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CN-120132809-B - Water purifying agent based on bionic adsorption principle and preparation process thereof

CN120132809BCN 120132809 BCN120132809 BCN 120132809BCN-120132809-B

Abstract

The invention relates to the technical field of water treatment, in particular to a water purifying agent based on a bionic adsorption principle and a preparation process thereof, wherein the water purifying agent is obtained by an inner layer, an intermediate layer and an outer layer composite framework; the inner layer is a polydopamine nanofiber network; the external layer is a spider silk protein-polydopamine macroporous skeleton structure, the spider silk protein-polydopamine macroporous skeleton is an external layer through a framework multi-layer composite structure, the spider silk protein-polydopamine composite layer is an intermediate layer, the polydopamine nanofiber network is an internal layer, gradient capturing of micron-level to nanometer-level pollutants is achieved, and the limitation of the traditional adsorbent is broken through a bionic tough skeleton design, a dynamic aperture regulation mechanism, a hierarchical adsorption synergistic effect and a bionic adhesion enhancement technology.

Inventors

  • SHI ZHIJIE
  • ZHANG GANG

Assignees

  • 山东正康生态科技有限公司

Dates

Publication Date
20260512
Application Date
20250319

Claims (8)

  1. 1. A preparation process of a water purifying agent based on a bionic adsorption principle is characterized in that the water purifying agent is obtained by an inner layer, an intermediate layer and an outer layer composite framework; wherein the inner layer is a polydopamine nanofiber network; the middle layer is a spider silk protein-paraffin composite layer; the outer layer is a spider silk protein-polydopamine macroporous skeleton structure; The preparation process of the water purifying agent comprises the following steps: s1.1, dissolving dopamine hydrochloride in Tris-HCl buffer solution with pH of 8.5-9 to obtain 10-15wt% dopamine hydrochloride solution, carrying out oxidative polymerization at room temperature for 24-48h under magnetic stirring at 800-1000rpm to obtain polydopamine solution with dissolved oxygen concentration of 8-10ppm, mixing polydopamine solution with polyvinyl alcohol, preparing a fiber structure through electrostatic spinning, setting electrostatic spinning parameters, and carrying out vacuum drying at 60-80 ℃ for 10-12h to obtain a polydopamine nanofiber network, namely an inner layer; S1.2, mixing molten short-chain paraffin wax and a composite emulsifier, mixing the short-chain paraffin wax and spider silk protein according to a mass ratio of 1:3.2-4.5, homogenizing at a high speed of 15000-16000rpm for 5-10min to form nano paraffin emulsion with a particle size of 50-200nm, dissolving the spider silk protein in a choline chloride/urea solvent, wherein the molar ratio of the choline chloride/urea solvent is 1:2, stirring for 5-6h at 55-60 ℃ to obtain a spider silk protein solution with a weight ratio of 12-14%w/v, adding the nano paraffin emulsion, and performing ultrasonic emulsification for 20-30min to obtain an intermediate layer solution; S1.3, coating an intermediate layer solution on the surface of an inner layer by adopting a dipping-spin coating method, then keeping the intermediate layer solution in an oven at 45-50 ℃ for 1.5-2h, transferring the intermediate layer solution into an environment at 20-25 ℃ for 8-12h, spraying a dopamine hydrochloride solution with the mass fraction of 0.5-0.8%, and performing oxidative polymerization for 12-16h to obtain an inner layer-intermediate layer compound; S1.4, dissolving spider silk protein in a choline chloride/urea solvent to obtain 10-12wt% of spider silk protein solution, adding 2-4wt% of polydopamine solution, mixing and stirring for 3-4 hours, adding NaCl, performing ultrasonic dispersion for 20-30 minutes, forming by a freeze casting method, setting a program to obtain a porous block, finally filling the porous block into a mould, maintaining the pressure for 30 minutes under 3-5MPa for shaping, soaking in 0.5-1wt% of genipin for crosslinking for 4-6 hours, and flushing to pH 7.2-7.4 by using phosphate buffer solution to obtain a spider silk protein-polydopamine macroporous skeleton structure, namely an outer layer; S1.5, immersing the outer layer into a solution of genipin with the pH of 8.5-9 and the mass fraction of 0.5-0.8% for oxidative polymerization for 12-16h, placing the solution in a hot press, pressurizing and shaping according to a gradient program to combine the outer layer with the inner layer-middle layer composite to obtain a composite structure, immersing the composite structure into the solution of genipin with the pH of 1.0-1.2% for crosslinking for 6-8h, cleaning and drying to obtain the water purifying agent; the spider silk protein is a semi-crystalline molecular spring structure formed by beta-sheet consisting of alanine and A-helix rich in proline, and a tightly packed secondary structure thereof.
  2. 2. The preparation process of the water purifying agent based on the bionic adsorption principle of claim 1, wherein in S1.1, the volume ratio of the polydopamine solution to the polyvinyl alcohol is 2-3:1, the mass fraction of the polyvinyl alcohol is 8-12%, the electrostatic spinning parameter is voltage 18-25kV, the receiving distance is 15-20cm, the flow rate is 0.5-0.8mL/h, and the environmental humidity is 30-40%.
  3. 3. The preparation process of the water purifying agent based on the bionic adsorption principle of claim 1 is characterized in that in S1.2, the mass ratio of the molten short-chain alkane paraffin to the composite emulsifying agent is 1:3-5, and the composite emulsifying agent is obtained by mixing Span 80 and Tween 80 according to the mass ratio of 1-2:1.
  4. 4. The process for preparing the water purifying agent based on the bionic adsorption principle according to claim 1, wherein the dipping speed is 3-5mm/S, and the spin coating parameter is 2000rpm multiplied by 30S in the step S1.3.
  5. 5. The preparation process of the water purifying agent based on the bionic adsorption principle according to claim 1, wherein in S1.4, the particle size of NaCl is 100-150 mu m, and the adding amount is 60-65wt%.
  6. 6. The preparation process of the water purifying agent based on the bionic adsorption principle according to claim 1 is characterized in that in the step S1.4, specific parameters of a set program are pre-freezing, quick freezing of 80 ℃ liquid nitrogen for 4 hours, primary drying, maintaining at 50 ℃ and 10Pa for 24 hours, and analytical drying, and maintaining at 25 ℃ and 1Pa for 6 hours.
  7. 7. The preparation process of the water purifying agent based on the bionic adsorption principle according to claim 1, wherein in the step S1.5, specific parameters of the gradient program pressurization setting are 35 ℃ in the first stage, 0.5MPa in the second stage, 25 ℃ in the second stage, 1MPa in the third stage, 2h in the third stage, 10 ℃ in the third stage, 2MPa in the third stage.
  8. 8. The process for preparing the water purifying agent based on the bionic adsorption principle according to claim 1, wherein the thickness of the inner layer is 0.3-0.5mm, the thickness of the middle layer is 0.8-1.0mm, and the thickness of the outer layer is 1.2-1.5mm.

Description

Water purifying agent based on bionic adsorption principle and preparation process thereof Technical Field The invention relates to the technical field of water treatment, in particular to a water purifying agent based on a bionic adsorption principle and a preparation process thereof. Background The main pollutants for water pollution comprise heavy metal ions (such as lead, cadmium and mercury), organic pollutants (such as pesticides and dyes), microorganisms (such as bacteria and viruses), microplastic and the like, the traditional water purification technology (such as coagulation, precipitation, filtration and disinfection) has the problems of low efficiency, high cost, secondary pollution and the like when dealing with complex pollutants, the development of novel efficient water purification materials is needed to be urgently carried out, in recent years, the development of bionics and material science provides a new thought for the development of water purification agents, and the principle of biomimetic adsorption is to simulate the adsorption process in organisms, and the adsorption efficiency is improved by designing materials with specific microstructures and functional groups. However, under the condition of dynamic filtration, the framework of the existing adsorbent is broken in particles due to insufficient mechanical strength, the risk of system blockage is increased, meanwhile, in the conventional adsorbent based on the bionic structure design, pollutants are easy to deposit in pore channels of the water purifying agent in the dynamic filtration or long-term operation, so that the pore channels are gradually blocked. Disclosure of Invention The invention aims to provide a water purifying agent based on a bionic adsorption principle and a preparation process thereof, so as to solve the problems in the background technology. The invention provides a water purifying agent based on a bionic adsorption principle, which comprises the following components of an inner layer, an intermediate layer and an outer layer composite framework; wherein the inner layer is a polydopamine nanofiber network; the middle layer is a spider silk protein-paraffin composite layer; the outer layer is a spider silk protein-polydopamine macroporous skeleton structure; the water purifying agent has the specific structure that the outer layer is a macropore skeleton constructed by spider silk protein/polydopamine, the suspended matters are prefiltered, the middle layer is a spider silk protein-paraffin (C18-C22 short-chain alkane paraffin) composite layer for intercepting colloid-state pollutants, and the inner layer is a polydopamine nanofiber network for chelating heavy metal ions and micromolecular organic matters; The spider silk protein is a very special fibrin, is formed by beta-sheet formed by alanine and A-helix rich in proline, and a tightly packed secondary structure thereof, so that the spider silk protein is a molecular spring structure in a semi-crystalline state, and has the characteristics of high strength and high toughness, therefore, the spider silk protein is adopted as an adsorbent framework structure, but the high strength is insufficient, a certain toughness is also required to keep the structural integrity of the adsorbent particles, and therefore, polydopamine is added to endow the particles with flexibility to keep the particles intact in high-speed water flow; The paraffin is a phase change material, the volume can be changed in the phase change process, the pore diameter is reduced due to the fact that a protein network is extruded during melting and expansion, the stress is released during solidification and shrinkage, and the pore diameter is recovered, so that the paraffin can be used as a micro valve to play a role in adjusting the pore diameter in a small amplitude, and the paraffin is solidified and shrunk to release the stress when the pollutant is adsorbed and blocked, the pore diameter is recovered to actively eject the adsorbed pollutant, the pore diameter is reduced to block, and the anti-blocking capacity is improved; by constructing the multilayer composite structure, the cooperative action between layers is utilized, and pollutants can be adsorbed in a grading manner according to the environmental temperature change and different water environments, so that the adsorption efficiency is improved. On the other hand, the invention provides a preparation process of the water purifying agent based on the bionic adsorption principle, which is used for any one of the water purifying agents based on the bionic adsorption principle, and comprises the following steps: s1.1, dissolving dopamine hydrochloride in Tris-HCl buffer solution with pH of 8.5-9 to obtain 10-15wt% dopamine hydrochloride solution, carrying out oxidative polymerization at room temperature for 24-48h under magnetic stirring at 800-1000rpm to obtain polydopamine solution with dissolved oxygen concentration of 8-10ppm, mixin