Multilayer nano-activated material, its preparation method and application in sterilization and odor removal
By designing multi-layered nano-activated materials, the problems of single function, poor stability and inaccurate response in existing technologies have been solved, realizing multi-functional synergistic purification of formaldehyde catalytic degradation, intelligent sterilization and odor decomposition, and improving the stability and purification efficiency of the materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGZHOU JINHAOLONG ENVIRONMENTAL PROTECTION TECHNOLOGY CO LTD
- Filing Date
- 2026-02-11
- Publication Date
- 2026-05-29
Smart Images
Figure CN122098703A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of air purification materials technology, specifically relating to a multilayer nano-activated material, its preparation method, and its application in sterilization and deodorization. Background Technology
[0002] With the continuous improvement of public awareness of health and environmental safety, the market demand for multifunctional materials that combine high-efficiency purification, long-lasting effects, and environmental compatibility is becoming increasingly urgent. In various fields such as indoor air purification, personal care, functional textiles, and building coatings, formaldehyde pollution, microbial growth, and complex odors composed of multiple components such as volatile organic compounds, sulfides, and ammonia are the three long-standing core pollution problems.
[0003] Traditional solutions often rely on single-function materials for pollution control, which has significant limitations and is difficult to overcome: physical adsorption materials can only temporarily accumulate pollutants, are prone to adsorption saturation, require frequent replacement, and cannot completely decompose pollutants; some oxidizing bactericides have bactericidal effects, but generally suffer from poor storage stability, uncontrollable release of activity, and may even produce chemical residues that cause secondary pollution; for complex odors, simple masking or physical adsorption methods can only alleviate the sensory experience and cannot decompose odor molecules at the source, thus only treating the symptoms and not the root cause.
[0004] In recent years, the development of nanocatalysis technology has provided a new technological path for the deep purification of pollutants. Among them, manganese dioxide-based nanomaterials have attracted widespread attention in the field of volatile organic compound (VOC) treatment due to their ability to catalytically oxidize formaldehyde into carbon dioxide and water at room temperature. Meanwhile, chlorine dioxide slow-release systems with sodium chlorite as a precursor have been widely used in the field of disinfection due to their broad-spectrum and highly efficient bactericidal properties. However, existing technologies are still in the stage of single-function optimization and have not yet achieved efficient integration of multiple functions such as catalytic degradation, efficient sterilization, and odor decomposition. In particular, they face three core technical challenges in practical applications, which have not been effectively solved to date: (1) Oxidizing functional components, such as sodium chlorite, are easily affected by environmental factors such as temperature and humidity during long-term storage, and there is a risk of premature reaction, activity decay or failure; (2) The spatial arrangement of multiple functional components lacks orderly design, making it difficult to achieve "coordination of each function without interference", which easily leads to performance degradation caused by interaction between components and cannot give full play to the synergistic effect of multiple functions; (3) There is a lack of precise response mechanism to environmental stimuli, such as humidity and pollutant concentration, making it difficult to regulate the generation rate and release of active species according to the actual pollution scenario, resulting in a difficulty in balancing purification efficiency and safety of use. Summary of the Invention
[0005] To overcome the shortcomings of the prior art, this invention provides a multilayer nano-activated material and its preparation method. This material integrates multiple functions such as formaldehyde catalytic degradation, intelligent sterilization, and odor decomposition, achieving an organic unity of stable storage, intelligent triggering, and efficient synergistic purification. The technical solution to achieve the purpose of this invention is as follows: A multilayer nano-activating material includes, from bottom to top, a structural reinforcement layer, a catalytic oxidation layer, an isolation layer, and an acid source layer; the structural reinforcement layer includes cystamine-modified chondroitin sulfate and nanocellulose; the catalytic oxidation layer includes mesoporous silica loaded with sodium chlorite and metal-phenolic nanoparticles@metal-doped hollow mesoporous manganese dioxide; the isolation layer includes pullulan polysaccharide and hydrophobic nanosilica; and the acid source layer includes citric acid microcapsules and sodium alginate.
[0006] The mass ratio of cystamine-modified chondroitin sulfate to nanocellulose in the structural reinforcement layer is (1~3):1; the mass ratio of sodium chlorite-loaded mesoporous silica to metal-phenolic nanoparticles@metal-doped hollow mesoporous manganese dioxide in the catalytic oxidation layer is (0.5~2):1; the mass ratio of pullulan to hydrophobic nanosilica in the isolation layer is (5~10):1; and the mass ratio of citric acid microcapsules to sodium alginate in the acid source layer is (0.5~2):1.
[0007] The preparation method of the cystamine-modified chondroitin sulfate includes the following steps: The carboxyl group of chondroitin sulfate was activated to form chondroitin sulfate succinimide active ester, which was then mixed and reacted with cystamine. After the reaction was completed, the chondroitin sulfate was purified and freeze-dried to obtain cystamine-modified chondroitin sulfate.
[0008] The method for activating the carboxyl group of chondroitin sulfate to form chondroitin sulfate succinimide active ester is to react sodium chondroitin sulfate, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and N-hydroxysuccinimide in a molar ratio of 1:(2~3):(2~3).
[0009] The method for preparing the mesoporous silica supported on sodium chlorite includes the following steps: Hexadecyltrimethylammonium bromide was mixed with tetraethyl orthosilicate and reacted. After the reaction was completed, the precipitate was collected by centrifugation, washed, dried, and then calcined to obtain mesoporous silica. The dried mesoporous silica was dispersed in a saturated sodium chlorite aqueous solution to obtain a wet loaded product. After freeze-drying, mesoporous silica powder loaded with sodium chlorite was obtained.
[0010] The preparation method of the metal-phenolic nanoparticles@metal-doped hollow mesoporous manganese dioxide includes the following steps: Nano-silica was dispersed in water to form a uniform suspension. In a separate beaker, potassium permanganate, soluble metal hydrate, glucose, and hexadecyltrimethylammonium bromide were added sequentially to deionized water. The two solutions were mixed and heated to 50-70°C for reaction. After the reaction, the mixture was purified to obtain metal-doped silica@manganese dioxide core-shell nanospheres. The silica was then etched with sodium carbonate and purified to obtain metal-doped mesoporous manganese dioxide. The metal-doped mesoporous manganese dioxide was mixed with epigallocatechin gallate, and ferric chloride solution was added dropwise while stirring. After the reaction, the product was collected by centrifugation, purified, and dried to obtain metal-phenolic nanoparticles@metal-doped mesoporous manganese dioxide.
[0011] The molar ratio of potassium permanganate, soluble metal hydrate, glucose, and hexadecyltrimethylammonium bromide is 1:(0.2~0.3):(0.45~0.6):(0.05~0.1); the soluble metal hydrate is selected from one or more of ferric chloride, cobalt chloride, and nickel chloride hydrates.
[0012] A method for preparing a multilayer nano-activated material, characterized by comprising the following steps: (I) Separate preparation of functional layer precursor solutions (1) Catalytic oxidation layer dispersion: Mesoporous silica loaded with sodium chlorite and metal-phenolic nanoparticles@metal-doped hollow mesoporous manganese dioxide were dispersed in an aqueous solution of sodium alginate and ultrasonically dispersed to obtain dispersion A. (2) Acid source layer dispersion: Citric acid microcapsules were dispersed in an aqueous solution of sodium alginate to obtain dispersion B; (3) Isolation layer solution: Pullulan polysaccharide and hydrophobic nano-silica were co-dispersed in deionized water and sonicated to obtain suspension C; (4) Structural reinforcement layer solution: Cystamine-modified chondroitin sulfate and nanocellulose were co-dispersed in an aqueous acetic acid solution to obtain solution D; (II) Sequential casting and stabilization of multilayer aerogels (1) Forming of structural reinforcement layer: Pour solution D into polytetrafluoroethylene mold; place the mold on a pre-cooled copper plate, immerse the other end of the copper plate in liquid nitrogen for unidirectional freezing; after complete freezing, transfer to cryogenics; (2) Casting of catalytic oxidation layer: Transfer the mold to a low temperature operating table at 0°C. When the bottom surface shows a mirror-like reflection, indicating that it has been slightly melted and formed a thin water film, pour the dispersion A onto it; let it stand at 0°C, and then quickly transfer it back to deep freeze-thaw. (3) Construction of the isolation layer: On a 0℃ cryogenic stage, the isolation layer suspension C is uniformly poured onto the frozen intermediate layer surface; immediately move it back to cryogenic treatment; (4) Acid source layer casting: At 0°C, the acid source layer dispersion B is cast onto the frozen isolation layer; the entire mold is quickly moved back to cryogenic storage. (5) Freeze-drying: The four frozen layers were subjected to cryogenic freeze-drying to obtain primary aerogel; (6) Crosslinking and post-treatment: i. Liquid-phase crosslinking and neutralization: The primary aerogel is immersed in a buffer solution containing genipin for crosslinking; ii. Washing and drying: After crosslinking is completed, remove the aerogel, wash it several times with deionized water to remove residual crosslinking agent and salt, and then dry it; iii. Post-treatment: Transfer the dried aerogel to a vacuum oven for further treatment to thoroughly remove residual moisture; (7) Cutting and storage: Cut the aerogel and vacuum seal the product for storage.
[0013] The precooling temperature is -10 to -30°C; the cryogenic temperature is -70 to -90°C; the genipin concentration of the genipin buffer solution is 0.1% to 1%, and the pH is 7.5 to 8.5; the liquid phase crosslinking temperature is 25 to 35°C, and the time is 12 to 24 hours; the post-treatment conditions are 50 to 70°C and -0.05 to -0.1 MPa.
[0014] Another objective of this invention is to protect the application of the aforementioned multilayer nano-activated materials in air purifiers, personal care products, textile fibers, building coatings, and wall materials, specifically in the fields of air purifiers, air conditioner mesh, and ion deodorizers.
[0015] Beneficial effects
[0016] This invention provides a multilayer nano-activated material and its preparation method, integrating multiple functions such as formaldehyde catalytic degradation, intelligent sterilization, and odor decomposition. Furthermore, the specific multilayer sequential casting and stabilization structure of this invention is a necessary condition for achieving functional isolation, on-demand triggering, and intelligent response systems, rather than a simple superposition of the functions of each component. This highlights the inventiveness of the invention and includes the following beneficial effects: 1. Constructing an intelligent response system of "functional isolation - on-demand triggering": Through precise multi-layered structural design, including a structural reinforcement layer, a catalytic oxidation layer, an isolation layer, and an acid source layer, sensitive oxidizing components, acid sources, and catalysts are spatially and physically isolated. This design ensures good stability of the material under dry storage conditions, effectively preventing premature reactions between components. Only when the material comes into contact with moisture or liquid water in the usage environment does the moisture penetrate to the acid source layer, causing the wall material of the citric acid microcapsules to swell and rupture, thereby releasing citric acid. The released acid molecules penetrate the isolation layer, triggering the in-situ generation of highly active chlorine dioxide by the middle-layer oxidant, while simultaneously activating adjacent catalytic sites. This solves the technical pain point of long-term storage inactivation of oxidizing components, achieving "on-demand activation" of sterilization and catalytic functions.
[0017] 2. Achieving Deep Mineralization of Pollutants and Synergistic Decomposition of Odors: The purification function of the material is not limited to simple adsorption or killing, but achieves a deep purification effect. On the one hand, the in-situ generated chlorine dioxide can efficiently kill bacteria, viruses and other microorganisms; on the other hand, chlorine dioxide itself, together with the activated manganese-based catalytic center and the metal-phenolic nanoparticle modification layer, can efficiently oxidize and decompose formaldehyde and various odor molecules, ultimately mineralizing them into harmless carbon dioxide and water. This achieves root-cause decomposition of odors rather than sensory masking, completely eliminating the risk of secondary pollution.
[0018] 3. Achieving multifunctional synergy and performance enhancement: The modification effect of the metal-phenolic network not only significantly improves the dispersibility and stability of the manganese dioxide nanostructure, but its own redox catalytic activity can also form a synergistic effect with manganese dioxide and chlorine dioxide, further accelerating the oxidative decomposition kinetics of pollutants; while the loading design of sodium chlorite on mesoporous silica enables the controlled slow release of chlorine dioxide, effectively extending the purification time of the material.
[0019] 4. High flexibility in material form and application scenarios: The final material is a lightweight, high-porosity aerogel, which is easy to cut and process, and can be flexibly compounded with a variety of substrates, providing convenience for applications in multiple fields: it can be added to washing and care products as a functional filler to give it long-lasting antibacterial and freshening effects; it can be finished into textile fibers to prepare self-cleaning and odor-resistant functional textiles; it can also be incorporated into building coatings or wall materials to give indoor walls continuous air purification and odor decomposition capabilities. Attached Figure Description
[0020] Figure 1 Infrared spectra of chondroitin sulfate, cystamine, and cystamine-modified chondroitin sulfate. Detailed Implementation
[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0022] Unless otherwise specified, the experimental methods used in the embodiments are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.
[0023] The raw materials and equipment used in the embodiments and comparative examples are described below: Sodium alginate: viscosity 300 mPa.s, purchased from Qingdao Mingyue Algae Group Co., Ltd.
[0024] Gelatin: 160 Bloom, purchased from Shanghai Haohong Biomedical Technology Co., Ltd.
[0025] Pullulan: viscosity 15~180 mPa.s, purchased from Shanghai Haohong Biomedical Technology Co., Ltd.
[0026] Silica: 7~40 nm, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.
[0027] Hydrophobic nano-silica: 30~50 nm, purchased from Hangzhou Jikang New Materials Co., Ltd.
[0028] Cystamine-modified chondroitin sulfate: self-made, preparation method as follows: 1.0 eq of chondroitin sulfate sodium was dissolved in MES buffer at pH 5.5 to prepare a 1% solution. 2.5 eq of N-hydroxysuccinimide was dissolved in MES buffer for later use. 1.2 eq of cystamine was dissolved in MES buffer at pH 7.0 after nitrogen bubbling for deoxygenation, and prepared fresh for use. Under nitrogen protection and stirring in an ice bath, 2.5 eq of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide solution were slowly added to the chondroitin sulfate sodium solution. The reaction was carried out at 0–4 °C for 20 min, then moved to room temperature and continued for 15 min to activate the carboxyl group of chondroitin sulfate to the active chondroitin sulfate succinimide ester. Subsequently, pre-cooled cystamine solution was added dropwise to the above activation system, and the pH was adjusted to 7.0–7.5 with sodium hydroxide. The mixture was stirred for 6 h under nitrogen protection and at room temperature in the dark. After the reaction was completed, a 50% concentration of [unspecified ingredient] was added. Unreacted active esters were quenched with ethanolamine solution at pH 7.5 (mmol / L). The reaction solution was transferred to a dialysis bag with a molecular weight cutoff of 3.5 kDa and dialyzed twice at 4°C with 0.1 mol / L sodium chloride solution for 2 h each time, followed by dialyzed with 5 mmol / L sodium bicarbonate solution for 2 h each time, and finally dialyzed three times with ultrapure water for 2 h each time. After dialysis, cystamine-modified chondroitin sulfate was obtained by freeze drying.
[0029] Mesoporous silica supported on sodium chlorite: prepared in-house, the preparation method is as follows: 0.5 g of hexadecyltrimethylammonium bromide was dissolved in 240 mL of deionized water, and 1.75 mL of 2.0 mol / L sodium hydroxide solution was added with stirring. The mixture was heated to 80 °C in a water bath and kept at a constant temperature. 2.5 mL of tetraethyl orthosilicate was rapidly added with vigorous stirring, and the reaction was continued at a constant speed of 80 °C for 2 h. After the reaction was completed, the mixture was allowed to cool naturally to room temperature, and the white precipitate was collected by centrifugation. The precipitate was washed three times each with deionized water and anhydrous ethanol. The product was dried in a 60 °C oven for 12 h, and then heated to 550 °C in a muffle furnace at a rate of 1 °C / min and calcined at this temperature for 6 h to completely remove the hexadecyltrimethylammonium bromide template, yielding mesoporous silica. 100 mg of the dried mesoporous silica was dispersed in 5 mL of saturated sodium chlorite aqueous solution, placed in a vacuum desiccator, and evacuated to -0.095 MPa for 1 h. After restoring to normal pressure, the slurry was centrifuged at 8000 rpm at 4 °C for 5 h. After a short time, the supernatant was carefully discarded to obtain a wet loaded product. The sample was quickly rinsed with a saturated sodium chlorite ethanol solution, centrifuged again, and the wet sample was quickly transferred to a sample tray of a freeze dryer pre-cooled at -20°C. The sample was freeze-dried for 24 h at a temperature < -50°C and a vacuum degree < 10 Pa to obtain sodium chlorite-loaded mesoporous silica powder, which was then stored in a light-proof, desiccator.
[0030] Hollow mesoporous manganese dioxide: self-made, preparation method is as follows: Add 0.6 mL of tetraethyl orthosilicate to a round-bottom flask containing 50 mL of deionized water, 63.3 mL of isopropanol, and 6 mL of ammonia. Stir in a 35°C oil bath for 30 min. Then, add 5 mL of tetraethyl orthosilicate at a rate of 1 mL / min using a constant-pressure dropping funnel and continue stirring for 2 h. After the reaction, the resulting silica is washed three times each with ethanol and water, and then dried in a 60°C oven for 12 h to obtain well-dispersed silica for later use. Add 200 mg of the above silica to 80 mL of deionized water and sonicate at room temperature and 40 kHz for 30 min to prepare a homogeneous suspension. In another beaker, add 0.002 mol of potassium permanganate, 0.001 mol of glucose, and 0.1 mmol of hexadecyltrimethylammonium bromide to 20 mL of deionized water and stir until completely dissolved. While continuously stirring, mix the above suspension with the potassium permanganate solution and heat to 60°C for 4 hours. h; After the reaction was completed, the mixture was cooled to room temperature, centrifuged to collect the solid, and washed three times with deionized water to obtain mesoporous manganese dioxide-coated silica core-shell nanospheres; then the mesoporous manganese dioxide-coated silica core-shell nanospheres were redispersed in 100 mL of 0.2 mol / L sodium carbonate solution, and the dispersion was transferred to a polytetrafluoroethylene-lined high-pressure reactor and reacted at 80 °C for 2 h to completely dissolve the internal silica template; after the reaction was completed, the product was collected by centrifugation and transferred to a dialysis bag with a molecular weight cutoff of 3.5 kDa, dialyzed with deionized water for 24 h, with the water changed every 6 h, and finally the dialysate was freeze-dried to obtain hollow mesoporous manganese dioxide for later use.
[0031] Iron-doped mesoporous manganese dioxide: prepared in-house, the preparation method is as follows: 200 mg of silica was dispersed in 80 mL of deionized water and sonicated for 30 min to prepare a homogeneous suspension. In a separate beaker, 0.002 mol of potassium permanganate, 0.0005 mol of ferric chloride hexahydrate, 0.001 mol of glucose, and 0.1 mmol of hexadecyltrimethylammonium bromide were added sequentially to 20 mL of deionized water. The pH of the solution was adjusted to 4-6 with dilute hydrochloric acid and stirred until completely dissolved. The two solutions were mixed under continuous stirring and heated to 60 °C for 4 h. Under acidic and heated conditions, potassium permanganate decomposed and manganese dioxide was deposited, while iron ions were effectively doped into the manganese dioxide lattice. After the reaction, the mixture was cooled, centrifuged, and washed with water to obtain iron-doped silica@manganese dioxide core-shell nanospheres. The core-shell nanospheres were dispersed in 100 mL of 0.2 mol / L sodium carbonate solution and reacted at 80 °C for 2 h to etch the silica template. Subsequent dialysis and freeze-drying steps were the same as for hollow mesoporous manganese dioxide to obtain iron-doped mesoporous manganese dioxide.
[0032] Preparation of metal-phenolic nanoparticles@hollow mesoporous manganese dioxide: self-made, preparation method is as follows: 50 mg of hollow mesoporous manganese dioxide nanospheres were dispersed in 50 mL of Tris-HCl buffer at pH 8.0 and sonicated for 30 min. Then, 50 mL of epigallocatechin gallate solution at 1 mg / mL dissolved in the same Tris-HCl buffer was added. Under nitrogen protection and at 4 °C, 50 mL of ferric chloride solution at pH 8 dissolved in Tris-HCl was added dropwise to the mixture. After the addition was complete, the mixture was stirred at 4 °C for 12 h. After the reaction was completed, the product was collected by centrifugation, washed three times with Tris-HCl buffer at pH 8.0, washed once with anhydrous ethanol, and finally dried in a vacuum drying oven at 60 °C for 12 h to obtain metal-phenolic nanoparticles@hollow mesoporous manganese dioxide.
[0033] Metal-phenolic nanoparticles@iron-doped mesoporous manganese dioxide: self-made. The preparation method is the same as that of metal-phenolic nanoparticles@hollow mesoporous manganese dioxide, except that the hollow mesoporous manganese dioxide is replaced with iron-doped mesoporous manganese dioxide, while other conditions remain unchanged.
[0034] Citric acid microcapsules: homemade, preparation method as follows: Prepare 2% (w / v) gelatin aqueous solution and 2% (w / v) gum arabic aqueous solution separately, and keep them at 45°C. Mix citric acid solid powder (passed through a 300-mesh sieve) with olive oil containing 1% lecithin, where the concentration of citric acid in the mixture is 5%. Process the mixture using a high-speed shear disperser at 10,000 rpm for 3 min to prepare a citric acid / olive oil suspension, which serves as the core material. Keep the gelatin aqueous solution at 45°C in a container, and slowly add the prepared citric acid / olive oil suspension dropwise to the gelatin solution while stirring at 8,000 rpm. After the addition is complete, continue stirring at this high speed for 5 min. While continuously stirring at 300 rpm, slowly add the gum arabic solution dropwise to the above mixture at a rate of 2 mL / min, where the total mass ratio of citric acid and olive oil to the total mass ratio of gelatin and gum arabic is 1:2. Adjust the pH of the mixture to 4.2 with 10% (v / v) dilute acetic acid, and continue stirring for 30 minutes. Allow the coagulation to proceed fully; cool the system to 5°C in an ice bath and stir continuously at this temperature for 1.5 h; maintain the system at a low temperature of 5-10°C and gently stir at 300 rpm, slowly add pre-cooled PBS buffer with pH 6.0 until the pH of the system stabilizes at around 6.0, carefully remove most of the supernatant with a pipette, and slowly add pre-cooled PBS buffer with pH 7.5 while maintaining the temperature and stirring at 300 rpm until the pH of the system stabilizes at 7.0-7.5, slowly raise the temperature to 35°C, add 0.5% genipin solution, where the mass ratio of genipin to gelatin is 1:15, and stir for crosslinking for 8 h; after crosslinking is complete, cool the system to room temperature, then centrifuge at 3000 rpm for 5 min, collect the precipitate, and wash it 3 times with deionized water at a temperature close to the system temperature; freeze-dry the wet microcapsules at -50°C and <10 Pa for 24 h; after drying, pass through a 100-mesh sieve to obtain citric acid microcapsules.
[0035] Example
[0036] Example 1
[0037] Multilayer nano-activating material 1: Self-made, preparation method is as follows: (I) Separate preparation of functional layer precursor solutions (1) Catalytic oxide layer dispersion: Under light-proof, low-temperature and inert atmosphere, 50 mg of mesoporous silica loaded with sodium chlorite and 50 mg of metal-phenolic nanoparticles@iron-doped hollow mesoporous manganese dioxide were dispersed in 10 mL of aqueous solution containing 1.5 wt% sodium alginate. The dispersion was subjected to ultrasonic intermittent dispersion in an ice-water bath at a power of 100 W, with an interval of 2 s and 3 s for a total of 10 min, to obtain uniform dispersion A. (2) Acid source layer dispersion: 100 mg of citric acid microcapsules were uniformly dispersed in 10 mL of an aqueous solution containing 1.0 wt% sodium alginate to obtain dispersion B; (3) Isolation layer solution: 150 mg pullulan polysaccharide and 20 mg hydrophobic nano silica were dispersed together in 10 mL of deionized water and subjected to ultrasonic treatment at 40 kHz for 10 min to obtain a uniform suspension C; (4) Structural reinforcement layer solution: 100 mg of cystamine-modified chondroitin sulfate and 50 mg of nanocellulose were dispersed together in 10 mL of aqueous solution containing 0.1% (v / v) acetic acid and magnetically stirred until completely dissolved to obtain solution D; (II) Sequential casting and stabilization of multilayer aerogels (1) Forming of structural reinforcement layer: Pour solution D into polytetrafluoroethylene mold; place the mold on a copper plate pre-cooled to -20℃, immerse the other end of the copper plate in liquid nitrogen for unidirectional freezing; after complete freezing, transfer to -80℃ for deep freezing for 1 h; (2) Casting of catalytic oxidation layer: Transfer the mold to a low temperature operating table at 0℃ and control the temperature precisely by using an ice-water bath; keep it at 0℃ for 15 min to make the surface uniformly and slightly melted, and quickly pour the dispersion A onto it; let it stand at 0℃ for 20 min, and then quickly move it back to -80℃ to freeze; (3) Construction of the isolation layer: On a 0℃ low temperature stage, the isolation layer suspension C is uniformly poured onto the frozen middle layer surface; immediately move it back to -80℃ and freeze for 30 min; (4) Acid source layer casting: At 0℃, the acid source layer dispersion B is cast onto the frozen isolation layer; the entire mold is quickly moved back to -80℃ for deep cooling for 24 h; (5) Freeze-drying: The four frozen layers were freeze-dried at -80℃ to obtain the primary aerogel; (6) Crosslinking and post-treatment: i. Liquid-phase crosslinking and neutralization: The primary aerogel was immersed in a buffer solution containing genipin at a concentration of 0.5% and a pH of 7.5 for crosslinking at a temperature of 30°C for 24 h. ii. Washing and drying: After crosslinking is completed, remove the aerogel, wash it several times with deionized water to remove residual crosslinking agent and salt, and then dry it; iii. Post-treatment: The dried aerogel was transferred to a vacuum oven at 60°C and -0.1 MPa to remove residual moisture. (7) Cutting and storage: Using a sharp scalpel, the aerogel is cut into the required size to obtain multilayer nano-activated material 1; the product is stored in a vacuum aluminum foil bag.
[0038] Example 2
[0039] Multilayer nano-activating material 2: self-made. The preparation method is the same as that of multilayer nano-activating material 1. The difference is that in step (I) (1), 50 mg of mesoporous silica loaded with sodium chlorite and 50 mg of metal-phenolic nanoparticles@iron-doped hollow mesoporous manganese dioxide are replaced with 34 mg of mesoporous silica loaded with sodium chlorite and 66 mg of metal-phenolic nanoparticles@iron-doped hollow mesoporous manganese dioxide. In step (I) (2), 100 mg of citric acid microcapsules are replaced with 50 mg. In step (I) (3), 150 mg of pullulan polysaccharide and 20 mg of hydrophobic nano silica are replaced with 100 mg of pullulan polysaccharide and 20 mg of hydrophobic nano silica. In step (I) (4), 100 mg of cystamine-modified chondroitin sulfate and 50 mg of nanocellulose are replaced with 75 mg of cystamine-modified chondroitin sulfate and 75 mg of nanocellulose. All other conditions remain unchanged, and multilayer nano-activating material 2 is obtained.
[0040] Example 3
[0041] Multilayer nano-activating material 3: self-made. The preparation method is the same as that of multilayer nano-activating material 1. The difference is that in step (I) (1), 50 mg of mesoporous silica loaded with sodium chlorite and 50 mg of metal-phenolic nanoparticles@iron-doped hollow mesoporous manganese dioxide are replaced with 66 mg of mesoporous silica loaded with sodium chlorite and 34 mg of metal-phenolic nanoparticles@iron-doped hollow mesoporous manganese dioxide. In step (I) (2), 100 mg of citric acid microcapsules are replaced with 200 mg. In step (I) (3), 150 mg of pullulan and 20 mg of hydrophobic nano-silica are replaced with 200 mg of pullulan and 20 mg of hydrophobic nano-silica. In step (I) (4), 100 mg of cystamine-modified chondroitin sulfate and 50 mg of nanocellulose are replaced with 112.5 mg of cystamine-modified chondroitin sulfate and 37.5 mg of nanocellulose. All other conditions remain unchanged, and multilayer nano-activating material 3 is obtained.
[0042] Comparative Example Comparative Example 1 Multilayer nano-activating material 4: self-made. The preparation method is the same as that of multilayer nano-activating material 1. The difference is that in step (i) (1), the metal-phenolic nanoparticles@iron-doped hollow mesoporous manganese dioxide are replaced with metal-phenolic nanoparticles@hollow mesoporous manganese dioxide. All other conditions remain unchanged to obtain multilayer nano-activating material 4.
[0043] Comparative Example 2 Multilayer nano-activating material 5: self-made. The preparation method is the same as that of multilayer nano-activating material 1. The difference is that the cystamine-modified chondroitin sulfate in step (1) and (4) is replaced with chondroitin sulfate. All other conditions remain unchanged, and multilayer nano-activating material 5 is obtained.
[0044] Comparative Example 3 Multilayer Nano-Activated Material 6: Self-made. The preparation method is the same as that of Multilayer Nano-Activated Material 1, except that all functional layer components are simply physically mixed. The specific steps are as follows: Weigh the raw materials equivalent to the total amount of each layer component in Example 1: 100 mg cystamine-modified chondroitin sulfate, 50 mg nanocellulose, 50 mg mesoporous silica loaded with sodium chlorite, 50 mg metal-phenolic nanoparticles@iron-doped hollow mesoporous manganese dioxide, 150 mg pullulan, 20 mg hydrophobic nano-silica, and 100 mg citric acid microcapsules. Place all the above solid powders in a mortar and grind them manually for 10 min to make them initially uniform. Then, transfer the mixed powder to a container, add 10 mL of deionized water, and stir with a magnetic stirrer at 500 rpm for 30 min at room temperature to form a uniform slurry. Pour the slurry into the same polytetrafluoroethylene mold as in Example 1, place it directly at -80℃ for 24 h, and then freeze-dry at -80℃ to obtain Multilayer Nano-Activated Material 6.
[0045] The following are the test methods for performance parameters involved in this invention: 1. Fourier Transform Infrared Spectroscopy (FT-IR): Analysis was performed using a Thermo Nicolet IS10 Fourier Transform Infrared Spectrometer. In the infrared spectrum of chondroitin sulfate, 3480 cm⁻¹... -1 and 1650 cm -1 The absorption peaks at these locations are attributed to the -OH stretching vibration and C=O stretching vibration of the carboxyl group in chondroitin sulfate, respectively. After reaction with cystamine, these peaks shift to higher wavenumbers, appearing at 3485 cm⁻¹. -1 and 1655 cm -1 In addition, cystamine-modified chondroitin sulfate was observed at 1458 cm⁻¹. -1 A new absorption peak appeared at 770 cm⁻¹, attributed to the bending vibration of the -NH group in the amide bond; a new absorption peak appeared at 770 cm⁻¹ in the fingerprint region. -1 A weak new absorption peak was observed, attributed to the stretching vibration of the disulfide bond in cystamine. These results indicate the formation of an amide bond between chondroitin sulfate and cystamine, confirming the successful synthesis of cystamine-modified chondroitin sulfate.
[0046] 2. Chlorine dioxide release concentration determination: Experimental apparatus: PLT300 pump-type chlorine dioxide detector; Experimental chamber: 1m 3Sealed test chamber; Testing environment: Natural environment, temperature between 20~25℃ and humidity between 50~60% during testing; Testing method: Place the power supply, temperature and humidity detector, and chlorine dioxide detector into the test chamber, seal it, and let it stand for 1 hour to ensure that each instrument is functioning properly; Weigh 25 g of the samples from Examples 1~3 and Comparative Examples 1~3 and spread them evenly at the bottom of the test chamber, seal it, and record the chlorine dioxide concentration values at 1 d, 7 d, 14 d, 21 d, 28 d, 35 d, 42 d, 49 d, and 56 d. The experimental results are shown in Table 1 below.
[0047] 3. Evaluation of sterilization effect: Examples 1-3 and comparative examples 1-3 were evaluated according to the method in WS / T 650-2019 (5.2.2), with an action time of 24 h. The experimental results are shown in Table 2 below.
[0048] 4. Formaldehyde Removal Efficacy Evaluation: Examples 1-3 and Comparative Examples 1-3 were evaluated according to QB / T 2761-2006 standard. Test space: 1.5 m 3 The test chamber used 200 g of sample, and the results are shown in Table 3 below.
[0049] Table 1. Results of chlorine dioxide release concentration (ppm) in Examples 1-3 and Comparative Examples 1-3
[0050] Table 2. Evaluation results of sterilization effects in Examples 1-3 and Comparative Examples 1-3
[0051] Table 3. Evaluation results of formaldehyde removal effects in Examples 1-3 and Comparative Examples 1-3
[0052] As shown in Table 1, Example 1 exhibits ideal sustained-release characteristics: the initial concentration was low from day 1 to 7, indicating that the isolation layer effectively prevented premature and excessive penetration of environmental moisture; as moisture slowly penetrated, the acid source layer was triggered, and chlorine dioxide began to be generated stably, reaching and maintaining a plateau period from day 21 to 35, confirming the successful construction of the "functional isolation-on-demand triggering" system; the release concentration remained stable within 56 days, showing that the material structure was stable and that no components were consumed prematurely. In Example 2, due to the reduced loading of both citric acid microcapsules and metal-phenolic nanoparticles@iron-doped hollow mesoporous manganese dioxide, the total amount of reactants for the triggering reaction was reduced, resulting in lower chlorine dioxide release concentrations at each time point than in Example 1. However, the release curves remained stable, indicating that even after proportionally reducing the loading of functional components, the multilayer structure still possessed good stability, and the functional logic remained consistent. In Example 3, due to the higher loading of citric acid microcapsules and metal-phenolic nanoparticles@iron-doped hollow mesoporous manganese dioxide, the initial and middle stages of chlorine dioxide release concentration were significantly higher than in Example 1. However, the release concentration slowly decreased after 42 days. This was because the high concentration of acid accelerated the consumption of local oxidant, or the high loading of components slightly affected the aerogel pore structure, slightly altering the mass transfer process, but the overall release was still at a high level. The chlorine dioxide release concentration in Comparative Example 1 was consistently lower than in all other examples, directly confirming the key role of iron doping—iron doping significantly enhances the catalytic activity of hollow mesoporous manganese dioxide, promoting the efficient decomposition of sodium chlorite to chlorine dioxide; without iron doping, the reaction conversion efficiency is low, resulting in insufficient chlorine dioxide yield. In Comparative Example 2, due to the lack of modification of the structural reinforcement layer and insufficient cross-linking, structural collapse occurred in the early stages of preparation or storage, leading to premature contact between the acid source and the oxidant. Therefore, a relatively high chlorine dioxide release concentration was detected at the beginning of the test, but this was due to the unexpected rapid consumption of the active ingredient. The concentration subsequently decreased sharply to undetectable levels, failing to achieve effective sustained release. This result conversely demonstrates the indispensability of cystamine modification for constructing stable multilayer structures, achieving functional isolation, and on-demand triggering. Comparative Example 3 showed a high chlorine dioxide release concentration at the beginning of the test, but this concentration rapidly decreased within a short period. This indicates that all components came into contact immediately after mixing, and the acid source rapidly triggered the oxidant reaction, leading to the rapid depletion of the active ingredient during storage and the initial testing phase, rendering it unable to achieve any sustained-release function.
[0053] As shown in Table 2, all examples and Comparative Example 2 exhibited high bactericidal rates against Escherichia coli, Staphylococcus aureus, and Candida albicans, indicating that as long as chlorine dioxide can be successfully generated and released, it can achieve sterilization as a broad-spectrum and highly effective bactericide. The bactericidal performance is positively correlated with the concentration of chlorine dioxide released; therefore, the bactericidal effects of Examples 1 and 3 are superior to that of Example 2. The bactericidal rate of Comparative Example 1 is significantly lower than that of the examples, especially its effect on Candida albicans is poor. This is not because chlorine dioxide lacks bactericidal ability, but because the total amount of chlorine dioxide generated is too low, failing to reach the exposure dose required to completely kill microorganisms. This again confirms, from the perspective of application effect, the importance of iron doping in improving the overall system efficiency, including bactericidal performance.
[0054] As shown in Table 3, Example 1 exhibited the best formaldehyde removal rate, thanks to its optimal synergistic system—the combination of sufficient chlorine dioxide oxidation and highly efficient iron-doped manganese dioxide catalysis—which effectively oxidized formaldehyde to carbon dioxide and water. Example 2 showed a slightly lower formaldehyde removal rate due to a reduction in the total amount of oxidant. Although Example 3 generated more chlorine dioxide, its formaldehyde removal rate was slightly lower than Example 1, possibly because the initial release was too rapid, preventing the optimal synergistic catalytic oxidation time window from reaching formaldehyde. This indicates that there is an optimal ratio of oxidizing to catalytic components. The significant decrease in formaldehyde removal rate in Comparative Example 1 demonstrates that, without iron doping to enhance catalytic activity, chlorine dioxide oxidation alone is insufficient for efficient formaldehyde degradation. This confirms the decisive synergistic effect of "metal-phenolic network modification" and "iron doping" in enhancing catalytic activity and achieving deep mineralization of pollutants. The formaldehyde removal rate of Comparative Example 2 was low, and this data may stem from an initial explosive reaction, lacking sustainability. This indicates that even with all active components present, if the multi-layered isolation structure is damaged, leading to disordered and rapid consumption of reactants, efficient and long-lasting formaldehyde purification cannot be achieved. This fully demonstrates the necessity of the "functional isolation" design concept. The above experimental results and analysis fully prove the rationality, effectiveness, and advancement of this patented technical solution.
[0055] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.
Claims
1. A multilayer nano-activating material, characterized in that, The material comprises, from the inside out, a structural reinforcement layer, a catalytic oxidation layer, an isolation layer, and an acid source layer, stacked sequentially. The structural reinforcement layer comprises cystamine-modified chondroitin sulfate and nanocellulose. The catalytic oxidation layer comprises mesoporous silica loaded with sodium chlorite and metal-phenolic nanoparticles@metal-doped hollow mesoporous manganese dioxide. The isolation layer comprises pullulan polysaccharide and hydrophobic nanosilica. The acid source layer comprises citric acid microcapsules and sodium alginate.
2. The multilayer nano-activating material as described in claim 1, characterized in that, The mass ratio of cystamine-modified chondroitin sulfate to nanocellulose in the structural reinforcement layer is (1~3):1; the mass ratio of sodium chlorite-loaded mesoporous silica to metal-phenolic nanoparticles@metal-doped hollow mesoporous manganese dioxide in the catalytic oxidation layer is (0.5~2):1; the mass ratio of pullulan to hydrophobic nanosilica in the isolation layer is (5~10):1; and the mass ratio of citric acid microcapsules to sodium alginate in the acid source layer is (0.5~2):
1.
3. The multilayer nano-activating material as described in claim 1, characterized in that, The preparation method of the cystamine-modified chondroitin sulfate includes the following steps: The carboxyl group of chondroitin sulfate was activated to form chondroitin sulfate succinimide active ester, which was then mixed and reacted with cystamine. After the reaction was completed, the chondroitin sulfate was purified and freeze-dried to obtain cystamine-modified chondroitin sulfate.
4. The multilayer nano-activating material as described in claim 3, characterized in that, The method for activating the carboxyl group of chondroitin sulfate to form chondroitin sulfate succinimide active ester is to react sodium chondroitin sulfate, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and N-hydroxysuccinimide in a molar ratio of 1:(2~3):(2~3).
5. The multilayer nano-activated material as described in claim 1, characterized in that, The method for preparing the mesoporous silica supported on sodium chlorite includes the following steps: Hexadecyltrimethylammonium bromide was mixed with tetraethyl orthosilicate and reacted. After the reaction was completed, the precipitate was collected by centrifugation, washed, dried, and then calcined to obtain mesoporous silica. The dried mesoporous silica was dispersed in a saturated sodium chlorite aqueous solution to obtain a wet loaded product. After freeze-drying, mesoporous silica powder loaded with sodium chlorite was obtained.
6. The multilayer nano-activating material as described in claim 1, characterized in that, The preparation method of the metal-phenolic nanoparticles@metal-doped hollow mesoporous manganese dioxide includes the following steps: Nano-silica was dispersed in water to form a uniform suspension. In a separate beaker, potassium permanganate, soluble metal hydrate, glucose, and hexadecyltrimethylammonium bromide were added sequentially to deionized water. The two solutions were mixed and heated to 50-70°C for reaction. After the reaction, the mixture was purified to obtain metal-doped silica@manganese dioxide core-shell nanospheres. The silica was then etched with sodium carbonate and purified to obtain metal-doped mesoporous manganese dioxide. The metal-doped mesoporous manganese dioxide was mixed with epigallocatechin gallate, and ferric chloride solution was added dropwise while stirring. After the reaction, the product was collected by centrifugation, purified, and dried to obtain metal-phenolic nanoparticles@metal-doped mesoporous manganese dioxide.
7. The multilayer nano-activating material as described in claim 6, characterized in that, The molar ratio of potassium permanganate, soluble metal hydrate, glucose, and hexadecyltrimethylammonium bromide is 1:(0.2~0.3):(0.45~0.6):(0.05~0.1); the soluble metal hydrate is selected from one or more of ferric chloride, cobalt chloride, and nickel chloride hydrates.
8. The method for preparing the multilayer nano-activated material according to any one of claims 1 to 7, characterized in that, Includes the following steps: (I) Separate preparation of functional layer precursor solutions (1) Catalytic oxidation layer dispersion: Mesoporous silica loaded with sodium chlorite and metal-phenolic nanoparticles@metal-doped hollow mesoporous manganese dioxide were dispersed in an aqueous solution of sodium alginate and ultrasonically dispersed to obtain dispersion A. (2) Acid source layer dispersion: Citric acid microcapsules were dispersed in an aqueous solution of sodium alginate to obtain dispersion B; (3) Isolation layer solution: Pullulan polysaccharide and hydrophobic nano-silica were co-dispersed in deionized water and sonicated to obtain suspension C; (4) Structural reinforcement layer solution: Cystamine-modified chondroitin sulfate and nanocellulose were co-dispersed in an aqueous acetic acid solution to obtain solution D; (II) Sequential casting and stabilization of multilayer aerogels (1) Forming of structural reinforcement layer: Pour solution D into polytetrafluoroethylene mold; place the mold on a pre-cooled copper plate, immerse the other end of the copper plate in liquid nitrogen for unidirectional freezing; after complete freezing, transfer to cryogenics; (2) Casting of catalytic oxidation layer: Transfer the mold to a low temperature operating table at 0°C. When the bottom surface shows a mirror-like reflection, indicating that it has been slightly melted and formed a thin water film, pour the dispersion A onto it; let it stand at 0°C, and then quickly transfer it back to deep freeze-thaw. (3) Construction of the isolation layer: On a 0℃ cryogenic stage, the isolation layer suspension C is uniformly poured onto the frozen intermediate layer surface; immediately move it back to cryogenic treatment; (4) Acid source layer casting: At 0°C, the acid source layer dispersion B is cast onto the frozen isolation layer; the entire mold is quickly moved back to cryogenic storage. (5) Freeze-drying: The four frozen layers were subjected to cryogenic freeze-drying to obtain primary aerogel; (6) Crosslinking and post-treatment: i. Liquid-phase crosslinking and neutralization: The primary aerogel is immersed in a buffer solution containing genipin for crosslinking; ii. Washing and drying: After crosslinking is completed, remove the aerogel, wash it several times with deionized water to remove residual crosslinking agent and salt, and then dry it; iii. Post-treatment: Transfer the dried aerogel to a vacuum oven for further treatment to thoroughly remove residual moisture; (7) Cutting and storage: Cut the aerogel and vacuum seal the product for storage.
9. The method for preparing multilayer nano-activated materials as described in claim 8, characterized in that, The precooling temperature is -10 to -30°C; the cryogenic temperature is -70 to -90°C; the genipin concentration of the genipin buffer solution is 0.1% to 1%, and the pH is 7.5 to 8.5; the liquid phase crosslinking temperature is 25 to 35°C, and the time is 12 to 24 hours; the post-treatment conditions are 50 to 70°C and -0.05 to -0.1 MPa.
10. The application of the multilayer nano-activated material as described in any one of claims 1 to 7 in air purifiers, personal care products, textile fibers, building coatings, and wall materials.