63 results about "Biphenylamine" patented technology

The invention discloses a method for constructing a dual-mode sensor through smartphone-assisted surface molecular imprinting for detecting diphenyl phosphate and application of the dual-mode sensor, and belongs to the technical fields of biochemical analysis, functional nano materials and life science. In synthesis, solubility and selectivity of a target object and photo-initiation efficiency in a polymerization process are optimized, and diphenyl phosphate molecularly imprinted nano-enzyme MIPs is rapidly prepared through a molecular imprinting technology; in the detection, H2O2 and 3, 3, 5, 5-tetramethyl benzidine TMB are catalyzed by peroxidase-like activity of Fe and N-CDs to generate a chromogenic reaction and an inner filter effect of oxTMB is used for inhibiting a fluorescence signal, dual-signal cross validation is realized in cooperation with a smart phone, and the colorimetric-fluorescence sensor for detecting diphenyl phosphate is constructed. The sensor has specific recognition selectivity and binding affinity of diphenyl phosphate, is simple to operate and low in cost, can realize sensitive detection of diphenyl phosphate in a wide linear range, has the detection limit as low as 16 pg / mL, and is suitable for field analysis of trace DPhP in a complex water environment.

The invention relates to a diatomic catalyst for detecting carbosulfan pesticide residue and a preparation method, and belongs to the technical field of food safety detection. According to the invention, a reducing sulfide generated by breaking a nitrogen-sulfur (N-S) bond of carbosulfan under an acidic condition is used as a specific substance. The reductive sulfide not only can prevent bimetal active sites in the diatomic catalyst, but also consumes hydroxyl radicals generated by catalyzing hydrogen peroxide (H2O2), and the sensing switch enzyme formed by a dual enzyme inhibition mechanism causes the enzyme substrate 3, 4-dihydroxyl-3, 4-dione to be converted into the diatomic catalyst, so that the catalytic activity of the diatomic catalyst is improved. The blue color of the 3, 3 ', 5, 5'-tetramethyl benzidine (TMB) gradually becomes light along with the increase of the concentration of carbosulfan, sensitive visual detection is implemented, and after a blue product is read by using an ultraviolet spectrophotometer, the absorbance value generated by an ultraviolet absorption spectrum at 654 nm is linearly dependent on carbosulfan. The prepared diatomic catalyst effectively improves the detection sensitivity of the carbosulfan pesticide residue, and has good popularization and application prospects.

The invention discloses a method for detecting aflatoxin B1 in coffee based on colorimetric and photo-thermal dual modes of MXene (at) Pt nano-enzyme, which comprises the following steps: etching Ti3AlC2 by using LiF and HCl to obtain MXene, synthesizing platinum nano-particle modified MXene nano-enzyme (MXene (at) Pt) by using dopamine carbon dots and sodium borohydride as reducing agents and adopting an in-situ reduction technology, and detecting aflatoxin B1 in coffee by using the MXene (at) Pt nano-enzyme (MXene (at) Pt nano-enzyme (MXene (at) Pt nano-enzyme (MXene (at) Pt nano-enzyme (MXene (at) Pt). The MXene (at) Pt shows near-infrared light stimulation enhanced peroxidase-like activity and photo-thermal performance and can catalyze blue deepening and temperature rising of a substrate 3, 3 ', 5, 5'-tetramethyl benzidine (TMB), when aflatoxin B1 exists, POD-like activity of MXene (at) Pt nano-enzyme is inhibited, and colorimetric and temperature signals are reduced; a method for detecting the AFB1 by the colorimetric temperature dual-mode sensor is established, and the method has the characteristics of high sensitivity, strong specificity, simplicity and rapidness in operation and the like.

This application relates to a terphenylamine skeleton compound, its preparation method, and its application, belonging to the field of chemical synthesis technology. The preparation method of the terphenylamine skeleton compound of this application includes the following steps: dissolving 2,4,6-triphenylaniline with thiazole-4-carboxaldehyde or thiophene-3-carboxaldehyde in a solvent, conducting a reductive amination reaction under reducing agent conditions, quenching, extraction, washing, concentration to remove solvent, and purification to obtain the terphenylamine skeleton compound. This application provides a simple and mild synthetic method for the natural active products 5'-phenyl-N-(thiazol-4-ylmethyl)-[1,1':3',1''-terphenyl]-2'-amine and 5'-phenyl-N-(thiophene-3-ylmethyl)-[1,1':3',1''-terphenyl]-2'-amine, which can only be extracted from the secondary metabolites of the marine fungus Aspergillus sp. Furthermore, this method utilizes widely available raw materials, which is beneficial for large-scale industrial production of these natural active products.

A dichroic bis-azo biphenyl dye of the following formula:The substituents R1, R2, R3, R4 are alkyl (CnH2n+1) or alkenyl (CnH2n−1) groups with n=1-18. At least one substituent among R1R2R3R4 is different from the other substituents. A benzidine-free method of making a dichroic bis-azo biphenyl dye is provided in which the biphenyl portion of the dye is formed from different first and second mono-azo dyes by a cross-coupling reaction, which may be a Suzuki reaction. A polarizer is formed from a photoaligned layer of the bis-azo biphenyl dye on a substrate and exhibits a dichroic ratio of at least 40. Chemical modification of the photoaligned bis-azo biphenyl dye layer creates a broad-band thin film polarizer with low light scattering and high thermal and photo tolerances.

A resin composition contains a polyimide precursor and a solvent. The polyimide precursor is a copolymer of a tetracarboxylic dianhydride component and a diamine component containing pyromellitic dianhydride and 3,3',4,4'-biphenyltetracarboxylic dianhydride as tetracarboxylic dianhydride components and 2,2'-bis(trifluoromethyl)benzidine as a diamine component. The weight average molecular weight of the polyimide precursor is 260,000-1,000,000, and the concentration of the polyimide precursor in the resin composition is 5-20 mass%.

The present invention discloses the use of a copper-iron bimetallic oxide in the colorimetric detection of hexavalent chromium. The present invention utilizes a coprecipitation method to synthesize the copper-iron bimetallic oxide in a single step. This inexpensive and readily available copper-iron bimetallic oxide can highly selectively catalyze the Cr(VI) and 3,3',5,5'-tetramethylbenzidine (TMB) system to produce a visual blue color. Within a certain concentration range, the depth of the blue color is proportional to the Cr(VI) concentration, thus establishing a new colorimetric method for the detection of Cr(VI). In this system, the linear range for Cr(VI) detection is 0.3 μmol / L to 26 μmol / L, with a detection limit of 0.17 μmol / L. The system can be used for the detection and analysis of Cr(VI) in the environment and food.

The invention discloses a preparation method of polyurethane chain extender 2-methoxy-2'-aminobenzidine, which relates to the technical field of polyurethane chain extenders. The preparation method comprises the following steps: weighing o-chloroaniline and methanol in proportion; adding o-chloroaniline into a high-pressure reactor, adding methanol and a copper catalyst, heating, and keeping the reaction at a constant temperature; sampling and analyzing the reacted substances; and cooling the product after recovering methanol. The advantages of the invention are as follows: 2-methoxy-2'-aminobenzidine is directly synthesized from o-chloroaniline and methanol under the catalysis, the reaction steps are simple, the product is safe and non-toxic, the raw material cost for preparation is low, the preparation cost is reduced, and it is suitable for industrial production. The tensile strength of the polyurethane product chain-extended by 2-methoxy-2'-aminobenzidine is improved, the requirements for the tensile strength of polyurethane can be met, and the actual application range is wider.

The invention relates to the technical field of harmful substance detection, in particular to a three-channel colorimetric sensor for simultaneously detecting aflatoxin and a precursor thereof as well as a preparation method and application of the three-channel colorimetric sensor. According to the method, COFFe / NiP-Ph is utilized for catalyzing 3, 3 ', 5, 5'-tetramethylbenzidine (TMB) to be oxidized to generate blue oxTMB, o-phenylenediamine (OPD) is utilized for generating yellow oxOPD, and then the aflatoxin and the precursor thereof are detected through a three-channel colorimetric sensor. Purple ox4-AT is generated by using a mixture of N-ethyl-N-(3-sulfopropyl)-3-methylaniline sodium and 4-aminoantipyrine (4-AT), so that the colorimetric response is realized in a short time. The preparation method of the COFFe / NiP-Ph nano enzyme comprises the following steps: 1, a synthesis process of Fe-TAPP; 2, synthesis of Ni-TAPP is carried out; and 3, synthesizing the iron / nickel porphyrin covalent organic framework. The colorimetric sensor can be prepared into a detection reagent or a kit so as to realize qualitative and quantitative detection of aflatoxin and a precursor thereof in a sample to be detected. The detection method is simple and convenient to operate, and complex pretreatment on a to-be-detected sample is not needed; the detection cost is low, the detection is quick, and the requirement on a detection instrument is low.

The invention relates to a preparation method of furan-containing polybenzimidazole (PBI), in particular to a method for preparing furan-containing polybenzimidazole (PBI) by using bio-based furandicarboxylic acid (FDCA) as a diacid monomer instead of a traditional petroleum-based monomer and by using specific aromatic tetramine including 3, 3 ', 5'-tetracarboxylic acid (FDCA) as a diacid monomer. The novel polybenzimidazole polymer is synthesized by the following steps of: reacting 3, 3 '-diaminobenzidine, 3, 3', 4, 4 '-tetraamino diphenyl ether or 3, 3', 4, 4 '-tetraamino diphenyl sulfone at 150-160 DEG C for 2-4 hours under the protection of nitrogen in the presence of an ionic liquid solvent and a dehydrating agent phosphorus pentoxide, and reacting at 165-215 DEG C for 4-30 hours. The invention solves the problems of high processing difficulty, high cost and fossil raw material dependence of the traditional petroleum-based PBI.

The invention discloses a high-performance notebook computer shell composite material and a preparation method thereof, and relates to the technical field of composite materials. Comprising the following raw materials in parts by weight: 20-30 parts of carbon fibers, 20-30 parts of polyphenylene sulfide, 10-20 parts of a functional polymer, 1-3 parts of a coupling agent, 3-5 parts of nano titanium dioxide, 1-3 parts of an aluminum hydroxide flame retardant, 2-4 parts of a catalyst A and 3-5 parts of benzidine disulfonic acid. The functional polymer comprises structural units introduced by the following monomers: 3, 3 '-diamino-4, 4'-difluorodiphenyl sulfone and 1, 4-cyclohexanedicarboxylic acid. The composite material has the advantages of favorable mechanical properties, favorable flame retardancy, excellent high-temperature resistance and excellent aging resistance.

The invention relates to a cross-linked polyimide aerogel and a normal pressure drying preparation method thereof, and the preparation method comprises the following steps: taking 2, 2 '-dimethyl benzidine and 3, 3', 4, 4 '-biphenyl tetracarboxylic dianhydride as raw materials, cross-linking through 1, 3, 5-tri (4-aminophenoxy) benzene to prepare cross-linked polyimide, and drying under a normal pressure condition to obtain the cross-linked polyimide aerogel. The production difficulty of the cross-linked polyimide aerogel can be reduced, and a new thought is provided for preparation of the cross-linked polyimide aerogel.

The application discloses a method for colorimetric and photothermal dual-mode detection of aflatoxin B1 in coffee based on MXene@Pt nanozyme, wherein MXene is obtained by etching Ti3AlC2 with LiF and HCl, dopamine carbon dots and sodium borohydride are used as reducing agents, and in-situ reduction technology is adopted to synthesize MXene nanozyme modified with platinum nanoparticles (MXene@Pt). The MXene@Pt shows peroxidase-like activity and photothermal performance enhanced by near-infrared light stimulation, can catalyze the blue deepening of the substrate 3,3',5,5'-tetramethylbenzidine (TMB) and temperature rise, and when aflatoxin B1 exists, the POD-like activity of the MXene@Pt nanozyme is inhibited, and the colorimetric and temperature signals are reduced. The colorimetric and temperature dual-mode sensor detection method for AFB1 is established, and the method has the characteristics of high sensitivity, strong specificity, simple operation, rapidness and the like.

The invention discloses phosphate matrix composite fluorescent powder and a preparation method thereof, belongs to the technical field of solid luminescent materials, and aims to solve the problems that a single phosphate fluorescent material in the prior art is low in luminous efficiency and short in excitation spectrum; the thermal stability of the added organic light-emitting material is poor, and the like. The invention relates to a preparation method of phosphate matrix composite fluorescent powder. The preparation method comprises the following steps: coating a composite inorganic fluorescent material containing divalent europium and ammonium phosphite with modified polylactic acid; benzidine and (3-bromophenyl)-9H-carbazole react and then are matched with iridium trichloride hydrate, and the high-molecular organic fluorescent material is obtained. And self-assembling the high-molecular organic fluorescent material and calixarene to obtain the composite high-molecular fluorescent material. The phosphate matrix composite fluorescent powder prepared by the invention has the advantages of long spectral range and high thermal stability.

This invention provides an energy-storing, luminescent phase-change hot-melt road marking material and its preparation method, made from the following raw materials: C5 petroleum resin, glass microspheres, silane coupling agent, polyoxymethylene, polyoxyethylene, sodium sulfate, multi-walled carbon nanotubes, expanded graphite, oligomeric dopamine, isophorone diisocyanate, tetraethylenepentamine, perhydropolysilazane, N,N,N',N'-tetramethylbenzidine, 2,8-bis(diphenylphospho)dibenzo[b,d]thiophene, silica aerogel powder, nano-titanium dioxide powder, calcium carbonate powder, barite powder, lauric acid, palmitic acid, hexadecyltrimethylammonium bromide, polyethylene glycol octylphenyl ether, dioctyl phthalate, and acetic acid. While ensuring the visibility and durability of the road markings, this invention reduces high-temperature deformation and low-temperature cracking of the hot-melt road markings, minimizes the propagation of internal cracks, increases the service life of the hot-melt road markings, and reduces maintenance and repainting costs.

The invention relates to the technical field of wastewater treatment, and discloses a wastewater treatment adsorbent and a preparation method thereof.Acrylic acid, acrylamide and 4-vinylbenzaldehyde dihydroxybenzidine Schiff base are subjected to cross-linking polymerization to obtain a hydrogel-based wastewater treatment adsorbent, a large number of benzene rings are introduced into a hydrogel skeleton, and the hydrogel-based wastewater treatment adsorbent is prepared. The rigidity of the hydrogel is enhanced, and the tensile strength and the mechanical property are improved. The hydrogel-based wastewater treatment adsorbent contains a plurality of o-hydroxyl Schiff base structures and can form a coordination effect with metal ions such as lead, the adsorption performance of the hydrogel on the metal ions such as lead is improved, meanwhile, phenolic hydroxyl groups in the hydrogel, phenolic hydroxyl groups of phenol and N atoms of 4-vinyl imidazole can form hydrogen bonds and other interactions, and the adsorption performance of the hydrogel on the metal ions such as lead is improved. A synergistic adsorption effect is achieved with carboxyl and amido bonds in the hydrogel, so that the adsorption strength of metal ions and organic pollutants in the hydrogel is remarkably enhanced, and a higher removal rate is shown.

The invention provides a donor-acceptor type covalent organic framework material B-COF photocatalyst and application thereof in synthesis of benzonitrile derivatives, and belongs to the technical field of catalytic chemistry. The B-COF can be prepared through solvothermal condensation of 2, 4, 6-triformyl phloroglucinol and a benzidine derivative, and is characterized in that a [100] crystal face diffraction peak appears at a position where 2theta is equal to 3.46 degrees in XRD (X-Ray Diffraction). The material can efficiently catalyze conversion from aromatic aldoxime to a benzonitrile derivative under light irradiation, and the thermal stability of the material is obviously superior to that of a traditional photocatalyst. According to the B-COF photocatalyst and the catalytic system thereof developed by the invention, the efficiency and the selectivity of photocatalytic organic conversion reaction are remarkably improved, and a new technical scheme is provided for developing an environment-friendly and sustainable chemical synthesis method.

This invention provides a multilayer polyimide film with excellent heat resistance, low dielectric loss tangent, and dimensional stability. The multilayer polyimide film comprises a heat-resistant polyimide layer and a heat-fusion polyimide layer laminated on one or both sides; the heat-resistant polyimide is obtained from a tetracarboxylic acid component containing more than 75 mol% of 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) and less than 25 mol% of pyromellitic dianhydride (PMDA), and a diamine component containing 70 mol% to 95 mol% of p-phenylenediamine and 5 mol% to 30 mol% of 2,2'-dimethylbenzidine; the heat-fusion polyimide is obtained from a tetracarboxylic acid component containing 10 mol% to 60 mol% of s-BPDA and 40 mol% to 90 mol% of PMDA, and a diamine component containing more than 50 mol% of 2,2-bis[4-(4-aminophenoxy)phenyl]propane.

The present invention discloses a dual-mode method for detecting nitrite by using MnO2 / Fe,B-CDs with peroxidase-like activity. In the present invention, iron and boron co-doped carbon dots (Fe,B-CDs) are synthesized by a microwave method and used as a reducing agent to prepare MnO2 / Fe,B-CDs nanomaterials. MnO2 / Fe,B-CDs have peroxidase-like activity and can oxidize 3,3',5,5'-tetramethylbenzidine (TMB) and H2O2 to produce blue oxTMB. On the one hand, when nitrite is added together with TMB and H2O2, the peroxidase-like activity of the nanozyme can be enhanced, deepening the blue color of the system. On the other hand, after MnO2 / Fe,B-CDs oxidize TMB and H2O2 to produce blue oxTMB, when nitrite is added, a diazo reaction occurs between nitrite and oxTMB, forming yellow diazonium salt. Thus, a new dual-color and dual-mode detection method for nitrite at wavelengths of 654 nm and 440 nm is established. Applying this method to the detection and analysis of nitrite in food and fermented food has the characteristics of accuracy, high sensitivity, strong specificity, simple operation and rapidity.

The invention relates to a method for the preparation of 2-aminobiphenyls, key intermediates in the preparation of compounds of interest in the agrochemical industry. The process comprises reacting an ortho-substituted aniline and a phenylboro derivative in the presence of a base and a palladium catalyst, said palladium catalyst comprising a palladium source and a biphenyl phosphine ligand of formula (III) or a salt thereof.

The invention discloses an A-D-A type COF photocatalyst as well as a preparation method and application thereof, and the COF photocatalyst is constructed by taking 4 ', 4' ', 4' ''-(1, 3, 5-triazinyl-2, 4, 6-triyl) tri (([1, 1 '-biphenyl]-4-amine)) (TB) and 2, 7-dibenzaldehyde-benzothiadiazole (BTDA) as units; the preparation method comprises the following steps: (1) adding TB and BTDA into an organic solvent, and uniformly mixing; (2) continuously adding an acid catalyst, uniformly mixing, and removing air; and (3) carrying out an aldehyde-amine condensation reaction on the air-removed mixture in the step (2) to obtain a yellow precipitate, washing, and drying to obtain the photocatalyst. According to the invention, a novel acceptor-donor-acceptor (A-D-A) COF is synthesized from TB and BTDA, and the COF has an excellent catalytic effect on photocatalytic synthesis of H2O2.

The invention discloses pigment yellow 83 and a preparation method thereof, and relates to the technical field of pigments, in the pigment yellow 83, 3, 3 '-dichlorobenzidine is taken as a diazo component and is coupled with acetyl-4-chloro-2, 5-dimethoxyaniline, and modified rosin prepared by copolymerization of rosin, monoethyl maleate and cetyl alcohol is introduced in the later stage of reaction; and then mixing with calcium chloride and other raw materials. Carboxyl and long-chain alkyl are introduced into the modified rosin, so that hydrophilic-hydrophobic balance of the surface of the pigment is realized, and compatibility and dispersion stability with a coating system are enhanced; the calcium chloride can promote the pigment to be separated out from a water phase to form solid particles and can be further combined with carboxyl in the modified rosin, so that particle aggregation is inhibited, and the solubility of the modified rosin in pigment molecules is improved. The pigment yellow 83 has the advantages of being good in hydrophobic performance, coloring strength and dispersing performance.

The present invention discloses a method for rapid detection of acrylamide by dual-mode Fe / PDA-Au-janusAg@AuNPs combined with an aptamer. The method synthesizes Au-Ag Janus nanoparticles were further reduced with sodium borohydride to prepare Au‑janusAg@AuNPs, and Fe / PDA and Au‑janusAg@AuNPs complexes (Fe / PDA‑Au‑janusAg@AuNPs) were prepared by self-assembly. The complex was incubated with acrylamide aptamer to obtain Fe / PDA‑Au‑janusAg@AuNPs‑Apt, which has the dual activity of mimicking enzymes and increasing surface enhanced Raman scattering (SERS). In the presence of hydrogen peroxide, the colorless substrate 3,3',5,5'‑tetramethylbenzidine (TMB) was oxidized to the SERS-active oxidized blue oxTMB, while the addition of glutathione (GSH) inhibited the oxidation of TMB. Then, based on the thiol‑ene Michael addition reaction between GSH and acrylamide (AA), the increase in AA concentration accelerated the oxidation of TMB and restored the deep blue color. Based on this principle, a new selective and strong AA colorimetric-SERS detection method was established, with a detection limit of 0.012µg / kg, which can meet the relevant national food safety requirements.

The invention relates to the technical field of ternary organic solar cells, in particular to a high-efficiency ternary organic solar cell active layer and a preparation method thereof.A modular monomer library containing a p-benzoquinone-benzidine structure is constructed, the monomer library comprises three monomers M1, M2 and M3, third components P1, P2 and P3 are synthesized through functional group regulation and control and a one-step polymerization process, and the third components P1, P2 and P3 are synthesized through a one-step polymerization process; a ternary blending active material for constructing an intermediate coating of a device is prepared, in a final assembly structure of the device, the upper layer is PNDIT-F3N, the middle layer is a ternary active layer obtained by blending P1, P2, P3, D18 and L8-BO, and the lower layer is PEDOT: PSS. Through structural regulation and control of a dynamic adjustable monomer library, one-step synthesis of three differentiated third components is realized, and the preparation process is simple and convenient. Complex modification or noble metal catalysts are not needed, so that the cost is reduced.

The invention relates to the technical field of nondestructive testing, and discloses a non-combustible fluorescent penetrant flaw detection agent composition which comprises the following components in parts by weight: 8-10 parts of a solvent system; 0.1 to 0.2 part of a tetramethyl benzidine derivative; 0.1 to 0.2 part of polyoxyethylene octyl phenyl ether; the invention also provides a preparation method of the non-combustible fluorescent penetrant flaw detection agent composition, and the preparation method comprises the following steps: mixing the solvent matrix to form a solvent system; adding a fluorescent dye, wherein the fluorescent dye is dispersed in a solvent system; the surfactant is introduced to regulate the wettability of the composition; integration of the additive system is used to enhance thermal stability and dispersion stability. According to the invention, the solvent matrix ratio is optimized, and the thermal stability reinforcing agent and the dispersing agent are introduced to achieve a synergistic effect, so that the stability of the flaw detection agent in a high-temperature environment, the fluorescence signal uniformity of crack detection and the long-term storage performance are improved.

The invention discloses a preparation method of methyl p-pentyloxy tribenzoate and anidulafungin side chains, and the preparation method of the methyl p-pentyloxy tribenzoate comprises the following steps: Gomberg-Bachmann reaction: dissolving a first reactant and an acidic solution in a first solvent, adding sodium nitrite or a solution thereof, then adding a second reactant and an alkaline solution, reacting, filtering, washing, and drying to obtain the methyl p-pentyloxy tribenzoate. The methyl p-pentyloxy tribenzoate is obtained; wherein the first reactant is 4-aminobenzoic acid methyl ester, 4-pentyloxy aniline, 4-aminobiphenyl-4-carboxylic acid methyl ester or 4 '-pentyloxy biphenyl-4-amine, and the second reactant is 4-aminobenzoic acid methyl ester or 4'-pentyloxy biphenyl-4-amine; the second reactants are 4-pentyloxy biphenyl, biphenyl-4-methyl formate, pentyloxy benzene or methyl benzoate in sequence in one-to-one correspondence. And carrying out hydrolysis reaction on the prepared methyl p-pentyloxy tribenzoate to obtain the anidulafungin side chain. The prepared anidulafungin side chain is high in purity and low in impurity content, and the preparation method has the advantages of cost and production.

The present invention discloses an application of a bifunctional platinum-modified nickel-iron layered double metal hydroxide in the quantitative and qualitative detection of polyphenols. The present invention prepares Pt / NiFe‑LDH, which can be used as a nanozyme material for colorimetric analysis and a matrix for LDI MS. Among them, the abundant hydroxyl groups on LDH can selectively capture hydroxyl-containing molecules such as polyphenols, and Pt / NiFe‑LDH exhibits high peroxidase activity, which can catalyze the decomposition of hydrogen peroxide to oxidize 3,3',5,5'‑tetramethylbenzidine to blue, and the antioxidant properties of polyphenols can affect the color depth of the system, and the linear relationship between the absorbance under the detection signal and the polyphenol content in the system can be used to achieve polyphenol quantification. On the other hand, Pt / NiFe‑LDH-assisted LDI MS has good signal intensity feedback in the monomer detection of polyphenols, and can monitor the oxidation process of polyphenols by virtue of a short detection time interval (a few seconds).

The application discloses a diphenylamine-based organic solvent composite nanofiltration membrane and a preparation method thereof, and belongs to the technical field of separation membranes. The diphenylamine-based organic solvent composite nanofiltration membrane is prepared by the following steps: taking polyacrylonitrile or polyimide ultrafiltration membrane as a base film, removing a surface pore preserving agent, immersing in an aqueous solution containing a 2,2'-diphenylamine-based compound, then immersing in an organic solution containing a polybasic acid chloride to perform an interfacial polymerization reaction, and finally performing a heat crosslinking post-treatment to obtain the composite nanofiltration membrane. The prepared composite nanofiltration membrane has an about 8 times flux increase compared with a traditional polyamide membrane due to the introduction of the rigid twistable monomer diphenylamine-based compound, and the selectivity of the prepared composite nanofiltration membrane to organic small molecule dyes is not obviously reduced. Meanwhile, the prepared composite nanofiltration membrane has high stability in tests of various polar solvents, and therefore has high economic value in separation of organic solvent systems in the industry.

The invention belongs to the technical field of oil exploitation, and particularly relates to an oil-displacing agent for improving the recovery efficiency and a preparation method and application thereof. The preparation method comprises the following steps: adding 5-aminoisophthalic acid, first DMF (Dimethyl Formamide) and triethylamine into a reactor, cooling, slowly dropwise adding first malonyl chloride, and continuously reacting; dissolving benzidine disulfonic acid in second DMF, dropwise adding into the reactor, and continuously reacting; dropwise adding second malonyl chloride into the reactor, and continuously reacting; dissolving fatty amine in third DMF, dropwise adding into the reactor, and continuously reacting; and carrying out heating dissolution, cooling, solid precipitation, centrifugation and drying so as to obtain the product oil-displacing agent. The oil-displacing agent disclosed by the invention has the characteristics of high interfacial activity, good emulsifying effect and strong anti-shearing capability.