Industrial process production method for surface modification of nano calcium carbonate

Abstract

The invention discloses a method for modifying the surface of nano calcium carbonate with metal ions or metal oxides, and aims to remarkably improve the dispersity, stability and functionality of nano calcium carbonate. According to the method, efficient modification of the surface of the nano calcium carbonate is realized through industrial equipment by adopting ultrasonic dispersion, metal ion modification and metal oxide generation technologies. Firstly, nano calcium carbonate powder is uniformly dispersed in a solution through an ultrasonic disperser, then modification reaction is carried out in a metal ion solution, and the reaction temperature and the pH value are strictly controlled to ensure the uniformity of a modification layer. According to requirements, a hydrothermal method or a solvothermal method can be adopted in the modification process, and the modification effect and stability are further improved. And finally, cleaning the sample through industrial centrifugation and filtration equipment, and drying the sample by using a vacuum freeze drying technology to ensure the purity and performance of the final product. The method has high process stability, economical efficiency and expandability, is suitable for large-scale industrial production, and can be widely applied to the fields of catalysis, environmental governance, medicine and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for surface modification of nano calcium carbonate, in particular an industrial process for modifying the surface of nano calcium carbonate by metal ions or metal oxides. The technology of the present application is widely used in catalysts, fillers, environmental protection, medicine and other fields, and has important application value in large-scale production and enhancing the surface properties, dispersibility and stability of nano calcium carbonate. BACKGROUND

[0002] Nano calcium carbonate is a common inorganic nanomaterial, which has a wide application prospect in various industries due to its low cost, non-toxicity, abundant source and good biocompatibility. Especially in the fields of material science, drug delivery, environmental protection, catalysis, filler and other fields, nano calcium carbonate has been fully researched and applied. Due to its high specific surface area and unique physical and chemical properties, nano calcium carbonate shows excellent performance in many aspects. However, although it has application potential in many fields, the actual use of nano calcium carbonate faces many challenges, especially its poor dispersibility, serious agglomeration and insufficient surface functionality, which directly affects the effect of nano calcium carbonate in practical application. The agglomeration of nano calcium carbonate is a major problem in liquid systems. In aqueous solution or organic solvent, nano calcium carbonate particles are easy to aggregate due to their large surface energy and electrostatic force, which greatly reduces their effective specific surface area and affects their performance. For example, in catalytic reactions, if nano calcium carbonate agglomerates, its catalytic efficiency and reaction selectivity will be greatly reduced. In drug delivery systems, the agglomeration of nano calcium carbonate may lead to a decrease in the release efficiency of drug carriers. Therefore, how to improve the dispersibility and stability of nano calcium carbonate has become the key to improving its application effect. In addition to the problem of poor dispersibility, the surface functionality of nano calcium carbonate is also a limitation in some applications. The surface of unmodified nano calcium carbonate is relatively flat and lacks sufficient active groups, which limits its interaction with other molecules, ions or materials. Especially in high-end applications such as catalysis and drug delivery, the surface functionality of nano calcium carbonate is often insufficient to meet the actual needs. In order to endow nano calcium carbonate with more functions and improve its surface activity, researchers have tried various surface modification techniques.

[0003] Currently, there are mainly two methods for surface modification of nano calcium carbonate: physical modification and chemical modification. Physical modification methods mainly change the surface properties through physical means such as surface coating, coating, etc. However, these methods can only improve the dispersibility of nano calcium carbonate, and it is difficult to greatly adjust its surface functionality. Chemical modification methods introduce specific functional groups or materials on the surface of nano calcium carbonate through chemical reactions. This method can improve the surface properties of nano calcium carbonate to some extent and endow it with new functions. Common chemical modification methods include polymer grafting, fatty acid root modification, and polydopamine coating. Although these methods have achieved some success in improving the dispersibility, stability, and hydrophilicity of nano calcium carbonate, they also have certain limitations. For example, the polydopamine coating method may have uneven coating and unstable modification layer; the fatty acid root modification method can enhance the hydrophobicity of nano calcium carbonate, but its stability in aqueous solution is poor; the polymer grafting method has strong modification effect, but the process is complex and the cost is high.

[0004] Therefore, finding a surface modification method that can significantly improve the performance of nano calcium carbonate while having high stability and economic efficiency is one of the current research focuses. In recent years, metal ion and metal oxide surface modification methods have gradually attracted attention and become an effective solution. The advantages of metal ion modification and metal oxide modification are that they can endow nano calcium carbonate with more functions such as catalysis, antibiosis, and magnetism. Compared with traditional polymer or fatty acid root modification methods, metal ion and metal oxide modification has significant advantages. Metal ions (such as zinc, calcium, magnesium, etc.) and metal oxides (such as titanium dioxide, aluminum oxide, zinc oxide, etc.) exhibit excellent performance in catalysis, antibiosis, optics, and magnetism. Metal ion or metal oxide modification not only significantly improves the performance of nano calcium carbonate, but also has strong controllability. By adjusting the type, concentration, and reaction conditions of metal ions, the thickness, composition, and distribution of the modification layer can be precisely controlled, thereby endowing nano calcium carbonate with the desired specific functions. This method is simple, low-cost, and can optimize the surface properties without changing the original structure of nano calcium carbonate. Therefore, the method of modifying nano calcium carbonate with metal ions or metal oxides not only overcomes the shortcomings of traditional modification methods, but also endows nano calcium carbonate with more functions. This provides more possibilities for its application in catalysis, environmental protection, and medicine.

[0005] Meanwhile, with the continuous development of these modification techniques, the industrial production of nano calcium carbonate has gradually become a key issue that needs to be addressed. The existing preparation methods of nano calcium carbonate are mostly focused on laboratory scale, lacking large-scale and efficient production modes. Industrial production not only needs to ensure the stability of the modification process, but also needs to achieve efficient resource utilization, low energy consumption and low cost in the production process. The industrial production of metal ion and metal oxide modified nano calcium carbonate can greatly improve the production efficiency and stability by improving the reaction equipment, optimizing the reaction conditions, and using environmentally friendly solvents, thereby reducing the production cost. At the same time, the industrial scale production will enable the application of this nano material in the fields of catalysis, environmental remediation, drug delivery, etc. to be more extensive and in-depth. Therefore, the development of nano calcium carbonate modification technology with industrial potential has become an important issue to promote the development of related industries. SUMMARY

[0006] The present application provides an industrialized and streamlined production method for surface modification of nano calcium carbonate, aiming to significantly improve the performance of nano calcium carbonate through surface modification, overcome its poor dispersibility and poor stability in practical applications, and realize industrialization, streamlining and large-scale production. Nano calcium carbonate has a wide range of applications in catalysis, drug carriers, environmental remediation, fillers and other fields due to its unique physical and chemical properties. However, due to its high surface energy and hydrophilicity, nano calcium carbonate is prone to agglomeration in liquid phase, resulting in a significant decrease in its functionality and affecting its effectiveness in practical applications. Therefore, the present application introduces a metal ion or metal oxide modification layer on the surface of nano calcium carbonate to significantly improve its dispersibility and stability in solution.

[0007] Specifically, the present application uses metal ions (such as zinc, calcium, aluminum, etc.) or metal oxides (such as titanium dioxide, zinc oxide, etc.) as modifiers, and uniformly modifies them on the surface of nano calcium carbonate through chemical reaction. By precisely controlling the type, concentration and reaction conditions of metal ions or metal oxides, the functional properties of the surface of nano calcium carbonate can be adjusted, such as catalytic activity, antibacterial property, hydrophilicity or hydrophobicity, etc. This modification method not only improves the dispersibility of nano calcium carbonate, but also endows it with more functions, such as improving catalytic efficiency, improving drug carrier performance, enhancing antibacterial effect, etc., thereby expanding its application range in various fields. The nano calcium carbonate material prepared by this method has higher stability and better functional properties, which can meet the application requirements of higher requirements.

[0008] The following are the detailed experimental method steps of the present application:

[0009] Step one: preparation of nano calcium carbonate

[0010] Take 1 to 10 kg of high-purity nano-calcium carbonate powder and add it to 200 to 1000 liters of deionized water, then disperse it ultrasonically. The treated solution will be separated using a large industrial centrifuge at a speed of 12,000 to 18,000 rpm for 30 minutes to remove undispersed particles and impurities. During dispersion, the concentration of the nano-calcium carbonate solution must be maintained within the range of 2% to 5% to ensure solution stability and effective dispersion.

[0011] Step 2: Preparation of Metal Ion Solution

[0012] Select an appropriate metal salt (such as zinc chloride, magnesium chloride, aluminum chloride, titanium chloride, etc.) and dissolve it in a suitable solvent at a specific concentration (0.01M to 0.5M) to obtain a metal ion solution. This dissolution process uses a large industrial stirred reactor with a capacity of 500 to 2000 liters. The stirring rate is adjustable, reaching up to 300 to 500 rpm, and the temperature is controlled at 40°C to 60°C to ensure complete dissolution of the metal salt and the formation of a homogeneous metal ion solution. To improve dissolution efficiency, a heated stirrer can be used to raise the temperature to 60°C to 80°C, ensuring rapid dissolution of the metal salt and monitoring the solution concentration within the designed range.

[0013] Step 3: Modification reaction of metal ions with nano-calcium carbonate

[0014] The nano-calcium carbonate solution obtained in step one is added to the metal ion solution prepared in step two, ensuring full contact and reaction between the two. Mixing is performed using an industrial stirring device at a speed between 500 and 1500 rpm to ensure thorough mixing of the nano-calcium carbonate and metal ion solution. The reaction temperature is set between 30°C and 60°C, and the reaction time is 2 to 8 hours. To further enhance the modification effect of the metal ions, a solvothermal method can be used. This method, under controlled temperature and pressure, can promote efficient deposition of metal ions and enhance the adhesion of the modified layer. The solvothermal reaction is carried out in a heated reactor, heating the metal ion solution and the nano-calcium carbonate solution to 160°C to 200°C for a reaction time of 6 to 12 hours. This method can be carried out using a high-temperature and high-pressure reactor. The solvothermal method can promote more uniform modification of the nano-calcium carbonate surface with metal ions under high temperature and high pressure, thereby forming a more stable and uniform metal oxide modified layer.

[0015] Step 4: Formation and modification of metal oxides (optional)

[0016] To obtain a metal oxide modified layer, the metal ion-modified nano-calcium carbonate sample obtained in step three can be heated to promote the oxidation of metal ions into metal oxides. A large industrial furnace is used to heat the reactants to 300°C to 600°C and hold for 2 to 6 hours to ensure a uniform coating of metal oxides on the nano-calcium carbonate surface. A precise temperature control system is used to ensure the furnace temperature remains stable within the target range and that temperature fluctuations are kept within ±2°C. The furnace capacity can be adjusted according to production scale, typically between 500 liters and 2000 liters, to ensure the processing needs of large batches of samples.

[0017] Step 5: Post-treatment and cleaning

[0018] After the reaction is complete, the nano-calcium carbonate samples modified with metal ions or metal oxides are removed and washed. After each wash, the washing liquid and impurities are removed using a large centrifuge. Subsequently, a large filtration system is used to further remove residual metal salts and impurities, ensuring thorough removal of residues. After washing, the samples are placed in a large vacuum freeze dryer for drying.

[0019] The metal salt in step two can be an inorganic metal salt, such as zinc chloride, magnesium chloride, aluminum chloride, titanium chloride, copper chloride, calcium chloride, potassium chloride, ferric chloride, sodium chloride, calcium nitrate, magnesium nitrate, aluminum nitrate, ferric nitrate, copper nitrate, potassium nitrate, zinc nitrate, calcium phosphate, magnesium phosphate, aluminum phosphate, calcium sulfate, sodium sulfate, magnesium sulfate, copper sulfate, calcium carbonate, magnesium carbonate, sodium carbonate, copper carbonate, etc. Organometallic complexes such as zinc acetate, magnesium acetate, aluminum acetate, calcium acetate, copper acetate, zinc citrate, calcium citrate, magnesium citrate, aluminum citrate, zinc gluconate, calcium gluconate, magnesium gluconate, calcium lactate, magnesium lactate, zinc lactate, calcium acetate, zinc acetate, magnesium acetate, calcium oxalate, zinc oxalate, magnesium oxalate, calcium tannate, zinc tannate, and amino acid metal salts (such as zinc glycinate, zinc alanine, etc.). Solvents can be polar solvents, such as water, ethanol, isopropanol, acetone, chloroform, methanol, dimethyl thionamide (DMSO), acetonitrile, dichloromethane (DCM), ethylene glycol, ethylene glycol monomethyl ether, diethyl ether, N,N-dimethylformamide (DMF), N-methylpyrrolidone (NMP), and tetrahydrofuran (THF). In addition, non-polar solvents such as petroleum ether, cyclohexane, heptane, n-hexane, toluene, xylene, ethylbenzene, and solvent mixtures (such as mixtures of water and ethanol, or ethanol and acetone) are also acceptable. Other solvents include chlorinated solvents such as chloroform and carbon tetrachloride; the specific solvent selection should be adjusted according to the desired metal ion and modification effect.

[0020] The metal oxide modification layer in step four can be titanium dioxide, zinc oxide, aluminum oxide, calcium oxide, iron oxide, copper oxide, magnesium oxide, cobalt oxide, manganese oxide, tantalum oxide, chromium oxide, titanium oxide-aluminum composite oxide, zinc oxide-aluminum composite oxide, etc. These oxides are widely used in catalysis, antibacterial, photocatalysis, gas sensing, and other fields.

[0021] The specific advantages of an industrialized, process-oriented production method for surface-modified nano-calcium carbonate are as follows:

[0022] 1. High Dispersion and Reaction Efficiency: Utilizing industrial-grade ultrasonic dispersers (5-10 kW) and large centrifuges (12,000 to 18,000 rpm), large-scale solutions (200 to 1000 liters) can be processed, efficiently breaking up nano-calcium carbonate agglomerates, ensuring uniform dispersion, and improving reaction efficiency. Simultaneously, the use of efficient stirring equipment ensures thorough mixing of nano-calcium carbonate with the metal ion solution, reducing reaction time (2 to 8 hours) and significantly improving production efficiency.

[0023] 2. Precise reaction control: The temperature control system and automated pH adjustment system ensure precise control of the reaction temperature (30℃ to 60℃) and pH value (6 to 8), guaranteeing uniform modification of metal ions on the surface of nano-calcium carbonate. These control measures ensure the consistency of each batch of products and avoid the impact of temperature fluctuations and pH changes on product quality.

[0024] 3. Flexible application of multiple modification methods: Two modification methods are provided: hydrothermal and solvothermal. The solvothermal method promotes efficient deposition of metal ions under high temperature and pressure, enhancing the adhesion of the modified layer, and is suitable for high-end applications. The hydrothermal method is suitable for low-temperature reactions and has strong adaptability.

[0025] 4. Enhancing Material Functionality: Heating to 300℃ to 600℃ in an industrial furnace allows metal oxides to uniformly coat the surface of nano-calcium carbonate, endowing it with catalytic, antibacterial, and photocatalytic properties. This method significantly enhances the application potential of nano-calcium carbonate in environmental protection, medicine, and other fields.

[0026] 5. Optimized resource utilization and reduced costs: The efficient cleaning and drying process is carried out through large centrifuges and vacuum freeze dryers, reducing time and resource waste and lowering production costs. Vacuum drying ensures low energy consumption and does not damage the material structure. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. An embodiment of this invention provides a novel method for surface modification of nano-calcium carbonate, comprising the following steps:

[0028] 1. Preparation of Nano-Calcium Carbonate: In this step, first take 1 to 10 kg of high-purity nano-calcium carbonate powder and add it to 200 to 1000 liters of deionized water. Because nano-calcium carbonate powder has low solubility and small particle size, it is prone to agglomeration. Therefore, appropriate dispersion methods are needed to ensure its uniform distribution. To achieve efficient dispersion, an industrial ultrasonic disperser is used. The ultrasonic power range should be set between 5 kW and 10 kW to ensure that the ultrasound waves can effectively penetrate the entire solution and disperse the nano-calcium carbonate. The ultrasonic time is set between 30 and 60 minutes, and the specific processing time can be adjusted according to the solution volume and concentration. The ultrasonic temperature should be controlled between 30°C and 40°C to avoid overheating affecting the material properties. During this process, the temperature control system will monitor the temperature in real time to ensure uniform ultrasonic action and avoid localized overheating. The treated solution needs to be separated using a large industrial centrifuge. Select a centrifuge speed of 12,000 rpm to 18,000 rpm and a centrifugation time of 30 minutes to remove incompletely dispersed particles and impurities. To ensure the stability of the dispersion, the solution concentration should be maintained between 2% and 5%. This concentration range helps to ensure the stability of the solution and avoids particle agglomeration caused by excessive concentration.

[0029] 2. Preparation of Metal Ion Solution: In this step, a suitable metal salt (such as zinc chloride, magnesium chloride, aluminum chloride, titanium chloride, etc.) is selected and dissolved in a suitable solvent at a certain concentration (0.01M to 0.5M) to prepare a metal ion solution. The dissolution process requires a large industrial stirred reactor with a capacity between 500 and 2000 liters. The stirring speed is set to 300 to 500 rpm to ensure complete dissolution of the metal salt and thorough mixing with the solvent. Under the reactor's temperature control system, the temperature must be maintained between 40°C and 60°C to ensure complete dissolution of the metal salt. If higher dissolution efficiency is required, a heated stirrer can be used to control the temperature within the range of 60°C to 80°C to accelerate the dissolution process. During this process, the concentration of the solution needs to be monitored in real time to ensure that the metal ion solution is within the ideal concentration range.

[0030] 3. Modification reaction of metal ions with nano-calcium carbonate: In this step, the nano-calcium carbonate solution obtained in step one is added to the metal ion solution prepared in step two, ensuring sufficient contact and reaction between the two. To ensure good mixing of the nano-calcium carbonate and metal ion solution, an industrial stirring device is used. The stirring speed is set between 500 and 1500 rpm to ensure sufficient reaction. A high-shear stirring head should be used, which can provide uniform mixing and sufficient shear force to ensure uniform contact between the metal ions and nano-calcium carbonate during the reaction. The reaction temperature should be set between 30°C and 60°C, and the reaction time should be controlled between 2 and 8 hours. The specific reaction time can be adjusted appropriately according to the type of metal ions and the concentration of the solution. During the reaction, the temperature is monitored in real time using a temperature control system to ensure that it fluctuates within the set range, and the pH value of the solution is maintained between 6 and 8 by an automated pH adjustment system. If necessary, the pH of the solution can be adjusted by an online pH monitoring device to ensure optimal reaction results. In this process, a solvothermal method can also be used to further enhance the modification effect of metal ions. The solvothermal method promotes metal ion deposition under high temperature and pressure, enhancing the adhesion of the modified layer. The solvothermal method uses a high-temperature, high-pressure reactor to heat the metal ion solution and nano-calcium carbonate solution to 160°C to 200°C for 6 to 12 hours. The solvothermal reaction, under high temperature and pressure conditions, promotes more uniform deposition of metal ions onto the surface of nano-calcium carbonate, forming a more stable and uniform metal oxide modified layer.

[0031] 4. Formation and Modification of Metal Oxides (Optional): If a metal oxide modified layer is desired, the metal ion-modified nano-calcium carbonate sample obtained in step three can be heated to promote the oxidation of metal ions into metal oxides. The reactants are heated to 300°C to 600°C using a large industrial furnace and held at that temperature for 2 to 6 hours to ensure a uniform coating of metal oxides on the surface of the nano-calcium carbonate. During this process, a temperature control system is used to ensure precise temperature control within the furnace, with fluctuations maintained within ±2°C. The furnace capacity can be adjusted according to production scale requirements, typically from 500 liters to 2000 liters, to meet the requirements of large-scale production.

[0032] 5. Post-processing and cleaning: After the reaction is complete, the nano-calcium carbonate samples modified with metal ions or metal oxides are removed and cleaned. First, the samples are washed 3 to 5 times with deionized water. After each wash, the washing liquid and impurities are removed using a large centrifuge. The centrifugation speed is set at 12,000 rpm to 18,000 rpm for 30 minutes to ensure thorough removal of metal salts and other impurities from the solution. Subsequently, a large filtration system is used to further remove residual metal salts and impurities, using a filter membrane with a pore size of 0.45 μm to 1 μm to ensure sample purity. After cleaning, the samples are placed in a large vacuum freeze dryer for drying. The freeze-drying temperature is -40℃ to -20℃ under vacuum conditions, and the vacuum pressure is controlled at 0.01 to 0.1 MPa, until the samples are completely dry.

[0033] The metal salt in step two can be an inorganic metal salt, such as zinc chloride, magnesium chloride, aluminum chloride, titanium chloride, copper chloride, calcium chloride, potassium chloride, ferric chloride, sodium chloride, calcium nitrate, magnesium nitrate, aluminum nitrate, ferric nitrate, copper nitrate, potassium nitrate, zinc nitrate, calcium phosphate, magnesium phosphate, aluminum phosphate, calcium sulfate, sodium sulfate, magnesium sulfate, copper sulfate, calcium carbonate, magnesium carbonate, sodium carbonate, copper carbonate, etc. Organometallic complexes such as zinc acetate, magnesium acetate, aluminum acetate, calcium acetate, copper acetate, zinc citrate, calcium citrate, magnesium citrate, aluminum citrate, zinc gluconate, calcium gluconate, magnesium gluconate, calcium lactate, magnesium lactate, zinc lactate, calcium acetate, zinc acetate, magnesium acetate, calcium oxalate, zinc oxalate, magnesium oxalate, calcium tannate, zinc tannate, and amino acid metal salts (such as zinc glycinate, zinc alanine, etc.). Solvents can be polar solvents, such as water, ethanol, isopropanol, acetone, chloroform, methanol, dimethyl thionamide (DMSO), acetonitrile, dichloromethane (DCM), ethylene glycol, ethylene glycol monomethyl ether, diethyl ether, N,N-dimethylformamide (DMF), N-methylpyrrolidone (NMP), and tetrahydrofuran (THF). In addition, non-polar solvents such as petroleum ether, cyclohexane, heptane, n-hexane, toluene, xylene, ethylbenzene, and solvent mixtures (such as mixtures of water and ethanol, or ethanol and acetone) are also acceptable. Other solvents include chlorinated solvents such as chloroform and carbon tetrachloride; the specific solvent selection should be adjusted according to the desired metal ion and modification effect.

[0034] The metal oxide modification layer in step four can be titanium dioxide, zinc oxide, aluminum oxide, calcium oxide, iron oxide, copper oxide, magnesium oxide, cobalt oxide, manganese oxide, tantalum oxide, chromium oxide, titanium oxide aluminum composite oxide, zinc oxide aluminum composite oxide, etc.

[0035] The present invention will be further described below with reference to specific embodiments.

[0036] Example 1

[0037] In this example, metal oxide-modified nano-calcium carbonate material was applied to the photocatalytic degradation of organic pollutants in water treatment. 10 grams of high-purity nano-calcium carbonate powder was added to 500 ml of deionized water and dispersed using an industrial ultrasonic disperser (8 kW) for 45 minutes to ensure uniform dispersion. The treated solution was then centrifuged (15,000 rpm, 30 minutes) to remove undispersed particles, maintaining a concentration of 3% to 5%. Next, 2 grams of titanium chloride were dissolved in 200 ml of deionized water and stirred for 1 hour to obtain a metal ion solution. The nano-calcium carbonate solution from step one was then added to the metal ion solution, and an industrial stirring device was used at a stirring rate of 1000 rpm, a reaction temperature of 50°C, and a reaction time of 6 hours. To further enhance the modification effect, a solvothermal method was employed, heating both materials to 160°C to 200°C and reacting for 6 to 12 hours. After heating, the sample was heated to 500°C and held for 2 hours to promote the oxidation of titanium chloride to titanium dioxide, forming a metal oxide-modified layer. After the reaction, the sample was washed 3 to 5 times with deionized water, and impurities were removed by centrifugation (15,000 rpm, 30 minutes). Residues were then removed using a 0.45 μm filtration system. Finally, the sample was dried in a vacuum freeze dryer at -40°C to -20°C and a vacuum pressure controlled at 0.01 to 0.1 MPa until completely dry. The prepared metal oxide-modified nano-calcium carbonate material was applied to the photocatalytic degradation of organic pollutants in water treatment. Under ultraviolet light irradiation, the titanium dioxide-modified nano-calcium carbonate significantly degraded organic pollutants in water, achieving a degradation efficiency of over 90%, demonstrating excellent photocatalytic performance and broad application prospects.

[0038] Example 2

[0039] In this example, metal ion-modified nano-calcium carbonate material was applied to a drug delivery system to improve drug dispersibility and release efficiency. 15 grams of high-purity nano-calcium carbonate powder was added to 500 ml of deionized water and ultrasonically dispersed for 45 minutes using an industrial ultrasonic disperser (8 kW) to ensure uniform dispersion. The treated solution was then centrifuged (15,000 rpm, 30 minutes) to remove undispersed particles, maintaining a concentration of 3% to 5%. Next, 2 grams of calcium chloride were dissolved in 200 ml of deionized water and stirred for 1 hour to obtain a metal ion solution. The nano-calcium carbonate solution from step one was added to the metal ion solution, and an industrial stirring device was used at a stirring rate of 1000 rpm, a reaction temperature of 50°C, and a reaction time of 6 hours. To further enhance the modification effect, a solvothermal method was employed, heating both materials to 160°C to 200°C and reacting for 6 to 12 hours. After heating, the sample was heated to 500°C and held for 2 hours to promote the oxidation of calcium chloride to calcium oxide, forming a metal oxide modification layer. After the reaction, the sample was washed 3 to 5 times with deionized water, and impurities were removed by centrifugation (15,000 rpm, 30 minutes). Residues were then removed using a 0.45 μm filtration system. Finally, the sample was dried in a vacuum freeze dryer at -40°C to -20°C and a vacuum pressure controlled at 0.01 to 0.1 MPa until completely dry. The prepared metal oxide-modified nano-calcium carbonate material was applied to a drug delivery system as a drug delivery carrier. The calcium oxide-modified nano-calcium carbonate exhibits good biocompatibility and drug carrying capacity. Experiments show that this material can effectively improve drug dispersibility, promote stable drug release, and the release rate can be adjusted as needed to achieve a longer duration of efficacy. This material has broad application potential in the pharmaceutical and drug delivery fields, especially suitable for targeted drug delivery and slow-release drug systems.

[0040] Example 3

[0041] In this example, metal oxide-modified nano-calcium carbonate material is applied to an air purification system, particularly for removing harmful gases from the air. 20 grams of high-purity nano-calcium carbonate powder was added to 500 ml of deionized water and ultrasonically dispersed for 45 minutes using an industrial ultrasonic disperser (8 kW) to ensure uniform dispersion. The treated solution was then centrifuged (15,000 rpm, 30 minutes) to remove undispersed particles, maintaining a concentration of 3% to 5%. Next, 2 grams of barium chloride were dissolved in 200 ml of deionized water and stirred for 1 hour to obtain a metal ion solution. The nano-calcium carbonate solution from step one was added to the metal ion solution, and an industrial stirring device was used at a stirring rate of 1000 rpm, a reaction temperature of 50°C, and a reaction time of 6 hours. To further enhance the modification effect, a solvothermal method was employed, heating both materials to 160°C to 200°C and reacting for 6 to 12 hours. After heating, the sample was heated to 500°C and held for 2 hours to promote the oxidation of barium chloride to barium oxide, forming a metal oxide-modified layer. After the reaction, the sample was washed 3 to 5 times with deionized water, impurities were removed by centrifugation (15,000 rpm, 30 minutes), and residues were removed using a 0.45 μm filtration system. Finally, the sample was dried in a vacuum freeze dryer at -40°C to -20°C and a vacuum pressure controlled at 0.01 to 0.1 MPa until completely dry. The prepared metal oxide-modified nano-calcium carbonate material was applied to air purification systems, particularly for removing harmful gases (such as ammonia and volatile organic compounds) from the air. Barium oxide-modified nano-calcium carbonate exhibits excellent adsorption capacity, effectively adsorbing and degrading harmful substances in the air. Experiments show that this material can significantly reduce the concentration of ammonia and volatile organic compounds in the air within a short time, with a purification efficiency exceeding 85%. This material has broad application potential in environmental protection, especially in industrial waste gas treatment and indoor air purification.

[0042] Example 4

[0043] In this example, metal oxide-modified nano-calcium carbonate material is applied to food packaging to enhance the antibacterial properties of the packaging material and extend the shelf life of the food. 15 grams of high-purity nano-calcium carbonate powder was added to 500 ml of deionized water and ultrasonically dispersed for 45 minutes using an industrial ultrasonic disperser at 8 kW to ensure uniform dispersion of the nano-calcium carbonate. The treated solution was then centrifuged (15,000 rpm, 30 minutes) to remove undispersed particles, maintaining a concentration of 3% to 5%. Next, 2 grams of silver chloride were dissolved in 200 ml of deionized water and stirred for 1 hour to obtain a metal ion solution. The nano-calcium carbonate solution from step one was added to the metal ion solution, and an industrial stirring device was used at a stirring rate of 1000 rpm, a reaction temperature of 50°C, and a reaction time of 6 hours. To further enhance the modification effect, a solvothermal method was employed, heating both materials to 160°C to 200°C and reacting for 6 to 12 hours. After heating, the sample was heated to 500℃ and held at that temperature for 2 hours to promote the oxidation of silver chloride to silver oxide, forming a metal oxide modified layer. After the reaction, the sample was washed 3 to 5 times with deionized water, and impurities were removed by centrifugation (15,000 rpm, 30 minutes). Residues were then removed using a 0.45 μm pore size filtration system. Finally, the sample was placed in a vacuum freeze dryer for drying at a temperature of -40℃ to -20℃ and a vacuum pressure controlled at 0.01 to 0.1 MPa until completely dry. The prepared metal oxide-modified nano-calcium carbonate material was applied in food packaging, particularly for manufacturing packaging materials with antibacterial properties. The silver oxide-modified nano-calcium carbonate effectively inhibited the growth of bacteria and fungi, extending the shelf life of food. Experiments showed that this material significantly reduced bacterial growth inside the packaging and delayed food spoilage, making it particularly suitable for perishable foods such as fruits, vegetables, and meats. Its antibacterial effect lasted for approximately 14 days in experiments, demonstrating excellent performance. This material has broad application prospects in the food packaging industry, especially in maintaining food freshness and extending shelf life.

[0044] Example 5

[0045] In this example, metal oxide-modified nano-calcium carbonate material is applied in oral care products, particularly as a synergistic ingredient in toothpaste to enhance its cleaning, antibacterial, and anti-inflammatory functions. First, 10 grams of high-purity nano-calcium carbonate powder was added to 500 ml of deionized water and ultrasonically dispersed for 45 minutes using an industrial ultrasonic disperser at 8 kW to ensure uniform dispersion. The treated solution was then centrifuged (15,000 rpm, 30 minutes) to remove undispersed particles, maintaining a concentration of 3% to 5%. Next, 2 grams of silver chloride were dissolved in 200 ml of deionized water and stirred for 1 hour to obtain a metal ion solution. The nano-calcium carbonate solution from step one was added to the metal ion solution, and an industrial stirring device was used at 1000 rpm, a reaction temperature of 50°C, and a reaction time of 6 hours. To further enhance the modification effect, a solvothermal method was employed, heating both materials to 160°C to 200°C and reacting for 6 to 12 hours. After heating, the sample was heated to 500℃ and held for 2 hours to promote the oxidation of silver chloride to silver oxide, forming a metal oxide modified layer. Following the reaction, the sample was washed 3 to 5 times with deionized water, centrifuged (15,000 rpm, 30 minutes) to remove impurities, and then filtered using a 0.45 μm pore size filter system to remove residues. Finally, the sample was placed in a vacuum freeze dryer at a temperature of -40℃ to -20℃ and a vacuum pressure controlled at 0.01 to 0.1 MPa until completely dry. The prepared metal oxide-modified nano-calcium carbonate material was applied to toothpaste as a synergistic ingredient, providing additional antibacterial, anti-inflammatory, and stain-removing functions. Silver oxide-modified nano-calcium carbonate effectively inhibits the growth of bacteria, fungi, and other microorganisms in the oral cavity, thereby reducing the occurrence of oral problems such as gingivitis and oral ulcers. Furthermore, titanium dioxide-modified nano-calcium carbonate can also help remove stains from the tooth surface and restore the natural luster of teeth. Experiments have shown that this material, when used in oral care products, can significantly reduce the number of oral bacteria, effectively reduce bad breath, and improve oral health. This material has broad application prospects in the field of oral care, especially in products such as toothpaste and mouthwash, where it can provide long-term antibacterial protection and oral cleaning effects.

[0046] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for the industrial and flow production of nanometric calcium carbonate surface-modified, characterized by, The industrialized flow production method of the surface modified nano calcium carbonate includes the following steps: Step one: Preparation of nano calcium carbonate: Take 1 to 10 kilograms of high purity nano calcium carbonate powder and add it to 200 to 1000 liters of deionized water after ultrasonic dispersion. The treated solution will be separated by a large industrial centrifuge, with a centrifugal speed setting of 12,000 rpm to 18,000 rpm and a centrifugal time of 30 minutes to remove undispersed particles and impurities. During the dispersion process, the concentration of the nano calcium carbonate solution should be maintained at 2% to 5% to ensure the stability and effective dispersion of the solution. Step two: Preparation of metal ion solution: Select appropriate metal salts (such as zinc chloride, magnesium chloride, aluminum chloride, titanium chloride, etc.) and dissolve them in a suitable solvent at a certain concentration (0.01M to 0.5M) to obtain a metal ion solution. This dissolution process uses a large industrial stirring reactor with a capacity of 500 to 2000 liters, adjustable stirring rate up to 300 to 500 rpm, and temperature control at 40°C to 60°C to ensure complete dissolution of the metal salt and formation of a uniform metal ion solution. To improve the dissolution efficiency, a heating stirrer can be used to increase the temperature to 60°C to 80°C, ensuring rapid dissolution of the metal salt and monitoring the solution concentration to remain within the designed range. Step three: Modification reaction of metal ions and nano calcium carbonate: Add the nano calcium carbonate solution obtained in step one to the metal ion solution prepared in step two to ensure sufficient contact and reaction. Use an industrial stirring device for mixing, with a stirring rate set between 500 to 1500 rpm to ensure sufficient mixing of nano calcium carbonate and metal ion solution. The reaction temperature is set between 30°C to 60°C, and the reaction time is 2 to 8 hours. To further enhance the modification effect of metal ions, a solvothermal method can also be used, which can promote the efficient deposition of metal ions under temperature and pressure control, enhancing the adhesion of the modification layer. Solvothermal reaction is carried out in a heated reactor, heating the metal ion solution and nano calcium carbonate solution to 160°C to 200°C, and the reaction time is 6 to 12 hours. This method can be carried out by using a high temperature and high pressure reactor, which can promote the more uniform modification of metal ions to the surface of nano calcium carbonate, forming a more stable and uniform metal oxide modification layer. Step four: Generation and modification of metal oxide (optional): If a metal oxide modification layer is desired, the metal ion modified nano calcium carbonate sample obtained in step three can be heated to promote the oxidation of metal ions to metal oxides. Use a large industrial furnace to heat the reactants to 300°C to 600°C, with a holding time of 2 to 6 hours to ensure uniform coverage of the metal oxide on the surface of the nano calcium carbonate. Use a precise temperature control system to ensure that the temperature in the furnace is stable within the target range, with a temperature fluctuation of ±2°C. The capacity of the heating furnace can be adjusted according to the production scale, usually between 500 liters to 2000 liters, to meet the processing needs of large quantities of samples. Step five: post-treatment and cleaning: after the reaction is completed, the metal ion or metal oxide modified nano calcium carbonate sample is taken out, washed, and after each washing, the washing liquid and impurities are removed by a large centrifuge. Subsequently, a large filtration system is used to further remove residual metal salts and impurities. Ensure that the residues are completely removed. After the cleaning is completed, the sample is placed in a large vacuum freeze dryer for drying.

2. The metal salt in step two can be an inorganic metal salt, such as zinc chloride, magnesium chloride, aluminum chloride, titanium chloride, copper chloride, calcium chloride, potassium chloride, iron chloride, sodium chloride, calcium nitrate, magnesium nitrate, aluminum nitrate, iron nitrate, copper nitrate, potassium nitrate, zinc nitrate, calcium phosphate, magnesium phosphate, aluminum phosphate, calcium sulfate, sodium sulfate, magnesium sulfate, copper sulfate, calcium carbonate, magnesium carbonate, sodium carbonate, copper carbonate, etc. Organic metal complexes such as zinc acetate, magnesium acetate, aluminum acetate, calcium acetate, copper acetate, zinc citrate, calcium citrate, magnesium citrate, aluminum citrate, zinc gluconate, calcium gluconate, magnesium gluconate, calcium lactate, magnesium lactate, zinc lactate, calcium acetate, zinc acetate, magnesium acetate, calcium oxalate, zinc oxalate, magnesium oxalate, calcium tannate, zinc tannate, and amino acid metal salts (such as zinc glycinate, zinc alaninate, etc.). The solvent can be a polar solvent, such as water, ethanol, isopropanol, acetone, chloroform, methanol, dimethyl sulfoxide (DMSO), acetonitrile, dichloromethane (DCM), ethylene glycol, ethylene glycol monomethyl ether, diethyl ether, N,N-dimethylformamide (DMF), N-methyl pyrrolidone (NMP), tetrahydrofuran (THF). In addition, non-polar solvents such as petroleum ether, cyclohexane, heptane, n-hexane, toluene, xylene, ethylbenzene, and solvent mixtures (such as a mixed solvent of water and ethanol, a mixed solvent of ethanol and acetone) are also optional. Other solvents include chlorinated solvents such as chloroform, carbon tetrachloride, etc., and the choice of specific solvent should be adjusted according to the desired metal ion and modification effect.

3. The metal oxide modification layer in step four can be titanium dioxide, zinc oxide, aluminum oxide, calcium oxide, iron oxide, copper oxide, magnesium oxide, cobalt oxide, manganese oxide, tantalum oxide, chromium oxide, titanium aluminum composite oxide, zinc aluminum composite oxide, etc.

4. The method of claim 1, wherein, The metal oxide modification layer is formed by heating in an industrial furnace, with a temperature setting of 300°C to 600°C and a holding time of 2 to 6 hours.