CN-122006658-A - Kaolinite-based double-layer structural material and preparation method thereof

Abstract

The invention relates to a kaolinite-based double-layer structure material and a preparation method thereof, belonging to the technical field of new materials. Aims at solving the technical problems of no adsorption performance and low use added value of the traditional kaolinite on anionic pollutants. According to the invention, the kaolinite is used as a growth template, and hydrotalcite nano-sheets are grown on the surface of the template in situ by a hydrothermal method, so that a double-layer composite structure material is formed. The preparation process includes the steps of precursor solution preparation, kaolinite dispersion, hydrothermal reaction, washing, drying and the like. The material has the laminar characteristics of the kaolinite and hydrotalcite, can simultaneously adsorb anionic and cationic pollutants such as methyl orange and methylene blue, can be loaded with an anionic and cationic corrosion inhibitor such as NO 2 ‑ 、Ce 3+ , has adsorption capacities of 78-86 mg/g and 63-72 mg/g respectively, remarkably improves the functional diversity and additional value of the kaolinite, and expands the application potential of the kaolinite in the water purification and corrosion inhibition fields.

Inventors

• ZHENG JIAXIN
• JING CHUAN
• TAO SHENGRONG
• DONG YIRAN
• Tang changyu
• LU CHENXI
• Fu Menglin

Assignees

• 重庆邮电大学

Dates

Publication Date

20260512

Application Date

20260210

Claims (8)

1. 1. The preparation method of the kaolinite-based double-layer structural material is characterized by comprising the following steps of: S1, preparing an LDH precursor aqueous solution, weighing Mg (NO 3 ) 2 ·6H 2 O、Al(NO 3 ) 2 ·9H 2 O and urea are dissolved in deionized water, and fully and uniformly stirring to obtain the LDH precursor aqueous solution; s2, adding the kaolinite into the LDH precursor aqueous solution, and continuously stirring and dispersing uniformly until the kaolinite has no obvious agglomeration; s3, reacting in a reaction vessel, namely transferring the mixed solution obtained in the step S2 into a hydrothermal reaction kettle for reacting; and S4, after the reaction is finished, centrifugally washing the reaction product by using deionized water and ethanol to obtain a solid product, and drying in an oven to obtain the kaolinite-based double-layer structural material.
2. 2. The method according to claim 1, wherein in the step S1, the molar concentration ratio of Mg (NO 3 ) 2 ·6H 2 O、Al(NO 3 ) 2 ·9H 2 O, urea) is 2:1:10.
3. 3. The method of claim 1, wherein in step S1, the volume ratio of Mg (NO 3 ) 2 ·6H 2 O、Al(NO 3 ) 2 ·9H 2 O and urea) to deionized water is (40-80) mM 35: 35 mL.
4. 4. The method of claim 1, wherein in step S2, the dosage ratio of the kaolinite to the LDH precursor aqueous solution is (20-60) mg/35 mL.
5. 5. The preparation method of the water-based thermal reactor according to claim 1, wherein in the step S3, the reaction temperature of the water-based thermal reactor is 80-140 ℃ and the time is 4-16 hours, and in the step S4, the drying temperature is 40-80 ℃ and the time is 10-24 hours.
6. 6. A kaolinite-based bilayer structured material prepared according to the preparation method of any one of claims 1 to 5.
7. 7. The use of the material with a double-layer structure based on kaolinite according to claim 6 for preparing water purifying agent.
8. 8. The use of a material of a kaolinite-based bilayer structure according to claim 6 for the preparation of a corrosion inhibitor.

Description

Kaolinite-based double-layer structural material and preparation method thereof Technical Field The invention belongs to the technical field of new materials, and relates to a kaolinite-based double-layer structure material and a preparation method thereof. Background Kaolinite is a naturally occurring layered clay mineral whose basic structure consists of 2 layers of Si-OH tetrahedra and 1 layer of Al-OH octahedra. Portions of Al 3+ and Mg 2+ replace the Si-OH tetrahedra and Al-OH octahedra, respectively, resulting in a laminate anion charge excess. To balance the charge, exchangeable cations are introduced between the kaolinite layers (K +、Na+、Ca2+, etc.). Based on the exchangeable property of interlayer ions, the kaolinite has the advantage of being exchangeable of interlayer ions, has good adsorption effect on cationic pollutants such as methyl orange and congo red, and is increasingly widely applied in the field of pollutant adsorption. Meanwhile, the characteristic that the kaolinite can be loaded with cations can be used as a corrosion inhibitor carrier, and the long-acting corrosion inhibition and self-repairing performance of the metal organic coating are improved through the slow release effect of the corrosion inhibitor, so that the research on the application direction is still deficient at the present stage. The kaolinite has excellent physical and chemical properties by virtue of the unique crystal structure, so that the kaolinite has extremely broad application prospect. However, compared with the foreign research level and technical development degree, the research in the field of the kaolinite in China still has obvious gap and has larger promotion space. The kaolinite as natural mineral material has inherent microstructure and physical and chemical properties, and the material can only adsorb cationic pollutant and load cationic corrosion inhibitor due to the electronegativity of the laminate, so that the application range of the kaolinite is greatly limited. Currently, along with the sustainable development of the economy and society, the development of high-value-added and high-grade mineral resource utilization technology has become a mainstream trend in the industry, and how to increase the additional value of kaolinite mineral resources has become a key subject to be overcome by vast scientific researchers. In recent years, a technical route for preparing a composite material by taking a mineral material as a template and further improving specific physicochemical properties of the mineral material has become common knowledge of a person skilled in the art. Based on the technical thought, the development of the preparation technology of the kaolinite-based composite material is a key way for effectively solving the problem of application limitation of the kaolinite. Among the many potential, available materials for compounding, hydrotalcite (MgAl LDH) has been of great interest because of its also layered structure. The main layer of hydrotalcite is composed of Mg-OH octahedron, and Al 3+ partially replaces Mg 2+ ions in Mg-OH octahedron, so that positive charges of the main layer are excessive, and anions (CO 32-、SO42-, etc.) are introduced between layers to balance the excessive charges. Interlayer ions of hydrotalcite can be exchanged, and the hydrotalcite has better application potential in adsorption or corrosion inhibitor loading. The interlayer ions of hydrotalcite have interchangeability as well, and have good application potential in the fields of pollutant adsorption and corrosion inhibitor loading. However, how to realize efficient combination of the kaolinite and the hydrotalcite, fully exert the structural and performance advantages of the two materials to generate a synergistic effect, further improve the pollutant adsorption efficiency and the corrosion inhibitor loading capacity of the materials, and finally improve the added value of the kaolinite mineral resources, and become a technical problem to be solved in the field. Disclosure of Invention In view of the above, the conventional kaolinite material has no adsorption performance on anionic pollutants and has low added value. The invention aims to provide a composite material, so that the kaolinite has the functions of adsorbing anionic pollutants or loading anionic corrosion inhibitors, the application range of the kaolinite can be expanded, and the added value of the kaolinite is improved. In order to achieve the above purpose, the present invention provides the following technical solutions: the invention provides a preparation method of a kaolinite-based double-layer structure material, which comprises the following steps: S1, preparing an LDH precursor aqueous solution, weighing Mg (NO 3)2·6H2O、Al(NO3)2·9H2 O and urea are dissolved in deionized water, and fully and uniformly stirring to obtain the LDH precursor aqueous solution; s2, adding the kaolinite into the LDH precursor aqueous solution, and continuously