Energy-storage luminous nano coating material and preparation method thereof

Abstract

The invention relates to the technical field of energy-storage luminous paint, in particular to an energy-storage luminous nano coating material and a preparation method thereof. The composite luminescent powder with a three-layer structure of a luminescent inner core, a transition layer and a shell is designed and synthesized, the inner core provides basic luminescent performance, the transition layer reduces interface defects and promotes electron transfer through lattice matching, and the shell optimizes luminous efficiency and afterglow characteristics; meanwhile, the modified GQDs are combined to expand the light absorption range, the modified nano SiO2 is used for enhancing the compactness of the coating, the modified bentonite is used for improving the dispersion stability, the synergistic effect of all the components is achieved through the processes of step-by-step ball milling, calcination and the like, and the coating material with efficient luminescence and excellent weather resistance is formed.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage luminescent coatings, in particular to an energy storage luminescent nano coating material and a preparation method thereof. Background Art

[0002] Energy-storage luminescent coatings are a class of functional materials that absorb and store light energy, then autonomously release visible light in the dark. Their core value lies in achieving long-lasting, energy-independent luminescence. They are widely used in safety warnings, emergency guidance, environmental beautification, and intelligent interaction. In safety and protection scenarios, these coatings can be used for fire escape signs, tunnel escape guides, and industrial equipment warnings, leveraging their long afterglow properties to provide a reliable light source even in power outages or smoky environments. In architecture and decoration, their self-luminous properties can replace nighttime lighting while also creating a dynamic aesthetic effect on building exteriors. Existing energy-storage luminescent coating materials fall into three main categories: First, silicate and nitride systems are suitable for aerospace and high-temperature industrial equipment markings, but they suffer from low initial luminescence intensity and rapid afterglow decay. Second, undoped metal halide systems achieve long afterglow without rare earth doping. However, these systems contain heavy metals, which do not meet environmental standards, have poor mechanical strength and are prone to flaking, and their luminescent wavelengths have low penetration in smoky environments. The third is the rare earth activated aluminate system, which has high initial luminous intensity and long afterglow time. It is widely used in traffic signs, fire-fighting equipment and building curtain walls, but its resistance to strong acids and alkalis is poor and it is easily degraded in specific chemical environments. Summary of the Invention

[0003] In response to the shortcomings of the existing technology, the present application provides an energy storage luminescent nano-coating material and a preparation method thereof. A composite luminescent powder with a three-layer structure of a luminescent core, a transition layer and an outer shell is designed and synthesized, wherein the core provides basic luminescent performance, the transition layer reduces interface defects and promotes electron transfer through lattice matching, and the outer shell optimizes the luminescent efficiency and afterglow characteristics; at the same time, modified GQDs are combined to expand the light absorption range, modified nano-SiO2 is enhanced to enhance the density of the coating, and modified bentonite is improved to improve the dispersion stability. The synergistic effect of each component is achieved through step-by-step ball milling, calcination and other processes to form a coating material with both high-efficiency luminescence and excellent weather resistance.

[0004] To achieve the above objectives, this application adopts the following technical solutions:

[0005] In a first aspect, the present application provides an energy storage luminescent nano-coating material, comprising modified nano-SiO2, silicone acrylic emulsion, polycarboxylate dispersant, composite luminescent powder and modified bentonite in a mass ratio of (1.8-2):100:1.8:(28-32):(0.5-0.7);

[0006] The composite luminescent powder is obtained by reacting a luminescent powder precursor, modified GQDs, ethyl orthosilicate and methyltrimethoxysilane;

[0007] The luminescent powder precursor is obtained by calcining a luminescent intermediate material with SrCO3, Al2O3, Eu2O3, Dy2O3 and Li2CO3 in a mass ratio of 100:(14-16):(40-42):(1.5-2):(1-1.3):(0.06-0.08) in a mixed atmosphere; the luminescent intermediate material is obtained by calcining a luminescent core material with SrCO3 and Al2O3 in a mass ratio of (19-21):3:6 in a mixed atmosphere; the luminescent core material is obtained by calcining SrCO3, Al2O3 and Eu2O3 in a molar ratio of 1:(1-1.02):0.002 in a mixed atmosphere;

[0008] The mixed atmosphere includes reducing gas and inert gas;

[0009] The modified GQDs are obtained by modifying GQDs with 3-mercaptopropyltrimethoxysilane;

[0010] The modified nano-SiO2 is obtained by modifying nano-SiO2 with a first silane coupling agent;

[0011] The modified bentonite is obtained by modifying bentonite with a second silane coupling agent.

[0012] In a feasible implementation scenario, the luminescent powder precursor is dispersed in anhydrous ethanol to obtain a luminescent powder precursor dispersion, and the modified GQDs are dispersed in anhydrous ethanol to obtain a modified GQDs dispersion. The volume ratio of the modified GQDs dispersion, the luminescent powder precursor dispersion, ethyl orthosilicate and methyltrimethoxysilane is (1-1.2):50:4:0.25; the volume percentage of the reducing gas in the mixed atmosphere is 5%, the reducing gas is hydrogen, and the inert gas is one of nitrogen and argon; the first silane coupling agent and the second silane coupling agent are both KH-570.

[0013] In a feasible implementation scenario, the polycarboxylate dispersant is a sodium polycarboxylate dispersant with a solid content of 43% to 45%; the montmorillonite content in the bentonite is ≥95%, and the bentonite particle size D50 is ≤30μm; the GQDs size is 5-10nm; the silicone-acrylic emulsion is an acrylate-silicone emulsion with a solid content of 38% to 40%, a viscosity of 90-110mPa·s, a particle size of 80-100nm, and a pH of 7-8; the particle size of the nano-SiO2 is 10-30nm; and the particle size of the SrCO3 and Al2O3 is <1μm.

[0014] In a second aspect, the present application provides a method for preparing an energy storage luminescent nano-coating material, comprising the following steps:

[0015] S1. SrCO3, Al2O3 and Eu2O3 are mixed, subjected to a first ball milling process, and then subjected to a first calcination in a mixed atmosphere to obtain a luminescent core material; the luminescent core material, SrCO3 and Al2O3 are mixed, subjected to a second ball milling process, and then subjected to a second calcination in a mixed atmosphere to obtain a luminescent intermediate material; the luminescent intermediate material is mixed with SrCO3, Al2O3, Eu2O3, Dy2O3 and Li2CO3, subjected to a third ball milling process, and then subjected to a third calcination in a mixed atmosphere to obtain a luminescent powder precursor;

[0016] S2. Add 3-mercaptopropyltrimethoxysilane to the GQDs dispersion to perform a first heating reaction to obtain modified GQDs; disperse the modified GQDs in anhydrous ethanol to obtain a modified GQDs dispersion; disperse the luminescent powder precursor in anhydrous ethanol to obtain a luminescent powder precursor dispersion; mix the modified GQDs dispersion and the luminescent powder precursor dispersion, add tetraethyl orthosilicate and methyltrimethoxysilane, adjust to a set pH, and react at room temperature to obtain a composite luminescent powder;

[0017] S3, dispersing nano-SiO2 in anhydrous ethanol to obtain a nano-SiO2 dispersion, adding a first silane coupling agent to the nano-SiO2 dispersion, and performing a second heating reaction to obtain modified nano-SiO2; using the second silane coupling agent to prepare a silane hydrolyzate, mixing bentonite with anhydrous ethanol to obtain a bentonite slurry, heating to a set temperature, and dropwise adding the silane hydrolyzate to the bentonite slurry, and maintaining the temperature to react to obtain modified bentonite;

[0018] S4. After dispersing the modified nano-SiO2 in the silicone acrylic emulsion at a set stirring speed, maintain the stirring speed, and sequentially add the polycarboxylate dispersant, the composite luminescent powder and the modified bentonite at set intervals to obtain the energy storage luminescent nano-coating material.

[0019] In a feasible implementation scenario, the rotation speed of the first ball milling treatment is 300-400 rpm, and the time is 2 to 3 hours; the rotation speed of the second ball milling treatment is 300-400 rpm, and the time is 1 to 1.5 hours; the rotation speed of the third ball milling treatment is 350-450 rpm, and the time is 2 to 2.5 hours; and anhydrous ethanol with the same mass as the solid material is added before the first ball milling treatment, the second ball milling treatment, and the third ball milling treatment.

[0020] In a feasible implementation, the temperature of the first calcination is 1200-1250°C, and the time is 3-3.5 hours; the temperature of the second calcination is 1100-1150°C, and the time is 2-3 hours; the temperature of the third calcination is 1150-1200°C, and the time is 2-3 hours.

[0021] Ethanol as a dispersion medium can reduce the surface energy of inorganic powder (SrCO3, Al2O3, etc.), avoid agglomeration, and ensure uniform mixing of raw materials. In the first calcination stage, SrCO3 is decomposed into SrO at high temperature, and then reacts with Al2O3 to form SrAl2O3; Eu2O3 is reduced to EuO under H2 reduction atmosphere, and Eu 2+ is similar to Sr 2+ , replaces Sr 2+ into the SrAl2O4 lattice to form SrAl2O4:Eu 2+ core, forming a luminescent center, Eu 2+ is a luminescent active ion, providing luminescent performance; the reducing atmosphere avoids Eu 2+ oxidation into non-luminescent Eu 3+ . In the second calcination stage, the luminescent core material continues to be calcined with SrCO3 and Al2O3, SrCO3 is decomposed into SrO at high temperature, and reacts with Al2O3 and the SrAl2O4 on the surface of the core to form SrAl3O6, forming a "SrAl2O4@SrAl3O6" transition layer structure, reducing the interface defects such as dislocations and cracks between the core and the subsequent shell through lattice matching, providing a channel for the transfer of electrons from the core to the shell, and reducing non-radiative transition loss. In the third calcination stage, SrCO3 is decomposed into SrO at high temperature, and reacts with Al2O3 and the SrAl3O6 on the surface of the intermediate to form a SrAl4O7 shell; Dy 3+ (release ≈ 91 pm) replaces Sr 2+ into the lattice to form an electron trap that can capture Eu 2+ excited state electrons, store electrons to prolong afterglow, Li + (release ≈ 76 pm) doped to fine-tune lattice distortion, optimize Dy 3+ trap depth, improve the binding ability of the trap to electrons, and overall improve the afterglow time.

[0022] In a feasible implementation scenario, the concentration of the GQDs dispersion liquid is 1wt%-1.2wt%; the amount of 3-mercaptopropyltrimethoxysilane is 0.08%-0.12% of the GQDs dispersion liquid, the concentration of the modified GQDs dispersion liquid is 0.5wt%-0.8wt%; the concentration of the luminescent powder precursor dispersion liquid is 10wt%-12wt%, the temperature of the first heating reaction is 60-65℃, and the time is 2-3h; the set pH is 9, and the room temperature reaction time is 2-3h.

[0023] 3-Mercaptopropyltrimethoxysilane (MPTMS) is added to the GQDs dispersion, and the mercapto group (-SH) of MPTMS covalently bonds with the hydroxyl group (-OH) or carboxyl group (-COOH) on the surface of GQDs. At the same time, the siloxy group [-Si(OCH3)3] of MPTMS is hydrolyzed to form silanol group (-Si-OH), thereby functionalizing the surface of GQDs. The modified GQDs bind to SiO2 through silanol group, thereby improving the dispersion stability. GQDs retain wide spectral absorption and expand the light excitation range.

[0024] A modified GQD dispersion is mixed with a luminescent powder precursor dispersion, and tetraethyl orthosilicate (TEOS) and methyltrimethoxysilane (MTMS) are added. TEOS hydrolyzes under alkaline conditions to form a SiO2 sol, which condenses with the silanol groups on the GQDs' surface (-Si-OH + HO-Si- → -Si-O-Si- + H2O), forming a SiO2-GQD composite coating. MTMS contains methyl groups, which partially replace TEOS, reducing the coating's hydrophilicity and improving its water resistance. The coating protects the luminescent powder core from moisture, enhancing the GQDs' absorption of different light sources and shortening the illumination saturation time. The SiO2 layer improves the compatibility of the luminescent powder with the organic binder.

[0025] In a feasible implementation scenario, the concentration of the nano-SiO2 dispersion is 8wt%-10wt%, the amount of the first silane coupling agent is 10%-12% of the mass of the nano-SiO2; the temperature of the second heating reaction is 65-75°C, and the time is 1-2h; the set temperature is 60-65°C, the dripping rate is 1-3mL / min; the insulation reaction time is 2-3h; the volume ratio of the bentonite slurry and the silane hydrolyzate is (3.8-4):1.

[0026] When KH-570 is added to the nano-SiO2 dispersion, KH-570 hydrolyzes to generate -Si-OH, which condenses with the -OH on the surface of the nano-SiO2 and grafts acrylate groups (-C=C-). The modified nano-SiO2 has improved compatibility with silicone-acrylic emulsion (containing acrylate segments). After uniform dispersion, it fills microscopic defects in the coating, enhances density, and improves water resistance.

[0027] In a feasible implementation, the preparation steps of the silane hydrolyzate are as follows: a second silane coupling agent, anhydrous ethanol and deionized water are mixed at a ratio of (6-8):100:10, the pH is adjusted to 4-5 with hydrochloric acid, and the mixture is stirred for 20 to 30 minutes to obtain the obtained solution.

[0028] The -Si-OH generated by the hydrolysis of KH-570 condenses with the -OH on the surface of bentonite, grafting organic groups, changing the bentonite from hydrophilic to organophilic. The modified bentonite forms a three-dimensional network structure in the silicone-acrylic emulsion, improving the thixotropy (anti-settling) and construction properties (leveling) of the coating, and inhibiting the sedimentation of the composite luminescent powder.

[0029] In a feasible implementation, the set stirring speed is 1500-1600 rpm, and the set time is 15 to 30 minutes.

[0030] Polycarboxylate dispersant (containing -COO - Electrostatic repulsion stabilizes the composite luminescent powder and nano-SiO2 particles. The three-dimensional network of the modified bentonite and the filling effect of the nano-SiO2 synergize to balance the coating viscosity. The acrylate segments of the silicone-acrylic emulsion are highly compatible with the organic groups of the modified nano-SiO2 and bentonite, forming a continuous film phase. The uniform dispersion of all components ensures the coating has the ideal viscosity and stability for application, and the resulting film exhibits both high-efficiency luminescence and excellent weather resistance.

[0031] Beneficial technical effects:

[0032] In this application, a composite luminescent powder with a luminescent core, a transition layer and an outer shell is designed and synthesized, and a polycarboxylate dispersant, modified nano-SiO2 and modified bentonite are used to prepare an energy storage luminescent nano-coating material with high efficiency luminescence performance and excellent weather resistance. The core layer is prepared by preparing SrAl2O4:Eu 2+ , Dy 3+ Long afterglow luminescent powder to provide luminescent properties, using Eu 2+ At the same time as the transition of Dy 3+ As a trap energy level to extend the afterglow; the transition layer is formed by ball milling and mixing SrCO3, Al2O3 and other raw materials and calcining to form a dense SrAl3O6 coating layer, which not only protects the core luminescence center from external erosion, but also reduces the non-radiative transition of the luminescent ions through lattice matching, and synergistically improves the luminescence efficiency with the luminescent core; the outer shell is SrAl4O7:Eu 2+ ,Dy 3+ ,Li + , where Eu 2+ The gradient doping reduces the probability of agglomeration quenching and improves the luminescence utilization rate. 3+ As the trap level captures electrons to prolong the afterglow, Li +By fine-tuning the lattice to optimize the trap depth, electron storage and release channels with energy-level matching are formed with the luminescent core and transition layer. The synergistic effect of the three-layer structure not only improves the efficiency and durability of the luminescence performance, but also protects the luminescent core from external corrosion such as water vapor and oxygen through the physical barrier of the transition layer and the dense coating of the outer shell. After the modified bentonite is treated with silane hydrolyzate, the lamellar structure forms covalent bonds with the surface of the luminescent powder and the molecular chains of the acrylate-silicone emulsion through the silanol group, constructing a three-dimensional network in the coating. This not only uses thixotropy to inhibit the sedimentation of the luminescent powder, but also strengthens the interfacial bonding between the inorganic powder and the organic matrix through silane bridging. Through the mutual promotion of each link, the luminescence performance and weather resistance of the energy storage luminescent nanocoating material are synergistically enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of the preparation method of the energy storage luminescent nanocoating material in this application.

[0034] Figure 2 This is a physical picture of the energy storage luminescent nanocoating material prepared in Example 1 of this application. DETAILED DESCRIPTION

[0035] In order to make the technical problems, technical solutions, and beneficial effects to be solved by this application more clearly understood, the present application is further described in detail below with reference to the following examples. However, this should not be construed as limiting the scope of this application to the following examples. Without departing from the above-mentioned method concepts of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0036] In this application, the terms used in this application are for the purpose of describing specific embodiments only and are not intended to be limiting of the application.

[0037] As used in this application, the singular forms "for," "or," "an," "any," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0038] In addition, the terms “first” and “second”, if used, are only used for descriptive purposes and should not be understood as indicating or implying relative importance.

[0039] The bentonite used in the embodiments of the present invention has a montmorillonite content of ≥95% and a bentonite particle size D50 ≤30 μm; the particle size of nano-SiO2 is 10-30 nm; the particle sizes of SrCO3 and Al2O3 are <1 μm; the graphene quantum dots (GQDs) are 5-10 nm in size and are water-soluble; the silicone acrylic emulsion (acrylate-silicone emulsion) has a solid content of 38% to 40%, a viscosity of 90-110 mPa·s, a particle size of 80-100 nm, and a pH of 7-8.

[0040] The following will describe in detail an energy storage luminescent nano coating material and a preparation method thereof provided by the present application in combination with different embodiments.

[0041] Example 1

[0042] like Figure 1 As shown, a method for preparing an energy storage luminescent nano coating material comprises the following steps:

[0043] 1. Take SrCO3, Al2O3 and Eu2O3 with a molar ratio of 1:1.01:0.002, add anhydrous ethanol with the same mass as the solid material, ball mill at 350rpm for 2.5h, dry and grind through a 200 mesh sieve, place in a tube furnace, pass through a H2 / Ar mixed atmosphere containing 5% volume H2, calcine at 1200℃ for 3h, and cool naturally to room temperature to obtain a luminescent core material; the luminescent core material, SrCO3 and Al2O3 are mixed uniformly with a mass ratio of 20:3:6, add anhydrous ethanol with the same mass as the solid material, and ball mill at 350rpm for 1h. The mixture was placed in a tube furnace, introduced into a H2 / Ar mixed atmosphere containing 5% by volume of H2, and calcined at 1150°C for 2 hours to obtain a luminescent intermediate material; the luminescent intermediate material was mixed with SrCO3, Al2O3, Eu2O3, Dy2O3 and Li2CO3 in a mass ratio of 100:15:41:1.8:1.2:0.07, and anhydrous ethanol with the same mass as the solid material was added. The mixture was ball-milled at 400 rpm for 2 hours, and then placed in a tube furnace, introduced into a H2 / Ar mixed atmosphere containing 5% by volume of H2, and calcined at 1200°C for 2.5 hours. The mixture was sieved through a 300-mesh sieve to obtain a luminescent powder precursor;

[0044] 2. GQDs were ultrasonically dispersed in deionized water to obtain a 1.1wt% GQDs dispersion; 3-mercaptopropyltrimethoxysilane was added to the GQDs dispersion at a mass of 0.1% of the GQDs dispersion, and the mixture was reacted at 65°C for 2.5h. The modified GQDs were obtained after centrifugal washing; the modified GQDs were dispersed in anhydrous ethanol to obtain a 0.7wt% modified GQDs dispersion; the luminescent powder precursor was ultrasonically dispersed in anhydrous ethanol to obtain an 11wt% luminescent powder precursor dispersion, the modified GQDs dispersion and the luminescent powder precursor dispersion were mixed, and tetraethyl orthosilicate and methyltrimethoxysilane were added. The volume ratio of the modified GQDs dispersion, the luminescent powder dispersion, tetraethyl orthosilicate and methyltrimethoxysilane was 1.1:50:4:0.25. After mixing, the pH was adjusted to 9, the mixture was reacted at room temperature for 2.5h, and the composite luminescent powder was filtered and dried.

[0045] 3. Ultrasonic dispersion of nano-SiO2 in anhydrous ethanol to obtain a 9wt% nano-SiO2 dispersion, adding KH-570 with a mass fraction of 11% of nano-SiO2, reacting at 70°C for 1.5h, centrifuging, washing, and drying to obtain modified nano-SiO2; KH-570, anhydrous ethanol, and deionized water were mixed at a ratio of 7:100:10, and the pH was adjusted to 4.5 with hydrochloric acid. After stirring for 25min, a silane hydrolyzate was obtained, and bentonite and anhydrous ethanol were mixed and stirred uniformly to obtain a bentonite slurry. The bentonite slurry was heated to 65°C, and the silane hydrolyzate was added dropwise at a rate of 2mL / min. The volume ratio of the bentonite slurry to the silane hydrolyzate was 3.9:1. After the addition was complete, the mixture was kept warm for 2.5h, filtered, washed, dried, and passed through a 400-mesh sieve to obtain modified bentonite;

[0046] 4. After dispersing the modified nano-SiO2 in the silicone-acrylic emulsion at 1550rpm, maintain the stirring speed, and add the polycarboxylate dispersant, composite luminescent powder and modified bentonite in sequence every 20min. The mass ratio of modified nano-SiO2, silicone-acrylic emulsion, polycarboxylate dispersant, composite luminescent powder and modified bentonite is 1.9:100:1.8:30:0.6, and the following is obtained: Figure 2 The energy storage luminescent nanocoating material shown.

[0047] Example 2

[0048] like Figure 1 As shown, a method for preparing an energy storage luminescent nano coating material comprises the following steps:

[0049] 1. Take SrCO3, Al2O3 and Eu2O3 with a molar ratio of 1:1:0.002, add anhydrous ethanol with the same mass as the solid material, ball mill at 300rpm for 3h, dry and grind through a 200 mesh sieve, place in a tube furnace, pass through a H2 / Ar mixed atmosphere containing 5% volume H2, calcine at 1200℃ for 3.5h, and naturally cool to room temperature to obtain a luminescent core material; the luminescent core material, SrCO3 and Al2O3 are mixed uniformly in a mass ratio of 19:3:6, add anhydrous ethanol with the same mass as the solid material, ball mill at 300rpm for 1.5h The mixture was placed in a tube furnace, introduced into a H2 / Ar mixed atmosphere containing 5% by volume of H2, and calcined at 1100°C for 3 hours to obtain a luminescent intermediate material; the luminescent intermediate material was mixed with SrCO3, Al2O3, Eu2O3, Dy2O3 and Li2CO3 in a mass ratio of 100:14:42:1.5:1.3:0.06, and anhydrous ethanol with the same mass as the solid material was added. The mixture was ball-milled at 350 rpm for 2.5 hours, and then placed in a tube furnace, introduced into a H2 / Ar mixed atmosphere containing 5% by volume of H2, and calcined at 1150°C for 3 hours. The mixture was sieved through a 300-mesh sieve to obtain a luminescent powder precursor;

[0050] 2. GQDs were ultrasonically dispersed in deionized water to obtain a 1wt% GQDs dispersion; 3-mercaptopropyltrimethoxysilane was added to the GQDs dispersion at a mass of 0.08% of the GQDs dispersion, reacted at 60°C for 3h, and centrifuged to obtain modified GQDs; the modified GQDs were dispersed in anhydrous ethanol to obtain a 0.5wt% modified GQDs dispersion; the luminescent powder precursor was ultrasonically dispersed in anhydrous ethanol to obtain a 10wt% luminescent powder precursor dispersion, the modified GQDs dispersion and the luminescent powder precursor dispersion were mixed, and tetraethyl orthosilicate and methyltrimethoxysilane were added. The volume ratio of the modified GQDs dispersion, the luminescent powder dispersion, tetraethyl orthosilicate and methyltrimethoxysilane was 1:50:4:0.25. After mixing, the pH was adjusted to 9, stirred at room temperature for 2h, and filtered and dried to obtain a composite luminescent powder;

[0051] 3. Ultrasonic dispersion of nano-SiO2 in anhydrous ethanol to obtain 8wt% nano-SiO2 dispersion, adding KH-570 (10% by mass of nano-SiO2), incubating at 65°C in a water bath for 2h, centrifuging, washing, and drying to obtain modified nano-SiO2; mixing KH-570, anhydrous ethanol, and deionized water at a ratio of 6:100:10, adjusting the pH to 4 with hydrochloric acid, and stirring for 20min to obtain a silane hydrolyzate; mixing equal amounts of bentonite and anhydrous ethanol to obtain a bentonite slurry; heating the bentonite slurry to 60°C, and adding the silane hydrolyzate dropwise at a rate of 1mL / min; the volume ratio of the bentonite slurry to the silane hydrolyzate is 3.8:1; after the addition is complete, the mixture is kept warm for 2h, filtered, washed, dried, and passed through a 400-mesh sieve to obtain a modified bentonite;

[0052] 4. After dispersing the modified nano-SiO2 in the silicone-acrylic emulsion at 1500rpm, maintain the stirring speed and add polycarboxylate dispersant, composite luminescent powder and modified bentonite in sequence every 15min. The mass ratio of modified nano-SiO2, silicone-acrylic emulsion, polycarboxylate dispersant, composite luminescent powder and modified bentonite is 1.8:100:1.8:32:0.5 to obtain an energy storage luminescent nano-coating material.

[0053] Example 3

[0054] like Figure 1 As shown, a method for preparing an energy storage luminescent nano coating material comprises the following steps:

[0055] 1. Take SrCO3, Al2O3 and Eu2O3 with a molar ratio of 1:1.02:0.002 as raw materials, add anhydrous ethanol with the same mass as the solid material, ball mill at 400rpm for 2h, dry and grind through a 200-mesh sieve, place in a tube furnace, introduce a H2 / N2 mixed atmosphere containing 5% volume H2, calcine at 1250℃ for 3h, and naturally cool to room temperature to obtain a luminescent core material; the luminescent core material, SrCO3 and Al2O3 are mixed uniformly with a mass ratio of 21:3:6, add anhydrous ethanol with the same mass as the solid material, ball mill at 400rpm for 1h h and then placed in a tube furnace, introduced into a H2 / N2 mixed atmosphere containing 5% by volume of H2, and calcined at 1150°C for 2h to obtain a luminescent intermediate material; the luminescent intermediate material was mixed with SrCO3, Al2O3, Eu2O3, Dy2O3 and Li2CO3 in a mass ratio of 100:16:40:2:1:0.08, and anhydrous ethanol with the same mass as the solid material was added, and the mixture was ball-milled at 450rpm for 2h and then placed in a tube furnace, introduced into a H2 / N2 mixed atmosphere containing 5% by volume of H2, calcined at 1200°C for 2h, and passed through a 300-mesh sieve to obtain a luminescent powder precursor;

[0056] 2. GQDs were ultrasonically dispersed in deionized water to obtain a 1.2 wt% GQDs dispersion; 3-mercaptopropyltrimethoxysilane was added to the GQDs dispersion at a mass of 0.12% of the GQDs dispersion, reacted at 65°C for 2 hours, and centrifuged to obtain modified GQDs; the modified GQDs were dispersed in anhydrous ethanol to obtain a 0.8 wt% modified GQDs dispersion; the luminescent powder precursor was ultrasonically dispersed in anhydrous ethanol to obtain a 12 wt% luminescent powder precursor dispersion, the modified GQDs dispersion and the luminescent powder precursor dispersion were mixed, and tetraethyl orthosilicate and methyltrimethoxysilane were added. The volume ratio of the modified GQDs dispersion, the luminescent powder dispersion, tetraethyl orthosilicate and methyltrimethoxysilane was 1.2:50:4:0.25. After mixing, the pH was adjusted to 9, stirred at room temperature for 3 hours, and filtered and dried to obtain a composite luminescent powder;

[0057] 3. Ultrasonic dispersion of nano-SiO2 in anhydrous ethanol to obtain a 10wt% nano-SiO2 dispersion, adding KH-570 with a mass fraction of 12% of nano-SiO2, incubating at 75°C in a water bath for 1h, centrifuging, washing, and drying to obtain modified nano-SiO2; KH-570, anhydrous ethanol, and deionized water were mixed at a ratio of 8:100:10, and the pH was adjusted to 5 with hydrochloric acid and stirred for 30min to obtain a silane hydrolyzate; bentonite and anhydrous ethanol were mixed and stirred uniformly to obtain a bentonite slurry; the bentonite slurry was heated to 65°C, and the silane hydrolyzate was added dropwise at a rate of 3mL / min, with a volume ratio of bentonite slurry to silane hydrolyzate of 4:1. After the addition was complete, the mixture was kept warm for 3h, filtered, washed, dried, and passed through a 400-mesh sieve to obtain a modified bentonite;

[0058] 4. After dispersing the modified nano-SiO2 in the silicone-acrylic emulsion at 1600 rpm, maintain the stirring speed and add polycarboxylate dispersant, composite luminescent powder and modified bentonite in sequence every 30 minutes. The mass ratio of modified nano-SiO2, silicone-acrylic emulsion, polycarboxylate dispersant, composite luminescent powder and modified bentonite is 2:100:1.8:28:0.7 to obtain an energy storage luminescent nano-coating material.

[0059] Comparative Example 1

[0060] A method for preparing an energy storage luminescent nano-coating material, wherein the preparation steps and parameters are the same as those in Example 1, except that all SrCO3, Al2O3, Eu2O3, Dy2O3 and Li2CO3 used in Example 1 are directly mixed and ball-milled at one time, and calcined at 1200°C for 7.5h.

[0061] Comparative Example 2

[0062] A method for preparing an energy storage luminescent nano-coating material, wherein the preparation steps and parameters are the same as those in Example 1, except that modified nano-SiO2 is not added.

[0063] Comparative Example 3

[0064] A method for preparing an energy storage luminescent nanocoating material, wherein the preparation steps and parameters are the same as those in Example 1, except that modified GQDs are not added.

[0065] Performance testing:

[0066] Viscosity: The viscosity of the energy storage luminescent nano-coating materials prepared in Examples 1 to 3 and Comparative Examples 1 to 3 of the present application was tested using a rotational viscometer. The results are shown in Table 1.

[0067] Surface drying time: The energy storage luminescent nano-coating materials prepared in Examples 1 to 3 and Comparative Examples 1 to 3 of the present application were evenly applied on a tinplate (150 mm × 70 mm × 0.3 mm), and the coating thickness was controlled to be a wet film of 100 ± 10 μm. The coating was placed in a constant temperature and humidity environment (temperature 25°C, relative humidity 50%). Every 10 minutes, a clean finger was used to touch the coating surface for 1 to 2 seconds. The finger was observed to see if there was any obvious trace of the coating on the coating surface (no depression, no fingerprint residue). When the first appearance of "the finger does not stick to the coating, only slight fingerprints are left on the coating surface and can be quickly restored" appeared, the time at this time was recorded, which was the surface drying time. The results are shown in Table 1.

[0068] Alkali Resistance: The energy-storage luminescent nanocoating materials prepared in the Examples and Comparative Examples of this application were applied to cement asbestos boards (100 mm × 100 mm × 5 mm, cured for 28 days according to standard requirements) to a wet film thickness of 100 ± 10 μm. The boards were then dried at room temperature for 7 days to obtain test board coatings. A 0.1 mol / L NaOH solution was prepared and placed in a glass tank at a controlled temperature of 23 ± 2°C. The test boards were placed with the coated surface facing upward and immersed horizontally in the NaOH solution (with the liquid level 5 mm above the coating surface), ensuring that the test boards did not contact the tank walls. The solution was soaked for 96 hours (during which time evaporated water was replenished to maintain a stable concentration). The test boards were removed, rinsed with deionized water, and dried before observation. Any signs of blistering, flaking, discoloration, or chalking of the coating were recorded. The results are shown in Table 1.

[0069] Weather resistance: The energy storage luminescent nano-coating materials prepared in Examples 1 to 3 and Comparative Examples 1 to 3 of the present application were applied to tinplate to a wet film thickness of 100±10 μm. After drying for 7 days, a test panel coating was obtained. A xenon lamp aging chamber was used with an irradiance (at 340 nm) of 0.71 W / (m²・nm), a blackboard temperature of 65±3°C, a relative humidity of 50±5%, and a spraying cycle of 120 min (18 minutes of spraying and 102 minutes of drying). The test panel was fixed on the sample rack of the aging chamber and continuously exposed for 500 hours. The coating powdering grade (0-5), cracking degree, and discoloration were visually evaluated according to the standard, and the occurrence of peeling and blistering was recorded. The results are shown in Table 1.

[0070] Water resistance: The energy storage luminescent nanocoating materials prepared in Examples 1 to 3 and Comparative Examples 1 to 3 of the present application were applied to a tinplate to a wet film thickness of 100 ± 10 μm. After drying for 7 days, a test plate coating was obtained. The test plate coating was immersed in deionized water and allowed to stand at 23 ± 2°C for 120 h. The occurrence of peeling, blistering, and discoloration was recorded. The results are shown in Table 1.

[0071] Luminescence Performance Testing: The energy-storage luminescent nanocoating materials prepared in Examples 1-3 and Comparative Examples 1-3 of this application were applied to white PVC panels (100 mm x 100 mm) to a wet film thickness of 150 ± 10 μm. The panels were then dried at room temperature for 7 days. Using a simulated solar light box with an irradiance of 1000 ± 50 W / m², the panels were placed horizontally (coating facing upward) 30 cm from the light source and allowed to absorb sunlight for 2 hours. The panels were then quickly moved into a darkroom (shading efficiency ≥ 99%, temperature 25 ± 2°C) to avoid external light interference. In the darkroom, the afterglow brightness of an area 30 cm from the panel surface (aligned vertically with the center) was measured 10 minutes, 1 hour, and 2 hours after placement in the darkroom. The results are shown in Table 1.

[0072] Table 1 Performance test results of Examples 1 to 3 and Comparative Examples 1 to 3 of this application

[0073]

[0074] As shown in Table 1, the energy storage luminescent nano-coating materials prepared in Examples 1 to 3 have a viscosity of 83-88KU, and a surface drying time of ≤2h. They perform well in terms of alkali resistance (no abnormality after 96h), weather resistance (no abnormality after 500h), and water resistance (no abnormality after 120h). The afterglow brightness reaches 473-485mcd / m² at 10min, 64-77mcd / m² after 1h, and 24-29mcd / m² after 2h. The viscosity of Comparative Example 1 is 75KU, the surface drying time is extended to 3h, the alkali resistance has slight blistering, and the weather resistance is level 2. , water-resistant local whitening, and the afterglow brightness is significantly reduced (320mcd / m² in 10min, 42mcd / m² in 1h, and 15mcd / m² in 2h); in comparative example 2, because no modified nano-SiO2 is added, the viscosity is 79KU, the water-resistant edge peeling and weather-resistant powdering level is 1, and the afterglow brightness is slightly reduced (460mcd / m² in 10min); in comparative example 3, because no modified GQDs are added, the luminescence performance is significantly reduced (350mcd / m² in 10min, 45mcd / m² in 1h, and 18mcd / m² in 2h).

[0075] Comparative Example 1 is mixed and ball-milled and calcined at one time, without core-shell step-by-step preparation, resulting in reduced viscosity, prolonged surface drying time, deterioration of medium resistance (alkali resistance, water resistance, weather resistance), and a significant decrease in luminous brightness. Example 1 forms a structure of a luminescent core, a transition layer, and an outer shell layer by step-by-step calcination, and the transition layer (SrAl3O6) reduces interface dislocations and cracks by lattice matching. However, in Comparative Example 1, the matrix such as SrAl2O4 and SrAl4O7 is in direct contact during the one-time mixing and calcination, the lattice mismatch increases, and the defects formed at the interface increase, becoming a "trap" for electron-hole recombination, resulting in an increase in the probability of non-radiative transitions, a decrease in luminous efficiency, and a significant decrease in 10-min brightness compared to Example 1; at the same time, one-time mixing cannot achieve Eu 2+ Gradient doping (high concentration on the surface, low concentration inside) leads to Eu 2 + Local aggregation leads to fluorescence quenching; on the other hand, Dy 3+ He Li + The distribution is uneven, the trap depth is inconsistent, the electron storage capacity is reduced, and the afterglow time is shortened; the surface roughness of the luminescent powder particles without a core-shell structure is high, the interface bonding force with the silicone acrylic emulsion is weak, and the internal porosity of the coating is increased, resulting in a decrease in water resistance (local whitening after 120 hours) and weather resistance (powdering level 2 after 500 hours); at the same time, the uneven dispersion of the particles reduces the viscosity to 75KU and extends the surface drying time to 3h.

[0076] Comparative Example 2 does not add modified nano-SiO2, and the viscosity slightly decreases, the water resistance and weather resistance decrease, and the luminous brightness slightly decreases. In the embodiment, modified nano-SiO2 is grafted with acrylate groups through KH-570, forming a covalent bond with the organic chain segment of the silicone-acrylic emulsion, filling the coating micro defects and improving the density. After the comparative example 2 lacks this component, the coating porosity increases, and water molecules and oxygen are more easily permeable, resulting in a decrease in water resistance (120h edge peeling) and weakened weather resistance (500h powdering grade 1). In addition, nano-SiO2 can enhance the interfacial bonding between the luminescent powder and the base material. After the absence, the compatibility of the luminescent powder and the silicone-acrylic emulsion is slightly reduced, and microcracks appear locally, resulting in a decrease in the afterglow brightness at 10min. On the other hand, the high specific surface area of ​​nano-SiO2 can form a weak network structure through hydrogen bonds, which assists in thickening. When it is not added, the system relies solely on the thixotropy of the modified bentonite, and the viscosity drops slightly to 79KU.

[0077] In Comparative Example 3, the luminous brightness is significantly reduced without adding modified GQDs, while other properties (viscosity, surface dryness, and media resistance) remain basically unchanged. In the embodiment, the modified GQDs expand the excitation range through wide spectrum absorption, can efficiently absorb sunlight, and improve photon utilization. In Comparative Example 3, after the GQDs are missing, only SrAl2O4:Eu 2+ The inherent absorption of the GQDs reduces the excitation spectrum range and reduces the energy storage efficiency, resulting in a decrease in brightness after 10 minutes. The modified GQDs form an energy transfer channel with the luminescent powder through the SiO2 coating layer, which can convert long-wavelength light into Eu 2+ If the effective excitation light is not added, the channel will be interrupted and the long-wavelength light cannot be utilized, further reducing the luminescence intensity.

[0078] The above results show and describe the basic principles and main features of this application as well as the advantages of this application.

[0079] Those skilled in the art should understand that the present application is not limited to the above-described embodiments. The above-described embodiments and descriptions are merely illustrative of the principles of the present application. Various changes and improvements may be made to the present application without departing from the spirit and scope of the present application. Such changes and improvements are intended to fall within the scope of the present application. The scope of protection claimed in the present application is defined by the equivalents of the appended claims.

Claims

1. An energy storage luminescent nano coating material, characterized in that: The invention comprises modified nano-SiO2, silicone-acrylic emulsion, polycarboxylate dispersant, composite luminescent powder and modified bentonite in a mass ratio of (1.8-2):100:1.8:(28-32):(0.5-0.7); The composite luminescent powder is obtained by reacting a luminescent powder precursor, modified GQDs, ethyl orthosilicate and methyltrimethoxysilane; The luminescent powder precursor is obtained by calcining a luminescent intermediate material with SrCO3, Al2O3, Eu2O3, Dy2O3 and Li2CO3 in a mass ratio of 100:(14-16):(40-42):(1.5-2):(1-1.3):(0.06-0.08) in a mixed atmosphere; the luminescent intermediate material is obtained by calcining a luminescent core material with SrCO3 and Al2O3 in a mass ratio of (19-21):3:6 in a mixed atmosphere; the luminescent core material is obtained by calcining SrCO3, Al2O3 and Eu2O3 in a molar ratio of 1:(1-1.02):0.002 in a mixed atmosphere; The mixed atmosphere includes reducing gas and inert gas; The modified GQDs are obtained by modifying GQDs with 3-mercaptopropyltrimethoxysilane; The modified nano-SiO2 is obtained by modifying nano-SiO2 with a first silane coupling agent; The modified bentonite is obtained by modifying bentonite with a second silane coupling agent.

2. The energy storage luminescent nano coating material according to claim 1, characterized in that: The luminescent powder precursor is dispersed in anhydrous ethanol to obtain a luminescent powder precursor dispersion, and the modified GQDs are dispersed in anhydrous ethanol to obtain a modified GQDs dispersion. The volume ratio of the modified GQDs dispersion, the luminescent powder precursor dispersion, ethyl orthosilicate and methyltrimethoxysilane is (1-1.2):50:4:0.25; the volume percentage of the reducing gas in the mixed atmosphere is 5%, the reducing gas is hydrogen, and the inert gas is one of nitrogen and argon; the first silane coupling agent and the second silane coupling agent are both KH-570.

3. The energy storage luminescent nano coating material according to claim 1, characterized in that: The polycarboxylate dispersant is a sodium polycarboxylate dispersant with a solid content of 43% to 45%; the montmorillonite content in the bentonite is ≥95%, and the bentonite particle size D50 is ≤30μm; the GQDs size is 5-10nm; the silicone acrylic emulsion is an acrylate-organic silicone emulsion with a solid content of 38% to 40%, a viscosity of 90-110mPa·s, a particle size of 80-100nm, and a pH of 7-8; the particle size of the nano-SiO2 is 10-30nm; and the particle sizes of the SrCO3 and Al2O3 are <1μm.

4. A method for preparing the energy storage luminescent nano coating material according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1. SrCO3, Al2O3 and Eu2O3 are mixed, subjected to a first ball milling process, and then subjected to a first calcination in a mixed atmosphere to obtain a luminescent core material; the luminescent core material, SrCO3 and Al2O3 are mixed, subjected to a second ball milling process, and then subjected to a second calcination in a mixed atmosphere to obtain a luminescent intermediate material; the luminescent intermediate material is mixed with SrCO3, Al2O3, Eu2O3, Dy2O3 and Li2CO3, subjected to a third ball milling process, and then subjected to a third calcination in a mixed atmosphere to obtain a luminescent powder precursor; S2. Add 3-mercaptopropyltrimethoxysilane to the GQDs dispersion to perform a first heating reaction to obtain modified GQDs; disperse the modified GQDs in anhydrous ethanol to obtain a modified GQDs dispersion; disperse the luminescent powder precursor in anhydrous ethanol to obtain a luminescent powder precursor dispersion; mix the modified GQDs dispersion and the luminescent powder precursor dispersion, add tetraethyl orthosilicate and methyltrimethoxysilane, adjust to a set pH, and react at room temperature to obtain a composite luminescent powder; S3, dispersing nano-SiO2 in anhydrous ethanol to obtain a nano-SiO2 dispersion, adding a first silane coupling agent to the nano-SiO2 dispersion, and performing a second heating reaction to obtain modified nano-SiO2; using the second silane coupling agent to prepare a silane hydrolyzate, mixing bentonite with anhydrous ethanol to obtain a bentonite slurry, heating to a set temperature, and dropwise adding the silane hydrolyzate to the bentonite slurry, and maintaining the temperature to react to obtain modified bentonite; S4. After dispersing the modified nano-SiO2 in the silicone acrylic emulsion at a set stirring speed, maintain the stirring speed, and sequentially add the polycarboxylate dispersant, the composite luminescent powder and the modified bentonite at set intervals to obtain the energy storage luminescent nano-coating material.

5. The method for preparing an energy storage luminescent nano coating material according to claim 4, characterized in that: The rotation speed of the first ball milling treatment is 300-400 rpm, and the time is 2 to 3 hours; the rotation speed of the second ball milling treatment is 300-400 rpm, and the time is 1 to 1.5 hours; the rotation speed of the third ball milling treatment is 350-450 rpm, and the time is 2 to 2.5 hours; and anhydrous ethanol with the same mass as the solid material is added before the first ball milling treatment, the second ball milling treatment, and the third ball milling treatment.

6. The method for preparing an energy storage luminescent nano coating material according to claim 4, characterized in that: The temperature of the first calcination is 1200-1250° C., and the time is 3-3.5 hours; the temperature of the second calcination is 1100-1150° C., and the time is 2-3 hours; the temperature of the third calcination is 1150-1200° C., and the time is 2-3 hours.

7. The method for preparing an energy storage luminescent nano coating material according to claim 4, characterized in that: The concentration of the GQDs dispersion is 1wt%-1.2wt%; the amount of 3-mercaptopropyltrimethoxysilane used is 0.08%-0.12% of the GQDs dispersion, the concentration of the modified GQDs dispersion is 0.5wt%-0.8wt%; the concentration of the luminescent powder precursor dispersion is 10wt%-12wt%, the temperature of the first heating reaction is 60-65°C, and the time is 2-3h; the set pH is 9, and the time of the room temperature reaction is 2-3h.

8. The method for preparing an energy storage luminescent nano coating material according to claim 4, characterized in that: The concentration of the nano-SiO2 dispersion is 8wt%-10wt%, and the amount of the first silane coupling agent is 10%-12% of the mass of the nano-SiO2; the temperature of the second heating reaction is 65-75°C, and the time is 1-2h; the set temperature is 60-65°C, and the dropwise addition rate is 1-3mL / min; the insulation reaction time is 2-3h; the volume ratio of the bentonite slurry and the silane hydrolyzate is (3.8-4):

1.

9. The method for preparing an energy storage luminescent nano coating material according to claim 4, characterized in that: The silane hydrolyzate is prepared by mixing a second silane coupling agent, anhydrous ethanol and deionized water at a ratio of (6-8):100:10, adjusting the pH to 4-5 with hydrochloric acid, and stirring for 20-30 minutes to obtain the obtained solution.

10. The method for preparing an energy storage luminescent nano coating material according to claim 4, characterized in that: The set stirring speed is 1500-1600 rpm, and the set time is 15-30 minutes.

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