Novel polylysine / vermiculite composite aerogel material, preparation method and application
By preparing polylysine/vermiculite composite aerogel materials, and utilizing electrostatic crosslinking and boron nitride, the problems of rapid desorption and recycling of aerogel materials were solved, achieving rapid adsorption and decomposition of formaldehyde, thus improving environmental friendliness and sustainability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JIANGSU GUOYANG TECHNOLOGY MANUFACTURING CO LTD
- Filing Date
- 2025-07-07
- Publication Date
- 2026-07-14
AI Technical Summary
Existing aerogel materials are difficult to desorb quickly, cannot be recycled, and cannot decompose formaldehyde, which affects their environmental friendliness and sustainability.
By preparing polylysine/vermiculite composite aerogel materials, the electrostatic interaction between polylysine and vermiculite nanosheets is utilized to crosslink and form a hydrogel. Boron nitride is added as a thermal conductor and photocatalyst to form a porous aerogel, which enables rapid adsorption and desorption, recycling, and decomposition of formaldehyde.
It achieves rapid adsorption and desorption of aerogel materials, enabling them to be recycled in high-temperature environments and decompose formaldehyde under light, thus improving environmental friendliness and sustainability.
Smart Images
Figure CN120393977B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of formaldehyde removal technology, specifically to a novel polylysine / vermiculite composite aerogel material, its preparation method, and its application. Background Technology
[0002] Formaldehyde (HCHO) is a colorless, volatile organic compound with a strong, pungent odor. It is a gas at room temperature, readily soluble in water, and widely found in building materials and furniture adhesives. The World Health Organization classifies it as a Group 1 carcinogen; long-term exposure can lead to leukemia, nasopharyngeal carcinoma, and other malignant diseases, while short-term exposure can irritate the respiratory tract and mucous membranes, causing coughing, skin allergies, and eye irritation. It is particularly harmful to sensitive groups such as children and pregnant women. Adsorption methods capture and immobilize formaldehyde molecules through the physical or chemical action of porous materials, reducing the concentration of formaldehyde in the air. Aerogels, a nanoscale porous material (porosity >90%, specific surface area up to 1000 m² / g), efficiently capture and decompose formaldehyde through super-strong adsorption and chemical modification (such as loading with titanium dioxide). However, aerogels and other adsorbent materials suffer from difficulties in rapid desorption and cannot be recycled. Furthermore, adsorption cannot decompose formaldehyde. Therefore, there is an urgent need for a reusable material to improve the environmental friendliness and sustainability of formaldehyde removal materials. Summary of the Invention
[0003] The purpose of this invention is to provide a novel polylysine / vermiculite composite aerogel material, its preparation method, and its application. Through optimization, the most suitable polylysine loading and the maximum formaldehyde capture capacity were obtained.
[0004] The objective of this invention can be achieved through the following technical solutions:
[0005] A method for preparing a novel polylysine / vermiculite composite aerogel material includes the following steps:
[0006] Modified vermiculite was obtained by hydrothermal treatment of vermiculite powder with saturated sodium chloride solution.
[0007] Modified vermiculite was subjected to a second hydrothermal treatment with a lithium salt solution to obtain modified vermiculite powder. After shearing and exfoliation treatment, the exfoliated product was subjected to gradient centrifugation to obtain a vermiculite nanosheet dispersion.
[0008] A polylysine-vermiculite composite aerogel material with a three-dimensional porous network structure was obtained by uniformly mixing vermiculite nanosheet dispersion with polylysine aqueous solution and freeze-drying.
[0009] As a further aspect of the present invention, the ratio of vermiculite powder to saturated sodium chloride solution is (1.2-5.4) g : (1-200) mL.
[0010] As a further aspect of the present invention, the ratio of modified vermiculite to lithium salt solution is (1.2-5.4) g: (50-150) mL.
[0011] As a further aspect of the present invention, the amount of vermiculite nanosheet dispersion is 1-10 mol / L.
[0012] As a further aspect of the present invention: the mass ratio of vermiculite nanosheet dispersion to polylysine is (1-100) mg: (1-100) mg.
[0013] As a further aspect of the present invention: the mass ratio of vermiculite nanosheet dispersion to boron nitride is (1-100) mg: (1-100) mg.
[0014] As a further aspect of the present invention, the specific steps for gradient centrifugation of the stripping products are as follows:
[0015] First, unpeeled particles are removed by low-speed centrifugation. The supernatant is then collected and centrifuged at high speed. The resulting precipitate is redispersed to different concentrations of vermiculite nanosheet dispersions.
[0016] As a further aspect of the present invention: the speed of low-speed centrifugation is 100-500 rpm / min, and the time of low-speed centrifugation is 5-20 min;
[0017] The high-speed centrifugation speed is 5000-6000 rpm / min, and the high-speed centrifugation time is 20-40 min.
[0018] A novel polylysine / vermiculite composite aerogel material, characterized in that the composite aerogel material is prepared by the above-described method, and the composite aerogel material is as follows:
[0019] The hydrogel formed by the electrostatic interaction between polylysine and vermiculite nanosheets transforms into a high-porosity aerogel with an open pore structure after freeze-drying, exhibiting an ordered, layered structure. The addition of boron nitride results in a scaly layered structure with porous and loose properties, facilitating the adsorption of formaldehyde into an aerogel material.
[0020] Application of a novel polylysine / vermiculite composite aerogel material: The composite aerogel material prepared by the above method is used in formaldehyde removal.
[0021] The beneficial effects of this invention are:
[0022] This invention provides a novel polylysine / vermiculite composite aerogel material, its preparation method, and its applications. A novel adsorbent, polylysine / vermiculite composite aerogel, with a simple, economical, and environmentally friendly synthesis strategy is proposed for capturing formaldehyde from ambient air. Vermiculite nanosheets are a natural two-dimensional material with exposed surfaces and an inherent negative charge. Polylysine is used as a crosslinking agent to rapidly gel the vermiculite nanosheet dispersion to form a hydrogel, which is then freeze-dried to produce the polylysine / vermiculite composite aerogel. By precisely controlling the concentration of the vermiculite nanosheet dispersion and the loading of polylysine, the composition and microstructure of the resulting aerogel can be accurately adjusted. The loading of polylysine significantly affects the pore structure and specific surface area of the aerogel, thus influencing the formaldehyde capture capacity of the adsorbent. Through optimization, the optimal polylysine loading and the maximum formaldehyde capture capacity were obtained.
[0023] A cross-linked network structure is formed by the electrostatic interaction between polylysine and vermiculite, which is then freeze-dried to form an aerogel with a porous structure, enhancing formaldehyde adsorption. Boron nitride is added to the aerogel, which serves as a thermal conductor for rapid desorption at high temperatures, enabling recycling. Simultaneously, the boron nitride and vermiculite composite form a heterojunction material for photocatalytic decomposition of formaldehyde. This gel system can rapidly adsorb and desorb formaldehyde for rapid recycling, and it can also gradually decompose formaldehyde under light, enabling applications in various scenarios. Attached Figure Description
[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0025] Figure 1 SEM images of the aerogels prepared in Examples 1-6;
[0026] Figure 2 The graph shows the formaldehyde removal efficiency of the aerogels prepared in Examples 1-6.
[0027] Figure 3 The graph shows the formaldehyde removal efficiency of aerogel in Control Example 1 and Examples 1-6 under low humidity conditions.
[0028] Figure 4 The graph shows the formaldehyde removal effect of aerogel in control example 1 and examples 1-6 under high humidity conditions. Detailed Implementation
[0029] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of 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 skilled in the art without creative effort should fall within the scope of protection of the present invention.
[0030] Example 1
[0031] This invention provides a method for preparing a novel polylysine / vermiculite composite aerogel material, comprising the following steps:
[0032] Step 1, Preparation of modified vermiculite:
[0033] Vermiculite particles were ground and dried at 50°C. 3.6 g of the dried vermiculite powder was immersed in 100 mL of saturated sodium chloride (NaCl) solution, stirred evenly, and then added to a hydrothermal reactor. The reaction was carried out at 110°C for 2 h. After cooling to room temperature for 20 h, the mixture was vacuum filtered and washed with 500 mL of pure water until neutral to obtain the first filter residue. The first filter residue was dried in a drying oven at 50°C for 24 h to obtain modified vermiculite.
[0034] Step 2, prepare a concentrated vermiculite nanosheet dispersion:
[0035] Weigh 3.6g of modified vermiculite and immerse it in 100mL of 2mol / L lithium chloride (LiCl) solution. After stirring evenly, add it to a hydrothermal reactor and react at 110℃ for 2h. After cooling to room temperature for 20h, filter under vacuum and wash with 500mL of pure water until neutral to obtain the second filter residue. Dry the second filter residue in a 50℃ drying oven for 24h.
[0036] 3.6g of the dried second filter residue was immersed in 80 mL of deionized water and intermittently sheared and mixed at 20000 rpm / min for 10 min to separate the layers.
[0037] After the suspension was separated into layers, it was centrifuged at 300 rpm / min for 1 hour. The collected supernatant was the vermiculite nanosheet (VNs) dispersion. It was then centrifuged at 6000 rpm / min for 1 hour to concentrate it to a 5 mg / mL VNS dispersion.
[0038] Step 3: Preparation of polylysine-vermiculite composite aerogel
[0039] 20 mL of 5 mg / mL VNS dispersion was mixed with 1 mL of 100 mg / mL polylysine aqueous solution, stirred at room temperature, and sonicated in a water bath for 20 minutes; then 10 mL of 10 mg / mL boron nitride aqueous solution was added, stirred at room temperature, sonicated in a water bath for 20 minutes, and then cryo-cured at low temperature for 3 hours; the polylysine-vermiculite composite aerogel was obtained by freeze-drying.
[0040] The polylysine / vermiculite composite aerogel material is a hydrogel formed by the electrostatic interaction between polylysine and vermiculite nanosheets (VNs). After freeze-drying, it generates a high-porosity aerogel with an open pore structure, exhibiting an ordered layered structure. The addition of boron nitride results in a scaly layered structure, possessing porous and loose properties that facilitate formaldehyde adsorption.
[0041] Example 2
[0042] This invention provides a method for preparing a novel polylysine / vermiculite composite aerogel material, comprising the following steps:
[0043] This invention provides a method for preparing a novel polylysine / vermiculite composite aerogel material, comprising the following steps:
[0044] Step 1, Preparation of modified vermiculite:
[0045] Vermiculite particles were ground and dried at 50°C. 2.4 g of the dried vermiculite powder was immersed in 80 mL of saturated sodium chloride (NaCl) solution, stirred evenly, and then added to a hydrothermal reactor. The reaction was carried out at 110°C for 2 h. After cooling to room temperature for 20 h, the mixture was vacuum filtered and washed with 500 mL of pure water until neutral to obtain the first filter residue. The first filter residue was dried in a drying oven at 50°C for 24 h to obtain modified vermiculite.
[0046] Step 2, prepare a concentrated vermiculite nanosheet dispersion:
[0047] Weigh 2.4g of modified vermiculite and immerse it in 100mL of 1mol / L lithium chloride (LiCl) solution. After stirring evenly, add it to a hydrothermal reactor and react at 110℃ for 2h. After cooling to room temperature for 20h, filter under vacuum and wash with 500mL of pure water until neutral to obtain the second filter residue. Dry the second filter residue in a 50℃ drying oven for 24h.
[0048] 2.4g of the dried second filter residue was immersed in 80 mL of deionized water and intermittently sheared and mixed at 20000 rpm / min for 10 min to separate the layers.
[0049] After the suspension was separated into layers, it was centrifuged at 300 rpm / min for 30 minutes. The collected supernatant was the vermiculite nanosheet (VNs) dispersion. It was then centrifuged at 5000 rpm / min for 30 minutes to concentrate it to a 10 mg / mL VNS dispersion.
[0050] Step 3: Preparation of polylysine-vermiculite composite aerogel
[0051] 10 mL of 5 mg / mL VNS dispersion was mixed with 2 mL of 50 mg / mL polylysine aqueous solution, stirred at room temperature, and sonicated in a water bath for 10 minutes; then 5 mL of 10 mg / mL boron nitride aqueous solution was added, stirred at room temperature, sonicated in a water bath for 20 minutes, and cryo-cured at low temperature for 3 hours; the polylysine-vermiculite composite aerogel was obtained by freeze-drying.
[0052] The polylysine / vermiculite composite aerogel material is a hydrogel formed by the electrostatic interaction between polylysine and vermiculite nanosheets (VNs). After freeze-drying, it generates a high-porosity aerogel with an open pore structure, exhibiting an ordered layered structure. The addition of boron nitride results in a scaly layered structure, possessing porous and loose properties that facilitate formaldehyde adsorption.
[0053] Example 3
[0054] This invention provides a method for preparing a novel polylysine / vermiculite composite aerogel material, comprising the following steps:
[0055] Step 1, Preparation of modified vermiculite:
[0056] Vermiculite particles were ground and dried at 50°C. 1.2 g of the dried vermiculite powder was immersed in 50 mL of saturated sodium chloride (NaCl) solution, stirred evenly, and then added to a hydrothermal reactor. The reaction was carried out at 110°C for 2 h. After cooling to room temperature for 20 h, the mixture was vacuum filtered and washed with 500 mL of pure water until neutral to obtain the first filter residue. The first filter residue was dried in a drying oven at 50°C for 24 h to obtain modified vermiculite.
[0057] Step 2, prepare a concentrated vermiculite nanosheet dispersion:
[0058] Weigh 1.2g of modified vermiculite and immerse it in 80 mL of 1.5 mol / L lithium chloride (LiCl) solution. After stirring evenly, add it to a hydrothermal reactor and react at 110℃ for 2 h. After cooling to room temperature for 20 h, filter under vacuum and wash with 500 mL of pure water until neutral to obtain the second filter residue. Dry the second filter residue in a drying oven at 50℃ for 24 h.
[0059] 1.2g of the dried second filter residue was immersed in 80 mL of deionized water and intermittently sheared and mixed at 20000 rpm / min for 10 min to separate the layers.
[0060] After the suspension was separated into layers, it was centrifuged at 300 rpm / min for 45 minutes. The collected supernatant was the vermiculite nanosheet (VNs) dispersion. It was then centrifuged at 6000 rpm / min for 1 hour to concentrate it to a 10 mg / mL VNS dispersion.
[0061] Step 3: Preparation of polylysine-vermiculite composite aerogel
[0062] 10 mL of a 10 mg / mL VNS dispersion was mixed with 0.5 mL of a 100 mg / mL polylysine aqueous solution, stirred at room temperature, and sonicated in a water bath for 20 minutes; then 5 mL of a 10 mg / mL boron nitride aqueous solution was added, stirred at room temperature, sonicated in a water bath for 20 minutes, and then freeze-dried for 3 hours; the resulting polylysine-vermiculite composite aerogel was obtained by freeze-drying.
[0063] The polylysine / vermiculite composite aerogel material is a hydrogel formed by the electrostatic interaction between polylysine and vermiculite nanosheets (VNs). After freeze-drying, it generates a high-porosity aerogel with an open pore structure, exhibiting an ordered layered structure. The addition of boron nitride results in a scaly layered structure, possessing porous and loose properties that facilitate formaldehyde adsorption.
[0064] Example 4
[0065] This invention provides a method for preparing a novel polylysine / vermiculite composite aerogel material, comprising the following steps:
[0066] Step 1, Preparation of modified vermiculite:
[0067] Vermiculite particles were ground and dried at 50°C. 3 g of the dried vermiculite powder was immersed in 90 mL of saturated sodium chloride (NaCl) solution, stirred evenly, and then added to a hydrothermal reactor. The reaction was carried out at 110°C for 2 h. After cooling to room temperature for 20 h, the mixture was vacuum filtered and washed with 500 mL of pure water until neutral to obtain the first filter residue. The first filter residue was dried in a drying oven at 50°C for 24 h to obtain modified vermiculite.
[0068] Step 2, prepare a concentrated vermiculite nanosheet dispersion:
[0069] Weigh 3g of modified vermiculite and immerse it in 100 mL of 2.5 mol / L lithium chloride (LiCl) solution. Stir the solution evenly and then add it to a hydrothermal reactor. React at 110℃ for 2 hours. After cooling to room temperature for 20 hours, filter under vacuum and wash with 500 mL of pure water until neutral to obtain the second filter residue. Dry the second filter residue in a 50℃ drying oven for 24 hours.
[0070] Immerse 3g of the dried second filter residue in 80 mL of deionized water and intermittently shear and mix at 13000 rpm / min for 10 min to separate the layers.
[0071] After the suspension was separated into layers, it was centrifuged at 300 rpm / min for 45 minutes. The collected supernatant was the vermiculite nanosheet (VNs) dispersion. It was then centrifuged at 6000 rpm / min for 1 hour to concentrate it to a 10 mg / mL VNS dispersion.
[0072] Step 3: Preparation of polylysine-vermiculite composite aerogel
[0073] 15 mL of 5 mg / mL VNS dispersion was mixed with 0.4 mL of 100 mg / mL polylysine aqueous solution, stirred at room temperature, and sonicated in a water bath for 20 minutes; then 5 mL of 5 mg / mL boron nitride aqueous solution was added, stirred at room temperature, sonicated in a water bath for 20 minutes, and then freeze-dried at low temperature for 3 hours; the resulting polylysine-vermiculite composite aerogel was obtained by freeze-drying.
[0074] The polylysine / vermiculite composite aerogel material is a hydrogel formed by the electrostatic interaction between polylysine and vermiculite nanosheets (VNs). After freeze-drying, it generates a high-porosity aerogel with an open pore structure, exhibiting an ordered layered structure. The addition of boron nitride results in a scaly layered structure, possessing porous and loose properties that facilitate formaldehyde adsorption.
[0075] Example 5
[0076] This invention provides a method for preparing a novel polylysine / vermiculite composite aerogel material, comprising the following steps:
[0077] Step 1, Preparation of modified vermiculite:
[0078] The vermiculite particles were ground and dried at 50°C. 2g of the dried vermiculite powder was immersed in 120mL of saturated sodium chloride (NaCl) solution, stirred evenly, and then added to a hydrothermal reactor. The reaction was carried out at 110°C for 2 hours. After cooling to room temperature for 20 hours, the mixture was vacuum filtered and washed with 500mL of pure water until neutral to obtain the first filter residue. The first filter residue was dried in a drying oven at 50°C for 24 hours to obtain modified vermiculite.
[0079] Step 2, prepare a concentrated vermiculite nanosheet dispersion:
[0080] Weigh 2g of modified vermiculite and immerse it in 100 mL of 1 mol / L lithium chloride (LiCl) solution. Stir the solution evenly and then add it to a hydrothermal reactor. React at 110℃ for 2 hours. After cooling to room temperature for 20 hours, filter under vacuum and wash with 500 mL of pure water until neutral to obtain the second filter residue. Dry the second filter residue in a 50℃ drying oven for 24 hours.
[0081] Two g of the dried second filter residue was immersed in 80 mL of deionized water and intermittently sheared and mixed at 15000 rpm / min for 10 min to separate the layers.
[0082] After the suspension was separated into layers, it was centrifuged at 300 rpm / min for 25 minutes. The collected supernatant was the vermiculite nanosheet (VNs) dispersion. It was then centrifuged at 6000 rpm / min for 45 minutes to concentrate it to a 5 mg / mL VNS dispersion.
[0083] Step 3: Preparation of polylysine-vermiculite composite aerogel
[0084] 10 mL of 5 mg / mL VNS dispersion was mixed with 1 mL of 100 mg / mL polylysine aqueous solution, stirred at room temperature, and sonicated in a water bath for 20 minutes; then 8 mL of 10 mg / mL boron nitride aqueous solution was added, stirred at room temperature, sonicated in a water bath for 20 minutes, and then freeze-dried at low temperature for 3 hours; the resulting polylysine-vermiculite composite aerogel was obtained by freeze-drying.
[0085] The polylysine / vermiculite composite aerogel material is a hydrogel formed by the electrostatic interaction between polylysine and vermiculite nanosheets (VNs). After freeze-drying, it generates a high-porosity aerogel with an open pore structure, exhibiting an ordered layered structure. The addition of boron nitride results in a scaly layered structure, possessing porous and loose properties that facilitate formaldehyde adsorption.
[0086] Example 6
[0087] This invention provides a method for preparing a novel polylysine / vermiculite composite aerogel material, comprising the following steps:
[0088] Step 1, Preparation of modified vermiculite:
[0089] Vermiculite particles were ground and dried at 50°C. 5.4g of the dried vermiculite powder was immersed in 95mL of saturated sodium chloride (NaCl) solution, stirred evenly, and then added to a hydrothermal reactor. The reaction was carried out at 110°C for 2 hours. After cooling to room temperature for 20 hours, the mixture was vacuum filtered and washed with 500mL of pure water until neutral to obtain the first filter residue. The first filter residue was dried in a drying oven at 50°C for 24 hours to obtain modified vermiculite.
[0090] Step 2, prepare a concentrated vermiculite nanosheet dispersion:
[0091] 5.4 g of modified vermiculite was weighed and immersed in 80 mL of 1.5 mol / L lithium chloride (LiCl) solution. After stirring evenly, it was added to a hydrothermal reactor and reacted at 110℃ for 2 h. After cooling to room temperature for 20 h, it was vacuum filtered and washed with 500 mL of pure water until neutral to obtain the second filter residue. The second filter residue was dried in a drying oven at 50℃ for 24 h.
[0092] 5.4 g of the dried second filter residue was immersed in 80 mL of deionized water and intermittently sheared and mixed at 20,000 rpm / min for 10 min to separate the layers.
[0093] After the suspension was separated into layers, it was centrifuged at 300 rpm / min for 30 minutes. The collected supernatant was the vermiculite nanosheet (VNs) dispersion. It was then centrifuged at 6000 rpm / min for 1 hour to concentrate it to a 10 mg / mL VNS dispersion.
[0094] Step 3: Preparation of polylysine-vermiculite composite aerogel
[0095] 5 mL of 10 mg / mL VNS dispersion was mixed with 2 mL of 40 mg / mL polylysine aqueous solution, stirred at room temperature, and sonicated in a water bath for 20 minutes; then 15 mL of 5 mg / mL boron nitride aqueous solution was added, stirred at room temperature, sonicated in a water bath for 20 minutes, and cryo-cured at low temperature for 3 hours; the polylysine-vermiculite composite aerogel was obtained by freeze-drying.
[0096] The polylysine / vermiculite composite aerogel material is a hydrogel formed by the electrostatic interaction between polylysine and vermiculite nanosheets (VNs). After freeze-drying, it generates a high-porosity aerogel with an open pore structure, exhibiting an ordered layered structure. The addition of boron nitride results in a scaly layered structure, possessing porous and loose properties that facilitate formaldehyde adsorption.
[0097] Compare with Example 1
[0098] The present invention provides a method for preparing a polylysine / vermiculite composite aerogel material, comprising the following steps:
[0099] Grind the vermiculite particles and dry them at 50°C.
[0100] Weigh 3.6 g of the dried filter residue and immerse it in 50 mL of deionized water. Then, intermittently shear and mix the residue at 20,000 rpm / min for 10 min to separate the layers.
[0101] After the suspension was separated into layers, it was centrifuged at 300 rpm / min for 1 hour. The collected supernatant was the vermiculite nanosheet (VNs) dispersion. It was then centrifuged at 6000 rpm / min for 1 hour to concentrate it to a 5 mg / mL VNS dispersion.
[0102] Mix 10 mL of 10 mg / mL VNS dispersion with 10 mL of 100 mg / mL polylysine aqueous solution, stir at room temperature, and sonicate in a water bath for 10 minutes.
[0103] Add 10 mL of boron nitride with a concentration of 5 mg / mL, stir the resulting mixture at room temperature, sonicate it in a water bath for 10 minutes, and freeze-dry it to obtain polylysine-vermiculite composite aerogel.
[0104] Experimental Example
[0105] like Figure 1 As shown in the SEM image, the aerogels prepared in Examples 1-6 of this invention all exhibit irregular sheet-like or blocky structures with uneven surfaces and numerous undulations. This indicates that the material has a complex surface morphology, a large specific surface area, and a good effect on adsorbing formaldehyde.
[0106] Performance testing
[0107] Formaldehyde adsorption experiment: In a 200L sealed chamber, the temperature and humidity were controlled at 27℃ and 30%, respectively. The heating stage was preheated to 80℃. 150µl of formaldehyde solution was dropped into a glass petri dish and placed on the heating stage for 30 minutes to allow complete volatilization. Then, 15g of aerogel sample was added, and atmospheric samples were taken at different time points using an atmospheric sampler, with the values recorded. Results are as follows: Figure 3 As shown, the aerogels prepared in Examples 1-6 of the present invention and the aerogel prepared in Control Example 1 (Control Group 1) can effectively remove formaldehyde under drying conditions, while Example 1 of the present invention can remove up to 99% of formaldehyde within 24 hours.
[0108] Formaldehyde removal experiment: In a 200L sealed chamber, the temperature and humidity were controlled at 27℃ and 70%, respectively. The heating stage was preheated to 80℃. 150u of formaldehyde solution was dropped into a glass petri dish and placed on the heating stage for 30 minutes to allow complete volatilization. Then, 15g of aerogel sample was added, and atmospheric samples were taken at different time points using an atmospheric sampler, and the values were recorded. Results are as follows: Figure 4 As shown, the aerogels prepared in Examples 1-6 of this invention can all effectively remove formaldehyde. Among them, the aerogel prepared in Example 1 can still remove 99% of the formaldehyde within 24 hours. The aerogel prepared in Control Example 1 (Control Group 1) showed a formaldehyde removal effect that decreased to 50% under high humidity.
[0109] Aerogel cycle life determination experiment: In a 200L sealed chamber, the temperature and humidity were controlled at 27℃ and 30%, respectively. The heating stage was preheated to 80℃. 150µl of formaldehyde solution was dropped into a glass petri dish and placed on the heating stage for 30 minutes to allow complete formaldehyde volatilization. Then, 10g of aerogel sample was added, and atmospheric sampling was performed at different time points (0-24h) using an atmospheric sampler, and the data were recorded. The aerogel materials from Examples 1-6 were then placed in a 70℃ constant temperature chamber for formaldehyde desorption (0-24h), constituting one cycle. Five cycles were performed, and the formaldehyde removal rate was measured for each cycle. The formaldehyde removal rate was calculated as: 24h formaldehyde concentration / initial formaldehyde concentration. The results are shown below. Figure 2 As shown, the aerogels prepared in Examples 1-6 of the present invention and the aerogel prepared in Control Example 1 (Control Group 1) can effectively remove formaldehyde under drying conditions. After cyclic testing, the formaldehyde removal rate of both gradually decreased. After 5 cycles, the formaldehyde removal rate of Example 1 was the best.
[0110] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.
Claims
1. A method for preparing a polylysine / vermiculite composite aerogel material, characterized in that, Includes the following steps: Modified vermiculite was obtained by hydrothermal treatment of vermiculite powder with saturated sodium chloride solution. Modified vermiculite was subjected to a second hydrothermal treatment with a lithium salt solution to obtain modified vermiculite powder. After shearing and exfoliation treatment, the exfoliated product was subjected to gradient centrifugation to obtain a vermiculite nanosheet dispersion. A dispersion of vermiculite nanosheets was uniformly mixed with an aqueous solution of polylysine, and then an aqueous solution of boron nitride was added. The mixture was then freeze-dried to obtain a polylysine-vermiculite composite aerogel material with a three-dimensional porous network structure.
2. The method for preparing a polylysine / vermiculite composite aerogel material according to claim 1, characterized in that, The ratio of vermiculite powder to saturated sodium chloride solution is (1.2-5.4) g : (1-200) mL.
3. The method for preparing a polylysine / vermiculite composite aerogel material according to claim 1, characterized in that, The ratio of modified vermiculite to lithium salt solution is (1.2-5.4) g : (50-150) mL.
4. The method for preparing a polylysine / vermiculite composite aerogel material according to claim 1, characterized in that, The molar concentration of the vermiculite nanosheet dispersion is 1-10 mol / L.
5. The method for preparing a polylysine / vermiculite composite aerogel material according to claim 1, characterized in that, The mass ratio of vermiculite nanosheet dispersion to polylysine is (1-100) mg: (1-100) mg.
6. The method for preparing a polylysine / vermiculite composite aerogel material according to claim 1, characterized in that, The mass ratio of vermiculite nanosheet dispersion to boron nitride is (1-100) mg: (1-100) mg.
7. The method for preparing a polylysine / vermiculite composite aerogel material according to claim 1, characterized in that, The specific steps for gradient centrifugation of the stripped products are as follows: First, unpeeled particles are removed by low-speed centrifugation. The supernatant is then collected and centrifuged at high speed. The resulting precipitate is redispersed to different concentrations of vermiculite nanosheet dispersions.
8. The method for preparing a polylysine / vermiculite composite aerogel material according to claim 7, characterized in that, The speed of low-speed centrifugation is 100-500 rpm, and the time of low-speed centrifugation is 5-20 min; The high-speed centrifugation speed is 5000-6000 rpm, and the high-speed centrifugation time is 20-40 min.
9. A polylysine / vermiculite composite aerogel material, characterized in that, The composite aerogel material is prepared by the method described in any one of claims 1-8, and the composite aerogel material is: The hydrogel formed by the electrostatic interaction between polylysine and vermiculite nanosheets will generate a high-porosity aerogel with an open pore structure after freeze-drying, exhibiting an ordered layered structure; with the addition of boron nitride, it exhibits a scaly layered structure, with porous and loose properties, which facilitates the adsorption of formaldehyde into the aerogel material.
10. An application of a polylysine / vermiculite composite aerogel material, characterized in that, Application of the composite aerogel material prepared by the method according to any one of claims 1-8 in formaldehyde removal.