412 results about "Layer by layer self assembly" patented technology

The invention relates to a metal lithium anode with a protective coating and a preparation method based on molecule layer-by-layer self-assembly. The substance of the coating is a solid electrolyte interface membrane constructed by an assembling molecule layer and an inorganic fast ion conductor layer on an active material layer surface of the metal lithium anode. The solid electrolyte interface membrane has the following functions: (1) electrolyte solution and lithium wafers are effectively isolated and the lithium wafers are prevented from being eroded and reacted; (2) lithium ions are uniformly distributed and generation of lithium dendrites is restrained; (3) inorganic fast ion conductors can transmit the lithium ions, and membrane strength is effectively improved. Metal lithium electrode pieces protected by the protective coating are used in lithium batteries, the coulombic efficiency of the batteries can be effectively improved, and circulation life is prolonged.

Textile fibers and other fibrous substrates functionalized with particles are provided for use in the detection of targets of interest by spectroscopic methods. In one embodiment, a substrate is provided that comprises a conformal coating on its surface, wherein the coating comprises a plurality of chemically functional particles that are spectroscopically enhancing. Methods for producing such functionalized textile fibers are also provided. These textiles can be used as platforms for spectroscopic detection, including surface-enhanced Raman scattering (SERS), surface-enhanced infrared absorption (SEIRA), and surface-enhanced fluorescence (SEF). Functionalized textile fibers for use in the signature detection methods are produced by performing layer-by-layer self-assembly of particles on natural and synthetic textile substrates.

The invention belongs to the technical field of the advanced nanometre composite material, particularly to magnetic inorganic nano-particle / zeolite putamen compound microsphere and the preparation method. The invention first adopts the collosol-gel chemical synthesis, wraps a layer of amorphous silica on the external surface of the magnetic inorganic nano-particle, then uses the layer by layer self-assembly technology to adsorb the polyelectrolyte with positive charge and the zeolite nano-particle with negtive charge on the magnetic microsphere surface with negtive charge, finally wraps a layer of zeolite materials on the exterior of the magnetic microsphere through the air-solid phase crystal transformation technology, thereby obtaining the magnetic zeolite compound microsphere with the putamen structure. The compound microsphere has strong magnetic responsibility, and the surface can adsorb a great deal of polypeptide, thereby having wide application foreground on the aspect of bioseparation and high efficiency proteid enzymolysis. The invention has simple method, easy obtaining of the raw materials, which is suitable for the enlarged production.

The invention discloses a biological compatibility surface coater and self-assembling coating method of planted medical apparatus, which is characterized by the following: the coater is prepared by self-assembling coating method layer by layer, which accelerates esoderma and resists thrombus constituted by two or more macromolecular materials with certain positive and negative load; the positive load material is chitose, chitin, polylysine and so on; the negative load material is disebrin, hyaluronic acid, alginic acid, polyamino acid and so on; the crosslinker and biological active factor or drug can be added to accelerate the growth of the cell; the coater satisfies the request of biologically medical transplantation.

The invention discloses a method for preparing self-assembled medicine-carried microspheres by combining a high-voltage electrostatic liquid droplet method and a layer-by-layer self-assembly method. In the invention, growth factor-containing sodium alginate aqueous solution is used as raw material solution; calcium chloride solution is used as a gel bath; microcapsules are prepared in a high-voltage electrostatic field; growth factor is uniformly distributed in microgel; and then a plurality of high molecular polyelectrolyte membranes are assembled on the surface of the microgel by using an electrostatic nano layer-by-layer self-assembly technology to obtain the self-assembled medicine-carried microspheres. The self-assembled medicine-carried microspheres prepared by the method have smooth and round surfaces and high uniformity; the activity of the growth factor can be protected; burst release can be effectively avoided; and long-acting constant-speed release is realized.

The invention discloses a preparation method for a carbon nano tube composite film. The method comprises the following steps: first, allowing a phenolic hydroxyl group, a quinonyl group and other functional groups to be introduced on the surface of a carbon nano tube through oxidation autopolymerization reaction of catecholamine under an alkalescence condition, so as to realize the modification for the surface of the carbon nano tube; then, using water-soluble polymers with amino groups or mercapto groups as raw materials to realize layer-by-layer self-assembly under the action of chemical bonds formed by Schiff base or Michael Addition reaction, thereby obtaining the carbon nano tube composite film. The method has the advantages of mild reaction condition, environmental protection, simplicity and feasibility, and is suitable for industrialized production. The carbon nano tube composite film prepared by the method has the advantages of excellent thermal and chemical stability, ductility, mechanical strength and transparency.

The invention discloses a preparation method of TiO2 / porphyrin / MOFs (metal-organic frameworks) ultra-thin heteroplasmon, and belongs to the technical field of inorganic-organic composite functional material preparation. A TiO2 ultra-thin nano-sheet serves as a template, a porphyrin compound is anchored on the surface of the TiO2 ultra-thin nano-sheet by functional groups such as carboxyl and hydroxy on the periphery of the porphyrin compound, and MOFs wrap an outer layer of the porphyrin compound by means of metal-organic framework layer-by-layer self-assembly through residual functional groups such as carboxyl and hydroxy on the periphery of the porphyrin compound to obtain the TiO2 / porphyrin / MOFs ultra-thin heteroplasmon with efficient and stable catalytic activity. The preparation method has the advantages that ultra-thin heteroplasmon catalysis area / light absorption area / adsorption area layer construction and functional integration are creatively performed by the aid of TiO2, porphyrin and the MOFs, a novel catalytic material with excellent performance for photocatalytic reduction of carbon dioxide is developed, and the performance of the TiO2 / porphyrin / MOFs ultra-thin heteroplasmon is optimized based on adjustable structural and functional characteristics of porphyrin and MOFs materials.

The invention discloses a polyelectrolyte nanometer flame-retardant coating by adoption of layer-by-layer assembly and a preparation method thereof. The preparation method comprises following steps of: 1), preprocessing: putting and soaking base material into an acid solution and cleaning and drying base material with water; 2), self-assembly: putting and soaking pre-processed base material to a cationic polyelectrolyte solution in order to from a layer of ion membrane, taking out the layer of ion membrane and cleaning the ion membrane with water for drying, putting and soaking the ion membrane into the cationic polyelectrolyte solution in order to form an layer of anionic membrane, and cleaning the layer of anionic membrane with water and drying; sequentially repeating above self-assembly process for multiple times so that the polyelectrolyte nanometer flame-retardant coating is prepared by adoption of layer-by-layer assembly on the surface of the base material. The polyelectrolyte nanometer flame-retardant coating by adoption of layer-by-layer assembly and the preparation method thereof have following beneficial effects: the polyelectrolyte nanometer flame-retardant coating is green and eco-friendly and has a simple and feasible preparation method; damage to the internal structure of base material is avoided; high flame-retardant efficiency is obtained; and the preparation method is suitable for formation of flame-retardant coatings on material surfaces including fabric, wood, foam and plastics.

The invention belongs to the field of anticorrosion materials, and relates to a green and environment-friendly method for protecting metal from corroding, which can particularly control metal corrosion for long time effectively, and play a role in self-repairing the metal surface to a certain extent. The method is characterized in that an inhibitor molecule and polyelectrolyte are alternately deposited on the surface of a silicon dioxide nano-particle through green environment-friendly type metal inhibitor micromolecules and polyelectrolyte by adopting layer-by-layer self-assembly technology and utilizing the penetrating controllability of a polyelectrolyte self-assembly membrane so as to prepare a functional nano-particle with the inhibitor and the polyelectrolyte self-assembly composite membrane which are coated on the surface; and the prepared functional nano-particle is mixed with sol-gel to prepare the functional sol-gel membrane coated on the metal surface to be protected. The coating has the function of metal surface self-repairing, and ensures that the inhibitor molecules released by the functional membrane are adsorbed on the metal surface to reform a protecting membrane in a coating damaged microsection to play a certain role in self repairing. The method is applicable to corrosion protection of various metals.

The invention discloses a preparation method for an antibacterial coat for slowly releasing various cell growth factors on medical metal. According to the method, antibiotic with amino is grafted on graphene oxide by covalent binding, the graphene oxide grafted with the antibiotic is taken as a carrier, and nano-particles, which wrap the various cell growth factors respectively, are fixed between grapheme oxide layers by layer-by-layer self-assembly, so that the coat, which carries the various cell growth factors and the antibiotic at the same time, is obtained on the surface of the medical metal. The coat prepared by the method can independently control the various cell growth factors to be slowly and orderly released, the fixation amount of the cell growth factors is large and the bone induction effect is strong. In addition, the coat can release the antibiotic in the whole process of the slow release of the cell growth factors, thus achieving a long-term antibacterial effect. In addition, the cell growth factors do not interact with the antibiotics, so that the respective efficacy of the cell growth factors and the antibiotics is given full play.

The invention discloses a method for preparing a nanofiltration membrane by adopting a layer-by-layer self-assembly method, and relates to a preparation method of a nanofiltration membrane, aiming at solving the problems that a nanofiltration membrane prepared by adopting an existing method cannot have both good interception performance and high water flux. The method comprises the following steps: preparing a polyacrylonitrile solution, preparing a polyacrylonitrile basilar membrane, preparing a treated polyacrylonitrile basilar membrane, assembling a layer of polyethlenimine, assembling a layer of graphene oxide, and reassembling polyethlenimine and graphene oxide, thus obtaining the nanofiltration membrane. According to the method disclosed by the invention, a layer-by-layer self-assembly method is adopted, polyethlenimine and graphene oxide are adopted for modifying a PAN membrane, so that the hydrophilia and the pore size of the surface of the membrane are effectively adjusted; because the membrane is relatively thin, relatively large flux can be obtained, and the obtained nanofiltration membrane has good interception performance. The method can be applied to the fields of antibiotics separating, fruit juice concentrating and seawater desalting.

The invention relates to a preparation method of a layer-by-layer self-assembly metal-organic framework composite film. Polyethyleneimine (PEI) with positive charges, a methanol solution containing ZIF-8 and polyacrylic acid (PAA) with negative charges deposit on the surface of a polyether sulfone (PES) film layer by layer, ZIF-8 is wrapped in PEI and PAA through the electrostatic repulsion effect of the opposite charges, and a layer structure is formed on the surface of the PES film. By preparing the methanol solution containing ZIF-8, through the layer-by-layer self-assembly technology, ZIF-8 is successfully loaded on the surface of the PES film, the loading capacity of the PES film is maximized, and the composite film material with high permeation flux under no permselectivity compromise is successfully prepared.

The invention discloses a method for detecting staphylococcus aureus based on reduced graphene oxide-nanogold composite material in combination with aptamer, belonging to the field of electrochemistry. According to the basic principle of the method, the reduced graphene oxide-nanogold composite material is used to modify a sulfhydrylation whole staphylococcus aureus capture probe by a layer by layer self-assembly method. When the probe is incubated in staphylococcus aureus liquid, effective binding sites of the probe can be bound with the staphylococcus aureus to wrap the staphylococcus aureus in a three-dimensional space structure, thus, the whole capture to target bacteria is realizes. The electron transmission on the surface of an electrode is blocked after the target bacteria is bound, so that a electrochemical resistance value increases, and quantitative determination on the staphylococcus aureus can be realized based on the change of the resistance value. By virtue of excellent electron transmission capability of graphene and large specific surface area of nanogold, detection signals can be amplified, and detection time can be shortened. The new method provided by the invention can be applied to whole bacteria detection on the staphylococcus aureus, can expand application of impedance-based electrochemical unmarked detection, and has the advantages of strong specificity, high sensitivity, cheapness, rapidness, and so on.

The invention relates to a preparation method of a layer-by-layer self-assembly forward osmosis membrane and a layer-by-layer self-assembling forward osmosis membrane prepared by the method. The preparation method comprises the steps of carrying out modified treatment on a basic membrane, preparing a cationic polyelectrolyte solution, preparing an anionic polyelectrolyte and preparing a multilayer self-assembling membrane. By adopting the method, the deposition process in the prior art for adsorption only by virtue of an electrostatic effect can be changed, and a coordination effect better than the electrostatic effect is used as the driving force of the deposition process, so that the membrane has the characteristics of high water flux and low salt reverse osmotic quantity, other subsequent processes such as GA cross-linking and UV radiation are not needed, and thus the time for the preparation process can be greatly reduced.

The invention discloses a preparation method of a metal net membrane with self-cleaning and underwater super-oleophobic characteristics. The metal net membrane can achieve efficient oil-water separation and self cleaning. A traditional oil-water separation membrane has the defects that a preparation technology is complex, regeneration is difficult, and repeated using can not be achieved. With a copper net being a substrate, an anodic oxidation method is adopted for generating a copper hydroxide nanowire array, multiple layers of titanium dioxide are deposited on the nanowire array through layer-by-layer self-assembly, and the copper net membrane covered by a copper oxide / titanium dioxide composite membrane layer is generated through roasting. The net membrane is high in mechanical performance and resistant to high heat, has the super-hydrophilic and underwater super-oleophobic characteristics, can efficiently separate an oil-water mixture and meanwhile can perform self cleaning under photocatalysis active illumination of the titanium dioxide layer to achieve regeneration and repeated using. Compared with the preparation technology of the existing oil-water separation membrane, the method facilitates scale expansion, preparation is easy, raw materials are environmentally friendly, the cost is low, cyclic reuse can be achieved, and the net membrane is a novel oil-water separation net membrane which is more environmentally friendly and affordable.

The invention provides a hollow silicon magnetic microsphere, as well as the preparation method and the application thereof. The hollow silicon magnetic microspheres have the preparation method that a polystyrene / silicon dioxide composite microsphere is used as a core; Fe3O4 coats the periphery of the core through the layer-by-layer self-assembly method; then, a PS / SiO2 / Fe3o4 polymeric magnetic composite nanosphere is obtained, and polystyrene is removed through the high temperature sintering method, thereby forming a magnetic material with hollow structure; the inner layer of the hollow magnetic material is SiO2, and the stability is good, thereby the material is not easy to collapse at high temperature; furthermore, the specific surface area of the material can be improved, and the material is a monodisperse hollow magnetic microsphere material. The method has the advantages of low cost and good repetitiveness. The obtained product not only can be used as a magnetic targeting drug carrier material, but also can be used in the biological and the medical fields such as biosensors, immunologic diagnosis, drug delivery and tumor targeting therapy as well as DNA isolation, etc.

The invention discloses a preparation method of an antibacterial biological activity ceramic coating with magnetic responsiveness, and belongs to the technical field of biological materials. The preparation method is combined with a layer-by-layer self-assembly technology by using ultrahigh adhesiveness of polydopamine so as to construct a coating of a multilayer film structure on the surface of a base material coated with a polydopamine film. A single layer film is prepared by coating polydopamine functionalized magnetic particle dispersion liquid, polydopamine functionalized antibacterial particle dispersion liquid or polydopamine functionalized biological activity ceramic particle dispersion liquid. The coating prepared through the preparation method has good biocompatibility, biological activity and antibacterial property, the coating can respond to an external magnetic field, and the effect of the external magnetic field can strengthen the osteoinductivity of the coating; the preparation method disclosed by the invention can effectively control the composition, thickness and shape of the coating according to actual requirements; the problems that the binding force between films formed by multilayer inorganic particles in the coating and the binding force between the coating and the base material are not strong are solved. The method has significant research value and clinical significance in bone tissue engineering.

The invention discloses a stimulus-responsive self-repair anticorrosive coating material and a preparation method. The coating material comprises a CuO microcapsule and a coating matrix. The CuO microcapsule comprises a capsule core and a capsule core carrier, the capsule core is a corrosion inhibitor, and the capsule core carrier is porous CuO; and the surface of the CuO microcapsule is coated byan anionic polyelectrolyte layer and a cationic polyelectrolyte layer alternately. The invention successfully constructs the anticorrosive coating material with ph responsiveness and self-repair dualefficacy. The porous CuO can improve the loading rate and encapsulation rate of the capsule core substance; at the same time, the anionic polyelectrolyte can be adsorbed on the surface by means of layer-by-layer self-assembly, under the action of Coulomb force, then cationic polyelectrolyte can be adsorbed on the surface, thus improving the dispersibility of the microcapsule in the coating, solving the agglomeration problem of the porous substance CuO, and at the same time improving the bonding performance of the capsule core carrier and the coating matrix, and the anticorrosion performance of the coating material can be further improved.

The invention relates to a preparation method of a composite current collector combined by carbon nanotube thin layers and a copper sheet or an aluminium sheet, and application of the composite current collector in a lithium ion flow battery. The method comprises the steps of: functionalizing a carbon nanotube so as to make the carbon nanotube having carboxyl or amino groups, depositing the carbon nanotube thin layers on the copper sheet or aluminium sheet through a layer-by-layer self-assembly method under anion-cation interaction, then compacting the deposited copper sheet or aluminium sheet, and carrying out high temperature treatment in a reducing atmosphere, thus obtaining the composite current collector. With the composite current collector, an ion diaphragm, semisolid flow slurries formed by positive and negative electrode active materials in a lithium ion-containing organic solvent, a novel lithium ion flow battery can be assembled. Compared with a single copper sheet or aluminium sheet current collector, the composite current collector of the invention has the advantages of good electronic conductivity and small internal resistance. Compared with traditional lithium ion batteries and flow batteries, the lithium ion flow battery provided in the invention has the advantages of convenient electrode material replacement and high specific energy, thus boasting tremendous application prospects in power and energy storage battery fields.

The invention discloses a layer by layer self-assembly compound nanofiltration membrane based on natural cellulose polyelectrolyte and a preparation method, belonging to the technical field of membrane separation. The preparation method comprises the following steps: firstly, adopting an ultrafiltration membrane as a base membrane for preparing a compound nanofiltration membrane, carrying out chemical modification on the surface of the base membrane to ensure that the surface of the base membrane has a charge property so as to generate static reaction with a polyelectrolyte; and secondly, through alternating depositing anionic and cationic polyelectrolytes, preparing the compound nanofiltration membrane through a layer by layer self-assembly method. According to the preparation method, the adopted cationic polyelectrolyte is a natural cellulose polyelectrolyte; compared with a currently used synthetic polyelectrolyte, the natural cellulose polyelectrolyte is lower in cost, and is an environmental-friendly resource; and the prepared compound nanofiltration membrane containing natural cellulose is good in hydrophilcity and charge performance so that the surface of the membrane is good in pollution resistance; and the compound nanofiltration membrane has a good retaining property for dye molecules such as divalent metal ions such as Ni<2+>, xylenol orange sodium salt, and rhodamine B.

The invention discloses a preparation method of a drug-loaded layer-by-layer self-assembly coating. The preparation method comprises the following steps: A, performing aminating modification on hyaluronic acid by using dopamine; B, performing aminating modification on chitosan by using 3,4-dihydroxyl phenylpropionic acid; C, dissolving the dopamine in a trimethylol aminomethane solution with a PH value of 8.5 to form a mixed solution with dopamine concentration of 2mg / mL; soaking a matrix material in the mixed solution, reacting for time of t1 at a constant temperature, and washing the matrix material; D, preparing a modified hyaluronic acid solution with concentration of 2mg / mL and a PH value of 5.5, and dissolving a loaded drug into the modified hyaluronic acid solution to obtain a solution S1; preparing a modified chitosan solution with concentration of 2mg / mL, and dissolving the loaded drug to obtain a solution S2; soaking the matrix material obtained in step C into the solution S2 for a time of t2; then soaking in the solution S1 for a time of t3; and E, repeating the step D. The drug-loaded layer-by-layer self-assembly coating has good PH response and stability and is suitable for the matrix materials of any shapes; and moreover, the preparation method has the advantages of simple operation, simpleness of needed equipment, low preparation cost and high applicability.

The invention discloses a preparation method for a high-performance three-dimensional carbon nanotube composite negative electrode material. The preparation method comprises: by taking a carboxylated carbon nanotube as a three-dimensional network framework and taking a high-capacity material subjected to layer by layer self-assembly and modification as an active substance, uniformly mixing the carbon nanotube with the active substance under the action of electrostatic attraction; and then performing in-situ coating by taking a mixed element-containing N or S-doped carbon source as a three-dimensional coating layer, and performing high-temperature treatment to obtain the high-performance three-dimensional carbon nanotube composite negative electrode material. The invention furthermore discloses the high-performance three-dimensional carbon nanotube composite negative electrode material and an application thereof. According to the preparation method, the cycle performance of the active substance is remarkably improved, and the capacity of the composite material can be controllably adjusted by controlling a ratio of the carbon nanotube to the active substance. In addition, a solvent used in the method is water, so that the method is environmentally-friendly, good in repeatability and low in cost, and has relatively high potential of large-scale application and good industrialized prospects.

The invention relates to a preparation method and application of an electrochemical sensor for detection of heavy metal lead contaminants and belongs to the technical field of electrochemical detection. The preparation method is characterized by including; performing synthesis to obtain a Fe-MOFs nano material, reducing palladium-platinum bimetallic nanoparticles onto the Fe-MOFs nano material, and mixing a hairpin type DNA signal probe with the composite material to obtain a biological signal probe; performing layer-by-layer self-assembly through rGO-TEPA and avidin for fixing of '8-17'DNAzyme to obtain the electrochemical sensor for detection of the heavy metal lead contaminants. The sensor is successfully applied to detection of lead contaminants in the environment. The preparation method and application has the advantages of high flexibility, high specificity and rapid and convenient detection; experimental evidence is provided for research of lead contamination detection technology, and new concepts and new technology platforms are provided for monitoring the lead contaminants in the environment are provided.

The invention discloses a charged TiO2 / polyelectrolyte composite nanofiltration membrane as well as a preparation method and an application thereof, and belongs to the technical field of membrane separation. The preparation method comprises the following steps: firstly, the surface of a base membrane is charged, so that the base membrane and polyelectrolytes can conveniently generate an electrostatic effect; secondly, the composite nanofiltration membrane is prepared with a method for alternatively depositing anionic and cationic polyelectrolytes and performing electrostatic layer-by-layer self-assembly. Inorganic nanoparticles adopted in the preparation method are modified negatively charged / positively charged TiO2 nanoparticles; as TiO2 has the advantages of good photocatalytic performance, good hydrophilicity and the like, TiO2 is combined with layer-by-layer self-assembly to prepare the TiO2 / polyelectrolyte composite nanofiltration membrane; the preparation method is simple and convenient to operate and is an environment-friendly preparation method; moreover, the prepared TiO2-containing composite nanofiltration membrane has very good hydrophilicity and charge performance, has good pollution resistance, is uniform in structure and can be used for removing divalent metal ions such as Ni<2+> and the like in wastewater as well as dye molecules such as dimethylphenol orange, eriochrome black T and the like at the same time, thereby having a good application effect.

Nanoparticle compositions and methods are disclosed for the sustained release of small molecules, such as pharmaceutical compounds in vivo, for example ligand-lytic peptide conjugates. The construction of the nanoparticles helps to prevent self-aggregation of the molecules, and the consequent loss of effectiveness. The system employs layer-by-layer self-assembly of biocompatible polyelectrolyte layers, and layers of charged small molecules such as drug molecules, to form a multilayer nanoparticle in which the drug or other small molecule itself acts as one of the alternating charged layers in the multilayer assembly. The small molecules can then be released over time in a sustained manner. The LbL nano-assemblies can specifically target cancers, metastases, or other diseased tissues, while minimizing side effects.

The invention discloses a composite nano-drug for integrated tumor diagnosis and treatment and a preparation method thereof. A chemotherapeutic drug, a photodynamic drug and shRNA plasmids capable of reversing multidrug-resistant MDR1 genes of tumor cells are located through a nano-carrier, a magnetic nano-sphere with precious metal nano-particles arranged on the surface serves as a kernel of the nano-carrier, mesoporous silica with the surface modified with amino groups serves as a shell of the nano-carrier, and a polyelectrolyte thin film layer structure with pH response is formed on the surface of the kernel-shell structure through a layer-by-layer self-assembly technology. The composite nano-drug integrates targeted drug delivery, multimode imaging, chemotherapy, photodynamic therapy and gene therapy, can be applied to early diagnosis of tumors, image mediation and real-time monitoring treatment at the same time and overcomes the defect that tumor diagnosis and treatment are separate in the prior art; besides, the composite nano-drug is simple in preparation process, high in operability and suitable for industrial production.

The invention discloses polysaccharide / inorganic nanoparticles hybrid micron-nano medicine-carrying capsule. The capsule has the following structure characteristics: (1) a water in oil (W / O) microemulsion capsule core is prepared by using fat-soluble drug A or fat-soluble drug B which is dissolved in oily solvent, negative OSA modified polysaccharide derivative and water; (2) the polysaccharide and negative inorganic nanoparticles perform layer-by-layer self-assembly which is based on the electrostatic interaction to form a capsule wall; and (3) the grain size of the micron-nano medicine-carrying capsule is 50-1000nm. The micron-nano medicine-carrying capsule provided by the invention has high drug encapsulation efficiency for drug situ embedding, the raw materials are all adopted from biodegradable materials with good biocompatibility and biodegradability. In addition, the medicine-carrying system has double intelligent functions of targeting and controlled release.

The invention discloses a polyethylenimine-tannic acid / hydrolyzed polyacrylonitrile ultrathin composite membrane. The thickness of the polyethylenimine-tannic acid / hydrolyzed polyacrylonitrile ultrathin composite membrane is smaller than 300 nm. The polyethylenimine-tannic acid / hydrolyzed polyacrylonitrile ultrathin composite membrane comprises polyethylenimine layers and tannic acid layers. Reactive layer-by-layer self-assembly is carried out by the aid of polyethylenimine and tannic acid to form the polyethylenimine-tannic acid / hydrolyzed polyacrylonitrile ultrathin composite membrane. Alternate assembly frequencies of polyethylenimine solution and tannic acid solution are 1.5-5.5. A procedure for preparing the polyethylenimine-tannic acid / hydrolyzed polyacrylonitrile ultrathin composite membrane includes preparing polyacrylonitrile ultra-filtration membranes and hydrolyzing the polyacrylonitrile ultra-filtration membranes; preparing the polyethylenimine solution and the tannic acid solution and regulating the pH (potential of hydrogen) of the polyethylenimine solution and the pH of the tannic acid solution by the aid of HCl and NaOH; carrying out alternate assembly by the aid of the polyethylenimine solution and the tannic acid solution in a shaking table. The polyethylenimine-tannic acid / hydrolyzed polyacrylonitrile ultrathin composite membrane, the preparation and the application have the advantages that a method for preparing the polyethylenimine-tannic acid / hydrolyzed polyacrylonitrile ultrathin composite membrane is simple and convenient, excellent intramembrane covalence effects can be realized, and prepared membrane materials can be used for pervaporation ethanol dehydration, are excellent in permeation flux and have excellent separation factors.

A carbon nitride membrane composite material modified by black phosphorus / metal organic framework (MOF) and a preparation method and application thereof to waste gas treatment are disclosed. First, taking urea as a raw material to calcine at a high temperature and prepare porous carbon nitride nanosheet; then carrying out surface carboxylation on the porous carbon nitride nanosheet, and modifying metal organic framework (MOF) on the surface of the porous carbon nitride through a layer-by-layer self-assembling method; stripping block black phosphorus materials into a two-dimensional black phosphorus slice by solvent exfoliation method; mixing the MOF-modified porous carbon nitride material with the two-dimensional black phosphorus material, carrying out suction filtration on the mixture under a vacuum pump to obtain the black phosphorus / MOF-modified carbon nitride membrane composite material.