifuged, washed and dried to obtain deposited and embedded modified nanospheres;

[0017] S6. Modification: The deposited and embedded modified nanospheres were added to an aqueous ethanol solution, followed by the addition of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane and long-chain alkylsilane, acetic acid, and the mixture was heated and stirred. The mixture was then centrifuged, washed, and dried to obtain the modified nano-rare earth oxide composite.

[0018] As a further improvement of the present invention, the mass ratio of cerium nitrate, lanthanum nitrate, acetic acid, polyvinylpyrrolidone and porogen in step S1 is 2-4:1-3:1-3:1.4-1.8:0.5-1, the porogen is selected from hexadecyltrimethylammonium chloride or hexadecyltrimethylammonium bromide, the hydrothermal reaction temperature is 170-190℃ and the time is 20-24h, and the calcination temperature is 500-550℃ and the time is 3-5h.

[0019] As a further improvement of the present invention, the mass ratio of the porous hollow cerium oxide / lanthanum oxide nanospheres, melamine, and tannic acid in step S2 is 10:1-2:1-2, the pH value of the adjusted solution is 5-5.5, the pH value of the Tris-HCl solution is 8.5-9.5, the temperature of the heating and stirring reaction is 45-55℃, and the time is 3-5h.

[0020] As a further improvement of the present invention, the mass ratio of the modified nanospheres, zirconium citrate, aluminum isopropoxide, tetraethyl orthosilicate and water in step S3 is 12-15:0.5-1:0.7-1.2:0.8-1.5:5-10, the pH value of the solution is adjusted to 9-10, and the stirring reaction time is 4-6 hours.

[0021] As a further improvement of the present invention, the calcination temperature in step S4 is 900-950℃ and the time is 1-2h.

[0022] As a further improvement of the present invention, the mass ratio of carbon nanotubes deposited and embedded modified nanospheres, citric acid and urea in step S5 is 10:1-1.1:0.5-0.7, the hydrothermal reaction temperature is 150-170℃ and the time is 2-4h.

[0023] As a further improvement of the present invention, the mass ratio of the deposited embedded modified nanospheres, 1H,1H,2H,2H-perfluorodecyltrimethoxysilane and long-chain alkylsilane in step S6 is 10:2-3:1-2, the heating and stirring reaction temperature is 45-55℃, and the time is 2-4h, wherein the long-chain alkylsilane is selected from at least one of n-octyltriethoxysilane, dodecyltrimethoxysilane, hexadecyltrimethoxysilane, and octadecyltrimethoxysilane.

[0024] The present invention further protects a modified nano-rare earth oxide composite prepared by the above-described preparation method.

[0025] This invention further protects the application of the above-mentioned modified nano-rare earth oxide composite as a polishing material.

[0026] The present invention has the following beneficial effects: Using a hydrothermal method, porous hollow cerium oxide / lanthanum oxide nanospheres are prepared under the action of a pore-forming agent. In an aqueous solution system, organic solvents and additives such as polyvinylpyrrolidone and acetic acid are used to regulate the nucleation and growth of the nano-rare earth oxide particles, achieving highly dispersed, ultrafine, and controllable spherical preparation of the nanoparticles. The porous structure formed under the action of the pore-forming agent facilitates the subsequent embedding of ZrO2 / SiO2 / Al2O3 composites, thereby improving wear resistance and high-temperature resistance. Simultaneously, the large specific surface area and abundant pore structure allow for the adsorption of more polishing fluid components, enabling full contact with the polished surface during polishing, increasing the opportunities for friction and chemical reactions, thus improving polishing efficiency. Compared with traditional polishing materials such as silicon dioxide, the hollow cerium oxide / lanthanum oxide nanospheres have moderate hardness, avoiding both excessive hardness causing scratches and wear on the polished surface and excessive softness leading to low polishing efficiency. During the polishing process, it can remove surface imperfections while minimizing mechanical damage to the workpiece surface, resulting in a smoother and flatter surface.

[0027] The porous hollow cerium oxide / lanthanum oxide nanospheres are loaded with formaldehyde-melamine organic resin and further coated with tannic acid. This allows for the surface embedding and adsorption of organozzirconium salts, organoaluminum salts, and tetraethyl orthosilicate, thereby generating a ZrO2 / SiO2 / Al2O3 composite in situ. This composite exhibits advantages such as high hardness, high wear resistance, high temperature resistance, and corrosion resistance. Carbon nanotubes are then deposited on the surface using chemical vapor deposition (the pyrolysis and vaporization of formaldehyde-melamine organic resin serves as the carbon source, and metal ions are partially reduced to single-atom catalysts, catalyzing the deposition reaction to generate carbon nanotubes). On one hand, carbon nanotubes can toughen metal oxides and rare earth oxides; on the other hand, they can provide wear resistance and lubrication to the composite, improving the polishing material's ability to withstand greater pressure and friction, making it less prone to wear and breakage. This ensures polishing efficiency and quality while extending the lifespan of the polishing material.

[0028] Carbon quantum dots are further deposited on the surface of the carbon nanotube-modified nanospheres. The unique structure of carbon quantum dots and carbon nanotubes allows them to act like "nanobrushes" during polishing, penetrating deep into the tiny depressions and crevices of the polished surface to perform fine grinding and finishing, removing tiny protrusions and imperfections, thereby obtaining a smoother and flatter surface. At the same time, due to their chemical inertness, they will not undergo unnecessary chemical reactions with the polished material during polishing, thus avoiding potential chemical damage to the workpiece surface and ensuring the surface quality and performance of the workpiece. They also have good conductivity, which can promptly discharge static electricity generated by friction during polishing, avoiding the influence of static electricity on the polishing process.

[0029] The surface of the prepared deposited and embedded modified nanospheres is modified with hydrophobic long-chain alkyl silanes and fluorinated silanes. The hydrophobicity and excellent physical properties can avoid the influence of nanoparticle aggregation, thereby improving the suspension performance of the polishing slurry.

[0030] The modified nano-rare earth oxide composite prepared by this invention can be well suspended in polishing liquid, is not prone to agglomeration, has chemical inertness and conductivity, will not undergo unnecessary chemical reactions with the polished material during the polishing process, reduces static electricity generation, reduces the addition of organic matter in the polishing liquid, avoids cleaning difficulties, has low production cost, is easy to realize industrial application, and has broad application prospects. Detailed Implementation

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1

[0033] This embodiment provides a method for preparing a modified nano-rare earth oxide composite, including the following steps:

[0034] S1. Preparation of porous hollow cerium oxide / lanthanum oxide nanospheres: 2g of cerium nitrate and 1g of lanthanum nitrate were dissolved in a mixed solution of 30mL water and 40mL ethylene glycol. 1g of acetic acid was added dropwise, and the mixture was stirred for 10min. 1.4g of polyvinylpyrrolidone and 0.5g of hexadecyltrimethylammonium chloride were added, and the mixture was stirred for 30min. The mixture was then subjected to hydrothermal reaction at 170℃ for 20h. After centrifugation, washing, drying, and calcination at 500℃ for 3h, porous hollow cerium oxide / lanthanum oxide nanospheres were obtained.

[0035] S2. Organic resin loading and modification: 10g of porous hollow cerium oxide / lanthanum oxide nanospheres were added to 50mL of formaldehyde solution, 1g of melamine was added, the pH of the solution was adjusted to 5, and the reaction was stirred for 30min. The product was added to 100mL of Tris-HCl solution with pH 8.5, 1g of tannic acid was added, the mixture was heated to 45℃, stirred for 3h, centrifuged, washed, and dried to obtain modified nanospheres.

[0036] S3. Embedding of ZrO2 / SiO2 / Al2O3 composite: 12g of modified nanospheres were added to 200mL of ethanol, along with 0.5g of zirconium citrate, 0.7g of aluminum isopropoxide, 0.8g of tetraethyl orthosilicate and 5g of water. The pH of the solution was adjusted to 9, and the mixture was stirred for 4h. After centrifugation, washing and drying, the embedded modified nanospheres were obtained.

[0037] S4. Chemical vapor deposition of carbon nanotubes: Carbon nanotube-deposited embedded modified nanospheres were prepared by calcining the embedded modified nanospheres at 900℃ for 1 h under nitrogen protection.

[0038] S5. Deposition of carbon quantum dots: 10g of carbon nanotube-deposited and embedded modified nanospheres, 1g of citric acid and 0.5g of urea were added to 50mL of water and hydrothermally reacted at 150℃ for 2h. After centrifugation, washing and drying, deposited and embedded modified nanospheres were obtained.

[0039] S6. Modification: 10g of deposited and embedded modified nanospheres were added to 200mL of 60wt% ethanol-water solution, along with 2g of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane and 1g of hexadecyltrimethoxysilane. 5mL of acetic acid was added, and the mixture was heated to 45℃ and stirred for 2h. After centrifugation, washing, and drying, the modified rare earth oxide nanocomposite was obtained.

[0040] Example 2

[0041] This embodiment provides a method for preparing a modified nano-rare earth oxide composite, including the following steps:

[0042] S1. Preparation of porous hollow cerium oxide / lanthanum oxide nanospheres: 4g of cerium nitrate and 3g of lanthanum nitrate were dissolved in a mixed solution of 40mL water and 50mL ethylene glycol. 3g of acetic acid was added dropwise, and the mixture was stirred for 10min. 1.8g of polyvinylpyrrolidone and 1g of hexadecyltrimethylammonium chloride were added, and the mixture was stirred for 30min. The mixture was then subjected to hydrothermal reaction at 190℃ for 24h. After centrifugation, washing, drying, and calcination at 550℃ for 5h, porous hollow cerium oxide / lanthanum oxide nanospheres were obtained.

[0043] S2. Organic resin loading and modification: 10g of porous hollow cerium oxide / lanthanum oxide nanospheres were added to 50mL of formaldehyde solution, 2g of melamine was added, the pH of the solution was adjusted to 5.5, and the reaction was stirred for 30min. The product was added to 100mL of Tris-HCl solution with pH 9.5, 2g of tannic acid was added, the mixture was heated to 55℃, stirred for 5h, centrifuged, washed, and dried to obtain modified nanospheres.

[0044] S3. Embedding of ZrO2 / SiO2 / Al2O3 composite: 15g of modified nanospheres were added to 200mL of ethanol, along with 1g of zirconium citrate, 1.2g of aluminum isopropoxide, 1.5g of tetraethyl orthosilicate and 10g of water. The pH of the solution was adjusted to 10, and the mixture was stirred for 6h. After centrifugation, washing and drying, the embedded modified nanospheres were obtained.

[0045] S4. Chemical vapor deposition of carbon nanotubes: Carbon nanotube-deposited embedded modified nanospheres were prepared by calcining the embedded modified nanospheres at 950℃ for 2 hours under nitrogen protection.

[0046] S5. Deposition of carbon quantum dots: 10g of carbon nanotube-deposited and embedded modified nanospheres, 1.1g of citric acid and 0.7g of urea were added to 50mL of water and hydrothermally reacted at 170℃ for 4h. After centrifugation, washing and drying, deposited and embedded modified nanospheres were obtained.

[0047] S6. Modification: 10g of deposited and embedded modified nanospheres were added to 200mL of 60wt% ethanol-water solution, along with 3g of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane and 2g of octadecyltrimethoxysilane. 5mL of acetic acid was added, and the mixture was heated to 55℃ and stirred for 4h. After centrifugation, washing, and drying, the modified rare earth oxide nanocomposite was obtained.

[0048] Example 3

[0049] This embodiment provides a method for preparing a modified nano-rare earth oxide composite, including the following steps:

[0050] S1. Preparation of porous hollow cerium oxide / lanthanum oxide nanospheres: 3g of cerium nitrate and 2g of lanthanum nitrate were dissolved in a mixed solution of 35mL water and 45mL ethylene glycol. 2g of acetic acid was added dropwise, and the mixture was stirred for 10min. 1.6g of polyvinylpyrrolidone and 0.7g of hexadecyltrimethylammonium bromide were added, and the mixture was stirred for 30min. The mixture was then subjected to hydrothermal reaction at 180℃ for 22h. After centrifugation, washing, drying, and calcination at 520℃ for 4h, porous hollow cerium oxide / lanthanum oxide nanospheres were obtained.

[0051] S2. Organic resin loading and modification: 10g of porous hollow cerium oxide / lanthanum oxide nanospheres were added to 50mL of formaldehyde solution, 1.5g of melamine was added, the pH of the solution was adjusted to 5.2, and the reaction was stirred for 30min. The product was added to 100mL of Tris-HCl solution with pH 9, 1.5g of tannic acid was added, the mixture was heated to 50℃, stirred for 4h, centrifuged, washed, and dried to obtain modified nanospheres.

[0052] S3. Embedding of ZrO2 / SiO2 / Al2O3 composite: 13g of modified nanospheres were added to 200mL of ethanol, along with 0.7g of zirconium citrate, 1g of aluminum isopropoxide, 1.2g of tetraethyl orthosilicate and 8g of water. The pH of the solution was adjusted to 9.5, and the mixture was stirred for 5h. After centrifugation, washing and drying, the embedded modified nanospheres were obtained.

[0053] S4. Chemical vapor deposition of carbon nanotubes: Carbon nanotube-deposited embedded modified nanospheres were prepared by calcining the embedded modified nanospheres at 920℃ for 1.5h under nitrogen protection.

[0054] S5. Deposition of carbon quantum dots: 10g of carbon nanotube-deposited and embedded modified nanospheres, 1.05g of citric acid and 0.6g of urea were added to 50mL of water and hydrothermally reacted at 160℃ for 3h. After centrifugation, washing and drying, deposited and embedded modified nanospheres were obtained.

[0055] S6. Modification: 10g of deposited and embedded modified nanospheres were added to 200mL of 60wt% ethanol-water solution, along with 2.5g of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane and 1.5g of dodecyltrimethoxysilane. 5mL of acetic acid was added, and the mixture was heated to 50℃ and stirred for 3h. After centrifugation, washing, and drying, the modified nano-rare earth oxide composite was obtained.

[0056] Comparative Example 1

[0057] The difference from Example 3 is that the porogen cetyltrimethylammonium bromide was not added in step S1. Specifically:

[0058] S1. Preparation of hollow cerium oxide / lanthanum oxide nanospheres: 3g of cerium nitrate and 2g of lanthanum nitrate were dissolved in a mixed solution of 35mL water and 45mL ethylene glycol. 2g of acetic acid was added dropwise, and the mixture was stirred for 10min. 1.6g of polyvinylpyrrolidone was added, and the mixture was stirred for 30min. The mixture was then subjected to hydrothermal reaction at 180℃ for 22h. After centrifugation, washing, drying, and calcination at 520℃ for 4h, hollow cerium oxide / lanthanum oxide nanospheres were obtained.

[0059] Comparative Example 2

[0060] The difference from Example 3 is that tannic acid modification was not performed in step S2. Specifically:

[0061] S2. Organic resin loading and modification: 10g of porous hollow cerium oxide / lanthanum oxide nanospheres were added to 50mL of formaldehyde solution, 1.5g of melamine was added, the pH of the solution was adjusted to 5.2, and the mixture was stirred for 30min to obtain nanospheres.

[0062] Comparative Example 3

[0063] The difference from Example 3 is that zirconium citrate was not added in step S3. Specifically:

[0064] S3. Embedding of SiO2 / Al2O3 composite: 13.7g of modified nanospheres were added to 200mL of ethanol, along with 1g of aluminum isopropoxide, 1.2g of tetraethyl orthosilicate and 8g of water. The pH of the solution was adjusted to 9.5, and the mixture was stirred for 5h. After centrifugation, washing and drying, the embedded modified nanospheres were obtained.

[0065] Comparative Example 4

[0066] The difference from Example 3 is that aluminum isopropoxide was not added in step S3. Specifically:

[0067] S3. Embedding of ZrO2 / SiO2 composite: 14g of modified nanospheres were added to 200mL of ethanol, along with 0.7g of zirconium citrate, 1.2g of tetraethyl orthosilicate and 8g of water. The pH of the solution was adjusted to 9.5, and the mixture was stirred for 5h. After centrifugation, washing and drying, the embedded modified nanospheres were obtained.

[0068] Comparative Example 5

[0069] The difference from Example 3 is that tetraethyl orthosilicate was not added in step S3. Specifically:

[0070] S3. Embedding of ZrO2 / Al2O3 composite: 14.2g of modified nanospheres were added to 200mL of ethanol, along with 0.7g of zirconium citrate, 1g of aluminum isopropoxide and 8g of water. The pH of the solution was adjusted to 9.5, and the mixture was stirred for 5h. After centrifugation, washing and drying, the embedded modified nanospheres were obtained.

[0071] Comparative Example 6

[0072] The difference from Example 3 is that step S3 is not performed. Specifically:

[0073] S1. Preparation of porous hollow cerium oxide / lanthanum oxide nanospheres: 3g of cerium nitrate and 2g of lanthanum nitrate were dissolved in a mixed solution of 35mL water and 45mL ethylene glycol. 2g of acetic acid was added dropwise, and the mixture was stirred for 10min. 1.6g of polyvinylpyrrolidone and 0.7g of hexadecyltrimethylammonium bromide were added, and the mixture was stirred for 30min. The mixture was then subjected to hydrothermal reaction at 180℃ for 22h. After centrifugation, washing, drying, and calcination at 520℃ for 4h, porous hollow cerium oxide / lanthanum oxide nanospheres were obtained.

[0074] S2. Organic resin loading and modification: 10g of porous hollow cerium oxide / lanthanum oxide nanospheres were added to 50mL of formaldehyde solution, 1.5g of melamine was added, the pH of the solution was adjusted to 5.2, and the reaction was stirred for 30min. The product was added to 100mL of Tris-HCl solution with pH 9, 1.5g of tannic acid was added, the mixture was heated to 50℃, stirred for 4h, centrifuged, washed, and dried to obtain modified nanospheres.

[0075] S3. Chemical vapor deposition of carbon nanotubes: modified nanospheres were calcined at 920℃ for 1.5h under nitrogen protection to obtain carbon nanotube deposited nanospheres;

[0076] S4. Deposition of carbon quantum dots: 10g carbon nanotube deposited nanospheres, 1.05g citric acid and 0.6g urea were added to 50mL of water and hydrothermally reacted at 160℃ for 3h. After centrifugation, washing and drying, deposited nanospheres were obtained.

[0077] S5. Modification: 10g of deposited nanospheres were added to 200mL of 60wt% ethanol-water solution, along with 2.5g of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane and 1.5g of dodecyltrimethoxysilane. 5mL of acetic acid was added, and the mixture was heated to 50℃ and stirred for 3h. After centrifugation, washing, and drying, the modified nano-rare earth oxide composite was obtained.

[0078] Comparative Example 7

[0079] The difference from Example 3 is that step S5 is not performed. Specifically:

[0080] S1. Preparation of porous hollow cerium oxide / lanthanum oxide nanospheres: 3g of cerium nitrate and 2g of lanthanum nitrate were dissolved in a mixed solution of 35mL water and 45mL ethylene glycol. 2g of acetic acid was added dropwise, and the mixture was stirred for 10min. 1.6g of polyvinylpyrrolidone and 0.7g of hexadecyltrimethylammonium bromide were added, and the mixture was stirred for 30min. The mixture was then subjected to hydrothermal reaction at 180℃ for 22h. After centrifugation, washing, drying, and calcination at 520℃ for 4h, porous hollow cerium oxide / lanthanum oxide nanospheres were obtained.

[0081] S2. Organic resin loading and modification: 10g of porous hollow cerium oxide / lanthanum oxide nanospheres were added to 50mL of formaldehyde solution, 1.5g of melamine was added, the pH of the solution was adjusted to 5.2, and the reaction was stirred for 30min. The product was added to 100mL of Tris-HCl solution with pH 9, 1.5g of tannic acid was added, the mixture was heated to 50℃, stirred for 4h, centrifuged, washed, and dried to obtain modified nanospheres.

[0082] S3. Embedding of ZrO2 / SiO2 / Al2O3 composite: 13g of modified nanospheres were added to 200mL of ethanol, along with 0.7g of zirconium citrate, 1g of aluminum isopropoxide, 1.2g of tetraethyl orthosilicate and 8g of water. The pH of the solution was adjusted to 9.5, and the mixture was stirred for 5h. After centrifugation, washing and drying, the embedded modified nanospheres were obtained.

[0083] S4. Chemical vapor deposition of carbon nanotubes: Carbon nanotube-deposited embedded modified nanospheres were prepared by calcining the embedded modified nanospheres at 920℃ for 1.5h under nitrogen protection.

[0084] S5. Modification: 10g of carbon nanotube-deposited and embedded modified nanospheres were added to 200mL of 60wt% ethanol-water solution, along with 2.5g of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane and 1.5g of dodecyltrimethoxysilane, and 5mL of acetic acid. The mixture was heated to 50℃, stirred for 3h, centrifuged, washed, and dried to obtain the modified nano-rare earth oxide composite.

[0085] Comparative Example 8

[0086] The difference from Example 3 is that step S6 is not performed. Specifically:

[0087] S1. Preparation of porous hollow cerium oxide / lanthanum oxide nanospheres: 3g of cerium nitrate and 2g of lanthanum nitrate were dissolved in a mixed solution of 35mL water and 45mL ethylene glycol. 2g of acetic acid was added dropwise, and the mixture was stirred for 10min. 1.6g of polyvinylpyrrolidone and 0.7g of hexadecyltrimethylammonium bromide were added, and the mixture was stirred for 30min. The mixture was then subjected to hydrothermal reaction at 180℃ for 22h. After centrifugation, washing, drying, and calcination at 520℃ for 4h, porous hollow cerium oxide / lanthanum oxide nanospheres were obtained.

[0088] S2. Organic resin loading and modification: 10g of porous hollow cerium oxide / lanthanum oxide nanospheres were added to 50mL of formaldehyde solution, 1.5g of melamine was added, the pH of the solution was adjusted to 5.2, and the reaction was stirred for 30min. The product was added to 100mL of Tris-HCl solution with pH 9, 1.5g of tannic acid was added, the mixture was heated to 50℃, stirred for 4h, centrifuged, washed, and dried to obtain modified nanospheres.

[0089] S3. Embedding of ZrO2 / SiO2 / Al2O3 composite: 13g of modified nanospheres were added to 200mL of ethanol, along with 0.7g of zirconium citrate, 1g of aluminum isopropoxide, 1.2g of tetraethyl orthosilicate and 8g of water. The pH of the solution was adjusted to 9.5, and the mixture was stirred for 5h. After centrifugation, washing and drying, the embedded modified nanospheres were obtained.

[0090] S4. Chemical vapor deposition of carbon nanotubes: Carbon nanotube-deposited embedded modified nanospheres were prepared by calcining the embedded modified nanospheres at 920℃ for 1.5h under nitrogen protection.

[0091] S5. Deposition of carbon quantum dots: 10g of carbon nanotubes embedded modified nanospheres, 1.05g of citric acid and 0.6g of urea were added to 50mL of water and hydrothermally reacted at 160℃ for 3h. After centrifugation, washing and drying, the deposited and embedded modified nanospheres were obtained, which are the modified nano-rare earth oxide composites.

[0092] Test Example 1

[0093] The modified nano-rare earth oxide composites obtained in Examples 1-3 or Comparative Examples 1-8 were formulated into a polishing slurry with other raw materials. The slurry contained 2.5 kg of the modified nano-rare earth oxide composite, 0.325 kg of dodecyltrimethylammonium chloride, and 0.005 kg of n-butanol. The pH of the solution was adjusted to 7.5 with hydroxyethyl ethylenediamine. The mixture was thoroughly mixed to obtain the polishing slurry. A TFT-LCD glass substrate with dimensions of 20 mm × 20 mm, a thickness of 0.7 mm, and a surface roughness of 6 nm was selected as the polishing material. The experiment used a UNIPOL-1502 polishing machine and a polyurethane polishing pad, and the polishing time was 5 min. The results are shown in Table 1.

[0094] Before and after polishing, the glass was weighed using a precision electronic balance, and the material removal rate was calculated using formula (1). MRR = (M0-M1)×10 7 / (ρ×S1×t)(1)

[0095] In the formula, k MRR ρ is the material removal rate, in nm / min; M0 and M1 are the masses of the glass before and after polishing, in g; ρ is the density of the glass substrate, in g / cm³. 3 S1 is the area of ​​the glass surface, in cm². 2 t represents the polishing time, in minutes.

[0096] The surface morphology of the glass was observed using a scanning probe microscope (CSPM5000), and its surface roughness Ra (nm) was measured. The scanning area during the test was 10μm×10μm.

[0097] The transmittance of the glass was measured using a UV-Vis spectrophotometer (UV-1901 model), with the wavelength range being the visible light range, i.e., 400-800nm.

[0098] Table 1

[0099]

[0100] As can be seen from the table above, the polishing slurry prepared by the modified nano-rare earth oxide composites obtained in Examples 1-3 of the present invention has a high removal rate on glass substrates, low surface roughness, and high light transmittance.

[0101] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a modified nano-rare earth oxide composite, characterized in that, Includes the following steps: S1. Preparation of porous hollow cerium oxide / lanthanum oxide nanospheres: Cerium nitrate and lanthanum nitrate were dissolved in a mixed solution of water and ethylene glycol, acetic acid was added dropwise, the mixture was stirred and mixed, polyvinylpyrrolidone and a pore-forming agent were added, the reaction was stirred, hydrothermal reaction was carried out, centrifuged, washed, dried and calcined to obtain porous hollow cerium oxide / lanthanum oxide nanospheres. S2. Organic resin loading and modification: Porous hollow cerium oxide / lanthanum oxide nanospheres were added to formaldehyde solution, melamine was added, the pH of the solution was adjusted, the reaction was stirred, the product was added to Tris-HCl solution, tannic acid was added, the reaction was heated and stirred, centrifuged, washed, and dried to obtain modified nanospheres. S3. Embedding of ZrO2 / SiO2 / Al2O3 composite: Modified nanospheres were added to ethanol, along with zirconium citrate, aluminum isopropoxide, tetraethyl orthosilicate, and water. The pH of the solution was adjusted, the reaction was stirred, centrifuged, washed, and dried to obtain embedded modified nanospheres. S4. Chemical vapor deposition of carbon nanotubes: Carbon nanotube-deposited embedded modified nanospheres were prepared by calcining the embedded modified nanospheres under inert gas protection. S5. Deposition of carbon quantum dots: Carbon nanotubes were deposited and embedded in modified nanospheres, citric acid and urea were added to water, hydrothermal reaction was carried out, centrifuged, washed and dried to obtain deposited and embedded modified nanospheres; S6. Modification: The deposited and embedded modified nanospheres were added to an aqueous ethanol solution, followed by the addition of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane and long-chain alkylsilane, acetic acid, and the mixture was heated and stirred. The mixture was then centrifuged, washed, and dried to obtain the modified nano-rare earth oxide composite.

2. The method for preparing the modified nano-rare earth oxide composite according to claim 1, characterized in that, In step S1, the mass ratio of cerium nitrate, lanthanum nitrate, acetic acid, polyvinylpyrrolidone, and porogen is 2-4:1-3:1-3:1.4-1.8:0.5-1, and the porogen is selected from hexadecyltrimethylammonium chloride or hexadecyltrimethylammonium bromide; the hydrothermal reaction temperature is 170-190℃ and the time is 20-24h; the calcination temperature is 500-550℃ and the time is 3-5h.

3. The method for preparing the modified nano-rare earth oxide composite according to claim 1, characterized in that, In step S2, the mass ratio of the porous hollow cerium oxide / lanthanum oxide nanospheres, melamine, and tannic acid is 10:1-2:1-2; the pH of the adjusted solution is 5-5.5; the pH of the Tris-HCl solution is 8.5-9.5; and the heating and stirring reaction is carried out at a temperature of 45-55℃ for 3-5 hours.

4. The method for preparing the modified nano-rare earth oxide composite according to claim 1, characterized in that, In step S3, the mass ratio of the modified nanospheres, zirconium citrate, aluminum isopropoxide, tetraethyl orthosilicate, and water is 12-15:0.5-1:0.7-1.2:0.8-1.5:5-10, the pH of the solution is adjusted to 9-10, and the stirring reaction time is 4-6 hours.

5. The method for preparing the modified nano-rare earth oxide composite according to claim 1, characterized in that, The calcination temperature in step S4 is 900-950℃, and the time is 1-2 hours.

6. The method for preparing the modified nano-rare earth oxide composite according to claim 1, characterized in that, In step S5, the mass ratio of the carbon nanotube deposited and embedded modified nanospheres, citric acid, and urea is 10:1-1.1:0.5-0.7; the hydrothermal reaction temperature is 150-170℃, and the time is 2-4h.

7. The method for preparing the modified nano-rare earth oxide composite according to claim 1, characterized in that, In step S6, the mass ratio of the deposited embedded modified nanospheres, 1H,1H,2H,2H-perfluorodecyltrimethoxysilane, and long-chain alkylsilane is 10:2-3:1-2; the heating and stirring reaction is carried out at a temperature of 45-55℃ for 2-4 hours; the long-chain alkylsilane is selected from at least one of n-octyltriethoxysilane, dodecyltrimethoxysilane, hexadecyltrimethoxysilane, and octadecyltrimethoxysilane.

8. A modified nano-rare earth oxide composite prepared by the preparation method according to any one of claims 1-7.

9. The application of the modified nano-rare earth oxide composite as described in claim 8 as a polishing material.

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