阅读说明：本技术 亲水性两性离子封端碳酸钙寡聚体增强硅氧烷砂岩文物保护材料、其制备方法及应用 (Hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material, and preparation method and application thereof ) 是由 梁军艳 陈照宇 和玲 卢心愿 史承钰 潘爱钊 于 2021-07-21 设计创作，主要内容包括：本发明公开了亲水性两性离子封端碳酸钙寡聚体增强硅氧烷砂岩文物保护材料、其制备方法及应用,以甲基丙烯酰氧丙基三甲氧基硅烷与甲基丙烯酰氧乙基磷酰胆碱为反应单体,乙醇为溶剂,偶氮二异丁腈为引发剂,加热搅拌进行自由基聚合,得到第一聚合物溶液；用正己烷对第一聚合物溶液进行沉淀,进行纯化干燥后,再溶于乙醇形成第二聚合物溶液；将氯化钙溶于乙醇,并加入三乙胺后进行搅拌,搅拌的同时通入二氧化碳气体一定时间后,停止通入二氧化碳气体,再搅拌一定时间,形成碳酸钙寡聚体分散液；对分散液进行离心分离,得到碳酸钙寡聚体凝胶；将凝胶和第二聚合物溶液加入乙醇中,搅拌下加入四甲氧基硅烷,得到保护材料,本发明能长久发挥保护性作用。(The invention discloses a hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone relic protection material, a preparation method and application thereof.A first polymer solution is obtained by heating and stirring to carry out free radical polymerization by using methacryloxypropyltrimethoxysilane and methacryloxyethylphosphorylcholine as reaction monomers, ethanol as a solvent and azobisisobutyronitrile as an initiator; precipitating the first polymer solution by using n-hexane, purifying and drying, and dissolving in ethanol to form a second polymer solution; dissolving calcium chloride in ethanol, adding triethylamine, stirring, introducing carbon dioxide gas for a certain time while stirring, stopping introducing the carbon dioxide gas, and stirring for a certain time to form calcium carbonate oligomer dispersion liquid; carrying out centrifugal separation on the dispersion liquid to obtain calcium carbonate oligomer gel; the gel and the second polymer solution are added into ethanol, and tetramethoxysilane is added under stirring to obtain the protective material.)

1. A preparation method of a hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material is characterized by comprising the following steps:

step 1: mixing methacryloxypropyl trimethoxysilane and methacryloxyethyl phosphorylcholine serving as reaction monomers, ethanol serving as a solvent and azodiisobutyronitrile serving as an initiator, heating and stirring to perform free radical polymerization to obtain a first polymer solution;

step 2: precipitating the first polymer solution by using n-hexane, purifying and drying the precipitate, and dissolving the precipitate in ethanol to form a second polymer solution;

and step 3: dissolving calcium chloride in ethanol, adding triethylamine, stirring, introducing carbon dioxide gas for a certain time while stirring, stopping introducing the carbon dioxide gas, and stirring for a certain time to form calcium carbonate oligomer dispersion liquid;

and 4, step 4: performing centrifugal separation on the calcium carbonate oligomer dispersion liquid to obtain calcium carbonate oligomer gel;

and 5: and adding the calcium carbonate oligomer gel and the second polymer solution into ethanol, and adding tetramethoxysilane under stirring to obtain the hydrophilic zwitterionic end-capped calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material.

2. The preparation method of the hydrophilic zwitterionic end-capped calcium carbonate oligomer-reinforced siloxane sandstone relic protection material according to claim 1, wherein in the step 1, the total molar concentration of the methacryloxypropyltrimethoxysilane and the methacryloxyethyl phosphorylcholine is 0.5mmol/L to 1.5 mmol/L; the amount of the methacryloxypropyltrimethoxysilane substance accounts for 30-50% of the total amount of the methacryloxypropyltrimethoxysilane and the methacryloxyethyl phosphorylcholine.

3. The method for preparing the hydrophilic zwitterionic end-capped calcium carbonate oligomer-reinforced silicone sandstone relic protection material according to claim 1, wherein the addition amount of the azobisisobutyronitrile in the step 1 is 0.009 mmol/L-0.011 mmol/L.

4. The preparation method of the hydrophilic zwitterionic end-capped calcium carbonate oligomer-reinforced siloxane sandstone relic-protecting material according to claim 1, wherein in the step 1, the heating temperature is 60-65 ℃, and the stirring time is 16-20 h.

5. The preparation method of the hydrophilic zwitterionic end-capped calcium carbonate oligomer-reinforced siloxane sandstone relic protection material according to claim 1, wherein in the step 3, the concentration of the calcium chloride is 2.9-3 g/L, and the concentration of the triethylamine is 50-60 g/L.

6. The preparation method of the hydrophilic zwitterionic end-capped calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material as claimed in claim 1, wherein in the step 3, the carbon dioxide gas is introduced for 25-35 min, and the stirring time is 20-40 min after the introduction of the carbon dioxide gas is stopped.

7. The preparation method of the hydrophilic zwitterionic end-capped calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material as claimed in claim 1, wherein in the step 4, the centrifugal separation speed is 5500rpm to 6000rpm, and the centrifugal time is 5min to 10 min.

8. The method for preparing the hydrophilic zwitterionic end-capped calcium carbonate oligomer-reinforced silicone sandstone relic protection material according to claim 1, wherein in the step 5, the ratio of the calcium carbonate oligomer gel to the second polymer solution is (0.2 g-0.4 g): 0.3ml, and the addition amount of the tetramethoxysilane is 40 ml/L-80 ml/L.

9. A hydrophilic zwitterionic end-capped calcium carbonate oligomer-reinforced silicone sandstone cultural relic protection material, which is prepared by the preparation method of any one of claims 1 to 8.

10. The use of a hydrophilic zwitterionic end-capped calcium carbonate oligomer-reinforced silicone sandstone relic-protection material as claimed in claim 9, as an adhesion strengthening protectant, in sandstone relic protection.

Technical Field

The invention relates to the technical field of sandstone protection, in particular to a hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone relic protection material, and a preparation method and application thereof.

Background

Sandstone cultural relics are important material carriers of the long-standing Chinese civilization. After the sandstone cultural relics are exposed in a natural environment for a long time, the outdoor sandstone cultural relics can have weathering destruction behaviors such as freeze-thaw cycle destruction, crystallization-dissolution cycle of soluble salt, corrosion of microorganisms and the like under the severe change of temperature and humidity, so that the information of the surface cultural relics is damaged, and the inheritance and the development of human civilization are seriously threatened. Therefore, a targeted protective material is needed to reinforce and repair the surface layer of the outdoor sandstone cultural relic, so that the outdoor sandstone cultural relic is protected more effectively and durably.

Because sandstone naturally has the wetting characteristic of hydrophilicity, and the existing protective materials are mostly hydrophobic, the mismatching of the wetting performance can ensure that the water permeability and the air permeability of the sandstone after protection are reduced sharply, and the self characteristics of the sandstone cultural relic are changed. This protection method can exert a protective effect on the treated region, but causes damage to be transferred to an untreated region or a deeper region.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protective material, a preparation method and application thereof, which can improve the compatibility of the protective material and sandstone cultural relics, can maintain the preservation behavior of the cultural relics in the nature more easily and can play a protective role for a long time.

In order to solve the technical problems, the invention is realized by the following technical scheme:

a preparation method of a hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material comprises the following steps:

step 1: mixing methacryloxypropyl trimethoxysilane and methacryloxyethyl phosphorylcholine serving as reaction monomers, ethanol serving as a solvent and azodiisobutyronitrile serving as an initiator, heating and stirring to perform free radical polymerization to obtain a first polymer solution;

step 2: precipitating the first polymer solution by using n-hexane, purifying and drying the precipitate, and dissolving the precipitate in ethanol to form a second polymer solution;

and step 3: dissolving calcium chloride in ethanol, adding triethylamine, stirring, introducing carbon dioxide gas for a certain time while stirring, stopping introducing the carbon dioxide gas, and stirring for a certain time to form calcium carbonate oligomer dispersion liquid;

and 4, step 4: performing centrifugal separation on the calcium carbonate oligomer dispersion liquid to obtain calcium carbonate oligomer gel;

and 5: and adding the calcium carbonate oligomer gel and the second polymer solution into ethanol, and adding tetramethoxysilane under stirring to obtain the hydrophilic zwitterionic end-capped calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material.

Further, in the step 1, the total molar concentration of the methacryloxypropyltrimethoxysilane and the methacryloxyethyl phosphorylcholine is 0.5 mmol/L-1.5 mmol/L; the amount of the methacryloxypropyltrimethoxysilane substance accounts for 30-50% of the total amount of the methacryloxypropyltrimethoxysilane and the methacryloxyethyl phosphorylcholine.

In step 1, the addition amount of the azobisisobutyronitrile is 0.009 mmol/L-0.011 mmol/L.

Further, in the step 1, the heating temperature is 60-65 ℃, and the stirring time is 16-20 h.

Further, in the step 3, the concentration of the calcium chloride is 2.9-3 g/L, and the concentration of the triethylamine is 50-60 g/L.

Further, in the step 3, the time of introducing the carbon dioxide gas is 25min to 35min, and the stirring time is 20min to 40min after the introduction of the carbon dioxide gas is stopped.

Further, in the step 4, the centrifugal separation speed is 5500rpm to 6000rpm, and the centrifugal time is 5min to 10 min.

Further, in step 5, the ratio of the calcium carbonate oligomer gel to the second polymer solution is (0.2g to 0.4 g): 0.3ml, and the addition amount of the tetramethoxysilane is 40 ml/L-80 ml/L.

A hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material is prepared by applying the preparation method.

An application of a hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone relic protection material as an adhesion reinforcement protective agent in sandstone relic protection.

Compared with the prior art, the invention has at least the following beneficial effects:

the methacryloyloxyethyl phosphorylcholine and the calcium carbonate oligomer used in the invention have the characteristic of hydrophilicity, and the sandstone sample block protected by the invention has the characteristic of hydrophilicity wetting, so that the water absorption and air permeability of sandstone are not influenced, and the decay behavior of sandstone in natural environment is not changed.

The methacryloxypropyltrimethoxysilane and the tetramethoxysilane used in the invention can generate chemical bonding effect with sandstone, and a compact protective layer is formed on the surface and in the hole of the sandstone. The calcium carbonate used can be used as a filler in the protective material to reinforce the protective material. The sandstone sample block protected by the method has the advantages that the strength is improved to a certain degree, and the tolerance of the sandstone sample block to the natural environment is improved.

The calcium carbonate of tetramethoxysilane of the present invention has a small size characteristic, and can prevent its size from increasing due to the capping effect of methacryloyloxyethyl phosphorylcholine, and can impart transparency to the protective material. Therefore, the sandstone sample block protected by the method has good color fidelity.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a reaction formula for preparing a hydrophilic zwitterionic end-capped calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material of the invention:

FIG. 2 is a transmission electron microscope image of a hydrophilic zwitterionic end-capped calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material.

Detailed Description

To make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention relates to a preparation method of a hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material, which comprises the following steps:

step 1: mixing methacryloxypropyltrimethoxysilane and methacryloxyethyl phosphorylcholine serving as reaction monomers, ethanol serving as a solvent and azodiisobutyronitrile serving as an initiator, heating and stirring for free radical polymerization at the heating temperature of 60-65 ℃ for 16-20 hours to obtain a first polymer solution;

preferably, the total molar concentration of the methacryloxypropyltrimethoxysilane and the methacryloxyethyl phosphorylcholine is 0.5 mmol/L-1.5 mmol/L; the amount of the methacryloxypropyltrimethoxysilane substance accounts for 30 to 50 percent of the total amount of the methacryloxypropyltrimethoxysilane and the methacryloxyethyl phosphorylcholine; the addition amount of the azodiisobutyronitrile is 0.009 mmol/L-0.011 mmol/L.

Step 2: precipitating the first polymer solution by using n-hexane, purifying and drying the precipitate, and dissolving the precipitate in ethanol to form a second polymer solution;

and step 3: dissolving calcium chloride in ethanol, adding triethylamine, stirring, introducing carbon dioxide gas while stirring for 25-35 min, stopping introducing the carbon dioxide gas, and stirring for 20-40 min to form calcium carbonate oligomer dispersion liquid;

preferably, the concentration of calcium chloride is 2.9 g/L-3 g/L, and the concentration of triethylamine is 50 g/L-60 g/L.

And 4, step 4: carrying out centrifugal separation on the calcium carbonate oligomer dispersion liquid to obtain calcium carbonate oligomer gel;

preferably, the centrifugal separation speed is 5500rpm to 6000rpm, and the centrifugal time is 5min to 10 min.

And 5: adding the calcium carbonate oligomer gel and the second polymer solution into ethanol, and adding tetramethoxysilane under stirring to obtain a hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone relic protection material;

preferably, the ratio of the calcium carbonate oligomer gel to the second polymer solution is (0.2g to 0.4 g): 0.3ml, and the addition amount of tetramethoxysilane is 40 ml/L-80 ml/L.

The hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone relic protection material is prepared by the preparation method of the hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone relic protection material, and is used as an adhesion reinforcement protective agent to protect sandstone relics, and the specific application method is as follows:

dropwise coating the hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protective material on the surface of the sandstone cultural relic to completely coat the sandstone cultural relic protective material; preferably, 0.25ml of material is used per gram of sandstone cultural relics;

placing the sandstone cultural relic coated with the hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material in a temperature and humidity control environment for 1 week, then exposing the sandstone cultural relic in a room, and drying the sandstone cultural relic for 1 week; preferably, the temperature and humidity controlled environment is 55% RH and 20-25 deg.C.

Example 1:

a preparation method of a hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material comprises the following steps:

step 1: mixing methacryloxypropyltrimethoxysilane and methacryloxyethyl phosphorylcholine serving as reaction monomers, ethanol serving as a solvent and azodiisobutyronitrile serving as an initiator, heating and stirring for free radical polymerization at the heating temperature of 60 ℃ for 16 hours to obtain a first polymer solution, wherein the formula is shown in the upper left of the figure 1;

wherein the total molar concentration of the methacryloxypropyltrimethoxysilane and the methacryloxyethyl phosphorylcholine is 1 mmol/L; the amount of the substance of methacryloxypropyltrimethoxysilane accounts for 30 percent of the total substance of the methacryloxypropyltrimethoxysilane and the methacryloxyethyl phosphorylcholine; the addition amount of azobisisobutyronitrile was 0.011 mmol/L.

Step 2: the first polymer solution was precipitated with n-hexane, and after the precipitate was purified and dried, the precipitate was dissolved in ethanol to form a second polymer solution, in this example, the mass concentration of the second polymer solution was 15%.

And step 3: dissolving calcium chloride in ethanol, adding triethylamine, stirring, introducing carbon dioxide gas for 35min while stirring, stopping introducing carbon dioxide gas, and stirring for 30min to obtain calcium carbonate oligomer dispersion, as shown in the left lower equation and result chart of FIG. 1;

wherein the concentration of calcium chloride is 3g/L, and the concentration of triethylamine is 55 g/L.

And 4, step 4: carrying out centrifugal separation on the calcium carbonate oligomer dispersion liquid to obtain calcium carbonate oligomer gel;

wherein the centrifugal separation speed is 5500rpm, and the centrifugal time is 10 min.

And 5: adding the calcium carbonate oligomer gel and the second polymer solution into ethanol, and adding tetramethoxysilane under stirring to obtain a hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone relic protection material;

wherein the ratio of the calcium carbonate oligomer gel to the second polymer solution is 0.2 g: 0.3ml, and the addition amount of tetramethoxysilane was 40 ml/L.

The hydrophilic zwitterionic end-capped calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material prepared by the embodiment is used for protecting sandstone cultural relic samples, and the specific steps are as follows:

the hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protective material is dropwise coated on sandstone cultural relic with the porosity of 25.6 percent, the water absorption of 15.3 percent by weight and the capillary water absorption coefficient of 20Kg/m²h^1/2～30Kg/m²h^1/2The capillary water rise height per unit time is 9.9cm/h^1/2～13.8cm/h^1/2The sandstone cultural relics of the DaBuddha temple in Binxian county in Shaanxi province are completely coated;

and (3) placing the sandstone cultural relic coated with the hydrophilic zwitter-ion-terminated calcium carbonate oligomer reinforced siloxane sandstone cultural relic protection material in an environment with 55% RH and 20 ℃ for 1 week, then exposing the sandstone cultural relic in a room, and drying the sandstone cultural relic for 1 week.

The synthesis process of the embodiment is shown in fig. 1, the obtained hydrophilic zwitterionic end-capped calcium carbonate oligomer-reinforced siloxane sandstone relic protection material is colorless and slightly turbid at room temperature, has mild performance and no damage to sandstone bodies, and the size of calcium carbonate is extremely small and less than 20nm as shown in a transmission electron microscope image of fig. 2. The dispersion is applied to the sandstone surface by a dripping method, so that the sandstone surface is reinforced and enhanced, and excellent water absorption, air permeability and transparency are maintained. Compared with an unprotected sample, the sandstone sample block protected by the embodiment has the advantages that the water absorption rate is increased by 0.61%, the air permeability is increased by 2.4%, and the sandstone sample block has good water absorption and air permeability. The color difference value delta E of the two is 2.21, and the color fidelity is very good.

Example 2:

a preparation method of a hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material comprises the following steps:

step 1: mixing methacryloxypropyltrimethoxysilane and methacryloxyethyl phosphorylcholine serving as reaction monomers, ethanol serving as a solvent and azodiisobutyronitrile serving as an initiator, heating and stirring for free radical polymerization at the heating temperature of 60 ℃ for 20 hours to obtain a first polymer solution;

wherein the total molar concentration of the methacryloxypropyltrimethoxysilane and the methacryloxyethyl phosphorylcholine is 0.7 mmol/L; the amount of methacryloxypropyltrimethoxysilane material is 35 percent of the total amount of methacryloxypropyltrimethoxysilane and methacryloxyethyl phosphorylcholine; the addition amount of azobisisobutyronitrile was 0.011 mmol/L.

Step 2: the first polymer solution was precipitated with n-hexane, and after the precipitate was purified and dried, the precipitate was dissolved in ethanol to form a second polymer solution, in this example, the mass concentration of the second polymer solution was 15%.

And step 3: dissolving calcium chloride in ethanol, adding triethylamine, stirring, introducing carbon dioxide gas while stirring for 25min, stopping introducing the carbon dioxide gas, and stirring for 40min to form calcium carbonate oligomer dispersion liquid;

wherein the concentration of calcium chloride is 3g/L, and the concentration of triethylamine is 60 g/L.

And 4, step 4: carrying out centrifugal separation on the calcium carbonate oligomer dispersion liquid to obtain calcium carbonate oligomer gel;

wherein the centrifugal separation speed is 5700rpm, and the centrifugal time is 8 min.

And 5: adding the calcium carbonate oligomer gel and the second polymer solution into ethanol, and adding tetramethoxysilane under stirring to obtain a hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone relic protection material;

wherein the ratio of calcium carbonate oligomer gel to second polymer solution is 0.4 g: 0.3ml, and the addition amount of tetramethoxysilane was 60 ml/L.

The hydrophilic zwitterionic end-capped calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material prepared by the embodiment is used for protecting sandstone cultural relic samples.

Example 3:

a preparation method of a hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material comprises the following steps:

step 1: mixing methacryloxypropyltrimethoxysilane and methacryloxyethyl phosphorylcholine serving as reaction monomers, ethanol serving as a solvent and azodiisobutyronitrile serving as an initiator, heating and stirring for free radical polymerization at the heating temperature of 65 ℃ for 18 hours to obtain a first polymer solution;

wherein the total molar concentration of the methacryloxypropyltrimethoxysilane and the methacryloxyethyl phosphorylcholine is 1.5 mmol/L; the amount of methacryloxypropyltrimethoxysilane material is 40% of the total amount of methacryloxypropyltrimethoxysilane and methacryloxyethyl phosphorylcholine; the addition amount of azobisisobutyronitrile was 0.01 mmol/L.

Step 2: the first polymer solution was precipitated with n-hexane, and after the precipitate was purified and dried, the precipitate was dissolved in ethanol to form a second polymer solution, in this example, the mass concentration of the second polymer solution was 15%.

And step 3: dissolving calcium chloride in ethanol, adding triethylamine, stirring, introducing carbon dioxide gas while stirring for 30min, stopping introducing the carbon dioxide gas, and stirring for 20min to form calcium carbonate oligomer dispersion liquid;

wherein the concentration of calcium chloride is 2.95g/L, and the concentration of triethylamine is 50 g/L.

And 4, step 4: carrying out centrifugal separation on the calcium carbonate oligomer dispersion liquid to obtain calcium carbonate oligomer gel;

wherein the centrifugal separation rate is 5600rpm, and the centrifugal time is 8 min.

And 5: adding the calcium carbonate oligomer gel and the second polymer solution into ethanol, and adding tetramethoxysilane under stirring to obtain a hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone relic protection material;

wherein the ratio of calcium carbonate oligomer gel to second polymer solution is 0.3 g: 0.3ml, and the addition amount of tetramethoxysilane was 80 ml/L.

The hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material prepared by the embodiment is used for protecting sandstone cultural relic samples.

Example 4:

a preparation method of a hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material comprises the following steps:

step 1: mixing methacryloxypropyltrimethoxysilane and methacryloxyethyl phosphorylcholine serving as reaction monomers, ethanol serving as a solvent and azobisisobutyronitrile serving as an initiator, heating and stirring for free radical polymerization at the heating temperature of 62 ℃ for 20 hours to obtain a first polymer solution;

wherein the total molar concentration of the methacryloxypropyltrimethoxysilane and the methacryloxyethyl phosphorylcholine is 0.9 mmol/L; the amount of methacryloxypropyltrimethoxysilane material is 45 percent of the total amount of methacryloxypropyltrimethoxysilane and methacryloxyethyl phosphorylcholine; the addition amount of azobisisobutyronitrile was 0.01 mmol/L.

Step 2: the first polymer solution was precipitated with n-hexane, and after the precipitate was purified and dried, the precipitate was dissolved in ethanol to form a second polymer solution, in this example, the mass concentration of the second polymer solution was 15%.

And step 3: dissolving calcium chloride in ethanol, adding triethylamine, stirring, introducing carbon dioxide gas while stirring for 25min, stopping introducing the carbon dioxide gas, and stirring for 30min to form calcium carbonate oligomer dispersion liquid;

wherein the concentration of calcium chloride is 2.9g/L, and the concentration of triethylamine is 50 g/L.

And 4, step 4: carrying out centrifugal separation on the calcium carbonate oligomer dispersion liquid to obtain calcium carbonate oligomer gel;

wherein the centrifugal separation speed is 6000rpm, and the centrifugal time is 5 min.

And 5: adding the calcium carbonate oligomer gel and the second polymer solution into ethanol, and adding tetramethoxysilane under stirring to obtain a hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone relic protection material;

wherein the ratio of calcium carbonate oligomer gel to second polymer solution is 0.4 g: 0.3ml, and the addition amount of tetramethoxysilane was 40 ml/L.

The hydrophilic zwitterionic end-capped calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material prepared by the embodiment is used for protecting sandstone cultural relic samples.

Example 5:

a preparation method of a hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material comprises the following steps:

step 1: mixing methacryloxypropyltrimethoxysilane and methacryloxyethyl phosphorylcholine serving as reaction monomers, ethanol serving as a solvent and azodiisobutyronitrile serving as an initiator, heating and stirring for free radical polymerization at the heating temperature of 65 ℃ for 16 hours to obtain a first polymer solution;

wherein the total molar concentration of the methacryloxypropyltrimethoxysilane and the methacryloxyethyl phosphorylcholine is 1.2 mmol/L; the amount of methacryloxypropyltrimethoxysilane is 50% of the total amount of methacryloxypropyltrimethoxysilane and methacryloxyethyl phosphorylcholine; the amount of azobisisobutyronitrile added was 0.009 mmol/L.

Step 2: the first polymer solution was precipitated with n-hexane, and after the precipitate was purified and dried, the precipitate was dissolved in ethanol to form a second polymer solution, in this example, the mass concentration of the second polymer solution was 15%.

And step 3: dissolving calcium chloride in ethanol, adding triethylamine, stirring, introducing carbon dioxide gas while stirring for 30min, stopping introducing the carbon dioxide gas, and stirring for 20min to form calcium carbonate oligomer dispersion liquid;

wherein the concentration of calcium chloride is 2.9g/L, and the concentration of triethylamine is 55 g/L.

And 4, step 4: carrying out centrifugal separation on the calcium carbonate oligomer dispersion liquid to obtain calcium carbonate oligomer gel;

wherein the centrifugal separation speed is 5900rpm, and the centrifugal time is 6 min.

And 5: adding the calcium carbonate oligomer gel and the second polymer solution into ethanol, and adding tetramethoxysilane under stirring to obtain a hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone relic protection material;

wherein the ratio of calcium carbonate oligomer gel to second polymer solution is 0.3 g: 0.3ml, and the addition amount of tetramethoxysilane was 60 ml/L.

The hydrophilic zwitter-ion-terminated calcium carbonate oligomer-reinforced siloxane sandstone cultural relic protection material prepared by the embodiment is used for protecting sandstone cultural relic samples.

Finally, it should be noted that: the above-mentioned embodiments are only specific embodiments of the present invention, which are used for illustrating the technical solutions of the present invention and not for limiting the same, and the protection scope of the present invention is not limited thereto, although the present invention is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: any person skilled in the art can modify or easily conceive the technical solutions described in the foregoing embodiments or equivalent substitutes for some technical features within the technical scope of the present disclosure; such modifications, changes or substitutions do not depart from the spirit and scope of the embodiments of the present invention, and they should be construed as being included therein. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.