Coated modified long-afterglow luminescent material as well as preparation method and application thereof

Abstract

The invention belongs to but is not limited to the technical field of self-luminescent materials, and discloses a coated modified long-afterglow luminescent material as well as a preparation method and application thereof, the organic-inorganic coated modified material comprises SiO2 and a coupling agent, and the coating thickness is 10-20nm; the long-afterglow fluorescent powder comprises the following components: SrAl2O3: Eu < 2 + >, Dy < 3 + >; the rare earth strontium aluminate material is subjected to organic-inorganic coating, so that the water resistance of the material is greatly improved. The luminescent powder is doped into concrete instead of a part of a cementing material, so that a self-luminescent cement-based material with stable and excellent luminescent property can be obtained. The hydrophobic modification performance is excellent, and the luminous concrete with poor water resistance is not easy to deliquesce, so that the luminous concrete has better luminous performance.

Description

Technical Field

[0001] The present invention belongs to, but is not limited to, the technical field of self-luminous materials, and particularly relates to a coated and modified long-afterglow luminescent material, a preparation method thereof, and an application thereof. Background Art

[0002] A long-afterglow luminescent material is a photoluminescent material that can absorb and store the energy of radiation under the irradiation of natural light or other artificial light sources, and can slowly release the stored energy in the form of visible light under the excitation of certain temperature conditions. Generally, long-afterglow luminescent materials can be divided into several types of systems such as sulfides, aluminates, silicates, phosphates, and titanates according to their matrix types.

[0003] Domestic and foreign experts and scholars have conducted extensive research on luminescent concrete for a long time. Due to the high production cost of luminescent materials, it is impossible to add a large amount of luminescent powder to concrete or mortar in the form of a filler. Therefore, the research methods used by different scholars to study luminescent concrete are also different: Western countries started researching luminescent concrete earlier. Japan invented fluorescent cement early on. It mainly uses cement as the matrix material, and mixes and stirs ZnS luminescent material pigments, sand and gravel aggregates, cement, water, etc. to make luminescent concrete. This kind of cement concrete can emit different colors of light such as blue, yellow, red, and green. It absorbs sunlight during the day for only a few minutes and can emit light at night for several hours, achieving a luminescent effect. Since fluorescent cement is fire-resistant, non-combustible, environmentally friendly, pollution-free, and durable, it can be used in various fields such as road markings, various warning signs, and crosswalks.

[0004] At present, there are many methods for the preparation research of luminescent bricks at home and abroad. Adding luminescent materials is one of the important methods. In order to reduce the preparation cost, most of them use ordinary concrete as the base, and the top surface layer is composed of luminescent powder, white cement, wear-resistant polyurethane materials, additives, etc. For example, enterprises represented by China State Construction Western Construction prepare luminescent concrete mainly by selecting long-afterglow stones as the aggregates for concrete production to prepare an imitation marble mottled effect, avoiding the radioactive radiation of natural marble and being able to emit light at night, achieving a very good effect.

[0005] Even though the research on the preparation technology of luminescent powder has been ongoing for a long time at home and abroad, the research on the production technology of luminescent concrete has just started. At present, most of the research on luminescent concrete is about directly adding long-afterglow luminescent materials into the concrete matrix material, and there are inevitably many problems: whether various chemical components in the luminescent powder will react with various components of the concrete, such as water, tricalcium silicate, dicalcium silicate, calcium ferroaluminate, etc., whether it will affect the subsequent luminescence effect, whether it will affect the mechanical structure of the surface layer after adding the luminescent powder, whether it will change the microstructure of the luminescent surface layer, and whether it will change other workability aspects such as the workability of the surface layer all require durability test research.

[0006] In view of the above analysis, the technical problems that urgently need to be solved in the existing technology are:

[0007] Adding long-afterglow luminescent materials into the concrete matrix material will cause significant deterioration of the mechanical properties of cement-based composites, including a decrease in compressive strength and attenuation of flexural strength. Summary of the Invention

[0008] In view of the problems existing in the existing technology, the present invention provides an organic-inorganic coated and modified long-afterglow luminescent cement-based material, its preparation method and application.

[0009] The present invention is realized as follows. An organic-inorganic coated and modified aluminate-based long-afterglow luminescent material, the organic-inorganic coated and modified material includes: SiO2 and silane coupling agent, with a coating thickness of 10-20 nm; the composition of the long-afterglow phosphor includes: SrAl2O3:Eu 2+ , Dy 3+ , with a particle size of 10-100 μm, a density of 3100 kg / m 3 , and a afterglow brightness of 80-360 mcd·m 2 , and the afterglow time ≥ 6 h.

[0010] Furthermore, the mass / volume ratio of the long-afterglow phosphor and the coated and modified material is 0.5 g:5 mL.

[0011] Another object of the present invention is to provide a preparation method of a coated and modified long-afterglow luminescent material, including the following steps:

[0012] Step 1, prepare the luminescent powder: accurately weigh high-purity SrCO3, Al2O3, Eu2O3, Dy2O3 in a ratio of 1:2:0.02:0.04, mix, grind, disperse in ethanol, and dry; sinter in a reducing atmosphere; after pulverization and grinding, obtain SrAl2O4:Eu 2+ , Dy 3+ powder;

[0013] Step 2: Weigh tetraethyl orthosilicate (TEOS), C2H5OH, and deionized water, stir them, and after the solutions are mixed evenly, heat them in a water bath, add dilute nitric acid dropwise to adjust the pH, continuously heat and stir to allow TEOS to hydrolyze fully; age to form a transparent sol;

[0014] Step 3: Add the luminescent powder to the homogeneous sol until the powder in the cup begins to expand and loosen, and a coating layer of appropriate thickness is formed on the surface of the powder; then place the gel-coated particles at the ventilation opening for aging, perform alcohol washing, drying, and grinding to obtain the luminescent powder coated with SiO2 inorganic material;

[0015] Step 4: Pour the coupling agent into a beaker containing anhydrous ethanol (60 g) and stir evenly. Subsequently, slowly mix the luminescent powder coated with SiO2 inorganic material into the above solution, seal it and heat it in a water bath. After the solvent evaporates, take it out after drying and grind it to obtain the luminescent powder with organic-inorganic hybrid coating.

[0016] Furthermore, in Step 1, the sintering temperature is 1100 °C and the sintering time is 4 h.

[0017] Furthermore, in Step 2, the ratio of tetraethyl orthosilicate (TEOS), C2H5OH, and deionized water is 1:10:15, the stirring time is 15 min; the water bath heating temperature is 60 °C, adjust the pH to about 2 - 3, and control the reaction time for 1 h.

[0018] Furthermore, the aging time in Step 2 is 30 min, and the aging time in Step 3 is 24 h.

[0019] Furthermore, in Step 4, the stirring time is 15 min, the water bath heating temperature is 60 °C, and the time is 2 h.

[0020] Another object of the present invention is to provide an application of the organic-inorganic coated and modified aluminate-based long afterglow luminescent material in the preparation of self-luminous cement-based materials.

[0021] Another object of the present invention is to provide a self-luminous high-strength cement-based material, including the organic-inorganic coated and modified aluminate-based long afterglow luminescent material; the cement-based material includes the following components in parts by weight:

[0022] Cement: 100 - 150 parts

[0023] Quartz sand: 140 - 250 parts

[0024] Luminescent material: 20 - 50 parts

[0025] Water: 40 - 60 parts

[0026] Toughening material: 2 - 6 parts.

[0027] Furthermore, the cement is P·Ⅱ 42.5 portland cement; the particle size of the quartz sand is 40 - 120 mesh; the luminescent material is the prepared strontium aluminate luminescent material; and the toughening material is glass fiber.

[0028] Another object of the present invention is to provide a preparation method of a self-luminous cement-based material, comprising the following steps:

[0029] (1) Mix the gel material, fine aggregate, coarse aggregate and fiber material evenly by stirring, pour them into a mold to obtain a concrete matrix with relatively high strength, cure it, and wait for the concrete to set and harden;

[0030] (2) Then mix the gel material, fine aggregate and organic-inorganic modified long afterglow phosphor evenly by low-speed stirring, add a certain amount of water and mix evenly to obtain a cement-based luminous surface layer, fill it on the surface of the concrete matrix and cure it to obtain the self-luminous cement-based material.

[0031] Furthermore, the speed of the low-speed stirring is 140 ± 10 r / min and the time is 2 min. The curing time is not less than 7 days.

[0032] Furthermore, the prepared luminous concrete has a luminous surface layer and a matrix layer; the gel material includes cement, mineral powder and fly ash; the organic-inorganic modified long afterglow phosphor accounts for 15 - 25% of the total mass of the long afterglow phosphor and cement.

[0033] Combined with the above technical solutions and the solved technical problems, the advantages and positive effects of the technical solution to be protected by the present invention are as follows:

[0034] First, the organic-inorganic hybrid modified long afterglow luminescent powder of the present invention has excellent hydrophobic properties, which can greatly improve the luminescent properties of the luminescent powder under conditions such as dampness and water accumulation.

[0035] By substituting part of the gelling material with the luminescent powder and incorporating it into the concrete, a self-luminous cement-based material with stable and excellent luminescent properties can be obtained.

[0036] The present invention greatly improves the water resistance of the material by performing organic-inorganic coating (silane layer and SiO2 layer) on the rare earth strontium aluminate material. The thickness of the coating layer is 20 - 50 nm, and the binding degree of the coating layer with the particles of the cement-based material and the luminescent material is good.

[0037] When the long afterglow luminescent powder prepared by the present invention is added to the cement-based material, the heat of hydration of the cement-based material will increase, and its mechanical properties such as compressive strength will be reduced to a certain extent. By using the method of pouring the luminous surface layer and the cement-based matrix in layers, the prepared cement-based material can have excellent luminescent properties while maintaining good mechanical properties. And the method of pouring in layers can greatly reduce the use of the luminescent powder, thereby reducing the construction cost.

[0038] The initial brightness and afterglow decay characteristics of the self-luminous cement-based material prepared by the present invention are related to the content of the luminescent powder in the cement-based material. Considering factors such as comprehensive mechanical properties, luminescent effect, and construction cost, the content of the luminescent powder is preferably about 20%. Compared with the cement-based material directly doped with the luminescent powder, the one doped with the coated and modified luminescent powder has better luminescent performance.

[0039] Second, by introducing a nanoscale SiO2 coating layer (with a thickness of 10 - 20 nm) on the surface of the SrAl2O4:Eu 2+ ,Dy 3+ long afterglow phosphor, a dense inorganic shell layer can be formed without affecting its photoluminescence performance, effectively isolating the quenching effect of active molecules such as moisture and CO2 on the luminescent center Eu 2+ ions. At the same time, further introducing a silane coupling agent to form an organic-inorganic synergistic cross-linking interface can enhance the interfacial compatibility between the phosphor and the polymer or cement-based material, solving the technical bottleneck of strong agglomeration and poor dispersion stability of traditional inorganic coated particles.

[0040] Using the hydrolysis-condensation reaction of tetraethyl orthosilicate (TEOS) under acidic conditions to form a transparent sol, combined with ethanol-assisted dispersion and 60°C water bath reaction control, the uniform deposition of the sol on the powder surface and the in-situ formation of a film structure can be achieved, avoiding defects such as local deposition and uneven coating thickness existing in traditional dry coating methods. By setting the aging time and pH value to regulate the condensation rate, precise control of the coating layer thickness and density can be realized, providing an active carrier basis for subsequent coupling modification.

[0041] In the present invention, by reacting the SiO2 inorganic shell layer with an organosilane coupling agent (such as KH-550 type) under hydrothermal sealing conditions, a flexible interfacial film layer containing Si–O–C bonds is formed, which not only improves the stability of the luminescent material in an extreme pH environment but also enhances the chemical anchoring with the hydroxyl groups in the cement-based system. This structure solves the engineering adaptability problems such as easy sedimentation, interfacial peeling, and serious light decay of traditional luminescent powders in cement-based composites.

[0042] Third, the SrAl2O4:Eu 2+ ,Dy 3+ luminescent powder prepared by the present invention has a high afterglow brightness (80 - 360 mcd·m 2 ) and a long persistent luminescence time (≥6 h). By regulating the particle size (10 - 100 μm) and the coating ratio (0.5 g:5 mL), the optimal matching of the material brightness and dispersibility can be achieved. It effectively avoids the agglomeration effect caused by overly fine micropowders, and at the same time ensures good afterglow response stability of the luminescent layer after photoexcitation, having significant application advantages in night vision safety and aesthetic applications.

[0043] The self-luminous cement-based material realizes the coordinated control of luminous function and material strength by doping 20-50 parts of composite-coated luminous powder while maintaining the mechanical system of traditional portland cement (P·Ⅱ 42.5) and quartz sand. By means of toughening with glass fiber (2-6 parts), the interfacial fracture toughness is effectively improved, and the problem of internal stress concentration caused by the introduction of luminous particles is controlled, so that the compressive strength and wear resistance of the material are not sacrificed while meeting the luminous performance.

[0044] Fourth, this material can continuously self-luminate at night or in a power-off environment, and is suitable for the visual guidance function requirements in low-illumination environments such as sidewalks, guardrails, subway passages, and underground garages. It has excellent water resistance, alkali resistance, and construction adaptability, solves the practical application pain points of existing cement luminous materials such as "rapid short-term brightness decay, easy peeling, and complex process", and has broad engineering promotion prospects in the fields of infrastructure function beautification, green energy-saving lighting, and emergency evacuation guidance.

[0045] The compatibility between long-afterglow luminous materials and concrete is poor. After the luminous powder is directly added to the concrete and mixed, the luminous duration is short and the luminous intensity is low.

[0046] The density of the luminous powder is greater than that of cement, so that most of the luminous powder is concentrated inside the concrete, making it difficult to exert its luminous performance. Brief Description of the Drawings

[0047] Figure 1 is a flow chart of the preparation method of the organic-inorganic coated and modified aluminate-based long-afterglow luminous material provided by the embodiment of the present invention.

[0048] Figure 2 is the fluorescence effect diagram of the uncoated long-afterglow material and the long-afterglow materials with different coating layers provided by the embodiment of the present invention.

[0049] Figure 3 is the morphology image and various element distribution images of the SiO2-silane coupling agent-coated long-afterglow material provided by the embodiment of the present invention.

[0050] Figure 4 is the morphology image and various element distribution images of the SiO2-aluminate coupling agent-coated long-afterglow material provided by the embodiment of the present invention.

[0051] Figure 5 is the morphology image and various element distribution images of the SiO2-titanate coupling agent-coated long-afterglow material provided by the embodiment of the present invention.

[0052] Figure 6 is the schematic diagram of the luminous concrete provided by the embodiment of the present invention.

[0053] Figure 7It is a schematic diagram of the cross-linking reaction between the organic-inorganic modified long afterglow material and the cement-based material provided by the embodiment of the present invention.

[0054] Figure 8 It is the luminescence effect diagram of the luminescent concrete at different times provided by the embodiment of the present invention. Specific embodiments

[0055] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0056] The present invention systematically explores the technical bottlenecks in the field of photoluminescent building materials. Due to its excellent photoluminescence properties, chemical stability and environmental friendliness, long afterglow luminescent materials have become a research hotspot for new building functional materials. However, experimental data show that the incorporation of long afterglow luminescent materials will cause significant deterioration of the mechanical properties of cement-based composites (such as a decrease in compressive strength and a decay in flexural strength), and reducing the doping concentration of long afterglow luminescent materials can alleviate the loss of mechanical properties, but it will lead to a reduction in the light output efficiency to the reference value, thus forming a typical performance inversion phenomenon.

[0057] During the research process of the present invention, a large number of compatibility experiments on aluminate-based long afterglow luminescent materials with water, cement and aggregates were carried out. It was found that when the aluminate-based long afterglow luminescent material meets water, the pH value of the water will rise to between 11 and 12. Due to the hydrolysis reaction of the luminescent material, its luminescence intensity and luminescence time are greatly reduced.

[0058] Compared with conventional luminescent cement-based materials, the present invention provides a cement-based material of a novel long afterglow luminescent material, that is, an organic-inorganic coating modification technology is used on the surface of the long afterglow luminescent material to increase the hydrophobicity and organic compatibility of the long afterglow luminescent material.

[0059] The embodiment of the present invention provides an organic-inorganic coated modified aluminate-based long afterglow luminescent material, including a long afterglow phosphor with a coated modification layer; the main raw materials of the surface coated modification layer are SiO2 and a coupling agent; the raw materials of the modification layer include a SiO2-silane coupling agent coating layer, a SiO2-aluminate coupling agent coating layer, and a SiO2-titanate coupling agent coating layer; the thickness of the modification layer is 10-20 nm;

[0060] The main components of the long afterglow phosphor include SrAl2O3:Eu 2+ , Dy 3+ ; the light it emits is yellow-green, and it has the advantages of high luminescence brightness and long luminescence time. The particle size of the long afterglow phosphor is 10-100 μm, and the density is 3100 kg / m3 , the afterglow brightness is 80 - 360 mcd·m 2 , and the afterglow time ≥ 6 h.

[0061] Furthermore, the mass / volume ratio of the long afterglow phosphor to the coating modification material is 0.5 g:5 mL.

[0062] As Figure 1 shown, the embodiment of the present invention provides a preparation method of a coating-modified long afterglow luminescent material, including the following steps:

[0063] Step 1, prepare the luminescent powder: accurately weigh the raw materials of high-purity SrCO3, Al2O3, Eu2O3, and Dy2O3 according to the ratio of 1:2:0.02:0.04, mix, grind, disperse in ethanol, and dry. Sinter at a temperature of 1100 °C for 4 h in a reducing atmosphere; after pulverization and grinding, obtain SrAl2O4:Eu 2+ ,Dy 3+ powder.

[0064] Step 2, weigh tetraethyl orthosilicate (TEOS), C2H5OH, and deionized water in a ratio of 1:10:15, stir for 15 min to make the solution evenly mixed, then heat in a water bath at 60 °C, and add dilute nitric acid to adjust the pH to about 2 - 3. Control the reaction time to 1 h and continue heating and stirring to fully hydrolyze TEOS; wait for 30 min of aging to form a transparent sol.

[0065] Step 3, add the luminescent powder to the homogeneous sol until the powder in the cup begins to expand and loosen to form a coating layer of appropriate thickness on the powder surface; then place the gel-coated particles at the ventilation opening for 24 h of aging, followed by alcohol washing, drying, and grinding to obtain the luminescent powder coated with SiO2 inorganic.

[0066] Step 4, pour the coupling agent into a beaker containing anhydrous ethanol (60 g), stir evenly for 15 min, then slowly mix the above luminescent powder into the above solution, seal and heat in a water bath at 60 °C for 2 h. After the solvent evaporates, take it out and dry, and grind to obtain the organic-inorganic hybrid coated luminescent powder.

[0067] The embodiment of the present invention provides a self-luminous cement-based material, and the cement-based material includes the following components in parts by weight:

[0068] Cement: 100 - 150 parts

[0069] Quartz sand: 140 - 250 parts

[0070] Luminescent material: 20 - 50 parts

[0071] Water: 40 - 60 parts

[0072] Toughening material: 2 - 6 parts

[0073] Furthermore, the cement is P·Ⅱ42.5 portland cement; the particle size of the quartz sand is 40 - 120 mesh; the luminescent material is the strontium aluminate luminescent material prepared above; the toughening material is glass fiber.

[0074] The embodiment of the present invention provides a preparation method of a self - luminous cement - based material, including the following steps: mixing a gelling material, fine aggregate, coarse aggregate, water and an admixture, stirring evenly, pouring into a mold to obtain a concrete matrix; then mixing a luminescent material, a gelling material, fine aggregate and water, stirring evenly to obtain a layer of luminescent cement surface layer, covering the surface of the concrete matrix and curing.

[0075] Furthermore, the stirring rate is 140±10r / min and the time is 2min. The curing time is not less than 7 days.

[0076] Through the above - mentioned preparation method, mixing each material in sequence is beneficial to fully stir each material evenly, improving the uniformity of the system, which is beneficial to improving the mechanical properties and afterglow properties of the prepared cement - based material. And this preparation method is very simple with low implementation difficulty. Using the vacuum pressing method for forming not only eliminates the curing time of the cement - based material, has high production efficiency, but also can greatly improve the compactness of the cement - based material, increasing the flexural strength and compressive strength of the cement - based material, and the product has good performance.

[0077] Example 1

[0078] A preparation method of SrAl2O4:Eu 2+ ,Dy 3+ luminescent powder:

[0079] By the high - temperature solid - state method. Accurately weigh high - purity SrCO3, Al2O3, Eu2O3, Dy2O3 in a ratio of 1:2:0.02:0.04, mix, grind, disperse in ethanol and dry. Sinter at a temperature of 1100℃ for 4h in a reducing atmosphere. After crushing and grinding, obtain SrAl2O4:Eu 2+ ,Dy 3+ powder.

[0080] Example 2

[0081] A preparation method of a hydrophobic modified long - afterglow luminescent material:

[0082] Weigh tetraethyl orthosilicate (TEOS), C2H5OH, and deionized water in a ratio of 1:10:15 and stir for 15 min. After the solution is mixed evenly, heat it in a water bath at 60 °C, and add dilute nitric acid dropwise to adjust the pH to about 2 - 3. Control the reaction time for 1 h with continuous heating and stirring to fully hydrolyze TEOS. After aging for 30 min to form a transparent sol, then add the luminescent powder prepared in Example 1 to this homogeneous sol until the powder in the cup begins to expand and loosen, and form a coating layer with an appropriate thickness on the surface of the powder. Secondly, place the gel-coated particles at the ventilation opening for aging for 24 h, then wash with alcohol, dry, and grind to obtain the luminescent powder coated with SiO2 inorganic coating.

[0083] Pour the silane coupling agent into a beaker containing anhydrous ethanol (60 g) and stir evenly for 15 min. Then slowly mix the above-mentioned luminescent powder into the above solution, seal it, and heat it in a water bath at 50 °C for 2 h. After the solvent evaporates, take it out after drying and grind to obtain the luminescent powder coated with SiO2 - silane coupling agent organic-inorganic hybrid.

[0084] Example 3

[0085] The difference from Example 2 is that the silane coupling agent in the organic coating is changed to aluminate coupling agent to obtain a coating layer of SiO2 - aluminate coupling agent.

[0086] Example 4

[0087] The difference from Example 2 is that the silane coupling agent in the organic coating is changed to titanate coupling agent to obtain a coating layer of SiO2 - titanate coupling agent.

[0088] Effect Example 1

[0089] Measure the fluorescence excitation light effect and hydrophobic effect of Examples 1, 2, 3, and 4.

[0090] (1) Use a fluorescence spectrophotometer, set the excitation wavelength to 340 nm, the starting emission wavelength to 350 nm, and the ending emission wavelength to 700 nm.

[0091] From Figure 2It can be seen that the selected luminescent material is an aluminate-based luminescent material, and the light it emits is yellow-green light, and the frequency of the excitation light is about 520 nm. The luminescence effect of Example 1 is the best. The luminescence effect of the SiO2-silane coupling agent coating layer used in Example 2 is the best, and the light transmittance of the coating layer is 88%. The light transmittances of Examples 2 and 3 are only 79% and 66% respectively. For the coating layer of Example 1, since both SiO2 and the silane coupling agent are colorless and transparent themselves, with a light transmittance of more than 90%, the combined coating layer also has a high light transmittance, taking into account the luminescence performance while improving the performance of the luminescent material. The worst luminescence performance is in Example 4. Since the titanate coupling agent itself is a light yellow and viscous liquid, compared with the silane coupling agent, it is not colorless and transparent itself, and the formed coating film is affected by this, resulting in a relatively large reduction in luminescence performance. In addition, because the titanate coupling agent itself is relatively viscous, the coated luminescent powder also has a certain viscosity.

[0092] (2) Through the hydrolysis reaction experiment, Examples 1, 2, 3, and 4 were added to distilled water, and the pH values of the solution and water were measured by a pH meter at different time intervals to judge the hydrophobic properties of the coated modified film.

[0093] Table 1 pH values of the solutions of Examples 1, 2, 3, and 4 and water at different time intervals

[0094] 1 min 10 min 30 min 60 min 180 min Water 7.2 7.2 7.2 7.2 7.2 Example 1 10.8 11.5 11.6 11.6 11.6 Example 2 7.4 7.4 7.4 7.4 7.6 Example 3 7.5 7.4 7.4 7.5 7.5 Example 4 7.6 7.6 7.6 7.6 7.6

[0095] As can be seen from Table 1, in comparison with water, for the luminescent material without any addition in Example 1, hydrolysis reaction occurred when it was added to water. The main driving force in its hydrolysis reaction comes from the aluminate ion (Al2O4 2- ), which reacts with H + or OH - in water to form corresponding products. Since the measured pH of Example 1 in water is about 12, the possible reaction is

[0096] SrAl2O4 + 3H2O → Sr(OH)2 + 2Al(OH)3. The three coating films of Examples 2, 3, and 4 effectively inhibit the hydrolysis reaction through the dual mechanisms of physical isolation and chemical regulation, significantly improving the hydrophobicity of the material. Specifically, the coating film can isolate the direct contact between water molecules and the substrate material, blocking the initial mass transfer path of the hydrolysis reaction. At the same time, through surface chemical modification or the introduction of functional components, the interfacial microenvironment is regulated to inhibit the hydrolysis kinetic process.

[0097] Effect Example 2

[0098] The scanning electron microscope was used to detect the microscopic morphology and phase distribution of the long afterglow luminescent materials under different organic-inorganic coating modifications. FromFigure 3 , Figure 4 As can be seen, the coating layers used in Examples 2 and 3 are more evenly coated on the surface of the long-afterglow powder, and the formed coating film is dense and uniform. Combining with Table 1, the coating film fully plays a role in inhibiting hydrolysis. From Figure 5 it can be seen that because the titanate coupling agent has a certain viscous property, the formed coating film also bonds the long-afterglow powder together. Although the long-afterglow luminescent material is no longer like powder, judging from Table 1, it also indeed plays a role in inhibiting the hydrolysis reaction. However, this coupling agent is not very suitable for powder materials.

[0099] Preparation of cement-based materials:

[0100] (1) Mix the cementitious material, fine aggregate, coarse aggregate, water, admixture and fiber materials with different dosages, and stir evenly. The stirring rate is 140 ± 10 r / min and the time is 2 min.

[0101] (2) Pour the obtained fresh mixture into the mold and demold after 24 h.

[0102] (3) The constant-temperature curing temperature is about 20 °C, and the curing age is not less than 7 days.

[0103] Example 5

[0104] 120 parts of cement, 15 parts of mineral powder, 15 parts of fly ash, 210 parts of quartz sand, 59 parts of water, 432 parts of coarse aggregate, and 0 part of fiber dosage.

[0105] Example 6

[0106] The difference from Example 5 is that there is a fiber dosage of 0.5%.

[0107] Example 7

[0108] The difference from Example 5 is that there is a fiber dosage of 1%.

[0109] Example 8

[0110] The difference from Example 5 is that there is a fiber dosage of 1.5%.

[0111] Example 9

[0112] The difference from Example 5 is that there is a fiber dosage of 2%.

[0113] Example 10

[0114] The difference from Example 5 is that there is a fiber dosage of 2.5%.

[0115] The obtained concrete matrix and compressive strength are shown in Table 2.

[0116] Table 2 Concrete matrix and compressive strength

[0117]

[0118] As can be seen from Table 2, the strength of the concrete prepared by the present invention is positively correlated with the content of the fiber material. When the fiber content is about 1.5%, the overall concrete strength improvement ratio is the highest. When the fiber content exceeds 2%, the improvement of the compressive strength of the concrete becomes smaller. Considering comprehensively, the fiber content of about 2% is more appropriate. The mix ratio of the subsequent concrete matrix is in accordance with Example 8.

[0119] Preparation of luminescent cement-based material:

[0120] (1) Mix different amounts of luminescent material, cementitious material, fine aggregate and water evenly to obtain a layer of luminescent cement surface layer, cover it on the surface of the above concrete matrix, and carry out curing.

[0121] (2) The constant temperature curing temperature is about 20°C, and the curing age is not less than 7 days.

[0122] Example 11

[0123] 120 parts of cement, 15 parts of slag powder, 15 parts of fly ash, 210 parts of quartz sand, 59 parts of water, 30 parts of luminescent material (the luminescent material is strontium aluminate rare earth coated with SiO2-silane coupling agent).

[0124] Example 12

[0125] The difference from Example 11 is that the luminescent material is changed to 15 parts, and the rest remains unchanged.

[0126] Example 13

[0127] The difference from Example 11 is that the luminescent material is changed to 22.5 parts, and the rest remains unchanged.

[0128] Example 14

[0129] The difference from Example 11 is that the luminescent material is changed to 37.5 parts, and the rest remains unchanged.

[0130] Performance detection experiment:

[0131] Compressive strength: Refer to GB / T 35160.3-2017 to test the compressive strength of the concrete.

[0132] Luminous intensity: Adopt GB / T 24981.2-2010. Taking the stop of xenon lamp irradiation as the initial time, record the brightness value as the luminous brightness data, and the qualified standard ≥ 0.32 mcd / m 2 (The lowest visible brightness of the human eye).

[0133] Table 3 Performance data of the luminescent concrete prepared in Examples 11 - 14

[0134] Compressive strength / MPa <![CDATA[Luminous intensity / (mcd / m 2 )]]> Luminescence duration / h Example 11 28.0 185 6.5 Example 12 28.6 165 6 Example 13 28.5 178 6 Example 14 27.0 190 6.5

[0135] As can be seen from Table 3, with the increase in the content of luminescent powder, the mechanical properties of the concrete material decrease. On the one hand, after the luminescent powder is added as a admixture to the concrete, it will change the original paste-aggregate ratio (the ratio of cementitious material to aggregate). An excessively high paste-aggregate ratio will lead to a decrease in the internal compactness of the concrete, thereby weakening its own strength. On the other hand, the difference in the thermal expansion coefficients between the luminescent material and the cement matrix will also cause micro-stresses when the temperature changes, accelerating the crack propagation under long-term action and further weakening the strength of the concrete. However, because the present invention adopts layered casting, the compressive strength of the concrete does not decrease significantly. The luminescence brightness and duration are positively correlated with the increase in the content of luminescent powder, but with the equal-proportion increase in the luminescent powder, the increase amounts of the overall luminescence brightness and duration of the luminescent concrete are getting lower and lower. Considering the comprehensive strength and luminescence performance, the overall effect of Example 11 is relatively good.

[0136] Comparative Example 1

[0137] The difference from Example 11 is that the luminescent material is replaced with uncoated luminescent powder, and the rest remains unchanged.

[0138] Comparative Example 2

[0139] The difference from Example 11 is that the luminescent material is replaced with luminescent powder coated with SiO2 - aluminate coupling agent, and the rest remains unchanged.

[0140] Table 4 Performance data of the luminescent concrete of Example 11 and Comparative Examples 1 and 2

[0141] Compressive strength / MPa <![CDATA[Luminous intensity / (mcd / m 2 )]]> Luminescence duration / h Example 11 28.0 185 6.5 Comparative Example 1 26.6 146 4 Comparative Example 2 28.1 176 6.5

[0142] As can be seen from Table 4, due to the difference in the light transmission performance of the surface coating layer, the luminescent powder with the SiO2 - silane coupling agent coating layer in Example 11 has better luminescence performance. When the untreated luminescent powder is added to the cement-based material, due to the presence of water, on the one hand, its own hydrolysis reaction occurs, thus affecting the luminescence effect of the powder, and both the luminescence brightness and duration have a relatively obvious decrease; on the other hand, the luminescent powder reacts with water, and a part of the free water is adsorbed on its surface, inhibiting the hydration reaction of the cement and other cementitious materials in the cement, resulting in a reduction in the hydration products and thus reducing the overall strength of the gel system.

[0143] In summary, the self-luminous cement substrate prepared by the method of layered pouring of the present invention takes into account both mechanical properties and afterglow properties, has excellent compressive strength, high luminous brightness, long luminous time, and the luminous brightness after 6 hours of losing the light source irradiation excitation can still meet the requirements of the lowest visible brightness of the human eye (0.32 mcd / m 2 ), and the compressive strength of the cement substrate at 7-day age can reach 28.0 MPa, which can be sufficiently used in most daily environments and has excellent comprehensive performance.

[0144] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention by those skilled in the art within the technical scope disclosed by the present invention shall be covered by the protection scope of the present invention.

Claims

1. An organic-inorganic coated and modified long afterglow luminescent material, characterized in that, The organic-inorganic coated and modified material includes: SiO2 and a silane coupling agent, with a coating thickness of 10-20 nm; the composition of the long-afterglow phosphor includes: SrAl2O3:Eu 2+ , Dy 3+ , with a particle size of 10-100 μm, a density of 3100 kg / m 3 , and a afterglow brightness of 80-360 mcd·m 2 , and the afterglow time ≥ 6 h; The mass / volume ratio of the long-afterglow phosphor and the coating modification material is 0.5 g:5 mL.

2. The preparation method of the organic-inorganic coated and modified long afterglow luminescent material according to claim 1, wherein, It includes the following steps: Step 1, prepare the luminescent powder: Weigh high-purity SrCO3, Al2O3, Eu2O3, and Dy2O3 accurately according to the ratio of 1:2:0.02:0.04, mix, grind, disperse in ethanol, and dry; sinter in a reducing atmosphere; after crushing and grinding, obtain SrAl2O4:Eu 2+ ,Dy 3+ powder; Step 2: Weigh tetraethyl orthosilicate (TEOS), C2H5OH, and deionized water, stir them, and after the solution is mixed evenly, heat it in a water bath, and add dilute nitric acid to adjust the pH. Keep heating and stirring to fully hydrolyze TEOS; age to form a transparent sol. Step 3: Add the luminescent powder into the uniform sol until the powder in the cup starts to expand and loosen to form a coating layer of appropriate thickness on the powder surface; then place the gel-coated particles at the ventilation opening for aging, wash with alcohol, dry, and grind to obtain the luminescent powder coated with SiO2 inorganic. Step 4: Pour the coupling agent into a beaker containing absolute ethanol and stir evenly. Then slowly mix the luminescent powder coated with SiO2 inorganic into the above solution, seal it and heat it in a water bath. After the solvent evaporates, take it out and dry it, and grind it to obtain the organic-inorganic hybrid-coated luminescent powder.

3. The preparation method of the organic-inorganic coated and modified long afterglow luminescent material according to claim 2, wherein, In the said Step 1, the sintering temperature is 1100 °C and the sintering time is 4 h.

4. The preparation method of the organic-inorganic coated and modified long afterglow luminescent material according to claim 2, characterized in that, In the said Step 2, the ratio of tetraethyl orthosilicate (TEOS), C2H5OH, and deionized water is: 1:10:15, the stirring time is 15 min; the water bath heating temperature is 60 °C, adjust the pH to about 2 - 3, and control the reaction time for 1 h.

5. The preparation method of the organic-inorganic coated and modified long afterglow luminescent material according to claim 2, wherein, In the said Step 2, the aging time is 30 min, and in Step 3, the aging time is 24 h.

6. The preparation method of the organic-inorganic coated and modified long afterglow luminescent material according to claim 2, wherein, In the said Step 4, there is 60 g of absolute ethanol, the stirring time is 15 min, the water bath heating temperature is 60 °C, and the time is 2 h.

7. A self-luminous high-strength cement-based material, characterized in that, It includes the organic-inorganic coated and modified long-afterglow luminescent material prepared by the method described in Claims 2 - 6; the cement-based material includes the following components in parts by weight: 100 - 150 parts of cement 140 - 250 parts of quartz sand 20 - 50 parts of luminescent material 40 - 60 parts of water 2 - 6 parts of toughening material The said cement is P·Ⅱ 42.5 Portland cement; the particle size of the quartz sand is 40 - 120 mesh; the luminescent material is the prepared strontium aluminate luminescent material; the toughening material is glass fiber.

8. A method for preparing a self-luminous cement-based material as claimed in claim 7, characterized in that, It includes the following steps: (1) Mix the gel material, fine aggregate, coarse aggregate, and fiber material evenly by stirring, pour them into a mold to obtain a concrete matrix with relatively high strength, cure it, and wait for the concrete to set and harden. (2) Then mix the gel material, fine aggregate, and the organic-inorganic modified long-afterglow phosphor evenly by low-speed stirring, add a certain amount of water and mix evenly to obtain a cement-based luminescent surface layer, fill it on the surface of the concrete matrix and cure it to obtain the self-luminous cement-based material.

9. The preparation method of the self-luminous cement-based material according to claim 8, characterized in that, The speed of the said low-speed stirring is 140 ± 10 r / min, and the time is 2 min. The curing time is not less than 7 days.

10. The preparation method of the self-luminous cement-based material according to claim 8, characterized in that, The prepared luminescent concrete has a luminescent surface layer and a matrix layer; the said gel material includes cement, mineral powder, and fly ash; the organic-inorganic modified long-afterglow phosphor accounts for 15 - 25% of the total mass of the long-afterglow phosphor and cement.

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