Nanometer rare earth oxide, its preparation process and application

Abstract

The application provides a kind of nano rare earth oxide and its preparation process and application, it relates to nanometer material technical field.The nano rare earth oxide includes the following raw materials: rare earth ions, chitosan-hexadecyl trimethyl ammonium bromide, tea saponin, nanocellulose and hydroxyapatite nanorod;The rare earth ions are selected from at least one of cerium ions Ce 3+ 、yttrium ions Y 3+ 、samarium ions Sm 3+ 、terbium ions Tb 3+ 、lanthanum ions La 3+ 、praseodymium ions Pr 3+ 、neodymium ions Nd 3+ .The nano rare earth oxide prepared by the application can be used as an independent antibacterial agent, and can also be used as a functional filler and a polymer composite, which has application potential in the fields of medical device coatings, food packaging, etc.

Description

Technical Field

[0001] This invention relates to the field of nanomaterials technology, specifically to a nano-rare earth oxide, its preparation process, and its applications. Background Technology

[0002] Rare earth elements, due to their unique 4f electron structure, possess excellent physical and chemical properties, including electrical, optical, magnetic, and thermal properties. They are widely used in traditional industries and high-tech fields such as petroleum, chemical, metallurgy, ceramics, textiles, glass, and permanent magnet materials, for applications such as the preparation of metal matrix composites, polishing materials, luminescent materials, laser materials, fibers, and ceramic materials. Rare earth oxides can be used as dopants, sintering aids, catalysts, and magneto-optical storage, making them key fundamental materials in today's high-tech materials field. With the advancement of science and technology, the value of rare earth oxides will continue to increase. Nanoscale rare earth oxides, in addition to possessing the excellent properties of traditional rare earth oxides, also exhibit the unique properties of nanomaterials, possessing a larger specific surface area, surface energy, and better fluidity and dispersibility, displaying unique comprehensive physicochemical characteristics. This significantly improves their various properties and broadens their application prospects. As the application fields and levels of rare earths continue to expand, the quality requirements for high-tech materials, including the control of crystal form, particle size, morphology, and specific surface area of ​​nanoscale rare earth oxides, will become increasingly stringent.

[0003] Methods for preparing nano-rare earth oxides mainly include solid-phase synthesis, hydrothermal synthesis, sol-gel method, spray pyrolysis, microemulsion method, and precipitation method. Among these, solid-phase synthesis methods often produce products with unsatisfactory particle size and dispersibility. While hydrothermal, sol-gel, spray pyrolysis, and microemulsion methods can produce high-quality nano-products, their high cost, low efficiency, and long production cycles hinder large-scale production. Currently, precipitation remains the optimal choice for preparing nano-oxide powders. Precipitation allows for precise control of the chemical composition of materials, while also offering low raw material costs, lower equipment requirements, simpler processes, and convenient operation, resulting in products with high surface activity and purity. However, the precipitation method suffers from difficulties in controlling the crystal nucleation rate during precipitation, requiring precise control of the crystal growth process. The research status of "Precipitation Method for Preparing Nano-Rare Earth Oxides" (Rare Earth, Xiong Xiaobai, Liu Lingsheng, et al., April 2013, Vol. 34, No. 2) discloses that the precipitation method for preparing ultrafine rare earth oxide powders has many advantages, but the precipitation reaction, drying, and calcination stages all lead to varying degrees of agglomeration, which in turn affects the uniformity of the product particle size. How to inhibit particle agglomeration is a key issue. Therefore, preparing nano-rare earth compounds with specific morphologies and particle sizes is quite difficult.

[0004] Chinese patent application CN116730377A discloses a method for preparing nano-rare earth oxides by thermal decomposition of rare earth carbonates. The method employs spray drying to rapidly remove water from nano-rare earth carbonates, reducing the impact of water on powder agglomeration during dehydration. Then, the dried nano-rare earth carbonates are directly placed in a temperature of 600-900℃ for thermal decomposition. The nano-rare earth carbonates decompose instantly, releasing a large amount of carbon dioxide, which also helps to break up the powder. These two steps work synergistically to solve the problem of easy agglomeration of nano-rare earth oxide powder prepared by the existing wet precipitation method. However, the particle size of the nano-rare earth oxides is relatively large, ranging from 60nm to 230nm.

[0005] Chinese patent application CN102531022A discloses a method for preparing monodisperse rare earth oxide nanospheres. Using coarse rare earth oxide powder as raw material and urea as a precipitant, monodisperse rare earth oxide nanospheres are prepared by adding the surfactant polyvinylpyrrolidone and adjusting the ratio of ethanol to water as solvents via a homogeneous hydrothermal coprecipitation method. This method allows for effective control over the size and dispersibility of the nanospheres. However, the resulting rare earth oxide nanospheres exhibit uneven size distribution, which not only increases costs but also negatively impacts product purity.

[0006] Based on this, a nano-rare earth oxide and its preparation process are provided. By improving the raw materials, formulations, and preparation methods, parameters such as particle size, uniformity, and specific surface area can be improved, which is the focus of research in this field. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides a nano-rare earth oxide, its preparation process, and its applications.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a nano-rare earth oxide comprising the following raw materials: rare earth ions, chitosan-hexadecyltrimethylammonium bromide, tea saponin, nanocellulose, and hydroxyapatite nanorods; wherein the rare earth ions are selected from cerium ions (Ce). 3+ Yttrium ions 3+ Samarium ions (Sm) 3+ terbium ions (Tb) 3+ Lanthanum ion La 3+ Praseodymium ion Pr 3+ Neodymium ions (Nd) 3+ At least one of them.

[0009] Preferably, the rare earth ions are cerium ions (Ce). 3+ Yttrium ions 3+ Samarium ions (Sm) 3+ and terbium ions Tb 3+ composition.

[0010] Preferably, the cerium ion Ce 3+ Yttrium ions 3+ Samarium ions (Sm) 3+ and terbium ions Tb 3+ The molar ratio is (8-10):(0.8-1.2):(0.4-0.6):(0.2-0.4).

[0011] More preferably, the cerium ion Ce 3+ Yttrium ions 3+ Samarium ions (Sm) 3+ and terbium ions Tb 3+ The molar ratio is (8-9):(0.9-1.0):(0.4-0.5):(0.2-0.3).

[0012] More preferably, the cerium ion Ce 3+ Yttrium ions 3+ Samarium ions (Sm) 3+ and terbium ions Tb 3+ The molar ratio is 9:1:0.5:0.3.

[0013] Preferably, the preparation method of the chitosan-hexadecyltrimethylammonium bromide (chitosan-CTAB) includes the following steps: (1) Chitosan is dissolved in 0.5-1.5 wt% acetic acid solution to obtain 1.5-2.5 wt% chitosan solution; (2) Hexadecyltrimethylammonium bromide (CTAB), isopropanol and water are mixed at 50-60℃ in a mass-volume ratio of 1g:(4-6)mL:(18-20)mL to obtain a CTAB solution; (3) The chitosan solution of 1.5-2.5 wt% is mixed with the CTAB solution to obtain the solution.

[0014] Preferably, in step (1), the pH of the chitosan solution is 4.8-5.2.

[0015] Preferably, in step (2), the mixing is stirring, and the time is 20-30 minutes.

[0016] Preferably, in step (3), the mass ratio of the 1.5-2.5 wt% chitosan solution to the CTAB solution is 1:(0.9-1.1).

[0017] More preferably, the preparation method of the chitosan-CTAB includes the following steps: (1) Chitosan was dissolved in 1.0 wt% acetic acid solution, ultrasonically dispersed for 30 min, and the pH was adjusted to 5 with ammonia water to obtain a 2.0 wt% chitosan solution; (2) Hexadecyltrimethylammonium bromide (CTAB), isopropanol and water were stirred at 55°C for 30 min in a mass-volume ratio of 1 g: 5 mL: 20 mL to obtain a CTAB solution; (3) Slowly add 2.0 wt% chitosan solution to CTAB solution at a mass ratio of 1:1 and mix well to obtain the final product.

[0018] Preferably, the mass ratio of tea saponin to nanocellulose is 1:(1.8-2.2).

[0019] More preferably, the mass ratio of tea saponin to nanocellulose is 1:2.

[0020] Preferably, the mass of the hydroxyapatite nanorods is 0.3-0.6% of the total mass of the nano-rare earth oxide raw materials.

[0021] Preferably, the aspect ratio of the hydroxyapatite nanorods is 10-20.

[0022] More preferably, the mass of the hydroxyapatite nanorods is 0.5% of the total mass of the nano-rare earth oxide raw materials.

[0023] Preferably, the raw materials comprise, by weight, the following: 2-5 parts rare earth ions, 0.8-1.1 parts chitosan-CTAB, 0.8-1.1 parts tea saponin, 1.8-2.2 parts nanocellulose and 0.01-0.05 parts hydroxyapatite nanorods; More preferably, the ingredients include the following raw materials in parts by weight: 2-4 parts rare earth ions, 0.9-1.1 parts chitosan-CTAB, 0.9-1.1 parts tea saponin, 1.9-2.2 parts nanocellulose and 0.016-0.045 parts hydroxyapatite nanorods; Secondly, the present invention provides a method for preparing the above-mentioned nano-rare earth oxides, comprising the following steps: S1: Contains cerium ions (Ce) 3+ Yttrium ions 3+ Samarium ions (Sm) 3+ and terbium ions Tb 3+ The rare earth salts were mixed with the solvent, and then chitosan-CTAB was added to obtain mixture 1; S2: Mixture 1 is mixed with tea saponin, nanocellulose and hydroxyapatite nanorods to obtain mixture 2; S3: Mixture 2 is transferred to an autoclave for hydrothermal reaction, and the precipitate is collected; S4: The precipitate obtained in step S3 is calcined once, then calcined a second time after heating, to obtain the final product.

[0024] Preferably, in step S1, the rare earth salt is cerium acetylacetonate (Ce(acac)3), yttrium nitrate (Y(NO3)3), samarium nitrate (Sm(NO3)3) and terbium nitrate (Tb(NO3)3).

[0025] Preferably, in step S1, the solvent is an aqueous solution of ethanol; More preferably, in step S1, the solvent is an aqueous solution of 25wt%-30wt% ethanol.

[0026] Preferably, in step S1, the total mass of the rare earth salt to the mass-volume ratio of the solvent is 1g:15-20mL.

[0027] Preferably, in step S2, the mixing is stirring, the temperature is 50-60℃, and the time is 1.5-2.5h.

[0028] More preferably, in step S2, the mixing is stirring, the temperature is 60°C, and the time is 2 hours.

[0029] Preferably, in step S3, the temperature of the hydrothermal reaction is 170-190℃ and the time is 10-12h.

[0030] More preferably, in step S3, the hydrothermal reaction is carried out at a temperature of 180°C for 12 hours.

[0031] Preferably, in step S4, the temperature of the first calcination is 280-320℃ and the time is 40-60 min; the temperature of the second calcination is 580-620℃ and the time is 1-1.5 h.

[0032] More preferably, in step S4, the temperature of the first calcination is 300°C and the time is 60 min; the temperature of the second calcination is 600°C and the time is 1 h.

[0033] Thirdly, the present invention provides the application of the above-mentioned nano-rare earth oxides in the preparation of antibacterial products.

[0034] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention employs a Ce³⁺ / Y³⁺ / Sm³⁺ / Tb³⁺ quaternary system in a specific molar ratio, which significantly improves its antibacterial properties. Combined with the positively charged antibacterial effect of chitosan, the inhibition rate against Staphylococcus aureus is significantly improved, and the cytotoxicity is lower than that of pure rare earth oxides.

[0035] 2. This invention introduces a chitosan-CTAB composite template agent. Through the synergistic effect of the cationic surface activity of CTAB and the amino groups of chitosan, the nucleation and growth of rare earth oxides are controlled, resulting in nanoparticles with a more uniform particle size distribution. The combination of tea saponin and nanocellulose improves dispersion stability and reduces agglomeration rate by more than 40%. The addition of 0.5 wt% hydroxyapatite nanorods with an aspect ratio ≥10 further improves dispersibility and reduces the possibility of agglomeration by coordinating the phosphate groups on their surface with rare earth ions, while ensuring mechanical properties.

[0036] 3. The present invention employs a specific preparation method: a dual-temperature zone treatment of 300℃ pre-calcination + 600℃ final calcination. The low-temperature zone removes organic matter while retaining the mesoporous structure, and the high-temperature zone completes the crystal transformation without sintering, which significantly increases the specific surface area of ​​the product.

[0037] 4. The nano-rare earth oxides prepared by this invention can be used as independent antibacterial agents or as functional fillers in polymer composites, and have application potential in fields such as medical device coatings and food packaging. Detailed Implementation

[0038] To make the technical means, creative features, achieved objectives, and effects of this invention readily understandable, the invention is further illustrated below with specific embodiments. However, these embodiments are merely preferred embodiments and not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments described herein without creative effort are all within the scope of protection of this invention. It is worth noting that the raw materials used in this invention are all common commercially available products, and their sources are not specifically limited. The technical and scientific terms used in the embodiments have the meanings commonly understood by those skilled in the art to which this invention pertains.

[0039] Hydroxyapatite nanorods: purchased from Suzhou Beike Nanotechnology Co., Ltd., with an aspect ratio of 10-20.

[0040] Example 1 A nano-rare earth oxide, comprising the following raw materials by mass parts: 3 parts rare earth ions, 1 part chitosan-CTAB, 1 part tea saponin, 2 parts nanocellulose and 0.035 parts hydroxyapatite nanorods; Rare earth ions: composed of cerium acetylacetone (Ce(acac)3), yttrium nitrate (Y(NO3)3), samarium nitrate (Sm(NO3)3) and terbium nitrate (Tb(NO3)3) in a molar ratio of 9:1:0.5:0.3.

[0041] The preparation method is as follows: S1: Cerium acetylacetone (Ce(acac)3), yttrium nitrate (Y(NO3)3), samarium nitrate (Sm(NO3)3) and terbium nitrate (Tb(NO3)3) were mixed with an aqueous solution of 28 wt% ethanol. The total mass of the rare earth salts and the mass-volume ratio of the aqueous ethanol solution were 1 g: 15 mL. Then chitosan-CTAB was added to obtain mixture 1. S2: Mixture 1 is mixed with tea saponin, nanocellulose and hydroxyapatite nanorods and stirred at 60℃ for 2 hours to obtain mixture 2. S3: Mixture 2 is transferred to an autoclave for hydrothermal reaction at a temperature of 180°C for 12 hours, and the precipitate is collected. S4: The precipitate obtained in step S3 is calcined once at 300℃ for 60 min; then calcined again at 600℃ for 1 h to obtain the final product.

[0042] The preparation method of chitosan-CTAB is as follows: (1) Chitosan was dissolved in 1.0 wt% acetic acid solution, ultrasonically dispersed for 30 min, and the pH was adjusted to 5 with ammonia water to obtain a 2.0 wt% chitosan solution; (2) Hexadecyltrimethylammonium bromide (CTAB), isopropanol and water were stirred at 55°C for 30 min in a mass-volume ratio of 1 g: 5 mL: 20 mL to obtain a CTAB solution; (3) Slowly add 2.0 wt% chitosan solution to CTAB solution at a mass ratio of 1:1 and mix well to obtain the final product.

[0043] Example 2 A nano-rare earth oxide, comprising the following raw materials by mass parts: 2 parts rare earth ions, 0.8 parts chitosan-CTAB, 1.1 parts tea saponin, 1.98 parts nanocellulose and 0.016 parts hydroxyapatite nanorods; Rare earth ions: composed of cerium acetylacetone (Ce(acac)3), yttrium nitrate (Y(NO3)3), samarium nitrate (Sm(NO3)3) and terbium nitrate (Tb(NO3)3) in a molar ratio of 8:1.2:0.4:0.2.

[0044] The preparation method is as follows: S1: Cerium acetylacetone (Ce(acac)3), yttrium nitrate (Y(NO3)3), samarium nitrate (Sm(NO3)3) and terbium nitrate (Tb(NO3)3) were mixed with an aqueous solution of 25 wt% ethanol. The total mass of the rare earth salts and the mass-volume ratio of the aqueous solution of ethanol were 1 g: 18 mL. Then chitosan-CTAB was added to obtain mixture 1. S2: Mixture 1 is mixed with tea saponin, nanocellulose and hydroxyapatite nanorods and stirred at 50℃ for 2.5h to obtain mixture 2; S3: Mixture 2 is transferred to an autoclave for hydrothermal reaction at a temperature of 190°C for 10 hours, and the precipitate is collected. S4: The precipitate obtained in step S3 is calcined once at 320℃ for 40 min; then calcined again at 580℃ for 1.5 h to obtain the final product.

[0045] The preparation method of chitosan-CTAB is as follows: (1) Chitosan was dissolved in 0.5 wt% acetic acid solution, ultrasonically dispersed for 20 min, and the pH was adjusted to 4.8 with ammonia water to obtain a 2.5 wt% chitosan solution; (2) Hexadecyltrimethylammonium bromide (CTAB), isopropanol and water were stirred at 55°C for 30 min in a mass-volume ratio of 1 g: 4 mL: 18 mL to obtain a CTAB solution; (3) Slowly add 2.0 wt% chitosan solution to CTAB solution at a mass ratio of 1:1 and mix well to obtain the final product.

[0046] Example 3 The nano-rare earth oxide comprises the following raw materials by mass parts: 5 parts rare earth ions, 1.1 parts chitosan-CTAB, 1.1 parts tea saponin, 2.2 parts nanocellulose and 0.05 parts hydroxyapatite nanorods; Rare earth ions: composed of cerium acetylacetone (Ce(acac)3), yttrium nitrate (Y(NO3)3), samarium nitrate (Sm(NO3)3) and terbium nitrate (Tb(NO3)3) in a molar ratio of 10:0.8:0.6:0.4.

[0047] The preparation method is as follows: S1: Cerium acetylacetone (Ce(acac)3), yttrium nitrate (Y(NO3)3), samarium nitrate (Sm(NO3)3) and terbium nitrate (Tb(NO3)3) were mixed with an aqueous solution of 30wt% ethanol. The total mass of the rare earth salts and the mass-volume ratio of the aqueous ethanol solution were 1g:20mL. Then chitosan-CTAB was added to obtain mixture 1. S2: Mixture 1 is mixed with tea saponin, nanocellulose and hydroxyapatite nanorods and stirred at 55℃ for 1.5h to obtain mixture 2; S3: Mixture 2 is transferred to an autoclave for hydrothermal reaction at a temperature of 170°C for 12 hours, and the precipitate is collected. S4: The precipitate obtained in step S3 is calcined once at 280℃ for 60 min; then calcined again at 620℃ for 1 h to obtain the final product.

[0048] The preparation method of chitosan-CTAB is as follows: (1) Chitosan was dissolved in 1.5 wt% acetic acid solution, ultrasonically dispersed for 30 min, and the pH was adjusted to 5.2 with ammonia water to obtain a 1.5 wt% chitosan solution; (2) Hexadecyltrimethylammonium bromide (CTAB), isopropanol and water were stirred at 55°C for 30 min in a mass-volume ratio of 1 g: 6 mL: 19 mL to obtain a CTAB solution; (3) Slowly add 2.0 wt% chitosan solution to CTAB solution at a mass ratio of 1:1 and mix well to obtain the final product.

[0049] Comparative Example 1 A nano-rare earth oxide, compared to Example 1, only differs in the amount of raw materials used: 6 parts rare earth ions, 0.5 parts chitosan-CTAB, 0.3 parts tea saponin, 0.135 parts nanocellulose and 0.1 parts hydroxyapatite nanorods; Rare earth ions: composed of cerium acetylacetone (Ce(acac)3), yttrium nitrate (Y(NO3)3), samarium nitrate (Sm(NO3)3) and terbium nitrate (Tb(NO3)3) in a molar ratio of 1:1:1:1.

[0050] The rest is the same as in Example 1.

[0051] Comparative Example 2 A nano-rare earth oxide, compared to Example 1, replaces chitosan-CTAB with CTAB.

[0052] Raw materials, by mass parts, include: 3 parts rare earth ions, 1 part CTAB, 1 part tea saponin, 2 parts nanocellulose and 0.035 parts hydroxyapatite nanorods; Rare earth ions: composed of cerium acetylacetone (Ce(acac)3), yttrium nitrate (Y(NO3)3), samarium nitrate (Sm(NO3)3) and terbium nitrate (Tb(NO3)3) in a molar ratio of 9:1:0.5:0.3.

[0053] The preparation method is as follows: S1: Cerium acetylacetone (Ce(acac)3), yttrium nitrate (Y(NO3)3), samarium nitrate (Sm(NO3)3) and terbium nitrate (Tb(NO3)3) were mixed with an aqueous solution of 28 wt% ethanol. The total mass of the rare earth salts and the mass-volume ratio of the aqueous ethanol solution were 1 g: 15 mL. Then CTAB was added to obtain mixture 1. S2: Mixture 1 is mixed with tea saponin, nanocellulose and hydroxyapatite nanorods and stirred at 60℃ for 2 hours to obtain mixture 2. S3: Mixture 2 is transferred to an autoclave for hydrothermal reaction at a temperature of 180°C for 12 hours, and the precipitate is collected. S4: The precipitate obtained in step S3 is calcined once at 300℃ for 60 min; then calcined again at 600℃ for 1 h to obtain the final product.

[0054] Comparative Example 3 A nano-rare earth oxide, compared to Example 1, replaces tea saponin with rhamnolipin.

[0055] By weight, it includes the following raw materials: 3 parts rare earth ions, 1 part chitosan-CTAB, 1 part rhamnolipid, 2 parts nanocellulose and 0.035 parts hydroxyapatite nanorods; Rare earth ions: composed of cerium acetylacetone (Ce(acac)3), yttrium nitrate (Y(NO3)3), samarium nitrate (Sm(NO3)3) and terbium nitrate (Tb(NO3)3) in a molar ratio of 9:1:0.5:0.3.

[0056] The preparation method is as follows: S1: Cerium acetylacetone (Ce(acac)3), yttrium nitrate (Y(NO3)3), samarium nitrate (Sm(NO3)3) and terbium nitrate (Tb(NO3)3) were mixed with an aqueous solution of 28 wt% ethanol. The total mass of the rare earth salts and the mass-volume ratio of the aqueous ethanol solution were 1 g: 15 mL. Then chitosan-CTAB was added to obtain mixture 1. S2: Mixture 1 is mixed with rhamnolipin, nanocellulose and hydroxyapatite nanorods and stirred at 60℃ for 2 hours to obtain mixture 2. S3: Mixture 2 is transferred to an autoclave for hydrothermal reaction at a temperature of 180°C for 12 hours, and the precipitate is collected. S4: The precipitate obtained in step S3 is calcined once at 300℃ for 60 min; then calcined again at 600℃ for 1 h to obtain the final product.

[0057] The rest is the same as in Example 1.

[0058] Comparative Example 4 A nano-rare earth oxide, compared with Example 1, replaces hydroxyapatite nanorods with zinc oxide nanowires.

[0059] By weight, it includes the following raw materials: 3 parts rare earth ions, 1 part chitosan-CTAB, 1 part tea saponin, 2 parts nanocellulose and 0.035 parts zinc oxide nanowires; Rare earth ions: composed of cerium acetylacetone (Ce(acac)3), yttrium nitrate (Y(NO3)3), samarium nitrate (Sm(NO3)3) and terbium nitrate (Tb(NO3)3) in a molar ratio of 9:1:0.5:0.3.

[0060] The preparation method is as follows: S1: Cerium acetylacetone (Ce(acac)3), yttrium nitrate (Y(NO3)3), samarium nitrate (Sm(NO3)3) and terbium nitrate (Tb(NO3)3) were mixed with an aqueous solution of 28 wt% ethanol. The total mass of the rare earth salts and the mass-volume ratio of the aqueous ethanol solution were 1 g: 15 mL. Then chitosan-CTAB was added to obtain mixture 1. S2: Mixture 1 is mixed with tea saponin, nanocellulose and zinc oxide nanowires and stirred at 60℃ for 2 hours to obtain mixture 2; S3: Mixture 2 is transferred to an autoclave for hydrothermal reaction at a temperature of 180°C for 12 hours, and the precipitate is collected. S4: The precipitate obtained in step S3 is calcined once at 300℃ for 60 min; then calcined again at 600℃ for 1 h to obtain the final product.

[0061] The rest is the same as in Example 1.

[0062] Test Example 1 The average particle size of the nano-rare earth oxides prepared in Examples 1-3 and Comparative Examples 1-4 is shown in Table 1 below.

[0063] Table 1. Average Particle Size

[0064] As shown in Table 1, compared with the comparative example, the nano-rare earth oxides prepared in the embodiments of the present invention have smaller average particle size and higher uniformity.

[0065] Test Example 2 The specific surface areas of the nano-rare earth oxides prepared in Examples 1-3 and Comparative Examples 1-4 are shown in Table 2 below.

[0066] Table 2. Specific surface area

[0067] As shown in Table 2, compared with the comparative example, the nano-rare earth oxides prepared in the embodiments of the present invention have a larger specific surface area.

[0068] Test Example 3 Stability test: The nano-rare earth oxides prepared in Examples 1-3 and Comparative Examples 1-4 were placed at room temperature and pressure for 6 months, and their average particle size was measured again. The results are shown in Table 3 below: Table 3. Average particle size after 6 months

[0069] As shown in Table 3, the stability of the nano-rare earth oxides prepared in the embodiments of the present invention is significantly improved compared with the comparative examples.

[0070] Test Example 4 Antibacterial properties test: The antibacterial properties of the rare earth nanoparticles prepared in Examples 1-3 and Comparative Examples 1-4 were tested. The rare earth nanoparticles were diluted with 15 times their volume of water, and the inhibitory effect of different rare earth nanoparticles on Escherichia coli (purchased from Ningbo Taisto Biotechnology Co., Ltd., product number TS337391) was detected. The specific testing method is as follows: I. Preparatory Work 1) Bacterial strains and culture media Escherichia coli: Inoculated on LB liquid medium (purchased from Beijing Solarbio Science & Technology Co., Ltd.)

[0071] 2) Control group setup Negative control: Sterile water replaced nano-rare earth oxides.

[0072] II. Detection of antibacterial activity using the plate count method (1) Escherichia coli inhibition experiment: Take 100 μL of Escherichia coli solution (concentration ≈ 10) 6 Mix (CFU / mL) with 900 μL of nano-rare earth oxide dilution solution and incubate at 37°C for 24 h. Then, serially dilute the mixture (10 CFU / mL) with other solutions. -1 -10 -3 Spread the mixture onto LB agar plates and incubate at 37°C for 24 hours. Count the colonies.

[0073] (2) Formula for calculating antibacterial rate: Inhibition rate (%) = [(Number of colonies in negative control group - Number of colonies in experimental group) / Number of colonies in negative control group] × 100.

[0074] The results are shown in Table 4.

[0075] Table 4. Antibacterial activity

[0076] As shown in Table 4, compared with the comparative example, the antibacterial properties of the nano-rare earth oxides prepared in the embodiments of the present invention are significantly improved.

[0077] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A nano-rare earth oxide, characterized in that, The raw materials include, by mass parts: 2-5 parts rare earth ions, 0.8-1.1 parts chitosan-hexadecyltrimethylammonium bromide, 0.8-1.1 parts tea saponin, 1.8-2.2 parts nanocellulose, and 0.01-0.05 parts hydroxyapatite nanorods; wherein the rare earth ions are cerium ions (Ce) in a molar ratio of (8-10):(0.8-1.2):(0.4-0.6):(0.2-0.4). 3+ Yttrium ions 3+ Samarium ions (Sm) 3+ and terbium ions Tb 3+ composition; The preparation method of the chitosan-hexadecyltrimethylammonium bromide includes the following steps: (1) Chitosan is dissolved in 0.5-1.5 wt% acetic acid solution to obtain 1.5-2.5 wt% chitosan solution; (2) Hexadecyltrimethylammonium bromide, isopropanol and water are mixed at a mass-volume ratio of 1g:(4-6)mL:(18-20)mL at 50-60℃ to obtain a hexadecyltrimethylammonium bromide solution; (3) The chitosan solution of 1.5-2.5 wt% is mixed with a hexadecyltrimethylammonium bromide solution to obtain the product; The preparation method of the nano-rare earth oxide includes the following steps: S1: Contains cerium ions (Ce) 3+ Yttrium ions 3+ Samarium ions (Sm) 3+ and terbium ions Tb 3+ The rare earth salts were mixed with the solvent, and then chitosan-hexadecyltrimethylammonium bromide was added to obtain mixture 1; S2: Mixture 1 is mixed with tea saponin, nanocellulose and hydroxyapatite nanorods to obtain mixture 2; S3: Mixture 2 is transferred to an autoclave for hydrothermal reaction, and the precipitate is collected; S4: The precipitate obtained in step S3 is calcined once, and then calcined a second time after heating to obtain the final product; the temperature of the first calcination is 280-320℃ and the time is 40min-60min; the temperature of the second calcination is 580-620℃ and the time is 1-1.5h.

2. The nano-rare earth oxide according to claim 1, characterized in that, The cerium ion Ce 3+ Yttrium ions 3+ Samarium ions (Sm) 3+ and terbium ions Tb 3+ The molar ratio is (8-9):(0.9-1.0):(0.4-0.5):(0.2-0.3).

3. The nano-rare earth oxide according to claim 1, characterized in that, In step (1), the pH of the chitosan solution is 4.8-5.

2.

4. The nano-rare earth oxide according to claim 1, characterized in that, In step (3), the mass ratio of the 1.5-2.5 wt% chitosan solution to the hexadecyltrimethylammonium bromide solution is 1:(0.9-1.1).

5. The nano-rare earth oxide according to claim 1, characterized in that, The mass ratio of tea saponin to nanocellulose is 1:(1.8-2.2).

6. The nano-rare earth oxide according to claim 1, characterized in that, The mass of the hydroxyapatite nanorods is 0.3-0.6% of the total mass of the nano-rare earth oxide raw materials.

7. The nano-rare earth oxide according to claim 1, characterized in that, The aspect ratio of the hydroxyapatite nanorods is 10-20.

8. The nano-rare earth oxide according to claim 1, characterized in that, By weight, it includes the following raw materials: 2-4 parts rare earth ions, 0.9-1.1 parts chitosan-hexadecyltrimethylammonium bromide, 0.9-1.1 parts tea saponin, 1.9-2.2 parts nanocellulose and 0.016-0.045 parts hydroxyapatite nanorods.

9. The method for preparing the nano-rare earth oxide according to any one of claims 1-8, characterized in that, Includes the following steps: S1: Contains cerium ions (Ce) 3+ Yttrium ions 3+ Samarium ions (Sm) 3+ and terbium ions Tb 3+ The rare earth salts were mixed with the solvent, and then chitosan-hexadecyltrimethylammonium bromide was added to obtain mixture 1; S2: Mixture 1 is mixed with tea saponin, nanocellulose and hydroxyapatite nanorods to obtain mixture 2; S3: Mixture 2 is transferred to an autoclave for hydrothermal reaction, and the precipitate is collected; S4: The precipitate obtained in step S3 is calcined once, then calcined a second time after heating, to obtain the final product.

10. The preparation method according to claim 9, characterized in that, In step S1, the rare earth salts are cerium acetylacetonate (III), yttrium nitrate, samarium nitrate, and terbium nitrate.

11. The preparation method according to claim 9, characterized in that, In step S1, the solvent is an aqueous solution of ethanol.

12. The preparation method according to claim 9, characterized in that, In step S1, the total mass of the rare earth salt to the volume ratio of the solvent is 1g:15-20mL.

13. The preparation method according to claim 9, characterized in that, In step S2, the mixing is performed by stirring at a temperature of 50-60℃ for 1.5-2.5 hours.

14. The preparation method according to claim 9, characterized in that, In step S3, the hydrothermal reaction is carried out at a temperature of 170-190℃ for 10-12 hours.

15. The preparation method according to claim 9, characterized in that, In step S4, the temperature of the first calcination is 280-320℃ and the time is 40-60 min; the temperature of the second calcination is 580-620℃ and the time is 1-1.5 h.

16. The preparation method according to claim 15, characterized in that, In step S4, the temperature of the first calcination is 300℃ and the time is 60 min; the temperature of the second calcination is 600℃ and the time is 1 h.

17. The use of the nano-rare earth oxides according to any one of claims 1-8 in the preparation of antibacterial products.

Images