CN113088157B - Fluorescent coating with pH response, preparation method and application thereof - Google Patents

Fluorescent coating with pH response, preparation method and application thereof Download PDF

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CN113088157B
CN113088157B CN202110286990.XA CN202110286990A CN113088157B CN 113088157 B CN113088157 B CN 113088157B CN 202110286990 A CN202110286990 A CN 202110286990A CN 113088157 B CN113088157 B CN 113088157B
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fluorescent
coating
microspheres
resin
nano
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CN113088157A (en
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董泽华
冯学磊
蔡光义
曹祥康
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Huazhong University of Science and Technology
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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D163/00—Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G83/00—Macromolecular compounds not provided for in groups C08G2/00 - C08G81/00
    • C08G83/008—Supramolecular polymers
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
    • C09D5/22—Luminous paints
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
    • G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
    • G01N21/64—Fluorescence; Phosphorescence
    • G01N21/6428—Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes"
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2205/00—Polymer mixtures characterised by other features
    • C08L2205/03—Polymer mixtures characterised by other features containing three or more polymers in a blend
    • C08L2205/035—Polymer mixtures characterised by other features containing three or more polymers in a blend containing four or more polymers in a blend
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2205/00—Polymer mixtures characterised by other features
    • C08L2205/14—Polymer mixtures characterised by other features containing polymeric additives characterised by shape
    • C08L2205/18—Spheres
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
    • G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
    • G01N21/64—Fluorescence; Phosphorescence
    • G01N21/6428—Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes"
    • G01N2021/6439—Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" with indicators, stains, dyes, tags, labels, marks

Abstract

The invention discloses a fluorescent coating with pH response, a preparation method and application thereof. The fluorescent coating comprises resin and fluorescent nano-microspheres dispersed in the resin, the fluorescent nano-microspheres comprise polymer nano-microspheres and fluorescent substances growing on the polymer nano-microspheres in situ, and the fluorescent substances are obtained by performing coordination polymerization reaction on europium salt and a ligand, or are obtained by performing coordination polymerization reaction on terbium salt and the ligand. According to the invention, the corrosion condition in the coating is indicated through fluorescence luminescence, when the base metal under the coating is corroded, the pH value is reduced due to metal ion hydrolysis, the fluorescent filler in the coating is promoted to be degraded, so that the fluorescence is quenched, and the coating defect and the coating aging state are displayed in a visual form, so that the visual detection of the defect in the coating is realized. And the invention can also enhance the corrosion resistance of the coating through the micro-nano filler.

Description

Fluorescent coating with pH response, preparation method and application thereof
Technical Field
The invention belongs to the field of functional anticorrosive coatings, and particularly relates to a fluorescent coating with pH response, a preparation method and application thereof.
Background
Coating protection is the most common method for preventing metal corrosion, but the protection performance of the coating is reduced due to ultraviolet radiation, salt spray erosion, high and low temperature, and dry and wet alternating climate change and abrasion in the service process. During failure of the coating, the aqueous solution can penetrate to the coating/substrate interface through coating defects, resulting in corrosion of the metal substrate. Although not significantly altered by the naked eye after failure of many corrosion resistant coatings, corrosion resistance is lost and penetration of corrosive particles results in severe corrosion of the metal substrate and potential safety hazards. Therefore, the aging state of the coating must be monitored in time before the substrate is obviously corroded. Through modifying the coating filler, the local corrosion environment change can be sensed, and the coating defect and the coating aging state are displayed in a visual form, so that the method has important significance for prejudging the overall protective performance of the coating, preventing maintenance of the coating and prolonging the service life of equipment.
The luminescent material generally refers to a material which absorbs energy in various forms from the outside, converts the energy through radiative transition in an atomic structure and the like, and releases the energy in the form of photons, the most common luminescent material at present is rare earth fluorescent powder, 4f electrons of the rare earth fluorescent powder can shine after the transition between energy levels, and by utilizing the characteristic of rare earth, a complex of the rare earth fluorescent powder and an inorganic material can be combined to form a coating filler, wherein the rare earth serves as a matrix component and also can serve as a luminescent material activator. The rare earth luminescent material has the advantages of bright color, narrow emission band, concentrated energy, strong high temperature resistance and high emission intensity maintenance at high temperature, and has the advantages of multiple emission spectrum types, strong absorption capacity, bright color, high conversion efficiency, high physical and chemical stability and good stability under short ultraviolet radiation, so the rare earth luminescent material is widely applied, and europium is most applied as an active element.
The luminescent paint is important in the development of functional paint, and the paint is prepared by mixing luminescent pigment, resin, organic solvent and the like according to a certain proportion and emits light with different colors under the irradiation of an ultraviolet lamp or sunlight. The method is applied to the fields of anti-counterfeiting, identification and the like, and most researches are carried out at present aiming at the stimulus response of different local environments, so that the functionality of the coating is richer, for example, patent document CN109233547A discloses an oxygen concentration response high polymer photoluminescence coating and preparation and application thereof. However, these responses do not optimize the performance of the coating and do not allow visual detection of defects in the coating.
Disclosure of Invention
Aiming at the defects or improvement requirements of the prior art, the invention provides a fluorescent coating with pH response, a preparation method and application thereof, aiming at indicating the corrosion condition in the coating through fluorescence luminescence and enhancing the corrosion resistance of the coating through micro-nano filler, thereby solving the technical problem that the visual detection of the defects in the coating cannot be realized at present.
To achieve the above object, according to one aspect of the present invention, there is provided a fluorescent coating with pH response, the fluorescent coating comprises a resin, a fluorescent nanosphere dispersed in the resin, the fluorescent nanosphere comprises a polymer nanosphere and a fluorescent substance grown in situ on the polymer nanosphere, the fluorescent substance is obtained by coordination polymerization of europium salt and a ligand, or the fluorescent substance is obtained by coordination polymerization of terbium salt and a ligand.
Preferably, the europium salt is a europium salt hydrate and the terbium salt is a terbium salt hydrate.
Preferably, the ligand is one or two of tannic acid, maleic anhydride, tartaric acid and phenanthroline, and the europium salt is EuCl3·6H2O or Eu (NO)3)3·6H2O; the terbium salt is TbCl3·6H2O or Tb (NO)3)3·6H2O; the molar ratio of the europium salt to the ligand is 1: (5-20), wherein the molar ratio of the terbium salt to the ligand is 1: (5-20).
Preferably, the polymer ball is at least one of polymethyl methacrylate, polystyrene and polyacrylic acid.
Preferably, the mass content of the fluorescent nano-microspheres in the fluorescent coating is 0.5% -10%. When the content is less than 0.5%, fluorescence visualization cannot be realized, and the fluorescence intensity is too low; if the content is more than 10%, the corrosion resistance of the coating layer may be lowered.
According to another aspect of the present invention, there is also provided a method for preparing a fluorescent coating having a pH response, the method comprising the steps of:
(1) dispersing europium salt, ligand and polymer nano-microspheres in water, or dispersing terbium salt, ligand and polymer nano-microspheres in water to perform coordination polymerization reaction, and growing fluorescent materials on the polymer nano-microspheres in situ to obtain fluorescent nano-microspheres;
(2) and adding the fluorescent nano-microspheres into resin, adding a curing agent after uniform dispersion, and stirring uniformly to obtain the fluorescent coating.
Preferably, the curing agent is a low molecular polyamide; preferably, in the step (2), after the fluorescent nanospheres are added to the resin, the method further comprises: adding resin diluent, defoaming agent, leveling agent and dispersing agent.
Preferably, the resin diluent is one or two of dimethylbenzene and acetone, and the dispersant is one or two of BYK140 and BYK 142; the defoaming agent is BYKA-065, BYKA-141 or BYKA-530, and the flatting agent is BYK-300, BYK306 or BYK-333; preferably, the mass ratio of the resin diluent to the resin is 1 (5-20), and the mass content of the fluorescent nano-microspheres in the fluorescent coating obtained after the step (2) is 0.5-10%.
Preferably, the resin is one or more of polyurethane, epoxy resin, alkyd resin and acrylic resin; preferably, when the resin is one or more of polyurethane, epoxy resin and alkyd resin, an organic solvent is added into the resin for mixing, and the organic solvent is one or more of xylene, ethyl acetate, butyl acetate, acetone, butanone, 4-methyl-2-pentanone, n-propanol, isopropanol, n-octanol, n-hexane and n-octane.
According to a further aspect of the present invention, there is also provided a use of the fluorescent coating with pH response as described above for visually detecting corrosion defects of a metal substrate; coating the fluorescent coating on the surface of a metal matrix, and drying at room temperature; when the metal matrix is corroded, the fluorescent substance in the fluorescent coating is subjected to fluorescence quenching, so that the corrosion defect of the metal matrix is visually detected.
Preferably, the fluorescent coating is coated on the surface of the metal substrate by brushing, dipping, spraying or curtain coating, and the thickness of the fluorescent coating coated on the surface of the metal substrate after drying is 20-100 μm.
In general, at least the following advantages can be obtained by the above technical solution contemplated by the present invention compared to the prior art.
(1) The fluorescent coating with pH response provided by the invention not only can indicate the corrosion condition in the coating through fluorescence, but also can enhance the corrosion resistance of the coating through the fluorescent nano-microspheres, which is mainly due to the fact that the nano-particles form a physical barrier layer on the surface of the nano-particles. When the base metal under the coating is corroded, the metal ions are hydrolyzed to reduce the pH value, so that the fluorescent filler structure in the coating is damaged, and the fluorescence is quenched. Therefore, the visualization and the rapid identification of the corrosion defect of the substrate in the coating are realized through fluorescence quenching, and the corrosion defect can be found in time before the substrate is obviously corroded. The fluorescent coating provided by the invention can realize sensing of local corrosion environment change, and display of coating defects and coating aging state in a visual form, which is of great significance for prejudging the overall protective performance of the coating, preventive maintenance of the coating and prolonging of the service life of equipment.
(2) The coating has good adhesion. The tannin mainly contains hydroxyl, has good adsorbability, and increases the adhesion between the resin and the matrix.
(3) According to the invention, the fluorescent effect and the corrosion resistance of the coating are optimal by strictly controlling the fluorescent nano-microspheres in the fluorescent coating, when the content of the fluorescent nano-microspheres in the fluorescent coating is less than 0.5%, the fluorescent visualization can not be realized, and the fluorescent intensity is too low; and when the content of the fluorescent nano microspheres in the fluorescent coating is more than 10%, the corrosion resistance of the coating is reduced.
(4) The preparation method provided by the invention is carried out at room temperature, has mild conditions, does not need complex equipment and complex post-treatment process, and is suitable for large-area construction of members such as vehicles, bridges and the like.
Drawings
FIG. 1 is a flow chart of a method for preparing a fluorescent coating with pH response and brushing the fluorescent coating on the surface of a carbon steel plate, which is provided by an embodiment of the invention;
FIG. 2 is a graph of fluorescence intensity of pH-responsive fluorescent coatings provided in example 1 of the present invention at defects before and after corrosion;
FIG. 3 is a graph of electrochemical impedance obtained by performing a salt spray test on a fluorescent coating having a pH response provided in example 1 of the present invention;
FIG. 4 is a fluorescence intensity diagram of a fluorescent coating with pH response prepared by adding fluorescent nano-microspheres in an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
Example 1
This example provides a method for preparing a fluorescent coating with pH response, and the fluorescent coating is brushed on the surface of a carbon steel plate. The method comprises the following specific steps:
(1) PMMA was first synthesized by a dispersion polymerization process, comprising the steps of adding 10g of Methyl Methacrylate (MMA), 1g of Azobisisobutyronitrile (AIBN), 1.5g of polyvinylpyrrolidone (PVP), 60g of methanol, 27.5g H2O in this order to a 500ml two-necked round-bottomed flask, slowly heating to 75 ℃ with mechanical stirring at 160rpm, and then reacting at 75 ℃ for 6 hours. After the reaction is finished, standing for 3h at normal temperature, then washing for 5 times by using methanol to remove PVP adhered on the PMMA microspheres, wherein the specific washing step is to centrifuge the particles (8000r/min,2 min). And drying the prepared product in a vacuum drying oven for 24 hours, and grinding to obtain PMMA microspheres with the particle size of 2 microns.
(2) Referring to FIG. 1, according to EuCl3·6H2The molar ratio of O to tannic acid is 1: 0.3012g of EuCl were weighed3·6H2O dissolved in 30ml H2In O, 0.8016g of tannic acid was dissolved in 20ml of water, and PMMA microspheres were dispersed in 25ml of water. 100ML of water was put into a 500ML flask, and then the above solution was added to the flask. Reacting for 6h at normal temperature, then washing with water, drying and grinding. Obtaining the fluorescent nano-microsphere with pH response. Measured by a fluorescence spectrometer, the fluorescent nano-microsphereUnder fluorescence excitation, intense fluorescence can be emitted (see fig. 2).
(3) 28g of epoxy resin is weighed, 0.28g of the fluorescent nano-microspheres is added into the epoxy resin, and then the epoxy resin is dispersed under ultrasound. After dispersing the mixture uniformly, 7g of polyamide was added, followed by stirring with a glass rod. Putting the mixture into a vacuum oven for vacuumizing and removing bubbles. Then the coating is brushed on the surface of the carbon steel plate and cured and dried at room temperature, and the coating thickness is about 40 mu m. The ultraviolet lamp is used for irradiating to show that the coating has good fluorescence luminescence characteristics.
Example 2
This example provides a method for preparing a fluorescent coating with pH response, and the fluorescent coating is brushed on the surface of a carbon steel plate. The method comprises the following specific steps:
(1) according to EuCl3·6H2The molar ratio of O to tannic acid is 1: 20, 0.3012g of EuCl were weighed3·6H2O dissolved in 30ml H2In O, 0.3216g of tannic acid was dissolved in 80ml of water, and then PMMA microspheres prepared in the same manner as in example 1 were dispersed in 25ml of water. 100ml of water was put into a 500ml flask, and then the above solution was added to the flask. Reacting for 6h at normal temperature, then washing with water, drying and grinding. Obtaining the fluorescent nano-microsphere with pH response.
(2) Weighing 0.14g of the fluorescent nano-microspheres, adding the fluorescent nano-microspheres into 28.0g of epoxy resin, uniformly dispersing under ultrasonic waves, then adding 7g of polyamide, 0.2g of dispersant BYK182, 3-10 dripping flatting agents BYK-300 and 5-10 drops of defoaming agents BYK A-530, finally adding xylene with the total amount of about 20%, uniformly stirring by using a glass rod, and placing the mixture in a vacuum oven for vacuumizing to remove bubbles. Then brush-coating on the surface of the carbon steel sheet, curing and drying at room temperature, and the coating thickness is about 40 mu m.
Example 3
This example provides a method for preparing a fluorescent coating with pH response, and the fluorescent coating is brushed on the surface of a carbon steel plate. The method comprises the following specific steps:
(1) according to EuCl3·6H2The molar ratio of O to tannic acid is 1: 0.3012g of EuCl were weighed3·6H2O dissolved in 30ml H2In O, 0.8016g of tannic acid was dissolved in 80ml of water, and then PMMA microspheres prepared in the same manner as in example 1 were dispersed in 25ml of water. 100ml of water was put into a 500ml flask, and then the above solution was added to the flask. Reacting for 6h at normal temperature, then washing with water, drying and grinding. Obtaining the fluorescent nano-microsphere with pH response.
(2) Weighing 2.8g of the fluorescent nano-microspheres, adding the fluorescent nano-microspheres into 28.0g of epoxy resin, uniformly dispersing under ultrasonic wave, then adding 7g of polyamide, 0.2g of dispersant BYK182, 3-10 dripping flatting agents BYK-300 and 5-10 drops of defoaming agents BYK A-530, finally adding xylene with the total amount of about 20%, uniformly stirring by using a glass rod, and placing the mixture in a vacuum oven for vacuumizing to remove bubbles. Then brush-coating on the surface of the carbon steel sheet, curing and drying at room temperature, and the coating thickness is about 40 mu m.
Example 4
This example provides a method for preparing a fluorescent coating with pH response, and the fluorescent coating is brushed on the surface of a carbon steel plate. The method comprises the following specific steps:
(1) according to TbCl3·6H2The molar ratio of O to tannic acid is 1: 0.2687g of EuCl were weighed3·6H2O dissolved in 30ml H2In O, 0.3216g of tannic acid was dissolved in 80ml of water, and then PMMA microspheres prepared in the same manner as in example 1 were dispersed in 25ml of water. 100ml of water was put into a 500ml flask, and then the above solution was added to the flask. Reacting for 6h at normal temperature, then washing with water, drying and grinding. Obtaining the fluorescent nano-microsphere with pH response.
(2) Weighing 0.28g of the fluorescent nano-microspheres, adding the fluorescent nano-microspheres into 28.0g of epoxy resin, uniformly dispersing under ultrasonic wave, then adding 7g of polyamide, 0.2g of dispersant BYK182, 3-10 dripping flatting agents BYK-300 and 5-10 drops of defoaming agents BYK A-530, finally adding xylene with the total amount of about 20%, uniformly stirring by using a glass rod, and placing the mixture in a vacuum oven for vacuumizing to remove bubbles. Then brush-coating on the surface of the carbon steel sheet, curing and drying at room temperature, and the coating thickness is about 40 mu m.
The above specific examples were tested for performance:
(1) corrosion resistance test
The coating corrosion resistance adopts the electrochemistry impedance to evaluate, and the electrolyte is 3.5% NaCl solution, adopts standard three-electrode system, and the counter electrode is made to the platinum sheet, and the reference electrode is made to saturated calomel electrode, and the working electrode is the coating sample, and testing arrangement fast-assembling electrolytic cell, the body of the pool are the plastic tubing of internal diameter 3.5cm, and testing arrangement puts in the farley shielded cell, impedance test parameter: the alternating current amplitude is 20mV, the scanning frequency range is 100 kHz-0.01 Hz, logarithmic scanning is carried out, and 10 points/10 frequency multiplication is carried out.
Results and analysis:
referring to FIG. 3, the fluorescent coating prepared in example 1 was subjected to a salt spray test in a neutral salt spray box while performing corrosion resistance evaluation using electrochemical impedance, and the results are shown in FIG. 3, which shows that the low frequency impedance of the coating was maintained at 10 M.OMEGA.cm for 3 cycles of accelerated testing (48 hours per cycle)2Thus, the fluorescent coating has good corrosion resistance.
(2) Determination of adhesion
With reference to the adhesion test of colored paint and varnish by a pull-open method of GB/T5210-2006, a PositestAT-A type adhesion tester of the Defelsko company in America is used, the size of a spindle is 20mm, and the measurement range is 0-24 MPa. The average adhesion of the coating was calculated by testing three samples.
Results and analysis:
the fluorescent coatings prepared by examples 1, 2, X were subjected to an average adhesion test, the results of which are shown in table 1:
example 1 Example 2 Example 3 Example 4
Average adhesion 5.76MPa 4.83MPa 5.54Mpa 3.1MPa
(3) Fluorescence photometry
The coating was exposed to the corrosive luminescence with a hand-held UV lamp at 365nm and then tested for fluorescence using a Jasco model FP-6500 fluorescence spectrometer.
Results and analysis:
after the fluorescent coating prepared in example 1 was coated on the surface of the steel sheet, a cross was drawn on the surface of the coated steel sheet to simulate the coating defect, and the steel sheet sample coated with the fluorescent coating was immersed in a 3.5% NaCl solution for 72 hours or more to corrode it. Then, a sample is taken out to carry out fluorescence irradiation, and the defect of the coating shows obvious fluorescence quenching, the carbon steel matrix at the surface defect is corroded, the pH value of the local environment is reduced, the ligand in the fluorescent filler is decomposed, and the fluorescence disappears. The phenomenon can be used for visually monitoring the coating defects, and is beneficial to early finding the micro defects in the coating and evaluating the aging degree of the coating. The fluorescence results before and after corrosion by fluorescence spectroscopy are shown in fig. 2, where curve 1 shows the fluorescence intensity at the defect after corrosion and curve 2 shows the fluorescence intensity before corrosion. It can be seen that the fluorescent coating undergoes fluorescence quenching after corrosion.
After the fluorescent coatings prepared in the embodiments 1, 2 and 3 are coated on the surface of the steel sheet, fluorescent irradiation is performed, and the fluorescence intensity is tested by using a fluorescence spectrometer, wherein the mass content of the fluorescent nano-microspheres in the fluorescent coating in the embodiment 1 is 1%, the mass content of the fluorescent nano-microspheres in the fluorescent coating in the embodiment 2 is 0.5%, and the mass content of the fluorescent nano-microspheres in the fluorescent coating in the embodiment 2 is 10%. Referring to fig. 4, curve 1 shows that the mass content of the fluorescent nanospheres is 1%, curve 2 shows that the mass content of the fluorescent nanospheres is 10%, and curve 3 shows that the mass content of the fluorescent nanospheres is 0.5%. It can be seen that the fluorescence intensity is maximum when the mass content of the fluorescent nanospheres is 1%, and the fluorescence intensity is reduced when the mass content of the fluorescent nanospheres is increased or decreased.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (9)

1. The fluorescent coating with the pH response is characterized by comprising resin and fluorescent nanospheres dispersed in the resin, wherein the fluorescent nanospheres comprise polymer nanospheres and fluorescent substances growing on the polymer nanospheres in situ, and the fluorescent substances are obtained by coordination polymerization reaction of europium salt and a ligand or coordination polymerization reaction of terbium salt and the ligand;
wherein, the fluorescent nano-microsphere is prepared by the following method:
dispersing europium salt, ligand and polymer nano-microspheres in water, or dispersing terbium salt, ligand and polymer nano-microspheres in water to perform coordination polymerization reaction, and growing fluorescent materials on the polymer nano-microspheres in situ to obtain fluorescent nano-microspheres;
the ligand is one or two of tannic acid, maleic anhydride, tartaric acid and phenanthroline; the polymer ball is at least one of polymethyl methacrylate, polystyrene and polyacrylic acid; the mass content of the fluorescent nano-microspheres in the fluorescent coating is 0.5-10%.
2. The fluorescent coating of claim 1, characterized in thatCharacterized in that the europium salt is EuCl3·6H2O or Eu (NO)3)3·6H2O; the terbium salt is TbCl3·6H2O or Tb (NO)3)3·6H2O; the molar ratio of the europium salt to the ligand is 1: (5-20), wherein the molar ratio of the terbium salt to the ligand is 1: (5-20).
3. A method for preparing a fluorescent coating with pH response according to claim 1 or 2, characterized in that it comprises the following steps:
(1) dispersing europium salt, ligand and polymer nano-microspheres in water, or dispersing terbium salt, ligand and polymer nano-microspheres in water to perform coordination polymerization reaction, and growing fluorescent materials on the polymer nano-microspheres in situ to obtain fluorescent nano-microspheres;
(2) and adding the fluorescent nano-microspheres into resin, adding a curing agent after uniform dispersion, and stirring uniformly to obtain the fluorescent coating.
4. The production method according to claim 3, wherein in the step (2), the curing agent is polyamide; after the fluorescent nanospheres are added to the resin, the method further comprises: adding resin diluent, defoaming agent, leveling agent and dispersing agent.
5. The method according to claim 4, wherein the resin diluent is one or both of xylene and acetone, and the dispersant is one or both of BYK140 and BYK 142; the defoaming agent is BYKA-065, BYKA-141 or BYKA-530, and the flatting agent is BYK-300, BYK306 or BYK-333; the mass ratio of the resin diluent to the resin is 1 (5-20), and the mass content of the fluorescent nano-microspheres in the fluorescent coating obtained after the step (2) is 0.5-10%.
6. The preparation method according to claim 3, wherein the resin is one or more of polyurethane, epoxy resin, alkyd resin and acrylic resin.
7. The method according to claim 6, wherein when the resin is one or more of polyurethane, epoxy resin and alkyd resin, an organic solvent is added to the resin for mixing, and the organic solvent is one or more of xylene, ethyl acetate, butyl acetate, acetone, butanone, 4-methyl-2-pentanone, n-propanol, isopropanol, n-octanol, n-hexane and n-octane.
8. The application of the fluorescent coating with pH response according to claim 1 or 2, wherein the fluorescent coating is used for visually detecting the corrosion defect of the metal substrate, and is characterized in that the fluorescent coating is applied to the surface of the metal substrate and dried at room temperature; when the metal matrix is corroded, the fluorescent substance in the fluorescent coating is subjected to fluorescence quenching, so that the corrosion defect of the metal matrix is visually detected.
9. The use according to claim 8, wherein the fluorescent coating is applied to the surface of the metal substrate by brushing, dipping, spraying or curtain coating, and the thickness of the fluorescent coating applied to the surface of the metal substrate after drying is 20 μm to 100 μm.
CN202110286990.XA 2021-03-17 2021-03-17 Fluorescent coating with pH response, preparation method and application thereof Active CN113088157B (en)

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GB2489991A (en) * 2011-04-15 2012-10-17 London Metropolitan University Macrocyclic compounds, complexes and their uses
CN104017129A (en) * 2014-05-30 2014-09-03 吉林大学 Fluorescence functional polymer nanometer microsphere with dual responsiveness to temperature and pH, preparing method and applications
CN107446464A (en) * 2017-07-20 2017-12-08 中国科学院过程工程研究所 Polymeric coating material and preparation method with Corrosion monitoring and self-repair function
CN112342014A (en) * 2020-10-28 2021-02-09 安徽为臻生物工程技术有限公司 Preparation method of monodisperse polymer fluorescent microspheres

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2489991A (en) * 2011-04-15 2012-10-17 London Metropolitan University Macrocyclic compounds, complexes and their uses
CN104017129A (en) * 2014-05-30 2014-09-03 吉林大学 Fluorescence functional polymer nanometer microsphere with dual responsiveness to temperature and pH, preparing method and applications
CN107446464A (en) * 2017-07-20 2017-12-08 中国科学院过程工程研究所 Polymeric coating material and preparation method with Corrosion monitoring and self-repair function
CN112342014A (en) * 2020-10-28 2021-02-09 安徽为臻生物工程技术有限公司 Preparation method of monodisperse polymer fluorescent microspheres

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