Stone cultural relic protection material reinforcing agent with graphene compounded with nano aluminum phosphate as well as preparation and application of stone cultural relic protection material reinforcing agent
By preparing graphene composite nano-AlPO4 particles with matched lattice constants and HAP composite coatings, the problems of cracks and voids in the protective film of stone cultural relics were solved, achieving better film formation effect and mechanical strength, which is suitable for the protection of stone cultural relics.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- UNIV OF SCI & TECH BEIJING
- Filing Date
- 2026-01-26
- Publication Date
- 2026-05-12
AI Technical Summary
The existing HAP protective film for stone cultural relics has defects such as cracks and voids, resulting in poor film formation and inability to effectively prevent dissolution and powdering.
Graphene-based composite AlPO4 nanoparticles with lattice constants between those of marble and HAP were prepared by hydrothermal method. A graphene-based composite AlPO4-HAP composite reinforcement and protective coating was then prepared on a marble substrate by chemical method. The lattice matching advantage of graphene-based composite AlPO4 nanoparticles was used to reduce film cracking and to provide a nano-transition layer to promote uniform film formation of HAP.
It improves the integrity and uniformity of the protective film, significantly enhances the mechanical strength of stone artifacts, and maintains the original appearance and color of the artifacts, making it suitable for the protection of stone artifacts.
Smart Images
Figure CN122010596A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of cultural relic protection materials, and specifically relates to a graphene composite nano-aluminum phosphate reinforcing agent for stone cultural relic protection materials, its preparation and application. Background Technology
[0002] Stone artifacts, as a form of cultural heritage, are witnesses and bearers of ancient human civilization. They embody the value of inheriting cultural roots and promoting the spirit of the nation, and therefore, the protection of stone artifacts is of great significance.
[0003] However, under the influence of natural climate and human activities, most open-air stone cultural relics suffer from various physical, chemical, and biological weatherings over the years, resulting in damage such as cracks, powdering, peeling, disintegration, crusting, dissolution, defects, pollution, biological destruction, and improper restoration. Among these, dissolution and powdering are the most obvious and common damages to open-air marble cultural relics. Many stone carvings and inscriptions have become blurred, which not only damages the surface appearance of the relics and affects the interpretation of their historical and cultural value, but also destroys the bonding between the stone particles, providing conditions for the development of other damages. Therefore, a safe and effective protection solution is urgently needed.
[0004] Biomimetic inorganic mineral materials possess unique structures and functions. Hydroxyapatite (HAP), a major component of natural bone inorganic matter, exhibits a dense structure, strong compatibility, and excellent corrosion resistance. As a novel biomimetic material, it has been used in the field of stone artifact preservation for over a decade. Currently, most artifact preservation methods utilize chemical methods to directly prepare HAP on the stone surface in situ, such as reacting a certain concentration of ammonium phosphate solution with calcium ions dissolved from marble. However, the protective films prepared in this way generally suffer from defects such as cracks and voids, significantly reducing the film-forming effect. Summary of the Invention
[0005] To address the problems of existing technologies, the present invention aims to overcome their shortcomings and provide a graphene-composite nano-aluminum phosphate reinforcing agent for the preservation of stone cultural relics, its preparation, and application. A novel process for preparing graphene-composite nano-AlPO4 is provided, using a hydrothermal method to obtain graphene-composite nano-AlPO4 particles with a lattice constant between that of marble and HAP (Hydrogen Alpoise Phosphate). Furthermore, a graphene-composite nano-AlPO4-HAP composite reinforcing and protective coating with good compatibility with marble substrates and uniform film formation is prepared using a chemical method, thus solving the problem of easy cracking in existing HAP protective materials.
[0006] According to a first aspect of the present invention, a method for preparing a graphene-composite nano-aluminum phosphate reinforcing agent for the preservation of stone cultural relics is provided, comprising the following steps: Step (1): Dissolve diammonium hydrogen phosphate (DAP) in deionized water, stir in an electromagnetic water bath, mix graphene quantum dot aqueous solution with aluminum chloride hexahydrate and dissolve in deionized water, slowly add the resulting GQDs-AlCl3 mixed solution to the DAP solution, continue stirring in an electromagnetic water bath, and obtain graphene composite nano AlPO4 precursor solution. Step (2): The graphene composite nano AlPO4 precursor solution was transferred to a high-pressure reactor and reacted in an oven. The reaction product was then ultrasonically dispersed, washed several times by alternating centrifugation with deionized water and ethanol, dried in an oven, and ground to obtain graphene composite nano AlPO4 powder, which was used as a reinforcing agent for HAP materials for the protection of stone cultural relics.
[0007] Furthermore, the lattice constant of the graphene composite nano-AlPO4 powder is between that of stone artifacts and HAP.
[0008] Furthermore, the stone artifacts are marble artifacts.
[0009] Further, step (1) specifically includes: Dissolve 0.005-0.02 mol DAP in 10-40 ml of deionized water and stir in an electromagnetic water bath at 70-90℃ for 10-30 min; mix 0.5-2 ml GQDs with 0.005-0.02 mol AlCl3·6H2O and dissolve in 15-60 ml of deionized water, then slowly add the GQDs-AlCl3 mixed solution dropwise to the DAP solution and continue stirring in an electromagnetic water bath at 70-90℃ for 0.5-2 h to obtain a graphene composite nano AlPO4 precursor solution.
[0010] Furthermore, in step (1): Dissolve 0.01 mol DAP in 20 ml of deionized water and stir in an electromagnetic water bath at 80 °C for 20 min; dissolve 1 ml GQDs and 0.01 mol AlCl3·6H2O in 30 ml of deionized water, and slowly add the GQDs-AlCl3 mixed solution dropwise to the DAP solution. Continue stirring in an electromagnetic water bath at 80 °C for 1 h to obtain a graphene composite nano AlPO4 precursor solution.
[0011] Furthermore, step (2) specifically includes: The obtained graphene composite nano AlPO4 precursor solution was transferred to a high-pressure reactor and reacted in an oven at 170-180℃ for 8-12 hours. The reaction product was ultrasonically dispersed, and washed 2-4 times each by alternating centrifugation with deionized water and ethanol. It was then dried in an oven at 50-80℃ for 10-15 hours and ground to obtain graphene composite nano AlPO4 powder.
[0012] Furthermore, in step (2): The obtained graphene composite nano AlPO4 precursor solution was transferred to a high-pressure reactor and reacted in an oven at 170°C for 8 hours. The reaction product was ultrasonically dispersed, washed three times each by alternating centrifugation with deionized water and ethanol, dried in an oven at 60°C for 12 hours, and then ground to obtain graphene composite nano AlPO4 powder.
[0013] According to a second aspect of the technical solution of the present invention, a graphene composite nano-aluminum phosphate reinforcing agent for the preservation of stone cultural relics is provided, wherein the stone cultural relics preservation reinforcing agent is graphene composite nano-AlPO4 powder obtained by the preparation method described in any of the above aspects; The lattice constant of the graphene composite nano-AlPO4 powder is between that of stone artifacts and HAP.
[0014] According to a third aspect of the technical solution of the present invention, an application of a stone cultural relic protection material reinforcing agent using graphene composite nano-aluminum phosphate as described above is provided in the protection of cultural relics.
[0015] Furthermore, the application method is as follows: Step (21): Graphene composite nano AlPO4 powder is prepared into a deionized water nano dispersion, and the nano dispersion is dropped onto the surface of the stone artifact. After standing, a graphene composite nano AlPO4 deposition layer is obtained. Step (22): Immerse the stone artifact with the graphene composite nano-AlPO4 deposition layer in DAP solution. After several hours, take it out, wash it with deionized water, and let it air dry at room temperature to obtain a graphene composite nano-AlPO4-HAP bilayer film structure, thereby protecting the stone artifact.
[0016] Further, step (21) specifically includes: A graphene-based AlPO4 nanoparticle dispersion of 0.1-0.3 g / L in deionized water was prepared. The nanoparticle dispersion was then dispersed at a flow rate of 0.2-0.8 ml / cm³. 2 A small amount of material was added to the surface of a stone artifact and left to stand for more than 18 hours to obtain a graphene composite nano-AlPO4 deposition layer.
[0017] Furthermore, in step (21): A 0.25 g / L deionized water nano-dispersion was prepared by combining graphene and AlPO4 nanoparticles. The nano-dispersion was then dispersed at a flow rate of 0.5 ml / cm³. 2 A small amount of material was added to the surface of a stone artifact and left to stand for 24 hours to obtain a graphene composite nano-AlPO4 deposition layer.
[0018] Furthermore, step (22) specifically includes: Stone artifacts with the graphene composite nano-AlPO4 deposition layer were immersed in a 0.5-2 mol / L DAP solution for more than 18 hours. The samples were then removed, washed with deionized water, and naturally dried at room temperature to obtain a graphene composite nano-AlPO4-HAP bilayer film structure.
[0019] Furthermore, in step (22): The stone artifact with the graphene composite nano-AlPO4 deposited layer was immersed in a 1 mol / L DAP solution. After 24 hours, the sample was removed, washed with deionized water, and dried naturally at room temperature to obtain a graphene composite nano-AlPO4-HAP bilayer film structure.
[0020] The beneficial effects of this invention are: Reactants: This method uses DAP, AlCl3·6H2O, and GQDs as reactants, and the provided Al 3+ and PO4 3- AlPO4 can be synthesized in subsequent reactions, with NH4 in the reactants. 4+ H + Cl - Both are soluble and can be effectively removed during the nano-cleaning process. The precursor solution composed of this reactant can be subjected to hydrothermal reaction to obtain pure GQDs composite nano AlPO4, thereby obtaining a product with a consistent crystal structure, which is convenient for uniform composite with HAP.
[0021] Hydrothermal: Under high temperature and high pressure hydrothermal reaction conditions, the precursor solution is conducive to the generation of high-purity nano-AlPO4 with good crystallinity and uniform particle size. Moreover, the temperature range of the hydrothermal reaction will not cause the oxidation and denaturation of GQDs. Compared with methods such as sol-gel method, it is more suitable for the preparation of graphene composite nano-aluminum phosphate reinforcing agent for stone cultural relic protection materials.
[0022] Chemical methods: Hydrothermal and chemical methods correspond to the preparation of the GQDs composite nano-AlPO4 transition layer and the HAP protective layer, respectively. Because the GQDs composite nano-AlPO4 prepared by the hydrothermal method has a lattice constant that matches HAP, it can reduce the mismatch stress caused by lattice mismatch, thereby reducing film cracking. Simultaneously, the nano-transition layer provides a rough surface and nucleation sites, making it easier for HAP to grow epitaxially on this basis during subsequent chemical methods. Therefore, the combination of hydrothermal and chemical methods is beneficial for synthesizing protective layers with better film-forming effects for stone artifacts. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0024] Figure 1 This is a flowchart illustrating the preparation method of a graphene-composite nano-aluminum phosphate reinforcing agent for the preservation of stone cultural relics according to the technical solution of the present invention. Figure 2 To observe the surfaces of blank marble sample U, marble sample G treated with graphene composite nano-AlPO4 alone, marble sample P treated with HAP generated by DAP as a precursor, and marble sample GP treated with graphene composite nano-AlPO4-HAP (DAP as a precursor) using scanning electron microscopy, SEM images of samples U, G, P, and GP were obtained. Figure 3 This is a schematic diagram of the three-point flexural strength of samples U, G, P, and GP. Figure 4 This is a schematic diagram showing the colorimetric changes of samples G, P, and GP. Figure 5 This is an XRD pattern of graphene-composite AlPO4 nanoparticles. Figure 6 A comparative graph showing the lattice mismatch data between graphene composite nano-AlPO4, calcite marble, and HAP.
[0025] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0026] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.
[0027] The terms "first," "second," etc., used in this disclosure are for distinguishing similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that the embodiments of this disclosure described herein can be implemented, for example, in orders other than those illustrated or described herein.
[0028] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.
[0029] Multiple, including two or more.
[0030] And / or, it should be understood that, for the purposes of this disclosure, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.
[0031] To address the common defects such as cracks and voids in HAP protective films prepared on marble, which significantly reduce the film-forming effect, designing and preparing a protective material reinforcing agent with a lattice constant between that of stone and HAP to promote HAP film formation on marble surfaces is a key challenge and focus of protective material optimization. Currently, there is research on nano-graphene, nano-AlPO4, nano-lime, and nano-titanium dioxide in the field of cultural relic protection, but the development of graphene composite nano-AlPO4 is still lacking. Therefore, this invention provides a graphene composite nano-aluminum phosphate reinforcing agent for stone cultural relic protection, its preparation, and a method for cultural relic protection. Graphene composite nano-AlPO4 particles with a lattice constant between that of marble and HAP are obtained through a hydrothermal method, providing a new process for preparing graphene composite nano-AlPO4. Furthermore, a graphene composite nano-AlPO4-HAP composite reinforced protective coating with good compatibility with the marble substrate and uniform film formation is prepared through a chemical method. Here, based on the graphene composite nano-AlPO4 particles prepared by the hydrothermal method, when the graphene composite nano-AlPO4-HAP composite reinforced protective coating is prepared by the chemical method, the GQDs composite nano-AlPO4, with its lattice matching advantage, can reduce the mismatch stress during HAP growth and thus reduce film cracking. At the same time, the nano-transition layer provides a rough surface and nucleation sites, which is conducive to the epitaxial growth of HAP on this basis, making the protective film structure more uniform and complete.
[0032] Furthermore, the addition of GQDs increased the nucleation density of nano-AlPO4 during the hydrothermal reaction, inhibiting surface agglomeration and resulting in granular graphene-composite nano-AlPO4 with smaller nanoscale dimensions. In its interaction with HAP film formation, the graphene-composite nano-AlPO4 possesses a lattice constant intermediate between calcite and HAP, which is beneficial for the epitaxial growth of HAP on marble artifacts. Simultaneously, the nanoparticles provide nucleation sites for HAP and improve surface roughness, creating conditions conducive to HAP film formation.
[0033] Specifically, the technical solution of the present invention first provides a method for preparing a reinforcing agent for stone cultural relic protection materials composed of graphene composite nano-aluminum phosphate, the steps of which are as follows: Step (1): Dissolve DAP in deionized water, stir in an electromagnetic water bath, mix graphene quantum dot aqueous solution (GQDs) and aluminum chloride hexahydrate (AlCl3·6H2O) and dissolve in deionized water, slowly add the resulting GQDs-AlCl3 mixed solution to the DAP solution, continue stirring in an electromagnetic water bath, and obtain graphene composite nano AlPO4 precursor solution; Step (2): The graphene composite nano AlPO4 precursor solution was transferred to a high-pressure reactor and reacted in an oven. The reaction product was then ultrasonically dispersed, washed several times by alternating centrifugation with deionized water and ethanol, dried in an oven, and ground to obtain graphene composite nano AlPO4 powder with a lattice constant between that of stone artifacts and HAP, which was used as a reinforcing agent for HAP materials used to protect stone artifacts.
[0034] Furthermore, the stone artifacts are marble artifacts.
[0035] Further, step (1) specifically includes: Dissolve 0.005-0.02 mol DAP in 10-40 ml of deionized water and stir in an electromagnetic water bath at 70-90℃ for 10-30 min; mix 0.5-2 ml GQDs with 0.005-0.02 mol AlCl3·6H2O and dissolve in 15-60 ml of deionized water, then slowly add the GQDs-AlCl3 mixed solution dropwise to the DAP solution and continue stirring in an electromagnetic water bath at 70-90℃ for 0.5-2 h to obtain a graphene composite nano AlPO4 precursor solution.
[0036] Here, the parameters are designed based on the same number of moles of DAP and AlCl3·6H2O in order to obtain AlPO4 with an Al:PO4 ratio of 1:1. With the corresponding volume of deionized water, a 0.2 mol / L AlPO4 precursor solution is finally obtained. 0.2 mol / L is in the commonly used precursor concentration range for hydrothermal synthesis of nanomaterials, so it is selected.
[0037] The amount of GQDs added is determined based on Al (mol): GQDs (ml) = 100. This amount of GQDs added can provide sufficient nanonucleation density.
[0038] Stirring in an electromagnetic water bath at 70-90℃ for 10-30 minutes can ensure the complete dissolution of DAP in deionized water. Stirring the mixed solution at 70-90℃ for 0.5-2 hours can ensure the complete conversion of each reactant into an ionic state, especially the conversion of some slightly soluble and sparingly soluble intermediates.
[0039] Furthermore, in step (1): Dissolve 0.01 mol DAP in 20 ml of deionized water and stir in an electromagnetic water bath at 80 °C for 20 min; dissolve 1 ml GQDs and 0.01 mol AlCl3·6H2O in 30 ml of deionized water, and slowly add the GQDs-AlCl3 mixed solution dropwise to the DAP solution. Continue stirring in an electromagnetic water bath at 80 °C for 1 h to obtain a graphene composite nano AlPO4 precursor solution.
[0040] Furthermore, step (2) specifically includes: The obtained graphene composite nano AlPO4 precursor solution was transferred to a high-pressure reactor and reacted in an oven at 170-180℃ for 8-12 hours. The reaction product was ultrasonically dispersed, and washed 2-4 times each by alternating centrifugation with deionized water and ethanol. It was then dried in an oven at 50-80℃ for 10-15 hours and ground to obtain graphene composite nano AlPO4 powder.
[0041] Here, reacting in an oven at 170-180℃ for 8-12 hours ensures that the main component of the product is type B AlPO4 with a lattice constant that best matches marble and HAP. If the reaction time and temperature are less than this, other crystal forms of AlPO4 will be formed, which are not ideal. If the reaction time and temperature are greater than this, there is a risk of over-crystallization and coarsening.
[0042] Washing with deionized water and ethanol three times each helps to effectively remove soluble inorganic salt residues and organic pollutants.
[0043] Drying in an oven at 50-80℃ for 10-15 hours can ensure that the water in the nanopowder is basically removed, thus avoiding the interference of water on the subsequent application effect and test results of nano AlPO4.
[0044] Furthermore, in step (2): The obtained graphene composite nano AlPO4 precursor solution was transferred to a high-pressure reactor and reacted in an oven at 170°C for 8 hours. The reaction product was ultrasonically dispersed, washed three times each by alternating centrifugation with deionized water and ethanol, dried in an oven at 60°C for 12 hours, and then ground to obtain graphene composite nano AlPO4 powder.
[0045] According to a second aspect of the present invention, a graphene-composite nano-aluminum phosphate reinforcing agent for the preservation of stone cultural relics is provided, wherein the stone cultural relics preservation reinforcing agent is graphene-composite nano-AlPO4 powder obtained by the preparation method according to any one of the above aspects.
[0046] According to a third aspect of the technical solution of the present invention, a method for protecting cultural relics using a graphene-composite nano-aluminum phosphate reinforcing agent as described above is provided, comprising the following steps: Step (21): Graphene composite nano AlPO4 powder is prepared into a deionized water nano dispersion, and the nano dispersion is dropped onto the surface of the stone artifact. After standing, a graphene composite nano AlPO4 deposition layer is obtained. Step (22): Immerse the stone artifact with the graphene composite nano-AlPO4 deposition layer in DAP solution. After several hours, take it out, wash it with deionized water, and let it air dry at room temperature to obtain a graphene composite nano-AlPO4-HAP bilayer film structure, thereby protecting the stone artifact.
[0047] Further, step (21) specifically includes: A graphene-based AlPO4 nanoparticle dispersion of 0.1-0.3 g / L in deionized water was prepared. The nanoparticle dispersion was then dispersed at a flow rate of 0.2-0.8 ml / cm³. 2 A small amount of material was added to the surface of a stone artifact and left to stand for more than 18 hours to obtain a graphene composite nano-AlPO4 deposition layer.
[0048] Here, a standing time of more than 18 hours is required to ensure that the water in the dispersion evaporates.
[0049] Furthermore, in step (21): A 0.25 g / L deionized water nano-dispersion was prepared by combining graphene and AlPO4 nanoparticles. The nano-dispersion was then dispersed at a flow rate of 0.5 ml / cm³. 2 A small amount of material was added to the surface of a stone artifact and left to stand for 24 hours to obtain a graphene composite nano-AlPO4 deposition layer.
[0050] Furthermore, step (22) specifically includes: Stone artifacts with the graphene composite nano-AlPO4 deposition layer were immersed in a 0.5-2 mol / L DAP solution for more than 18 hours. The samples were then removed, washed with deionized water, and naturally dried at room temperature to obtain a graphene composite nano-AlPO4-HAP bilayer film structure.
[0051] Here, the bilayer membrane parameters ensure that a protective membrane structure with HAP as the main component is obtained.
[0052] Furthermore, in step (22): The stone artifact with the graphene composite nano-AlPO4 deposited layer was immersed in a 1 mol / L DAP solution. After 24 hours, the sample was removed, washed with deionized water, and dried naturally at room temperature to obtain a graphene composite nano-AlPO4-HAP bilayer film structure.
[0053] Example Step (1) Preparation of graphene composite nano-AlPO4: Graphene composite nano-AlPO4 was prepared using a hydrothermal method, with its lattice constant falling between that of marble and HAP. Figure 1 As shown, specifically: S1: Dissolve 0.01 mol DAP in 20 ml of deionized water and stir in an electromagnetic water bath at 80 °C for 20 min; dissolve 1 ml GQDs and 0.01 mol AlCl3·6H2O in 30 ml of deionized water, and slowly add the GQDs-AlCl3 mixed solution dropwise to the DAP solution. Continue stirring in an electromagnetic water bath at 80 °C for 1 h to obtain a graphene composite nano AlPO4 precursor solution.
[0054] S2: The obtained graphene composite nano AlPO4 precursor solution was transferred to a high-pressure reactor and reacted in an oven at 170°C for 8 hours; the reaction product was ultrasonically dispersed, washed three times each by alternating centrifugation with deionized water and ethanol, dried in an oven at 60°C for 12 hours, and ground to obtain graphene composite nano AlPO4 powder.
[0055] Step (2) Assembly of graphene composite nano-AlPO4-HAP material: After obtaining graphene composite nano-AlPO4, a graphene composite nano-AlPO4-HAP bilayer structure is prepared on the marble surface using a chemical method to connect the fragile stone particles and form a protective film with reinforcement and protection functions. Specifically: A 0.25 g / L deionized water nano-dispersion was prepared by combining graphene and AlPO4 nanoparticles. The nano-dispersion was then dispersed at a flow rate of 0.5 ml / cm³. 2 A small amount of material was added to the surface of a stone artifact and left to stand for 24 hours to obtain a graphene composite nano-AlPO4 deposition layer.
[0056] The stone artifact with the graphene composite nano-AlPO4 deposited layer was immersed in a 1 mol / L DAP solution. After 24 hours, the sample was removed, washed with deionized water, and dried naturally at room temperature to obtain a graphene composite nano-AlPO4-HAP bilayer film structure.
[0057] Experimental results show that: (1) Improve the integrity of the protective film Scanning electron microscopy was used to observe the surfaces of blank marble sample U, marble sample G treated with graphene composite nano-AlPO4 alone, marble sample P treated with HAP generated using DAP as a precursor alone, and marble sample GP treated with graphene composite nano-AlPO4-HAP (DAP as a precursor) according to the present invention. The results are as follows: Figure 2As shown, compared to the bare stone surface of sample U, the surface of sample G exhibits the adhesion of nanoparticles, increasing the surface roughness of the stone, but without forming a continuous film structure. Sample P shows the characteristic flower-like structure of nano-CaP, but it is distributed in an isolated, agglomerated manner, with voids between the CaP clusters. Samples GP all show a network-like structure of HAP, uniformly covering the stone surface, resulting in a protective film with better integrity.
[0058] (2) Improve the mechanical strength of stone A universal testing machine was used to conduct three-point mechanical flexural strength tests on U, G, P, and GP specimens. Five strength values were tested for each group of specimens. The results are as follows: Figure 3 As shown, after protective treatment, the three-point flexural strength of sample G and sample U are similar. Sample P can increase the average three-point flexural strength of marble by about 34%, and sample GP can increase the average three-point flexural strength of marble by about 54%. The addition of graphene composite nano-AlPO4 reinforcing agent can significantly improve the consolidation effect of the protective material, which is related to the dense structure observed in SEM.
[0059] (3) Does not significantly change the color of the stone The colorimetric variation data of each sample shows that (e.g.) Figure 4 The smaller ΔE of G indicates that the accumulation of nanoparticles on the surface has little impact on the stone's color. The larger standard deviation of ΔE for P may be related to uneven film formation leading to color inconsistencies. In the color comparison study, GP's ΔE is moderate. All treated samples meet the standards for cultural relic protection, with GP's ΔE < 2.3, which is within the range visible to the naked eye. In conclusion, the protective treatment does not significantly alter the appearance and color of marble, making it suitable for marble cultural relic protection applications.
[0060] Furthermore, to verify the necessity of lattice constant matching, the XRD patterns of the prepared graphene composite nano-AlPO4 were tested (e.g., Figure 5 ), and its lattice constant was determined (as shown in Table 1): Calculate the lattice mismatch between graphene-composite AlPO4 nanoparticles and calcite marble, and compare it with HAP data (e.g.) Figure 6 The results show that the prepared graphene composite nano-AlPO4 is a type B AlPO4 belonging to the hexagonal crystal system and space group P3221, with a lattice constant between that of calcite and HAP. The lattice mismatch between AlPO4 and calcite (1.0%) and between HAP and AlPO4 (4.5%) is less than that between HAP and calcite (5.5%). Therefore, AlPO4 can act as a buffer layer in terms of lattice matching, promoting the adhesion and integrity of the film.
[0061] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.
Claims
1. A method for preparing a graphene-composite nano-aluminum phosphate reinforcing agent for the preservation of stone cultural relics, characterized in that, The steps are as follows: Step (1): Dissolve diammonium hydrogen phosphate in deionized water, stir in an electromagnetic water bath, mix graphene quantum dot aqueous solution with aluminum chloride hexahydrate and dissolve in deionized water, slowly add the resulting GQDs-AlCl3 mixed solution to DAP solution, continue stirring in an electromagnetic water bath, and obtain graphene composite nano AlPO4 precursor solution. Step (2): The graphene composite nano AlPO4 precursor solution was transferred to a high-pressure reactor and reacted in an oven. The reaction product was then ultrasonically dispersed, washed several times by alternating centrifugation with deionized water and ethanol, dried in an oven, and ground to obtain graphene composite nano AlPO4 powder, which was used as a reinforcing agent for HAP materials for the protection of stone cultural relics.
2. The preparation method of the graphene-composite nano-aluminum phosphate reinforcing agent for the preservation of stone cultural relics according to claim 1, characterized in that, The lattice constant of the graphene composite nano-AlPO4 powder is between that of stone artifacts and HAP.
3. The preparation method of the graphene-composite nano-aluminum phosphate reinforcing agent for the preservation of stone cultural relics according to claim 1, characterized in that, The stone artifacts mentioned are marble artifacts.
4. The preparation method of the graphene-composite nano-aluminum phosphate reinforcing agent for the preservation of stone cultural relics according to claim 1, characterized in that, The specific steps (1) are as follows: Dissolve 0.005-0.02 mol DAP in 10-40 ml of deionized water and stir in an electromagnetic water bath at 70-90℃ for 10-30 min; mix 0.5-2 ml GQDs with 0.005-0.02 mol AlCl3·6H2O and dissolve in 15-60 ml of deionized water, then slowly add the GQDs-AlCl3 mixed solution dropwise to the DAP solution and continue stirring in an electromagnetic water bath at 70-90℃ for 0.5-2 h to obtain a graphene composite nano AlPO4 precursor solution.
5. The preparation method of the graphene-composite nano-aluminum phosphate reinforcing agent for the preservation of stone cultural relics according to claim 1, characterized in that, Step (2) specifically involves: The obtained graphene composite nano AlPO4 precursor solution was transferred to a high-pressure reactor and reacted in an oven at 170-180℃ for 8-12 hours. The reaction product was ultrasonically dispersed, and washed 2-4 times each by alternating centrifugation with deionized water and ethanol. It was then dried in an oven at 50-80℃ for 10-15 hours and ground to obtain graphene composite nano AlPO4 powder.
6. A graphene-composite nano-aluminum phosphate reinforcing agent for the preservation of stone cultural relics, wherein, The reinforcing agent for the stone cultural relic protection material is graphene composite nano AlPO4 powder obtained by the preparation method according to any one of claims 1 to 5; The lattice constant of the graphene composite nano-AlPO4 powder is between that of stone artifacts and HAP.
7. The application of a stone cultural relic protection material reinforcing agent using graphene composite nano-aluminum phosphate as described in claim 6 in the protection of cultural relics.
8. The application of the graphene-composite nano-aluminum phosphate reinforcing agent for stone cultural relic preservation according to claim 7 in cultural relic preservation, characterized in that, The application method is as follows: Step (21): Graphene composite nano AlPO4 powder is prepared into a deionized water nano dispersion, and the nano dispersion is dropped onto the surface of the stone artifact. After standing, a graphene composite nano AlPO4 deposition layer is obtained. Step (22): Immerse the stone artifact with the graphene composite nano-AlPO4 deposition layer in DAP solution. After several hours, take it out, wash it with deionized water, and let it air dry at room temperature to obtain a graphene composite nano-AlPO4-HAP bilayer film structure, thereby protecting the stone artifact.
9. The application of the graphene-composite nano-aluminum phosphate reinforcing agent for the preservation of stone cultural relics according to claim 8, characterized in that, The specific steps (21) are as follows: A graphene-based AlPO4 nanoparticle dispersion of 0.1-0.3 g / L in deionized water was prepared. The nanoparticle dispersion was then dispersed at a flow rate of 0.2-0.8 ml / cm³. 2 A small amount of material was added to the surface of a stone artifact and left to stand for more than 18 hours to obtain a graphene composite nano-AlPO4 deposition layer.
10. The application of the graphene-composite nano-aluminum phosphate reinforcing agent for the preservation of stone cultural relics according to claim 8, characterized in that, The specific steps (22) are as follows: Stone artifacts with the graphene composite nano-AlPO4 deposition layer were immersed in a 0.5-2 mol / L DAP solution for more than 18 hours. The samples were then removed, washed with deionized water, and naturally dried at room temperature to obtain a graphene composite nano-AlPO4-HAP bilayer film structure.