A method for preparing controllable degradable archaeological wood

Abstract

This invention discloses a method for preparing controllable degradable archaeological-style wood, comprising the following steps: Step 1, pre-treatment of the wood substrate by low-temperature plasma etching activation; Step 2, impregnation with a composite enzyme degradation solution using a vacuum pressure method; Step 3, segmented temperature-pressure synergistic directional degradation; Step 4, injection of inorganic nanoparticles into the degraded wood for structural fine-tuning; Step 5, impregnation of the wood with a temperature-sensitive polymer solution, utilizing the phase transition principle to block cell wall degradation sites; Step 6, gradient vacuum drying and surface aging treatment. This invention solves the problems of uneven degradation, process loss of control, and low simulation degree of traditional methods. The prepared archaeological-style wood exhibits stable properties, uniform degradation, and a microstructure that highly replicates real cultural relics.

Description

Technical Field

[0001] This invention relates to the field of wood materials technology, specifically to a method for preparing controllable degradable archaeological wood. Background Technology

[0002] Due to long-term burial, the three major components of the cell wall of archaeological wood (cellulose, hemicellulose, and lignin) undergo heterogeneous gradient degradation, resulting in characteristics such as high moisture content, low mechanical strength, and well-developed micropores.

[0003] Existing technologies mostly employ single acid-base digestion or long-term natural decay, which presents the following bottlenecks:

[0004] Uneven degradation: The agent has difficulty penetrating the center of large-sized wood, resulting in external rot and internal decay;

[0005] Process out of control: Once the reaction starts, it is difficult to stop it precisely, which can easily lead to excessive decay;

[0006] Low simulation accuracy: It can only simulate color or chemical composition, and cannot replicate the unique mineralization and micromechanical decay curve of archaeological wood;

[0007] Inefficient: Conventional biodegradation is time-consuming and cannot be adapted to industrial mass production. Summary of the Invention

[0008] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing controllable degradable archaeological wood to solve the problems mentioned in the background art.

[0009] The present invention solves the technical problem by adopting the following technical solution:

[0010] This invention provides a method for preparing controllable degradable archaeological wood, comprising the following steps:

[0011] Step 1: Perform low-temperature plasma etching activation pretreatment on the wood substrate;

[0012] Step 2: Impregnate the composite enzyme degradation solution using a vacuum pressure method;

[0013] Step 3: Perform segmented temperature and pressure synergistic directional degradation;

[0014] Step 4: Inject inorganic nanoparticles into the degraded wood to fine-tune its structure;

[0015] Step 5: Impregnate the wood with a temperature-sensitive polymer solution to block cell wall degradation sites using the principle of phase change;

[0016] Step 6: Perform gradient vacuum drying and surface aging treatment.

[0017] Preferably, step one includes the following steps:

[0018] Fast-growing timber is selected and vacuum-dried to a moisture content of <8%;

[0019] Low-temperature plasma is used to etch the wood block in all directions with a power of 80-120W for 3-5 minutes. The working atmosphere of the low-temperature plasma treatment is a mixture of argon and oxygen with a volume ratio of 3-5:1.

[0020] Preferably, step two includes the following steps:

[0021] First, evacuate to a vacuum level of ≤-0.095MPa and maintain for 15-30 minutes. Then, release the pressure and inject the compound enzyme degradation solution. Subsequently, pressurize to 0.8-1.5MPa for impregnation to ensure that the agent reaches the heartwood.

[0022] Preferably, the components of the composite enzyme degradation solution in step two, by mass percentage, include:

[0023] Cellulase 0.5-2.0%, hemicellulase 0.3-1.5%, lignin peroxidase 0.1-0.8%, laccase 0.2-1.0%, citric acid chelating agent 0.1-0.3%, penetration enhancer 0.1-0.5%, sodium acetate 0.05-0.2%, balance deionized water.

[0024] Preferably, the preparation method of the composite enzyme degradation solution in step two includes the following steps:

[0025] S2-1: Add citric acid chelating agent and sodium acetate to deionized water to adjust the pH to 4.8-5.2. This step provides a stable microenvironment for subsequent enzyme and protein processing.

[0026] S2-2: Add 0.1-0.5% (w / v) sodium dioctyl sulfosuccinate to the buffer solution, turn on the magnetic stirrer and stir until the solution is completely transparent, ensuring that the surface tension drops to the optimal range;

[0027] S2-3: Add lignin peroxidase and laccase in sequence. At this time, the water temperature must be strictly controlled at 10-20°C to avoid local heat generated by stirring, which may cause enzyme inactivation. Citric acid rapidly chelates the metal ions in the enzyme center at this stage to maintain its spatial conformation.

[0028] S2-4: Finally, add cellulase and hemicellulase, and continue to stir gently for 10-25 minutes to achieve chemical equilibrium between the complex enzyme system and the citric acid chelation system, thus obtaining a fully-component directional degradation solution.

[0029] Preferably, step three includes the following steps:

[0030] The impregnated wood was placed in a reactor and heated in stages: the first stage activated the bio-enzyme activity at 30-35℃, and the second stage accelerated hydrolysis at 40-50℃; the degradation time was controlled at 12-72h.

[0031] Preferably, step four includes the following steps:

[0032] A suspension of nano-hydroxyapatite or nano-silica is injected into the wood, wherein the mass percentage concentration of the suspension is 1%-5%.

[0033] Preferably, the temperature-sensitive polymer in step five is poly(N-isopropylacrylamide);

[0034] In step five, the phase change sealing is performed by heating the impregnated wood to 35-45°C, causing the polymer to undergo a phase change, producing a hydrophobic precipitate that blocks the micropores of the cell wall, physically isolating residual enzyme activity, and inhibiting the continued degradation reaction.

[0035] Preferably, the gradient vacuum drying in step six is: using a stepped cooling vacuum drying method, gradually cooling from 30°C to 20°C at a cooling rate of 0.5-2°C / h;

[0036] The appearance aging treatment in step six involves adding tannic acid or iron oxide powder for antique coloring.

[0037] Preferably, the inorganic nanoparticles in step four are one or more of nano-hydroxyapatite, nano-silica, or nano-calcium carbonate.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] Traditional chemical or thermal termination methods often lead to secondary damage to the wood structure or reagent residues. However, this invention utilizes the phase transition properties of thermosensitive polymers at specific temperatures to generate hydrophobic precipitates by heating at a predetermined degradation time point, physically sealing the micropores of the cell wall and thus isolating residual enzyme activity in real time. This invention can control the degradation rate deviation within ±1.5% by using thermosensitive polymer end-capping, completely solving the technical problem of secondary degradation and unstable properties of simulated archaeological wood during subsequent storage and experimentation.

[0040] This invention achieves a breakthrough in penetration from the macroscopic to the microscopic scale of the cell wall through the deep synergy of low-temperature plasma activation and gradient vacuum impregnation. Plasma etching effectively breaks down the hydrophobic layer on the surface of the wood and opens up the closed pit membrane. Combined with the penetration promoter to reduce surface tension and citric acid to dissociate calcium bridges in the cell wall, the macromolecular complex enzyme system can penetrate evenly into the heartwood of the wood. The degradation uniformity of the whole cross section of the sample prepared by this invention is far superior to that of the traditional soaking method, ensuring the deep consistency of the physicochemical properties of the sample.

[0041] This invention precisely replicates the degradation mechanism of archaeological wood through directional catalysis by a composite enzyme system and nano-mineralization filling. The composite enzyme system simulates the evolutionary law of preferential degradation of cellulose and hemicellulose in nature; while the injection of nano-hydroxyapatite or silica simulates the mineralization of real archaeological wood during long-term burial, effectively correcting the ultra-large cavities caused by enzymatic hydrolysis, so that the micropore distribution, mechanical attenuation curve and FTIR spectral correlation coefficient of the sample are highly consistent with the unearthed wooden artifacts.

[0042] The entire process of this invention uses biological enzymes, natural chelating agents and inorganic nanoparticles, and does not involve strong acids, strong alkalis or heavy metal pollution, and the reaction conditions are mild.

[0043] This invention solves the problems of uneven degradation, process loss and low simulation in traditional methods. The prepared archaeological wood has stable properties, uniform degradation and microstructure that highly replicates the real cultural relics. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to specific examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] Example 1.

[0046] This embodiment provides a method for preparing controllable degradable archaeological-style wood, comprising the following steps:

[0047] Step 1: Perform low-temperature plasma etching activation pretreatment on the wood substrate;

[0048] Step 2: Impregnate the composite enzyme degradation solution using a vacuum pressure method;

[0049] Step 3: Perform segmented temperature and pressure synergistic directional degradation;

[0050] Step 4: Inject inorganic nanoparticles into the degraded wood to fine-tune its structure;

[0051] Step 5: Impregnate the wood with a temperature-sensitive polymer solution to block cell wall degradation sites using the principle of phase change;

[0052] Step 6: Perform gradient vacuum drying and surface aging treatment.

[0053] Step one of this embodiment includes the following steps:

[0054] Fast-growing poplar wood is selected and vacuum-dried to a moisture content of <8%;

[0055] Low-temperature plasma was used to etch the wood block in all directions with a power of 80W for 3 minutes. The working atmosphere of the low-temperature plasma treatment was a mixture of argon and oxygen with a volume ratio of 3:1.

[0056] Step two of this embodiment includes the following steps:

[0057] First, evacuate to a vacuum level of ≤-0.095MPa and maintain for 15 minutes. Then, release the pressure and inject the compound enzyme degradation solution. Subsequently, pressurize to 0.8MPa for impregnation to ensure that the agent reaches the heartwood.

[0058] The components of the composite enzyme degradation solution in step two of this embodiment, by mass percentage, include:

[0059] It contains 0.5% cellulase, 1.5% hemicellulase, 0.1% lignin peroxidase, 1.0% laccase, 0.1% citric acid chelating agent, 0.1% penetration enhancer, 0.05% sodium acetate, and the balance is deionized water.

[0060] The preparation method of the composite enzyme degradation solution in step two of this embodiment includes the following steps:

[0061] S2-1: Add citric acid chelating agent and sodium acetate to deionized water to adjust the pH to 4.8. This step provides a stable microenvironment for subsequent enzyme proteins.

[0062] S2-2: Add 0.1% sodium dioctyl sulfosuccinate (permeation enhancer) to the buffer solution. Turn on the magnetic stirrer (200 rpm) and stir until the solution is completely transparent, ensuring that the surface tension drops to the optimal range.

[0063] S2-3: Add lignin peroxidase and laccase in sequence. At this time, the water temperature must be strictly controlled at 10°C to avoid local heat generated by stirring, which may cause enzyme inactivation. Citric acid rapidly chelates the metal ions in the enzyme center at this stage to maintain its spatial conformation.

[0064] S2-4: Finally, add cellulase and hemicellulase, and continue to stir gently for 10 minutes to achieve chemical equilibrium between the complex enzyme system and the citric acid chelation system, thus obtaining a fully-component directional degradation solution.

[0065] Step three of this embodiment includes the following steps:

[0066] The impregnated wood was placed in a reactor and heated in stages: the first stage activated the bio-enzyme activity at 30℃, and the second stage accelerated hydrolysis at 40℃; the degradation time was controlled at 12h.

[0067] Step four of this embodiment includes the following steps:

[0068] A suspension of nano-hydroxyapatite or nano-silica is injected into the wood, with a mass percentage concentration of 1%.

[0069] In this embodiment, the temperature-sensitive polymer in step five is polyN-isopropylacrylamide;

[0070] In step five, the phase change sealing process involves heating the impregnated wood to 35°C, causing the polymer to undergo a phase change, producing a hydrophobic precipitate that blocks the micropores of the cell wall, physically isolating residual enzyme activity, and inhibiting the continued degradation reaction.

[0071] In this embodiment, the gradient vacuum drying in step six is ​​as follows: a stepped cooling vacuum drying is adopted, with the temperature gradually decreasing from 30°C to 20°C at a cooling rate of 0.5°C / h.

[0072] The appearance aging process in step six involves adding tannic acid or iron oxide powder to create an antique-style color.

[0073] In this embodiment, the inorganic nanoparticles in step four are one or more of nano-hydroxyapatite, nano-silica, or nano-calcium carbonate.

[0074] Example 2.

[0075] This embodiment provides a method for preparing controllable degradable archaeological-style wood, comprising the following steps:

[0076] Step 1: Perform low-temperature plasma etching activation pretreatment on the wood substrate;

[0077] Step 2: Impregnate the composite enzyme degradation solution using a vacuum pressure method;

[0078] Step 3: Perform segmented temperature and pressure synergistic directional degradation;

[0079] Step 4: Inject inorganic nanoparticles into the degraded wood to fine-tune its structure;

[0080] Step 5: Impregnate the wood with a temperature-sensitive polymer solution to block cell wall degradation sites using the principle of phase change;

[0081] Step 6: Perform gradient vacuum drying and surface aging treatment.

[0082] Step one of this embodiment includes the following steps:

[0083] Fast-growing poplar wood is selected and vacuum-dried to a moisture content of <8%;

[0084] Low-temperature plasma was used to etch the wood block in all directions. The power was 100W and the treatment time was 4 minutes. The working atmosphere of the low-temperature plasma treatment was a mixture of argon and oxygen gas with a volume ratio of 4:1.

[0085] Step two of this embodiment includes the following steps:

[0086] First, evacuate to a vacuum level of ≤-0.095MPa and maintain for 22 minutes. Then, release the pressure and inject the compound enzyme degradation solution. Subsequently, pressurize to 1.2MPa for impregnation to ensure that the agent reaches the heartwood.

[0087] The components of the composite enzyme degradation solution in step two of this embodiment, by mass percentage, include:

[0088] It contains 1.2% cellulase, 0.9% hemicellulase, 0.5% lignin peroxidase, 0.6% laccase, 0.2% citric acid chelating agent, 0.3% penetration enhancer, 0.1% sodium acetate, and the balance is deionized water.

[0089] The preparation method of the composite enzyme degradation solution in step two of this embodiment includes the following steps:

[0090] S2-1: Add citric acid chelating agent and sodium acetate to deionized water and adjust the pH to 5.0. This step provides a stable microenvironment for subsequent enzyme proteins.

[0091] S2-2: Add 0.3% (w / v) sodium dioctyl sulfosuccinate (permeation enhancer) to the buffer solution, turn on magnetic stirring (250 rpm), and stir until the solution is completely transparent to ensure that the surface tension drops to the optimal range;

[0092] S2-3: Add lignin peroxidase and laccase in sequence. At this time, the water temperature must be strictly controlled at 15°C to avoid local heat generated by stirring, which may cause enzyme inactivation. Citric acid rapidly chelates the metal ions in the enzyme center at this stage to maintain its spatial conformation.

[0093] S2-4: Finally, add cellulase and hemicellulase, and continue to stir gently for 18 minutes to achieve chemical equilibrium between the complex enzyme system and the citric acid chelation system, thus obtaining a fully-component directional degradation solution.

[0094] Step three of this embodiment includes the following steps:

[0095] The impregnated wood was placed in a reactor and heated in stages: the first stage activated the bio-enzyme activity at 33℃, and the second stage accelerated hydrolysis at 45℃; the degradation time was controlled at 42h.

[0096] Step four of this embodiment includes the following steps:

[0097] A suspension of nano-hydroxyapatite or nano-silica is injected into the wood, with a mass percentage concentration of 3%.

[0098] In this embodiment, the temperature-sensitive polymer in step five is polyN-isopropylacrylamide;

[0099] In step five, the phase change sealing process involves heating the impregnated wood to 40°C, causing the polymer to undergo a phase change, producing a hydrophobic precipitate that blocks the micropores of the cell wall, physically isolating residual enzyme activity, and inhibiting the continued degradation reaction.

[0100] In this embodiment, the gradient vacuum drying in step six is ​​as follows: a stepped cooling vacuum drying is adopted, with the temperature gradually decreasing from 30°C to 20°C at a cooling rate of 1.2°C / h.

[0101] The appearance aging process in step six involves adding tannic acid or iron oxide powder to create an antique-style color.

[0102] In this embodiment, the inorganic nanoparticles in step four are one or more of nano-hydroxyapatite, nano-silica, or nano-calcium carbonate.

[0103] Example 3.

[0104] This embodiment provides a method for preparing controllable degradable archaeological-style wood, comprising the following steps:

[0105] Step 1: Perform low-temperature plasma etching activation pretreatment on the wood substrate;

[0106] Step 2: Impregnate the composite enzyme degradation solution using a vacuum pressure method;

[0107] Step 3: Perform segmented temperature and pressure synergistic directional degradation;

[0108] Step 4: Inject inorganic nanoparticles into the degraded wood to fine-tune its structure;

[0109] Step 5: Impregnate the wood with a temperature-sensitive polymer solution to block cell wall degradation sites using the principle of phase change;

[0110] Step 6: Perform gradient vacuum drying and surface aging treatment.

[0111] Step one of this embodiment includes the following steps:

[0112] Fast-growing poplar wood is selected and vacuum-dried to a moisture content of <8%;

[0113] Low-temperature plasma was used to etch the wood block in all directions. The power was 120W and the treatment time was 5 minutes. The working atmosphere of the low-temperature plasma treatment was a mixture of argon and oxygen gas with a volume ratio of 5:1.

[0114] Step two of this embodiment includes the following steps:

[0115] First, evacuate to a vacuum level of ≤-0.095MPa and maintain for 30 minutes. Then, release the pressure and inject the compound enzyme degradation solution. Subsequently, pressurize to 1.5MPa for impregnation to ensure that the agent reaches the heartwood.

[0116] The components of the composite enzyme degradation solution in step two of this embodiment, by mass percentage, include:

[0117] It contains 2.0% cellulase, 0.3% hemicellulase, 0.8% lignin peroxidase, 0.2% laccase, 0.3% citric acid chelating agent, 0.1% penetration enhancer, 0.2% sodium acetate, and the balance is deionized water.

[0118] The preparation method of the composite enzyme degradation solution in step two of this embodiment includes the following steps:

[0119] S2-1: Add citric acid chelating agent and sodium acetate to deionized water to adjust the pH to 5.2. This step provides a stable microenvironment for subsequent enzyme proteins.

[0120] S2-2: Add 0.5% (w / v) sodium dioctyl sulfosuccinate (permeation enhancer) to the buffer solution. Turn on the magnetic stirrer (300 rpm) and stir until the solution is completely transparent, ensuring that the surface tension drops to the optimal range.

[0121] S2-3: Add lignin peroxidase and laccase in sequence. At this time, the water temperature must be strictly controlled at 20°C to avoid local heat generated by stirring, which may cause enzyme inactivation. Citric acid rapidly chelates the metal ions in the enzyme center at this stage to maintain its spatial conformation.

[0122] S2-4: Finally, add cellulase and hemicellulase, and continue to stir gently for 25 minutes to achieve chemical equilibrium between the complex enzyme system and the citric acid chelation system, thus obtaining a fully-component directional degradation solution.

[0123] Step three of this embodiment includes the following steps:

[0124] The impregnated wood was placed in a reactor and heated in stages: the first stage activated the bio-enzyme activity at 35℃, and the second stage accelerated hydrolysis at 50℃; the degradation time was controlled at 72h.

[0125] Step four of this embodiment includes the following steps:

[0126] A suspension of nano-hydroxyapatite or nano-silica is injected into the wood, with a mass percentage concentration of 5%.

[0127] In this embodiment, the temperature-sensitive polymer in step five is polyN-isopropylacrylamide;

[0128] In step five, the phase change sealing process involves heating the impregnated wood to 45°C, causing the polymer to undergo a phase change, producing a hydrophobic precipitate that blocks the micropores of the cell wall, physically isolating residual enzyme activity, and inhibiting the continued degradation reaction.

[0129] In this embodiment, the gradient vacuum drying in step six is ​​as follows: a stepped cooling vacuum drying is used, with the temperature gradually decreasing from 30°C to 20°C at a rate of 2°C / h.

[0130] The appearance aging process in step six involves adding tannic acid or iron oxide powder to create an antique-style color.

[0131] In this embodiment, the inorganic nanoparticles in step four are one or more of nano-hydroxyapatite, nano-silica, or nano-calcium carbonate.

[0132] Comparative Example 1 (Traditional Strong Acid Hydrothermal Method): A 5% (mass fraction) sulfuric acid solution was used, and the mixture was treated at 120℃ and 0.15MPa for 6 hours without plasma pretreatment or nanomineralization.

[0133] Comparative Example 2 (Single Enzymatic Method): Only cellulase was used for atmospheric pressure soaking treatment, without lignin enzyme system and temperature-sensitive end-capping process.

[0134] Comparative Example 3 (Untreated control group): The composite enzyme solution of this application was used, but the low-temperature plasma activation in step one was skipped and vacuum impregnation was performed directly.

[0135] Comparative Example 4 (Non-nanomineralization control group): Steps one to three of this application were performed, but step four, nanoparticle implantation, was not performed.

[0136] Comparative Example 5 (Non-thermosensitive end-capping control group): Steps one to four of this application were used, but the thermosensitive polymer impregnation and phase change end-capping were not performed, and step six drying was performed directly.

[0137] Experimental detection indicators

[0138] Degradation uniformity (U): The difference in cellulose content between the surface layer and the center of the wood block is measured by splitting the wood block open.

[0139] Microscopic pore similarity: The porosity was compared with that of real water-saturated wood unearthed from the Song Dynasty using the mercury pressure method.

[0140] Long-term dimensional stability (S): Volume shrinkage rate after 90 days of storage at 25°C and 65% RH.

[0141] FTIR correlation coefficient: the degree of overlap between the infrared spectrum of the sample and the spectrum of real archaeological wood.

[0142] Experimental data and creative analysis were conducted on the same batch of fast-growing poplar (20 x 20 x 20 mm). The test results for each group are shown in the table below:

[0143]

[0144] Even with vacuum impregnation, the agent could not penetrate the S2 layer of the cell wall due to the natural hydrophobicity of the wood cell wall and the blockage of the pit membrane. This application introduces low-temperature plasma activation, which reduces the degradation uniformity deviation from 9.5% to less than 1.5%. This proves the deep synergy between physical activation and chemical impregnation, and achieves true uniform decay across the entire cross section.

[0145] In Comparative Example 5, the actual degradation rate shifted from 35% to 48.3% during storage due to the continued action of residual enzyme activity under suitable temperature and humidity, resulting in sample failure. This application pioneered a temperature-sensitive polymer end-capping technology, which physically blocks degradation sites through phase change, ensuring that the performance of the end-capped sample fluctuates minimally within 90 days, thus completely solving the problem of the inability to preserve archaeological wood for a long time and the instability of its properties.

[0146] The strong acid or single enzyme treatments in Comparative Examples 1 and 2 only resulted in component loss, and the wood often appeared bloated or crumbly. Due to long-term burial, real archaeological wood often has inorganic matter filling its pores. This application improves the FTIR correlation coefficient from about 0.8 to 0.96 by injecting nano-hydroxyapatite. The nanoparticles not only balance the mechanical properties, but also replicate the density characteristics of real archaeological wood at the microscale.

[0147] In summary, this application solves the problems of uneven degradation, process runaway, and poor simulation accuracy in existing technologies by complementing the technologies of each process stage.

[0148] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0149] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for preparing controllable degradable archaeological wood, characterized in that, Includes the following steps: Step 1: Perform low-temperature plasma etching activation pretreatment on the wood substrate; Step 2: Impregnate the composite enzyme degradation solution using a vacuum pressure method; Step 3: Perform segmented temperature and pressure synergistic directional degradation; Step 4: Inject inorganic nanoparticles into the degraded wood to fine-tune its structure; Step 5: Impregnate the wood with a temperature-sensitive polymer solution to block cell wall degradation sites using the principle of phase change; Step 6: Perform gradient vacuum drying and surface aging treatment.

2. The method for preparing controllable degradable archaeological wood according to claim 1, characterized in that, Step one includes the following steps: Fast-growing timber is selected and vacuum-dried to a moisture content of <8%; Low-temperature plasma is used to etch the wood block in all directions with a power of 80-120W for 3-5 minutes. The working atmosphere of the low-temperature plasma treatment is a mixture of argon and oxygen with a volume ratio of 3-5:

1.

3. The method for preparing controllable degradable archaeological wood according to claim 2, characterized in that, Step two includes the following steps: First, evacuate to a vacuum level of ≤-0.095MPa and maintain for 15-30 minutes. Then, release the pressure and inject the compound enzyme degradation solution. Subsequently, pressurize to 0.8-1.5MPa for impregnation to ensure that the agent reaches the heartwood.

4. The method for preparing controllable degradable archaeological wood according to claim 3, characterized in that, The components of the composite enzyme degradation solution in step two, by mass percentage, include: Cellulase 0.5-2.0%, hemicellulase 0.3-1.5%, lignin peroxidase 0.1-0.8%, laccase 0.2-1.0%, citric acid chelating agent 0.1-0.3%, penetration enhancer 0.1-0.5%, sodium acetate 0.05-0.2%, balance deionized water.

5. The method for preparing controllable degradable archaeological wood according to claim 1, characterized in that, The preparation method of the composite enzyme degradation solution in step two includes the following steps: S2-1: Add citric acid chelating agent and sodium acetate to deionized water to adjust the pH to 4.8-5.

2. This step provides a stable microenvironment for subsequent enzyme proteins. S2-2: Add 0.1-0.5% (w / v) of the permeation enhancer to the buffer solution, turn on the magnetic stirrer and stir until the solution is completely transparent, ensuring that the surface tension drops to the optimal range; S2-3: Add lignin peroxidase and laccase in sequence. At this time, the water temperature must be strictly controlled at 10-20°C to avoid local heat generated by stirring, which may cause enzyme inactivation. Citric acid rapidly chelates the metal ions in the enzyme center at this stage to maintain its spatial conformation. S2-4: Finally, add cellulase and hemicellulase, and continue to stir gently for 10-25 minutes to achieve chemical equilibrium between the complex enzyme system and the citric acid chelation system, thus obtaining a fully-component directional degradation solution.

6. The method for preparing controllable degradable archaeological wood according to claim 1, characterized in that, Step three includes the following steps: The impregnated wood was placed in a reactor and heated in stages: the first stage activated the bio-enzyme activity at 30-35℃, and the second stage accelerated hydrolysis at 40-50℃; the degradation time was controlled at 12-72h.

7. The method for preparing controllable degradable archaeological wood according to claim 1, characterized in that, Step four includes the following steps: A suspension of nano-hydroxyapatite or nano-silica is injected into the wood, wherein the mass percentage concentration of the suspension is 1%-5%.

8. The method for preparing controllable degradable archaeological wood according to claim 1, characterized in that, The temperature-sensitive polymer in step five is poly(N-isopropylacrylamide); In step five, the phase change sealing is achieved by heating the impregnated wood to 35-45°C, causing the polymer to undergo a phase change, producing a hydrophobic precipitate that blocks the micropores of the cell wall, physically isolating residual enzyme activity, and inhibiting the continued degradation reaction.

9. The method for preparing controllable degradable archaeological wood according to claim 1, characterized in that, The gradient vacuum drying in step six is ​​as follows: a stepped cooling vacuum drying is adopted, with the temperature gradually decreasing from 30℃ to 20℃ at a cooling rate of 0.5-2℃ / h. The appearance aging treatment in step six involves adding tannic acid or iron oxide powder for antique coloring.

10. The method for preparing controllable degradable archaeological wood according to claim 1, characterized in that, The inorganic nanoparticles mentioned in step four are one or more of nano-hydroxyapatite, nano-silica, or nano-calcium carbonate.

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