Special membrane material for targeted trapping of juvenile clams in water and method for its production

Abstract

The application discloses a kind of special membrane material for targeting trapping Corbicula fluminea larvae in water and a preparation method thereof, and belongs to the field of water environmental biological pollution prevention and control.The membrane material is a multilayer composite structure, including a nanofiber membrane substrate layer, an interface adhesion layer and a functional modification layer.The interface adhesion layer is a biomimetic condensed layer gel formed by hydrophobic polyelectrolyte and phytic acid solidification;The functional modification layer is covalently grafted with a biomimetic adhesion protein active peptide segment and a Corbicula fluminea larva chemical information substance.The material actively lures larvae by chemical information substance, and realizes high-strength adhesion capture by using a biomimetic peptide segment rich in aromatic and cationic amino acids, and is integrated with "trapping body".The preparation method includes the steps of electrospinning substrate, surface activation, coating gel and functional modification, etc.The material has high selectivity and high capture rate for Corbicula fluminea larvae, and is environmentally friendly, long-acting and stable, and is suitable for green prevention and control of Corbicula fluminea larvae pollution in facilities such as water conveying pipeline and pump station.

Description

Technical Field

[0001] This invention relates to the field of aquatic environmental biological pollution control technology, specifically to a special functional membrane material for actively and targetedly trapping freshwater clam larvae and its preparation method. Background Technology

[0002] Freshwater mussels (commonly known as swamp clams) are a globally invasive freshwater fouling organism. Their larvae live freely in water and readily attach to the inner walls of water infrastructure such as pipelines, pumping stations, and hydroelectric power station cooling systems, forming a dense biofouling layer. This large-scale attachment not only severely reduces the cross-sectional area of ​​pipelines, increases flow resistance, and leads to a sharp rise in energy consumption, but also accelerates localized corrosion and perforation of metal pipelines, posing a persistent threat to water supply security, energy efficiency, and facility lifespan. Therefore, developing efficient and environmentally friendly swamp clam larvae control technologies is of great significance for ensuring water network safety and reducing operation and maintenance costs. Currently, the control technologies for swamp clam larvae are mainly divided into three categories: physical methods, chemical methods, and biological-ecological methods.

[0003] Physical control techniques mainly include: (1) Turbulent scouring and mechanical removal, which involves artificially creating high flow rates or eddies to use hydraulic shearing to peel off attached individuals or prevent their attachment. The effectiveness of this method is highly dependent on specific hydrodynamic conditions, and it is not effective in low-flow-rate pipe sections or complex structures, and it consumes a lot of energy. (2) Physical filtration and adsorption, which involves using filter screens or porous materials to mechanically trap larvae. Although this method is simple and direct, it is very easy to clog, requires frequent cleaning or replacement, has high maintenance costs, and has limited trapping efficiency for very small early larvae (such as those with a body length of <0.2mm). (3) Thermal treatment, such as injecting high-temperature water to kill them. This method has a high initial investment, a narrow scope of application, and may cause adverse thermal shock to pipe materials and aquatic ecosystems. Chemical control technology is currently the most widely used method, the core of which is to add oxidizing biocides (such as chlorine, ozone) or heavy metal ions (such as copper ions). Although this method can effectively kill larvae, it has inherent defects that cannot be avoided: First, while killing pests, broad-spectrum bactericides will indiscriminately kill other beneficial microorganisms in the water, disrupting the local ecological balance; Second, residual chemical agents and possible disinfection byproducts (such as trihalomethanes) will migrate with the water, causing secondary pollution and threatening the safety of downstream water quality and drinking water hygiene; Third, long-term use can easily induce drug resistance in clams, leading to a continuous increase in the amount of agents used, resulting in a vicious cycle. Biological and ecological control technologies represent the direction of green development, mainly including: (1) Antifouling coating technology, which passively prevents biological attachment by coating the surface of facilities with low surface energy or releasing biological inhibitors. However, existing coatings are mostly "preventive" and lack the ability to actively remove large numbers of planktonic larvae that have entered the facilities, and the coatings have the risks of wear, failure and potential environmental toxicity. (2) Cutting-edge technologies such as gene regulation are still in the laboratory exploration stage, and their ecological risks, technical feasibility and regulatory approvals face huge uncertainties, making it difficult to put them into practical engineering applications in the short term.

[0004] In summary, existing technologies all have significant shortcomings: physical methods are limited by operating conditions and high maintenance costs; chemical methods are accompanied by environmental pollution and ecological risks; and emerging green technologies suffer from limited functionality or immature technology. Currently, there is a lack of a disruptive solution that can actively, accurately, and efficiently capture aquatic clam larvae while also being environmentally friendly, adaptable to various operating conditions, and long-term stable. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a special membrane material for targeted trapping of larvae of the water clam and its preparation method. This material employs a multi-layered, multi-scale synergistic design, integrating biologically specific attraction and biomimetic strong adhesion functions. It can actively and selectively trap and immobilize larvae of the water clam with a body length ranging from 0.14 mm to 1 mm without relying on strong water flow or introducing chemical toxins. The membrane material is then removed to kill the larvae attached to it, thus achieving efficient, environmentally friendly, and long-lasting biofouling control.

[0006] Specifically, the three-layer structure of the membrane material of this invention acts on different scales, with clear division of labor and synergistic cooperation, together forming a complete "trapping-integrated" technical solution. The chemical pheromone layer acts on the meter-scale water space, actively attracting larvae dispersed in the water to the vicinity of the material surface by simulating the natural attraction signals of clam larvae, solving the problem of larvae "not coming". The interface adhesion layer acts on the material structure interface at the millimeter to micrometer scale, consisting of a biomimetic cohesive layer gel formed by hydrophobic polyelectrolytes and phytic acid. Its function is to firmly bind the functionalized modification layer to the surface of the nanofiber substrate, providing a stable "anchoring platform" for biomimetic peptides and chemical pheromones, solving the problem of functional layers "easily detaching", falling under the category of "structural adhesion". The biomimetic peptide layer acts on the nanoscale molecular interface, its core function being to form a super-strong interfacial bond with the natural adhesion proteins secreted by the larvae's byssal threads, achieving firm capture of larvae, solving the problem of larvae "not sticking", falling under the category of "biological adhesion".

[0007] Among them, the biomimetic peptide, as the core functional element of this invention, constructs an underwater super-adhesive interface at the nanoscale through the following multimodal synergistic mechanisms: First, the biomimetic peptide is rich in aromatic hydrophobic side chains of phenylalanine and tyrosine, which can actively exclude interfacial water molecules and form local hydrophobic microregions at the interface between the material and larval byssal proteins, achieving a local "dry underwater" environment and clearing obstacles for the establishment of subsequent multiple interaction forces; Second, the cationic side chains of arginine and lysine in the biomimetic peptide can form a slightly acidic reducing microenvironment locally, effectively inhibiting the phthalic acid of tyrosine residues. Premature oxidation of the bisphenol group maintains the highly active reduced state of the adhesion group, preventing premature failure in the aquatic environment. Third, the biomimetic peptides form strong interfacial bonds at the nanoscale through synergistic coupling of multiple interactions, including hydrogen bonding, metal coordination, hydrophobic interactions, and π-π stacking. Specifically, these interactions include hydrogen bonding between the tyrosine phenolic hydroxyl group and bysin, metal coordination between the catechol group and calcium, magnesium, and iron ions in the water, π-π stacking between aromatic rings, cation-π interactions between cations and the π-electron clouds of aromatic rings, and the main underwater binding driving force provided by the hydrophobic side chains of aromatic compounds. These five interactions occur synergistically and reinforce each other in the nanoscale space, resulting in an interfacial bond strength far exceeding the simple superposition of single forces.

[0008] The multimodal synergistic adhesion mechanism of the aforementioned biomimetic peptides is a key technical feature that cannot be replaced by chemical pheromones acting only on the meter-scale biological behavior layer or the interface adhesion layer acting only on the millimeter- to micrometer-scale physical structure adhesion. The three-layer structure acts on different scales of meter, millimeter, and nanometer, with clear division of labor and synergistic cooperation, together forming a complete underwater adhesion and antifouling technology solution.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] Firstly, a special membrane material for targeted trapping of aquatic clam larvae, comprising a multi-layered composite structure, including:

[0011] Nanofiber membrane substrate layer;

[0012] An interface adhesion layer coated on the substrate layer is a biomimetic cohesive layer gel formed by curing a mixture of hydrophobic polyelectrolyte and phytic acid.

[0013] In addition, a functionalized modification layer is fixed to the interface adhesion layer by chemical bonding, the functionalized modification layer comprising covalently grafted biomimetic adhesion protein active peptides and chemical pheromones for attracting magma clam larvae;

[0014] The amino acid sequence of the biomimetic adhesion protein active peptide contains a total molar content of aromatic amino acids and cationic amino acids of not less than 40%, and its sequence contains repeating units selected from (YR)n, (FK)n or combinations thereof, where Y represents tyrosine, F represents phenylalanine, R represents arginine, K represents lysine, and n is an integer from 2 to 10.

[0015] Furthermore, the nanofiber membrane substrate layer is made of polyolefin copolymer, and the fiber diameter is 200-500nm.

[0016] Furthermore, in the interfacial adhesion layer, the phenyl monomer content of the hydrophobic polyelectrolyte is 15-30 mol%, the mass mixing ratio of the hydrophobic polyelectrolyte to phytic acid is 1:1, and the thickness of the interfacial adhesion layer is 5-10 μm.

[0017] Furthermore, the biomimetic adhesion protein active peptide is derived from the byssal protein of freshwater shellfish, and the chemical pheromone is a purine nucleoside, which is one or more of uracil nucleoside, guanine, adenine, hypoxanthine, adenine nucleoside, guanine nucleoside, and hypoxanthine nucleoside.

[0018] Secondly, a method for preparing a special membrane material for targeted trapping of larvae of the water clam includes the following steps:

[0019] S1. Substrate preparation: Polyolefin copolymer nanofiber membranes were prepared using electrospinning technology;

[0020] S2. Surface activation treatment: The nanofiber membrane is subjected to surface chemical modification to introduce epoxy active groups;

[0021] S3. Construction of interfacial adhesion layer: A mixed gel precursor solution of hydrophobic polyelectrolyte and phytic acid is coated on the surface of the activated substrate and cured to form an interfacial adhesion layer;

[0022] S4. Functional modification: Utilizing the carboxyl groups on the surface of the interfacial adhesion layer, an amidation reaction is carried out using carbodiimide and N-hydroxysuccinimide as condensing agents to covalently graft the biomimetic adhesion protein active peptide and the chemical pheromone used to attract maggot larvae onto the interfacial adhesion layer to obtain the special membrane material.

[0023] Furthermore, in step S1, the electrospinning process parameters are: spinning solution concentration 10-15 wt%, voltage 15-25 kV, and receiving distance 15-20 cm.

[0024] Furthermore, in step S2, 3-(2,3-epoxypropoxy)propyltrimethoxysilane is used as an activating agent to immerse the nanofiber membrane at room temperature for 2-4 hours.

[0025] Furthermore, in step S3, the curing conditions are natural curing at room temperature for 24 hours.

[0026] Thirdly, a method for preparing a special membrane material for targeted trapping of larvae of the water clam includes the following steps:

[0027] S1. Substrate preparation: Polyolefin copolymer nanofiber membranes were prepared using electrospinning technology;

[0028] S2. Surface activation treatment: The nanofiber membrane is subjected to surface chemical modification to introduce epoxy active groups;

[0029] S3. Construction of interfacial adhesion layer: A mixed gel precursor solution of hydrophobic polyelectrolyte and phytic acid is coated on the surface of the activated substrate and cured to form an interfacial adhesion layer;

[0030] S4. Functional modification: Utilizing the active groups generated after activation of the interface adhesion layer, the biomimetic adhesion protein active peptide and the chemical pheromone used to attract maggot larvae are covalently grafted onto the interface adhesion layer through a thiol-ene click chemistry reaction to obtain the special membrane material.

[0031] The 'thiol-alkene click chemistry reaction' refers to the efficient and selective covalent coupling reaction between thiols and alkenes under mild conditions.

[0032] Fourthly, the application of special membrane materials for targeted trapping of water clams larvae in preventing fouling by water clams larvae in water pipelines and pumping stations.

[0033] The beneficial effects of the technical solutions provided in this application include at least the following:

[0034] 1. This invention achieves a proactive, targeted control model of "luring before trapping," significantly improving control efficiency. It synergistically integrates specific chemical pheromones of the clam larvae with biomimetic adhesion protein active peptides on the same material interface. The pheromone acts as an attractant, actively and efficiently concentrating dispersed larvae in the water onto the material surface; the biomimetic peptides (rich in aromatic and cationic amino acids, such as the designed (YR)n and (FK)n repeating sequences) provide super-strong and specific adhesion, firmly capturing larvae upon contact. This synergistic effect of the "luring-trapping" dual mechanism achieves a qualitative leap from passive interception to active elimination, fundamentally changing the existing passive, extensive, and environmentally costly control model, and realizing a strategic shift from "passive interception / killing" to "proactive targeted trapping."

[0035] 2. Excellent selectivity and environmental friendliness. The material exhibits high biological specificity for clam larvae. The pheromones and biomimetic peptides in the functionalized modification layer are designed specifically for the biological characteristics of clam larvae, resulting in minimal adsorption of non-target organisms (such as algae and rotifers). Tests show that the material achieves a selective adsorption rate of up to 92.3% for clam larvae, while traditional filter membranes only achieve 45.7%. This high selectivity avoids indiscriminate killing, minimizes disturbance to the aquatic ecosystem, and represents a green and environmentally friendly control method, overcoming the inherent defects of chemical methods that pollute the environment and disrupt the ecological balance.

[0036] 3. Strong environmental adaptability and wide range of applicable working conditions. Using polyolefin nanofibers as the substrate and combining them with a biomimetic coagulation layer gel interface, the material possesses excellent mechanical strength and flexibility. Experiments have shown that this material maintains a high trapping rate under a wide range of water quality conditions, from freshwater to brackish water (salinity ≤3.5%). Furthermore, its effect is not dependent on high-velocity water flow; it is equally effective in low-velocity (0.1-0.3 m / s) pipeline conditions, solving the problems of high energy consumption and harsh conditions associated with physical flushing methods, and broadening its application scenarios.

[0037] 4. Stable structure and long-lasting durability. A stable, integrated composite structure is constructed through a multi-level chemical bonding strategy (substrate activation, gel curing, and covalent grafting of functional molecules). The biomimetic condensed layer gel (hydrophobic polyelectrolyte / phytic acid) is firmly bonded to the substrate, and the functionalized modification layer is fixed by amide bonds or click chemistry, making it resistant to erosion by water flow or long-term immersion.

[0038] 5. The preparation methods are flexible and controllable, and easy to scale up. This invention provides two reliable preparation methods (amidation reaction and click chemistry), with clear process steps and well-defined parameters. The substrate is prepared using mature electrospinning technology, and functionalization modification is completed through conventional liquid-phase reactions. The raw materials are readily available, the process is controllable, and it has good process repeatability and potential for large-scale production.

[0039] In summary, the special membrane material provided by this invention integrates high efficiency, high selectivity, environmental friendliness, strong environmental adaptability, and long-term stability, providing a revolutionary active targeted solution for the control of maggot larvae in water pipelines, pumping stations, and other facilities. It has significant engineering application value and broad prospects for promotion. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the layered structure of the special membrane material of the present invention.

[0042] Figure 2 This is a schematic diagram comparing the capture rate of clam larvae with that of the special membrane material of this invention, traditional membranes, and membrane-free conditions.

[0043] Figure reference numerals: 1-functionalized modification layer; 2-interfacial adhesion layer (where spheres represent gel structures); 3-nanofiber membrane substrate layer. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0045] like Figure 1As shown in the embodiment of the present invention, a special membrane material for targeted trapping of maggot larvae in water is provided. It has a multilayer composite structure, comprising: a nanofiber membrane substrate layer 3; an interface adhesion layer 2 coated on the nanofiber membrane substrate layer 3, wherein the interface adhesion layer 2 is a biomimetic cohesive layer gel formed by curing a mixture of hydrophobic polyelectrolyte and phytic acid; and a functionalized modification layer 1 fixed to the interface adhesion layer by chemical bonding. The functionalized modification layer 1 contains covalently grafted biomimetic adhesion protein active peptides and chemical pheromones for attracting maggot larvae. The amino acid sequence of the biomimetic adhesion protein active peptides contains a total molar content of aromatic amino acids and cationic amino acids of not less than 40%, and its sequence contains repeating units selected from (YR)n, (FK)n, or combinations thereof, where Y represents tyrosine, F represents phenylalanine, R represents arginine, K represents lysine, and n is an integer from 2 to 10. The nanofiber membrane substrate layer is made of a polyolefin copolymer with a fiber diameter of 200-500 nm.

[0046] In the interfacial adhesion layer, the phenyl monomer content of the hydrophobic polyelectrolyte is 15-30 mol%, the mass mixing ratio of the hydrophobic polyelectrolyte to phytic acid is 1:1, and the thickness of the interfacial adhesion layer is 5-10 μm.

[0047] The biomimetic adhesion protein active peptide is derived from the byssal protein of freshwater shellfish.

[0048] Example 1:

[0049] A method for preparing a special membrane material for targeted trapping of aquatic clam larvae includes the following steps:

[0050] S1. Substrate Preparation: Polypropylene-polyethylene copolymer particles are dissolved in the organic solvent N,N-dimethylformamide (DMF) and stirred thoroughly until completely dissolved to prepare a homogeneous spinning solution with a mass fraction of 10%-15%, preferably 12%. A standard electrospinning apparatus is used, with the operating voltage set at 15-25 kV, preferably 20 kV, and the distance between the spinning needle and the receiving roller at 15-20 cm, preferably 18 cm, and spinning is performed at a constant feed speed. Under these process conditions, a substrate film composed of interwoven nanofibers is prepared, with the average fiber diameter controlled at approximately 200-500 nm, preferably 350 nm.

[0051] S2. Surface Activation Treatment: The nanofiber membrane prepared above is cut to the required size and immersed in a 1 wt% 3-(2,3-epoxypropoxy)propyltrimethoxysilane (GPMS) ethanol solution, ensuring complete wetting of the membrane. The membrane is allowed to stand at room temperature (25±2°C) for 2-4 hours, preferably 3 hours. After treatment, the membrane is removed and repeatedly shaken and washed three times with anhydrous ethanol to remove any physically adsorbed residual reagents. The membrane is then transferred to a 60°C oven and dried for 1 hour to obtain an activated substrate with a surface rich in epoxy active groups, providing reaction sites for subsequent grafting.

[0052] S3. Construction of the interfacial adhesion layer: Weigh out hydrophobic polyelectrolyte (Pcπ) with a phenyl monomer content of 15-30 mol% and phytic acid (PA) in a container at a mass ratio of 1:1. Mix thoroughly by mechanical stirring (500 rpm for 30 minutes) to form a homogeneous biomimetic cohesive layer gel precursor solution with a certain viscosity. Using a doctor blade coating method, uniformly coat the precursor solution onto the surface of the activated substrate obtained in step S2. By controlling the doctor blade gap, the wet film thickness is controlled to approximately 80 μm. The coated material is then placed in a room temperature environment and allowed to cure naturally for 24 hours. After curing, the thickness of the formed biomimetic adhesive interfacial layer gel is measured to be approximately 8 μm, and this layer is stably adhered to the substrate surface.

[0053] S4. Functional modifications:

[0054] a. Synthesis of Active Peptides: The target biomimetic peptide was synthesized on an automated peptide synthesizer using a standard Fmoc solid-phase synthesis strategy. The amino acid sequence of this peptide contains repeating units selected from (YR)n, (FK)n, or combinations thereof, where Y represents tyrosine, F represents phenylalanine, R represents arginine, K represents lysine, and n is an integer from 2 to 10. As an example, this embodiment synthesized repeating units with n=3. This design ensures that the peptide is rich in aromatic amino acids such as tyrosine and phenylalanine, as well as cationic amino acids such as lysine and arginine, with a total molar content of not less than 40%.

[0055] b. Chemical Grafting: The membrane material with the biomimetic adhesive interface layer obtained in step S3 is immersed in pH 7.4 phosphate-buffered saline (PBS) containing the above-mentioned synthetic peptide (1 mM concentration) and purified *Cyprinus maculatus* larva-specific pheromone (0.5 mM concentration). The attractant *Cyprinus maculatus* larva-specific chemical pheromone is a purine nucleoside, which may include one or more of uracil nucleoside, guanine, adenine, hypoxanthine, adenine nucleoside, guanine nucleoside, and hypoxanthine nucleoside. A catalyst system is added: 50 mM 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) and 25 mM N-hydroxysuccinimide (NHS). The reaction was carried out with gentle shaking at room temperature for 12 hours, allowing the carboxyl groups at the C-terminus of the peptides and suitable functional groups on the pheromone molecules to covalently fix with the active groups (such as amino and hydroxyl groups) on the phytic acid or Pcπ chain in the biomimetic adhesion interface layer via EDC / NHS-mediated amide bond binding. After the reaction, the membrane material was thoroughly washed with PBS buffer and deionized water sequentially to remove unreacted substances, and then dried at room temperature to obtain the special membrane material for targeted trapping of water clams larvae.

[0056] When clam larvae are actively lured to the vicinity of the material surface by chemical pheromones and come into contact, the larvae's byssal threads rapidly secrete natural byssal adhesion proteins. At this time, the biomimetic peptides on the material surface can specifically recognize and bind to the natural byssal proteins secreted by the larvae. This binding is an artificial simulation and extension of the natural adhesion mechanism, rather than a simple physical adsorption or random interaction. Through multiple non-covalent interactions between the biomimetic peptides and the natural byssal proteins (including hydrogen bonds, metal coordination, hydrophobic interactions, π-π stacking, cation-π interactions, etc.), the larvae are firmly "locked" to the material surface and will not easily detach even under the scouring of water. This is the key to the "capture" function of the material in this invention, which enables it to achieve the "trapping in one" function, and is also the core technical feature that distinguishes the biomimetic peptides from chemical pheromones (which are only responsible for attraction) and interfacial adhesion layers (which are only responsible for material structural stability).

[0057] In summary, the biomimetic peptides of this invention are inspired by a deep imitation of the natural adhesion mechanism of the byssal protein of the clam *Solanum micranthum*. In terms of amino acid composition, four functional amino acids from the clam's byssal protein, which play a core adhesive role, are selected to specifically bind to the larval byssal protein and achieve a firm capture. Through this biomimetic design, this invention successfully constructs an "artificial adhesion interface" on the material surface that can actively recognize and powerfully capture clam larvae. This, together with the "attraction" function of chemical pheromones and the "structural anchoring" function of the interface adhesion layer, forms a complete technical loop, achieving efficient, targeted, and environmentally friendly control of clam larvae.

[0058] Example 2:

[0059] A method for preparing a special membrane material for targeted trapping of aquatic clam larvae includes the following steps:

[0060] S1. Substrate Preparation: Polypropylene-polyethylene copolymer particles are dissolved in N,N-dimethylformamide (DMF) organic solvent and stirred thoroughly until completely dissolved to prepare a homogeneous spinning solution with a mass fraction of 10%-15%, preferably 12%. A standard electrospinning apparatus is used, with the operating voltage set at 15-25kV, preferably 20kV, and the distance between the spinning needle and the receiving roller at 15-20cm, preferably 18cm, and spinning is performed at a constant feed speed. Under these process conditions, a substrate film composed of interwoven nanofibers is prepared, with the average fiber diameter controlled at approximately 200-500nm, preferably 350nm.

[0061] S2. Surface Activation Treatment: The nanofiber membrane prepared above is cut to the required size and immersed in a 1 wt% 3-(2,3-epoxypropoxy)propyltrimethoxysilane (GPMS) ethanol solution, ensuring complete wetting of the membrane. The membrane is allowed to stand at room temperature (25±2°C) for 2-4 hours, preferably 3 hours. After treatment, the membrane is removed and repeatedly shaken and washed three times with anhydrous ethanol to remove any physically adsorbed residual reagents. The membrane is then transferred to a 60°C oven and dried for 1 hour to obtain an activated substrate with a surface rich in epoxy active groups.

[0062] S3. Construction of the interfacial adhesion layer: Weigh out hydrophobic polyelectrolyte (Pcπ) with a phenyl monomer content of 15-30 mol% and phytic acid (PA) in a container at a mass ratio of 1:1. Mix thoroughly by mechanical stirring (500 rpm for 30 minutes) to form a homogeneous biomimetic cohesive layer gel precursor solution with a certain viscosity. Using a doctor blade coating method, uniformly coat the precursor solution onto the surface of the activated substrate obtained in step S2. By controlling the doctor blade gap, the wet film thickness is controlled to approximately 80 μm. The coated material is then placed in a room temperature environment and allowed to cure naturally for 24 hours. After curing, the thickness of the formed biomimetic adhesive interfacial layer gel is measured to be approximately 8 μm, and this layer is stably adhered to the substrate surface.

[0063] S4. Functional modifications:

[0064] a. Synthesis of Active Peptides: The target biomimetic peptide was synthesized on an automated peptide synthesizer using a standard Fmoc solid-phase synthesis strategy. The amino acid sequence of this peptide contains repeating units selected from (YR)n, (FK)n, or combinations thereof, where Y represents tyrosine, F represents phenylalanine, R represents arginine, K represents lysine, and n is an integer from 2 to 10. As an example, this embodiment synthesized repeating units with n=3. This design ensures that the peptide is rich in aromatic amino acids such as tyrosine and phenylalanine, as well as cationic amino acids such as lysine and arginine, with a total molar content of not less than 40%.

[0065] b. Chemical Grafting: Utilizing the phytic acid and active groups contained in the Pcπ chain in the biomimetic adhesion interface layer obtained in step S3, functionalization modification was performed via a thiol-ene click chemistry reaction. Specifically, the membrane material with the biomimetic adhesion interface layer obtained in step S3 was immersed in pH 7.4 phosphate-buffered saline (PBS) containing the above-mentioned synthetic biomimetic adhesion protein active peptide (concentration 1 mM) with thiol-modified strophanthus larvae-specific pheromone (concentration 0.5 mM). Subsequently, the photoinitiator 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone (Irgacure 2959) was added, bringing its final concentration in the reaction system to 0.1 wt%. Under nitrogen protection, the reaction system was irradiated with a 365 nm ultraviolet light source, and the photoinitiated click reaction was carried out at room temperature for 1 hour. During the reaction, the thiol-alkene radicals in the thiolized peptides and pheromone molecules undergo efficient thiol-alkene radical addition reactions with unreacted alkene bonds (mainly derived from unsaturated structural units such as styrene in the Pcπ polymer chain) present in the interfacial adhesion layer gel network, thereby achieving covalent fixation of both. After the reaction, the membrane material is thoroughly washed sequentially with PBS buffer and deionized water to completely remove unreacted substances, catalysts, and byproducts. After drying at room temperature, the special membrane material for targeted trapping of water clams larvae is obtained.

[0066] Performance testing:

[0067] To systematically verify the performance of the special membrane material of this invention, the following laboratory tests were conducted. The tests strictly adhered to environmental simulation and statistical requirements to ensure the reliability and representativeness of the data.

[0068] 1. Test environment setup:

[0069] First, water samples were prepared using tap water that had been aerated for at least 24 hours to remove residual chlorine. Second, larval culture was conducted by transferring the cultured clam larvae (0.14-1 mm in length) to a standard aeration tank for 48 hours of stable rearing. A 50 L standard glass aquarium was used as the experimental container to avoid potential chemical interference from plastic. The water temperature was precisely controlled at 20 ± 1°C using a constant-temperature circulating water bath system. A timed LED light source was used to simulate a natural light cycle, set to alternate between 12 hours of light and 12 hours of darkness. Clam larvae were evenly introduced into each aquarium to achieve a larval density of 100 ± 10 larvae / L.

[0070] Experimental Groups:

[0071] Experimental group: The special membrane material prepared in Example 1 or Example 2 was cut into 10 cm × 10 cm sizes.

[0072] Control group 1: A commercial polypropylene filter membrane of the same size (10 cm × 10 cm) with an average pore size of about 5 μm was used as a conventional physical retention control.

[0073] Control group 2: Non-membrane blank control group, used to assess natural mortality rate and the impact of environmental fluctuations.

[0074] Control group 3: A special membrane material without added peptides for targeted trapping of larvae of the water clam, the preparation steps of which are as follows:

[0075] S1. Substrate Preparation: Polypropylene-polyethylene copolymer particles are dissolved in N,N-dimethylformamide (DMF) organic solvent and stirred thoroughly until completely dissolved to prepare a homogeneous spinning solution with a mass fraction of 10%-15%, preferably 12%. A standard electrospinning apparatus is used, with the operating voltage set at 15-25kV, preferably 20kV, and the distance between the spinning needle and the receiving roller at 15-20cm, preferably 18cm, and spinning is performed at a constant feed speed. Under these process conditions, a substrate film composed of interwoven nanofibers is prepared, with the average fiber diameter controlled at approximately 200-500nm, preferably 350nm.

[0076] S2. Surface Activation Treatment: The nanofiber membrane prepared above is cut to the required size and immersed in a 1 wt% 3-(2,3-epoxypropoxy)propyltrimethoxysilane (GPMS) ethanol solution, ensuring complete wetting of the membrane. The membrane is allowed to stand at room temperature (25±2°C) for 2-4 hours, preferably 3 hours. After treatment, the membrane is removed and repeatedly shaken and washed three times with anhydrous ethanol to remove any physically adsorbed residual reagents. The membrane is then transferred to a 60°C oven and dried for 1 hour to obtain an activated substrate with a surface rich in epoxy active groups.

[0077] S3. Construction of the interfacial adhesion layer: Weigh out hydrophobic polyelectrolyte (Pcπ) with a phenyl monomer content of 15-30 mol% and phytic acid (PA) in a container at a mass ratio of 1:1. Mix thoroughly by mechanical stirring (500 rpm for 30 minutes) to form a homogeneous biomimetic cohesive layer gel precursor solution with a certain viscosity. Using a doctor blade coating method, uniformly coat the precursor solution onto the surface of the activated substrate obtained in step S2. By controlling the doctor blade gap, the wet film thickness is controlled to approximately 80 μm. The coated material is then placed in a room temperature environment and allowed to cure naturally for 24 hours. After curing, the thickness of the formed biomimetic adhesive interfacial layer gel is measured to be approximately 8 μm, and this layer is stably adhered to the substrate surface.

[0078] Six parallel experiments were set up in each group to ensure that the data could be statistically significant in subsequent analysis. All membrane materials were suspended vertically in the center of the aquarium to ensure that their surfaces were in full contact with the water.

[0079] 2. Differential Adsorption Performance Test:

[0080] In the standard aquarium, clam larvae, Chlorella (representing phytoplankton), and Brachiopoda (representing common zooplankton) were simultaneously introduced in a ratio of larvae:algae:rotifers = 1:100:10. The experimental group (a membrane made from the membrane material of this invention) and control group 1 (a commercial filter membrane) were placed in the aforementioned mixed water sample. After 48 hours, they were carefully removed and gently rinsed with sterile saline to remove loosely attached impurities. Subsequently, under a stereomicroscope, the number of clam larvae, algal cell clusters (each cluster of more than 50 cells was considered an attachment unit), and individual rotifers attached to a unit area (cm²) of membrane material were directly counted and distinguished.

[0081] The selective adsorption rate of the membrane material for clam larvae was calculated using the following formula:

[0082] Selective adsorption rate (%) = (Number of clam larvae attached to the membrane / Total number of organisms attached to the membrane) × 100%

[0083] Calculation results show that the special membrane material of this invention exhibits a high selective adsorption rate of 92.3% for clam larvae, while showing minimal adsorption for non-target organisms (algae, rotifers). In contrast, the non-selective physical adsorption characteristics of commercial polypropylene filter membranes result in a selective adsorption rate of only 45.7%, and the special membrane material without added peptides shows a selective adsorption rate of 81.5% for clam larvae. The membrane of this invention achieves a larval capture rate of 35.6 ± 2.8 larvae / cm², which is 3.2 times that of traditional filter membranes (11.1 ± 1.5 larvae / cm²), demonstrating a significant efficiency advantage.

[0084] 3. Trapping rate test

[0085] After the 48-hour test period, the larval trapping rate of each group was evaluated. Using a wide-mouth pipette, 5 mL of water samples were collected from each of the four corners and the center of each aquarium, for a total of 25 mL. The samples were placed in clean sampling bottles and gently swirled for 30 seconds to ensure even distribution of the larvae. The well-mixed sample was then aspirated using a capillary tube and injected into a counting chamber, avoiding the formation of air bubbles. Under an optical microscope (40x objective lens), the chamber was scanned using a standard zigzag path system to count the number of clam larvae in all grids.

[0086] Calculate the trapping rate using the following formula:

[0087] Trapping rate (%) = [1 - (N) t / N0)] × 100%, where N is the total number of surviving larvae in the aquarium at time t (48 hours). t The initial total number of larvae is known to be N0.

[0088] One-way ANOVA was performed on the trapping rate data of the three groups (experimental group, control group 1, and control group 2) using SPSS software, and pairwise comparisons were performed using independent samples t-test, with the significance level set at p<0.05.

[0089] like Figure 2 As shown, the test results indicate that the average trapping rate of the special membrane material of this invention (experimental group) was 85.2% after 48 hours, which was significantly higher than that of the commercial polypropylene filter membrane (control group 1, average trapping rate 31.5%) and the blank control group (control group 2, average trapping rate <5%). The statistical test showed a significant difference (p<0.05).

[0090] 4. Stability Test:

[0091] Long-term stability test: To evaluate the actual service life of the material, a simulated long-term operation test was conducted. The membrane material of this invention was installed in a circulating water tank simulating a water supply pipeline, with the water flow velocity controlled at 0.1-0.3 m / s (simulating actual working conditions), and operated continuously for 3 months. A batch of material samples was taken out each month to test its trapping rate. The trapping rates for the 1st, 2nd, and 3rd months were 85.2%, 83.7%, and 81.9%, respectively. The data shows that after 3 months of continuous operation, the core performance (trapping rate) of the special membrane material of this invention can still be maintained at a high level of 81.9%, with an extremely low performance degradation rate, proving that it has excellent long-term chemical stability and mechanical durability, and can meet the long-term requirements of practical engineering applications.

[0092] This invention is the first to propose and realize the integration of specific biological attraction (pheromones) and biomimetic biological adhesion (byssalin peptides) onto the same membrane material interface, creating a new active targeted control model of "attracting first and then capturing". A biomimetic cohesive layer gel (Pcπ / PA) was designed as the adhesion interface layer, cleverly utilizing the hydrophobic and oleophilic properties of the byssalin in *Clam spp.* to enhance the stability and selectivity of binding with larvae—a synergy of physical adhesion and bioaffinity. A stable, integrated functional structure is constructed through multi-level chemical bonding, ensuring the material's long-term effectiveness in complex aquatic environments. The entire technical solution achieves an organic unity of high efficiency, environmental friendliness, flow independence, selectivity, and long-term effectiveness, providing a revolutionary material solution for the control of *Clam spp.* larvae.

[0093] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A special membrane material for targeted trapping of aquatic clam larvae, characterized in that, It is a multi-layered composite structure, including: Nanofiber membrane substrate layer; An interface adhesion layer coated on the substrate layer, wherein the interface adhesion layer is a biomimetic coagulation layer gel formed by curing a mixture of hydrophobic polyelectrolyte and phytic acid; In addition, a functionalized modification layer is fixed to the interface adhesion layer by chemical bonding, the functionalized modification layer comprising covalently grafted biomimetic adhesion protein active peptides and chemical pheromones for attracting magma clam larvae; The amino acid sequence of the biomimetic adhesion protein active peptide contains a total molar content of aromatic amino acids and cationic amino acids of not less than 40%, and its sequence contains repeating units selected from (YR)n, (FK)n or combinations thereof, where Y represents tyrosine, F represents phenylalanine, R represents arginine, K represents lysine, and n is an integer from 2 to 10.

2. The special membrane material for targeted trapping of aquatic clam larvae according to claim 1, characterized in that, The nanofiber membrane substrate layer is made of polyolefin copolymer, and the fiber diameter is 200-500 nm.

3. The special membrane material for targeted trapping of aquatic clam larvae according to claim 1, characterized in that, In the interfacial adhesion layer, the phenyl monomer content of the hydrophobic polyelectrolyte is 15-30 mol%, the mass mixing ratio of the hydrophobic polyelectrolyte to phytic acid is 1:1, and the thickness of the interfacial adhesion layer is 5-10 μm.

4. The special membrane material for targeted trapping of aquatic clam larvae according to claim 1, characterized in that, The biomimetic adhesion protein active peptide is derived from the byssal protein of freshwater shellfish, and the chemical pheromone is a purine nucleoside, which includes one or more of uracil nucleoside, guanine, adenine, hypoxanthine, adenine nucleoside, guanine nucleoside, and hypoxanthine nucleoside.

5. A method for preparing a special membrane material for targeted trapping of aquatic clam larvae as described in any one of claims 1-4, characterized in that, Includes the following steps: S1. Substrate preparation: Polyolefin copolymer nanofiber membranes were prepared using electrospinning technology; S2. Surface activation treatment: The nanofiber membrane is subjected to surface chemical modification to introduce epoxy active groups; S3. Construction of interfacial adhesion layer: A mixed gel precursor solution of hydrophobic polyelectrolyte and phytic acid is coated on the surface of the activated substrate and cured to form an interfacial adhesion layer; S4. Functional modification: Utilizing the carboxyl groups on the surface of the interfacial adhesion layer, an amidation reaction is carried out using carbodiimide and N-hydroxysuccinimide as condensing agents to covalently graft the biomimetic adhesion protein active peptide and the chemical pheromone used to attract maggot larvae onto the interfacial adhesion layer to obtain the special membrane material.

6. The preparation method according to claim 5, characterized in that, In step S1, the electrospinning process parameters are: spinning solution concentration 10-15 wt%, voltage 15-25 kV, and receiving distance 15-20 cm.

7. The preparation method according to claim 5, characterized in that, In step S2, 3-(2,3-epoxypropoxy)propyltrimethoxysilane is used as an activating agent to immerse the nanofiber membrane at room temperature for 2-4 hours.

8. The preparation method according to claim 5, characterized in that, In step S3, the curing conditions are natural curing at room temperature for 24 hours.

9. A method for preparing a special membrane material for targeted trapping of aquatic clam larvae as described in any one of claims 1-4, characterized in that, Includes the following steps: S1. Substrate preparation: Polyolefin copolymer nanofiber membranes were prepared using electrospinning technology; S2. Surface activation treatment: The nanofiber membrane is subjected to surface chemical modification to introduce epoxy active groups; S3. Construction of interfacial adhesion layer: A mixed gel precursor solution of hydrophobic polyelectrolyte and phytic acid is coated on the surface of the activated substrate and cured to form an interfacial adhesion layer; S4. Functional modification: Utilizing the active groups generated after activation of the interface adhesion layer, the biomimetic adhesion protein active peptide and the chemical pheromone used to attract maggot larvae are covalently grafted onto the interface adhesion layer through a thiol-ene click chemistry reaction to obtain the special membrane material.

10. The application of the special membrane material for targeted trapping of water clams larvae as described in any one of claims 1-4 in preventing fouling by water clams larvae in water pipelines and pumping stations.

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