Novel micro-plastic composite adsorption material and preparation method thereof
By combining modified sodium alginate, nanofibers, and biochar with graphene-based composites, a highly efficient and recyclable microplastic composite adsorbent material was prepared, solving the problems of low adsorption capacity and difficult separation in existing technologies, and realizing rapid and efficient microplastic removal and multiple recycling.
Patent Information
- Application Number
- CN202511538692.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-27
- Publication Date
- 2025-12-12
AI Technical Summary
Existing composite materials have low adsorption capacity per unit mass when adsorbing microplastics. In particular, the proportion of active components decreases after the addition of inactive fillers, resulting in a decrease in overall capacity. Furthermore, traditional adsorption materials are difficult to separate and recover efficiently.
A novel microplastic composite adsorbent material was prepared by pyrolysis, stirring, and cross-linking using modified sodium alginate, modified nanofibers, modified biochar, and graphene-based composites. The graphene-based composites were modified with Ag3PO4 to form a porous network and high specific surface area. Combined with the hydrophobicity of modified sodium alginate and the multiple active sites of modified biochar, rapid and efficient adsorption was achieved.
It significantly improves the adsorption capacity and efficiency of microplastics. The material expands rapidly in water, enhancing its affinity for microplastics and achieving multi-target removal. The separation process is simplified through magnetic recovery, maintaining high adsorption rate and stability over multiple cycles.
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of microplastics, more particularly, it relates to a novel microplastic composite adsorption material and a preparation method thereof. BACKGROUND
[0002] Microplastics (MP) and nanoplastics (NP) are widely present in water bodies, soil and atmosphere. Traditional filtration, sedimentation and other technologies are high in cost and low in efficiency. Adsorbents have become a hot spot due to their simple operation, reusability and wide applicability. In recent years, research focus has shifted from single adsorbents to composite materials, which improve specific surface area, hydrophilic / hydrophobic regulation and chemical activity through structure and function synergy, so as to achieve higher adsorption capacity and faster kinetics.
[0003] Microplastics pose a great threat to humans and the environment. Microplastic pollution originates from multiple channels, including the production and use of plastic products, the release of fibers during laundry, the decomposition of plastic waste, and the use of plastic microbeads in personal care products. These microplastic particles enter the environment such as soil, rivers, lakes and oceans, causing negative impacts on ecosystems and biodiversity.
[0004] Microplastics can enter the human body through the food chain, and long-term intake of microplastics may cause damage to organs such as liver, kidney and immune system[8]. Microplastics may contain harmful substances such as phthalates, bisphenol A (BPA), etc. These chemicals are believed to have adverse effects on the endocrine and reproductive systems. Studies have shown that these harmful substances may interfere with the balance of estrogen and androgen, leading to hormonal imbalance, abnormal reproductive development, and the occurrence of diseases such as cancer. Microplastics may also affect the human nervous system. Studies have found that harmful substances in microplastics can cross the blood-brain barrier, affecting the normal function of nerve cells, leading to behavioral abnormalities, emotional fluctuations, and decreased cognitive ability.
[0005] In the prior art, although the composite material improves the affinity by introducing functional groups, the actual unit mass adsorption capacity is still lower than expected, especially after adding non-active fillers, the proportion of active components that actually play a role in adsorption decreases, leading to a decrease in overall capacity. SUMMARY
[0006] The present application provides a novel microplastic composite adsorption material and a preparation method thereof. The various composite materials exhibit rapid, efficient and highly selective performance, with excellent adsorption rate, far exceeding that of traditional adsorption materials.
[0007] In a first aspect, the present invention provides a novel microplastic composite adsorbent material comprising the following raw materials in parts by weight: 20-50 parts of modified sodium alginate, 8-12 parts of modified nanofibers, 3-8 parts of graphene-based composite, 2-4 parts of modified biochar, 2-6 parts of plasticizer, 1-3 parts of crosslinking agent, 0.5-1 part of antioxidant, and 0.5-1 part of L-2-amino-3-mercaptopropionic acid; The graphene-based composite was prepared by modifying the surface of a graphene gel with Ag3PO4.
[0008] Preferably, the mass ratio of Ag3PO4 to the graphene gel is 1~3:5~8.
[0009] Preferably, the modified sodium alginate is prepared by esterifying the hydroxyl groups on the sodium alginate molecule with formic acid, and then linking octanoyl chloride and formic acid through an ester group.
[0010] Preferably, in the process of esterifying the hydroxyl groups on sodium alginate molecules with formic acid, the mass ratio of formic acid to sodium alginate molecules is 1:2~3; and the mass ratio of octanoyl chloride to formic acid is 2~5:1~2.
[0011] Preferably, the modified nanofibers are prepared by mixing β-cyclodextrin polylactic acid loaded with thyme essential oil with polycaprolactone and spinning the mixture into nanofibers; the mass ratio of β-cyclodextrin polylactic acid loaded with thyme essential oil to polycaprolactone is 1~2:1~3.
[0012] Preferably, the modified biochar is prepared by modifying biochar with humic acid and Fe2O3; the mass ratio of humic acid, Fe2O3 and biochar is 1~2:2~3:5~11.
[0013] Preferably, the plasticizer is selected from at least one of acetylated tributyl citrate, triacetic acid citrate, dioctyl citrate, didecyl citrate, and triethyl citrate.
[0014] Preferably, the crosslinking agent is selected from at least one of N,N-methylenebisacrylamide, epichlorohydrin, glutaraldehyde, divinylbenzene, and N,N′-bisacrylamide dithioacetamide.
[0015] Preferably, the antioxidant is selected from at least one of 2,6-di-tert-butyl-4-methylphenol, 2,4-di-tert-butyl-6-hydroxytoluene, tris(2,4-di-tert-butyl-phenol) phosphite, and pentaerythritol tetrakis(β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate).
[0016] Secondly, the present invention provides a method for preparing a novel microplastic composite adsorbent material, comprising the following steps: (1) Modified nanofibers, modified biochar and graphene-based composites were pyrolyzed under an inert atmosphere of nitrogen at a temperature of 400~600℃ to obtain a co-pyrolyzed mixture; (2) After drying the co-pyrolysis mixture at 60~80℃, add it to the modified sodium alginate solution, stir thoroughly, and add plasticizer, crosslinking agent, antioxidant and L-2-amino-3-mercaptopropionic acid dropwise to obtain a gel; (3) After rinsing the gel with deionized water, dry it at 60~80℃ to obtain a novel microplastic composite adsorbent material.
[0017] In summary, the present invention has the following beneficial effects: This invention incorporates a graphene-based composite, prepared by modifying the surface of a graphene gel with Ag3PO4. The two-dimensional layered structure of graphene provides an extremely high specific surface area and a porous network, significantly increasing the number of adsorption sites and thus enhancing the adsorption capacity of the microplastics. The graphene hydrogel can rapidly expand in water, increasing the pore volume and thereby increasing the contact probability between the microplastics and the adsorbent, significantly improving adsorption efficiency. Loading Ag3PO4 onto the graphene gel surface utilizes both the high specific surface area, tunable surface chemistry, and excellent electron transport properties of graphene, and the visible-light photocatalytic activity of Ag3PO4, achieving efficient adsorption, in-situ degradation, and recycling of microplastics.
[0018] 2. The modified sodium alginate in this invention is prepared by esterifying the hydroxyl groups on the sodium alginate molecule with formic acid, and then linking octanoyl chloride to formic acid via ester groups. The formic acid esterification followed by the incorporation of long-chain ester groups from octanoyl chloride transforms the sodium alginate surface from hydrophilic to hydrophobic, enhancing its affinity for hydrophobic microplastics and thus increasing its adsorption capacity. The long-chain ester groups provide more nonpolar van der Waals interactions, resulting in strong adsorption of hydrocarbon chains on the microplastic surface; simultaneously, the original carboxyl groups are retained, allowing for synergistic adsorption with charged or polar pollutants through electrostatic / hydrogen bonding, achieving multi-target removal. The introduction of the hydrophobic chain enables the modified sodium alginate to better form a uniform composite with modified biochar, improving overall adsorption efficiency. The modified sodium alginate prepared using formic acid esterification-octanoyl chloride grafting retains the natural advantages of sodium alginate (degradable, low toxicity) while significantly improving hydrophobicity, mechanical strength, and adsorption performance through chemical modification.
[0019] 3. In the novel microplastic composite adsorbent material prepared by this invention, modified sodium alginate, modified nanofibers, and modified biochar are added. Sodium alginate provides a three-dimensional network with macroscopic support, nanofibers fill micropores, and modified biochar contributes micropores and abundant active sites, forming a macro-microporous hierarchical structure, thereby improving the overall adsorption capacity and permeation rate.
[0020] 4. In the novel microplastic composite adsorbent material prepared by this invention, the functional groups of each component are complementary. The carboxyl groups of sodium alginate, the quaternary ammonium groups of nanofibers, and the metal oxide / acidic functional groups of modified biochar provide a variety of adsorption mechanisms, including electrostatic attraction, hydrogen bonding, π-π interaction, and hydrophobic interaction, which enable the material to exhibit high efficiency in capturing microplastics of different types and different surface charges.
[0021] 5. The novel microplastic composite adsorbent material prepared by this invention has magnetic recovery and structural stability. The coupling of magnetic biochar and sodium alginate gel allows the entire material to be recovered in one go by an external magnetic field after adsorption, avoiding the disadvantage of traditional gels being difficult to separate. At the same time, the cross-linking of sodium alginate improves the mechanical strength of the composite material, ensuring that it maintains a high adsorption rate after multiple cycles (>20 times).
[0022] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit the scope of protection of the present invention. Detailed Implementation
[0023] The present invention will be further described in detail below with reference to the embodiments. It should be noted that: unless otherwise specified, the conditions in the following embodiments are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following embodiments can be obtained from commercially available sources.
[0024] Example Example 1 A novel microplastic composite adsorbent material comprises the following raw materials in parts by weight: 20 parts modified sodium alginate, 8 parts modified nanofibers, 3 parts graphene-based composite, 2 parts modified biochar, 2 parts plasticizer, 1 part crosslinking agent, 0.5 parts antioxidant, and 0.5 parts L-2-amino-3-mercaptopropionic acid. The graphene-based composite was prepared by modifying the surface of graphene gel with Ag3PO4, and the mass ratio of Ag3PO4 to graphene gel was 1:5.
[0025] Modified sodium alginate is prepared by esterifying the hydroxyl groups on sodium alginate molecules with formic acid, and then linking octanoyl chloride and formic acid through ester groups. In the process of esterifying the hydroxyl groups on sodium alginate molecules with formic acid, the mass ratio of formic acid to sodium alginate molecules is 1:2; the mass ratio of octanoyl chloride to formic acid is 2:1.
[0026] Modified nanofibers were prepared by adding thyme essential oil-loaded β-cyclodextrin polylactic acid and polycaprolactone, and then spinning the mixture into nanofibers; the mass ratio of thyme essential oil-loaded β-cyclodextrin polylactic acid to polycaprolactone was 1:1.
[0027] Modified biochar was prepared by modifying biochar with humic acid and Fe2O3; the mass ratio of humic acid, Fe2O3 and biochar was 1:2:5.
[0028] The plasticizer is selected from tributyl acetyl citrate; the crosslinking agent is selected from N,N-methylenebisacrylamide; and the antioxidant is selected from 2,6-di-tert-butyl-4-methylphenol.
[0029] A method for preparing a novel microplastic composite adsorbent material includes the following steps: (1) Modified nanofibers, modified biochar and graphene-based composites were pyrolyzed under an inert atmosphere of nitrogen at a temperature of 400℃ to obtain a co-pyrolyzed mixture; (2) After drying the co-pyrolysis mixture at 60°C, add it to the modified sodium alginate solution, stir thoroughly, and add plasticizer, crosslinking agent, antioxidant and L-2-amino-3-mercaptopropionic acid dropwise to obtain a gel; (3) After rinsing the gel with deionized water, it was dried at 60°C to obtain a novel microplastic composite adsorbent material.
[0030] Example 2 A novel microplastic composite adsorbent material comprises the following raw materials in parts by weight: 30 parts modified sodium alginate, 10 parts modified nanofibers, 4 parts graphene-based composite, 3 parts modified biochar, 3 parts plasticizer, 2 parts crosslinking agent, 0.8 parts antioxidant, and 0.6 parts L-2-amino-3-mercaptopropionic acid. The graphene-based composite was prepared by modifying the surface of graphene gel with Ag3PO4, and the mass ratio of Ag3PO4 to graphene gel was 2:5.
[0031] Modified sodium alginate is prepared by esterifying the hydroxyl groups on sodium alginate molecules with formic acid, and then linking octanoyl chloride and formic acid through ester groups. In the process of esterifying the hydroxyl groups on sodium alginate molecules with formic acid, the mass ratio of formic acid to sodium alginate molecules is 1:2; the mass ratio of octanoyl chloride to formic acid is 3:1.
[0032] Modified nanofibers were prepared by adding thyme essential oil-loaded β-cyclodextrin polylactic acid and polycaprolactone, and then spinning the mixture into nanofibers; the mass ratio of thyme essential oil-loaded β-cyclodextrin polylactic acid to polycaprolactone was 1:2.
[0033] Modified biochar was prepared by modifying biochar with humic acid and Fe2O3; the mass ratio of humic acid, Fe2O3 and biochar was 1:2:7.
[0034] The plasticizer is selected from tributyl acetyl citrate; the crosslinking agent is selected from N,N-methylenebisacrylamide; and the antioxidant is selected from 2,6-di-tert-butyl-4-methylphenol.
[0035] A method for preparing a novel microplastic composite adsorbent material includes the following steps: (1) Modified nanofibers, modified biochar and graphene-based composites were pyrolyzed under an inert atmosphere of nitrogen at a temperature of 450°C to obtain a co-pyrolyzed mixture; (2) After drying the co-pyrolysis mixture at 65°C, add it to the modified sodium alginate solution, stir thoroughly, and add plasticizer, crosslinking agent, antioxidant and L-2-amino-3-mercaptopropionic acid dropwise to obtain a gel; (3) After rinsing the gel with deionized water, it was dried at 65°C to obtain a novel microplastic composite adsorbent material.
[0036] Example 3 A novel microplastic composite adsorbent material comprises the following raw materials in parts by weight: 40 parts modified sodium alginate, 10 parts modified nanofibers, 5 parts graphene-based composite, 3 parts modified biochar, 4 parts plasticizer, 2 parts crosslinking agent, 0.9 parts antioxidant, and 0.8 parts L-2-amino-3-mercaptopropionic acid. The graphene-based composite was prepared by modifying the surface of graphene gel with Ag3PO4, and the mass ratio of Ag3PO4 to graphene gel was 3:5.
[0037] Modified sodium alginate is prepared by esterifying the hydroxyl groups on sodium alginate molecules with formic acid, and then linking octanoyl chloride and formic acid through ester groups. In the process of esterifying the hydroxyl groups on sodium alginate molecules with formic acid, the mass ratio of formic acid to sodium alginate molecules is 1:2; the mass ratio of octanoyl chloride to formic acid is 5:1.
[0038] Modified nanofibers were prepared by adding thyme essential oil-loaded β-cyclodextrin polylactic acid and polycaprolactone, and then spinning the mixture into nanofibers; the mass ratio of thyme essential oil-loaded β-cyclodextrin polylactic acid to polycaprolactone was 1:2.
[0039] Modified biochar was prepared by modifying biochar with humic acid and Fe2O3; the mass ratio of humic acid, Fe2O3 and biochar was 2:2:9.
[0040] The plasticizer is selected from tributyl acetyl citrate; the crosslinking agent is selected from N,N-methylenebisacrylamide; and the antioxidant is selected from 2,6-di-tert-butyl-4-methylphenol.
[0041] A method for preparing a novel microplastic composite adsorbent material includes the following steps: (1) Modified nanofibers, modified biochar and graphene-based composites were pyrolyzed under an inert atmosphere of nitrogen at a temperature of 500℃ to obtain a co-pyrolyzed mixture; (2) After drying the co-pyrolysis mixture at 70°C, add it to the modified sodium alginate solution, stir thoroughly, and add plasticizer, crosslinking agent, antioxidant and L-2-amino-3-mercaptopropionic acid dropwise to obtain a gel; (3) After rinsing the gel with deionized water, it is dried at 70°C to obtain a novel microplastic composite adsorbent material.
[0042] Example 4 A novel microplastic composite adsorbent material comprises the following raw materials in parts by weight: 50 parts modified sodium alginate, 12 parts modified nanofibers, 8 parts graphene-based composite, 4 parts modified biochar, 6 parts plasticizer, 3 parts crosslinking agent, 1 part antioxidant, and 1 part L-2-amino-3-mercaptopropionic acid. The graphene-based composite was prepared by modifying the surface of graphene gel with Ag3PO4, and the mass ratio of Ag3PO4 to graphene gel was 3:8.
[0043] Modified sodium alginate is prepared by esterifying the hydroxyl groups on sodium alginate molecules with formic acid, and then linking octanoyl chloride and formic acid through ester groups. In the process of esterifying the hydroxyl groups on sodium alginate molecules with formic acid, the mass ratio of formic acid to sodium alginate molecules is 1:3; the mass ratio of octanoyl chloride to formic acid is 5:2.
[0044] Modified nanofibers were prepared by adding thyme essential oil-loaded β-cyclodextrin polylactic acid and polycaprolactone, and then spinning the mixture into nanofibers; the mass ratio of thyme essential oil-loaded β-cyclodextrin polylactic acid to polycaprolactone was 2:3.
[0045] Modified biochar was prepared by modifying biochar with humic acid and Fe2O3; the mass ratio of humic acid, Fe2O3 and biochar was 2:3:11.
[0046] The plasticizer is selected from tributyl acetyl citrate; the crosslinking agent is selected from N,N-methylenebisacrylamide; and the antioxidant is selected from 2,6-di-tert-butyl-4-methylphenol.
[0047] A method for preparing a novel microplastic composite adsorbent material includes the following steps: (1) Modified nanofibers, modified biochar and graphene-based composites were pyrolyzed under an inert atmosphere of nitrogen at a temperature of 600℃ to obtain a co-pyrolyzed mixture; (2) After drying the co-pyrolysis mixture at 80°C, add it to the modified sodium alginate solution, stir thoroughly, and add plasticizer, crosslinking agent, antioxidant and L-2-amino-3-mercaptopropionic acid dropwise to obtain a gel; (3) After rinsing the gel with deionized water, it is dried at 80°C to obtain a novel microplastic composite adsorbent material.
[0048] Comparative Example 1 The difference from Example 1 is that no graphene-based composite was added.
[0049] Comparative Example 2 The difference from Example 1 is that no modified nanofibers were added.
[0050] Comparative Example 3 The difference from Example 1 is that no modified sodium alginate was added.
[0051] Table 1 Performance Test Results Microplastic adsorption rate (%) Example 1 98 Example 2 97 Example 3 96 Example 4 95 Comparative Example 1 82 Comparative Example 2 80 Comparative Example 3 78 The above description is merely an exemplary embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A novel microplastic composite adsorbent material, characterized in that, The raw materials include the following parts by weight: 20-50 parts of modified sodium alginate, 8-12 parts of modified nanofibers, 3-8 parts of graphene-based composite, 2-4 parts of modified biochar, 2-6 parts of plasticizer, 1-3 parts of crosslinking agent, 0.5-1 part of antioxidant and 0.5-1 part of L-2-amino-3-mercaptopropionic acid; The graphene-based composite was prepared by modifying the surface of a graphene gel with Ag3PO4.
2. The novel microplastic composite adsorbent material according to claim 1, characterized in that, The mass ratio of Ag3PO4 to the graphene gel is 1~3:5~8.
3. The novel microplastic composite adsorbent material according to claim 1, characterized in that, The modified sodium alginate is prepared by esterifying the hydroxyl groups on the sodium alginate molecule with formic acid, and then linking octanoyl chloride and formic acid through an ester group.
4. The novel microplastic composite adsorbent material according to claim 3, characterized in that, In the process of esterifying the hydroxyl groups on sodium alginate molecules with formic acid, the mass ratio of formic acid to sodium alginate molecules is 1:2~3; and the mass ratio of octanoyl chloride to formic acid is 2~5:1~2.
5. The novel microplastic composite adsorbent material according to claim 1, characterized in that, The modified nanofibers are prepared by mixing β-cyclodextrin polylactic acid loaded with thyme essential oil with polycaprolactone and spinning the mixture into nanofibers; the mass ratio of β-cyclodextrin polylactic acid loaded with thyme essential oil to polycaprolactone is 1~2:1~3.
6. The novel microplastic composite adsorbent material according to claim 1, characterized in that, The modified biochar is prepared by modifying biochar with humic acid and Fe2O3; the mass ratio of humic acid, Fe2O3 and biochar is 1~2:2~3:5~11.
7. The novel microplastic composite adsorbent material according to claim 1, characterized in that, The plasticizer is selected from at least one of acetylated tributyl citrate, triacetic acid citrate, dioctyl citrate, didecyl citrate, and triethyl citrate.
8. The novel microplastic composite adsorbent material according to claim 1, characterized in that, The crosslinking agent is selected from at least one of N,N-methylenebisacrylamide, epichlorohydrin, glutaraldehyde, divinylbenzene, and N,N′-bisacrylamide dithioacetamide.
9. The novel microplastic composite adsorbent material according to claim 1, characterized in that, The antioxidant is selected from at least one of 2,6-di-tert-butyl-4-methylphenol, 2,4-di-tert-butyl-6-hydroxytoluene, tris(2,4-di-tert-butyl-phenol) phosphite, and pentaerythritol tetrakis(β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate).
10. The method for preparing the novel microplastic composite adsorbent material according to any one of claims 1 to 9, characterized in that, Includes the following steps: (1) Modified nanofibers, modified biochar and graphene-based composites were pyrolyzed under an inert atmosphere of nitrogen at a temperature of 400~600℃ to obtain a co-pyrolyzed mixture; (2) After drying the co-pyrolysis mixture at 60~80℃, add it to the modified sodium alginate solution, stir thoroughly, and add plasticizer, crosslinking agent, antioxidant and L-2-amino-3-mercaptopropionic acid dropwise to obtain a gel; (3) After rinsing the gel with deionized water, dry it at 60~80℃ to obtain a novel microplastic composite adsorbent material.