Manufacturing method of loess rock core display specimen
By pretreating the loess core and grinding and polishing it after embedding the epoxy resin, the problem of poor color fidelity and storage durability of the loess core is solved, and the good color fidelity and long-term preservation ability of the specimen is achieved. .
Patent Information
- Application Number
- CN202411566982.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-05
- Publication Date
- 2025-02-14
AI Technical Summary
The existing core preservation methods cannot effectively maintain the color fidelity of the loess core and have poor storage durability.
The loess core was pretreated with hydrogen peroxide solution and dodecyldimethylbenzyl ammonium chloride solution, and then embedded and solidified with epoxy resin. Finally, the embedded core was polished and polished.
It achieves the best color fidelity of loess core specimens and can be preserved for a long time in an environment dominated by room temperature natural light sources.
Smart Images
Figure CN119445962A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of core specimen preparation, and in particular to a method for preparing a loess core display specimen. Background Art
[0002] The Loess Plateau, as the largest loess accumulation area in China and even in the world, has a unique geological history and ecological environment. The loess layer of the Loess Plateau, as the main geological feature of this area, contains rich geological information and records of environmental changes. However, most people lack in-depth understanding and knowledge of the Loess Plateau and loess. Therefore, by making loess core display specimens of the Loess Plateau, it can help people understand the geological composition, characteristics and evolution of the Loess Plateau more intuitively, and also provide powerful physical materials for research in geology, environmental science and other fields.
[0003] The existing core preservation method usually places the core in a core library with a suitable environment for preservation, or uses wax sealing to make specimens. However, the above methods are not suitable for the preservation of loess cores. The color fidelity of loess cores gradually decreases with the storage time, and due to the influence of factors such as air and moisture, the storage durability of loess core specimens is poor. Summary of the invention
[0004] The present invention provides a method for making a loess core display specimen, by performing treatments such as anti-corrosion, flattening, embedding and fixation, and grinding and polishing on the core, thereby achieving better color fidelity of the loess core specimen and a healthy life span of long-term preservation in an environment dominated by room temperature natural light.
[0005] The present invention provides a method for preparing a loess core display specimen, which is characterized by comprising the following steps:
[0006] At 15-25° C. and 40%-60% humidity, the loess core is sequentially infiltrated with a hydrogen peroxide solution and a dodecyl dimethyl benzyl ammonium chloride solution to obtain a pretreated loess core.
[0007] The pretreated loess core is embedded with epoxy resin and solidified to obtain an embedded core; the embedded core is ground and polished to obtain a loess core display specimen.
[0008] As a preferred implementation, the mass concentration of the hydrogen peroxide solution is 20% to 30%.
[0009] As a preferred embodiment, the time for the hydrogen peroxide solution immersion treatment is 24 to 30 hours.
[0010] As a preferred embodiment, the mass concentration of the dodecyldimethylbenzylammonium chloride solution is 40% to 50%.
[0011] As a preferred embodiment, the time for the infiltration treatment with the dodecyldimethylbenzylammonium chloride solution is 24 to 30 hours.
[0012] As a preferred implementation, the epoxy resin has a Gardner color number of ≤1.
[0013] As a preferred implementation, after curing, the thickness of the epoxy resin on the cross section of the loess core is 3 to 5 mm.
[0014] As a preferred embodiment, during grinding, 160 mesh, 240 mesh, 360 mesh, 600 mesh, 800 mesh, 1200 mesh and 2000 mesh sandpaper are used to grind the surface of the embedded core for 5 to 10 minutes respectively.
[0015] As a preferred embodiment, after being infiltrated with a hydrogen peroxide solution, the loess core is left to dry and then infiltrated with a dodecyl dimethyl benzyl ammonium chloride solution.
[0016] As a preferred implementation, the cross section of the loess core is flattened after being treated with hydrogen peroxide solution.
[0017] Compared with the prior art, the present invention has the following beneficial effects:
[0018] The present invention firstly uses hydrogen peroxide solution and dodecyl dimethyl benzyl ammonium chloride solution to sequentially infiltrate loess cores to obtain pretreated loess cores; uses epoxy resin to embed the pretreated loess cores, solidifies, and obtains embedded cores; and grinds and polishes the embedded cores to obtain loess core display specimens. The preparation method of the loess core display specimen provided by the present invention is simple, highly practical, and low in cost, and achieves the technical effect of better color fidelity of the loess core specimens and long-term preservation in an environment dominated by natural light at room temperature. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 This is a diagram of the infiltration treatment with hydrogen peroxide solution during the preparation of the loess core display specimen of the present invention.
[0020] Figure 2 This is a cross-sectional view of a loess core after the loess core is infiltrated with a hydrogen peroxide solution during the preparation of the loess core display specimen of the present invention.
[0021] Figure 3 This is a polishing diagram of the loess core specimen of the present invention.
[0022] Figure 4 This is a sample diagram showing the loess core of the present invention. DETAILED DESCRIPTION
[0023] In order to enable those skilled in the art to better understand the technical solution of the present invention and implement it, the present invention is further described below in conjunction with specific examples, but the examples are not intended to limit the present invention. The following test methods and detection methods, unless otherwise specified, are conventional methods; the reagents and raw materials, unless otherwise specified, are commercially available.
[0024] In view of the technical problems mentioned in the background technology of the present invention that the color fidelity of loess cores gradually decreases and the storage durability is poor due to the existing core preservation and specimen preparation methods, the present invention proposes a method for preparing loess core display specimens, comprising: sequentially infiltrating the loess cores with a hydrogen peroxide solution and a dodecyldimethylbenzylammonium chloride solution to obtain a pretreated loess core; embedding the pretreated loess core with an epoxy resin and curing it to obtain an embedded core; and grinding and polishing the embedded core to obtain a loess core display specimen.
[0025] The technical solution of the present invention is described in detail below.
[0026] The present invention provides a method for preparing a loess core display specimen, which is characterized by comprising the following steps:
[0027] At 15-25° C. and 40%-60% humidity, the loess core is sequentially infiltrated with a hydrogen peroxide solution and a dodecyl dimethyl benzyl ammonium chloride solution to obtain a pretreated loess core.
[0028] The pretreated loess core is embedded with epoxy resin and solidified to obtain an embedded core; the embedded core is ground and polished to obtain a loess core display specimen.
[0029] The present invention constructs the above loess core specimen preparation method for loess cores, and the specific technical ideas and processes are as follows:
[0030] a. Anti-corrosion treatment. The loess core specimens will be displayed for a long time at room temperature. To ensure that the specimens can be preserved for a long time at room temperature, the loess cores must be treated with reasonable mildew and algae removal to ensure that the displayed specimens will not breed bacteria and algae. The cores are infiltrated with broad-spectrum bactericidal and algae-removing agents hydrogen peroxide solution and dodecyl dimethyl benzyl ammonium chloride solution (commercially available 1227 stock solution) in sequence. The infiltration standard is that the core section is evenly wetted. After each agent treatment, it is necessary to wait for it to dry statically before operation. The static drying time is about 20 hours.
[0031] b. Smoothing of the core surface. The strong redox reaction between hydrogen peroxide solution and the substances in the loess causes the flat core cross section to be destroyed by the gas produced by the reaction. After treatment with hydrogen peroxide solution, a single-edged scraper is used to smooth the cross section.
[0032] c. Use slow-drying transparent epoxy resin to embed and fix the core to ensure that all bubbles in the resin are expelled without affecting the appearance of the finished product.
[0033] d. Surface grinding and polishing: First, use sandpaper with grits from 160 to 2000 in ascending order; then use polishing wax to polish the surface to a mirror effect.
[0034] e. Make good marks and records. After each loess core display specimen is completed, the core collection information should be marked on the back of the core tube.
[0035] In order to achieve a good infiltration effect, the mass concentration of the hydrogen peroxide solution is 20% to 30%. The hydrogen peroxide solution is used to uniformly wet the core section, so that the solution can evenly cover the core section without obvious flow or accumulation, ensuring that the solution fully penetrates into the core section, which is specifically affected by the core volume and water content. A good infiltration effect can be achieved by infiltrating with a hydrogen peroxide solution with a mass concentration of 20% to 30% for 24 to 30 hours.
[0036] In order to further improve the infiltration effect of the loess core, the mass concentration of the dodecyl dimethyl benzyl ammonium chloride solution is 40% to 50%. The infiltration treatment with the dodecyl dimethyl benzyl ammonium chloride solution with a mass concentration of 40% to 50% for 24 to 30 hours can achieve a better infiltration effect.
[0037] In order to maintain the high permeability of the loess core display specimen, the Gardner color number of the epoxy resin is ≤1.
[0038] In order to further achieve a good observation effect of the loess core display specimen, after curing, the thickness of the epoxy resin on the cross section of the loess core is 3 to 5 mm. If the epoxy resin coating is too little, a good coating effect cannot be achieved; if the epoxy resin coating is too much, the coating is too thick and affects the observation effect of the loess core specimen.
[0039] As a preferred embodiment, during grinding, 160 mesh, 240 mesh, 360 mesh, 600 mesh, 800 mesh, 1200 mesh, and 2000 mesh sandpaper are used to grind the surface of the embedded core for 5 to 10 minutes. The main purpose of grinding is to make the resin specimen as transparent as a mirror and improve the aesthetic appearance of the specimen. Finally, it is necessary to grind until there is no layer of resin wrapped, and it feels like you can directly see the real loess. If you use 2000 mesh sandpaper directly, you can achieve the desired effect, but it takes a long time to grind, and the amount of sandpaper consumed will also be more.
[0040] In order to ensure the flatness of the cross section of the loess core, the cross section of the loess core is leveled after being infiltrated with hydrogen peroxide solution. Specifically, a putty knife is used to repair and level the raised parts of the plane after hydrogen peroxide treatment to ensure the flatness of the cross section of the loess core when subsequently infiltrated with dodecyl dimethyl benzyl ammonium chloride solution.
[0041] The technical effects of the present invention are described below through specific embodiments.
[0042] Example 1
[0043] A method for preparing a loess core display specimen comprises the following steps:
[0044] S1, at 15°C and 40% humidity, the loess core is infiltrated with a 20% mass concentration hydrogen peroxide solution for 24 hours, dried for 20 hours, and then infiltrated with a 40% mass concentration dodecyldimethylbenzylammonium chloride solution for 24 hours to obtain a pretreated loess core.
[0045] S2, embedding the pretreated loess core with epoxy resin of Gardner color number ≤1, and curing to obtain an embedded core with epoxy resin thickness of 3 mm; grinding and polishing the embedded core, using 160 mesh, 240 mesh, 360 mesh, 600 mesh, 800 mesh, 1200 mesh, and 2000 mesh sandpaper to grind the surface of the embedded core for 5 minutes respectively to obtain a loess core display specimen.
[0046] Example 2
[0047] A method for preparing a loess core display specimen comprises the following steps:
[0048] S1, at 25°C and 60% humidity, the loess core is infiltrated with a 30% hydrogen peroxide solution for 30 hours, dried for 20 hours, and then infiltrated with a 50% dodecyldimethylbenzylammonium chloride solution for 30 hours to obtain a pretreated loess core.
[0049] S2, embedding the pretreated loess core with epoxy resin of Gardner color number ≤1, and curing to obtain an embedded core with epoxy resin thickness of 5 mm; grinding and polishing the embedded core, using 160 mesh, 240 mesh, 360 mesh, 600 mesh, 800 mesh, 1200 mesh, and 2000 mesh sandpaper to grind the surface of the embedded core for 10 minutes respectively to obtain a loess core display specimen.
[0050] Example 3
[0051] A method for preparing a loess core display specimen comprises the following steps:
[0052] S1, at 20°C and 50% humidity, the loess core was infiltrated with a 25% hydrogen peroxide solution for 28 hours, dried for 20 hours, and then infiltrated with a 45% dodecyldimethylbenzylammonium chloride solution for 26 hours to obtain a pretreated loess core.
[0053] S2, embedding the pretreated loess core with epoxy resin of Gardner color number ≤1, and curing to obtain an embedded core with epoxy resin thickness of 4 mm; grinding and polishing the embedded core, using 160 mesh, 240 mesh, 360 mesh, 600 mesh, 800 mesh, 1200 mesh, and 2000 mesh sandpaper to grind the surface of the embedded core for 8 minutes respectively to obtain a loess core display specimen.
[0054] Example 4
[0055] A method for preparing a loess core display specimen comprises the following steps:
[0056] S1, at 18°C and 45% humidity, the loess core was infiltrated with a hydrogen peroxide solution with a mass concentration of 22% for 26 hours, dried for 20 hours, and then infiltrated with a dodecyldimethylbenzylammonium chloride solution with a mass concentration of 48% for 28 hours to obtain a pretreated loess core.
[0057] S2, embedding the pretreated loess core with epoxy resin of Gardner color number ≤1, and curing to obtain an embedded core with epoxy resin thickness of 3 mm; grinding and polishing the embedded core, using 160 mesh, 240 mesh, 360 mesh, 600 mesh, 800 mesh, 1200 mesh, and 2000 mesh sandpaper to grind the surface of the embedded core for 10 minutes respectively to obtain a loess core display specimen.
[0058] Example 5
[0059] A method for preparing a loess core display specimen comprises the following steps:
[0060] S1, at 22°C and 55% humidity, the loess core was infiltrated with a hydrogen peroxide solution with a mass concentration of 28% for 28 hours, dried for 20 hours, and then infiltrated with a dodecyldimethylbenzylammonium chloride solution with a mass concentration of 43% for 26 hours to obtain a pretreated loess core.
[0061] S2, embedding the pretreated loess core with epoxy resin of Gardner color number ≤ 1, curing, and obtaining an embedded core with epoxy resin thickness of 5 mm; grinding and polishing the embedded core, during grinding, using 160 mesh, 240 mesh, 360 mesh, 600 mesh, 800 mesh, 1200 mesh, 2000 mesh sandpaper to grind the surface of the embedded core for 6 minutes, and obtaining a loess core display specimen. .
[0062] Example 6
[0063] A method for preparing a loess core display specimen comprises the following steps:
[0064] S1, at 23°C and 50% humidity, the loess core was infiltrated with a 26% hydrogen peroxide solution for 25 hours, dried for 20 hours, and then infiltrated with a 45% dodecyldimethylbenzylammonium chloride solution for 25 hours to obtain a pretreated loess core.
[0065] S2, embedding the pretreated loess core with epoxy resin of Gardner color number ≤1, and curing to obtain an embedded core with epoxy resin thickness of 4 mm; grinding and polishing the embedded core, using 160 mesh, 240 mesh, 360 mesh, 600 mesh, 800 mesh, 1200 mesh, and 2000 mesh sandpaper to grind the surface of the embedded core for 6 minutes respectively to obtain a loess core display specimen.
[0066] The loess core display specimens prepared in Examples 1 to 6 of the present invention were tested as follows:
[0067] Core specimen trial production scheme verification
[0068] According to the important value of the loess core, the display purpose of the specimens and the display storage environment, the trial production plan needs to be further verified in terms of the color fidelity and long-term preservation ability of the finished specimens. In order to verify the feasibility of the trial production plan, the following experiments were designed for the above two points.
[0069] 1. Color Fidelity
[0070] In view of the display properties of the core specimens, the color difference can be controlled within the color vision threshold of the human eye. It is generally believed that the three CIE LAB color difference units are the color vision threshold of the human eye. When the color difference is greater than 3.00, the human eye can recognize the difference between two colors; when the color difference is less than 1.50, the color difference is too small to be distinguished by the human eye. Therefore, the color card visual comparison method is used to test the effect of the mildew and algaecide on the color of the core.
[0071] a. Test method: Take a 1.2m loess core and divide it into 12 sections at 10cm intervals. Use Munsell soil colorimetric card to compare the color at the midpoint of each section and record the results. Four sections form a group, and each section in each group is treated with 30% hydrogen peroxide solution; dodecyl dimethyl benzyl ammonium chloride (1227) solution; 30% hydrogen peroxide solution and dodecyl dimethyl benzyl ammonium chloride (1227) solution; blank control. Observe the color changes of each section under natural light and compare with the color before treatment. In order to reduce the subjective influence of the colorimetric card visual comparison method, the color number result of the colorimetric card is the majority value under independent observation by multiple people in the team.
[0072] b. Results and Discussion
[0073] In Table 1, 1, 2, 3, and 4 represent the application of 30% hydrogen peroxide solution, dodecyl dimethyl benzyl ammonium chloride (1227) solution, 20% hydrogen peroxide solution and dodecyl dimethyl benzyl ammonium chloride (1227) solution, and blank control, respectively; A, B, and C represent three replicates on the same loess core. 5 / 4 and 4 / 3 represent different colors on the colorimetric card, respectively. The change in the numerical code indicates that this treatment method destroys the color fidelity of the specimen. 5 / 4 is the most original specimen color, and the color number of adding 30% H2O2 and the blank control is still 5 / 4, indicating that the color has not changed; the color number of adding 1227 changes to 4 / 3, and the color number of adding 30% H2O2+1227 at the same time changes to 5 / 3, which indicates that the specimen loses color after adding these two solutions separately, and cannot reflect the original color of the specimen, but the color of adding 30% H2O2+1227 at the same time (color number 5 / 3) is closer to the original specimen color (color number 5 / 4) than adding 1227 alone (color number 4 / 3), indicating that adding 30% H2O2+1227 at the same time can better reduce color distortion and better reflect the true color of the specimen than adding 1227 alone. In order to reduce the contamination and mildew of the specimen, the simultaneous use of 30% H2O2+1227 can not only keep the specimen in its original color, but also make the specimen less likely to be contaminated and damaged by mildew.
[0074] From the results in Table 1, it can be seen that the loess core has a significant color change after being treated with dodecyl dimethyl benzyl ammonium chloride solution. Because the dodecyl dimethyl benzyl ammonium chloride solution forms a very thin waxy film on the soil surface after solidification and drying, it affects the reflection and refraction properties of the soil surface, resulting in color difference. But at the same time, 30% H2O2 and dodecyl dimethyl benzyl ammonium chloride solution can better ensure color fidelity and sterilize and remove algae from loess core specimens. Therefore, in order to ensure color fidelity and sterilization and algae removal effects, 30% H2O2 and dodecyl dimethyl benzyl ammonium chloride solution can achieve the effect of long-term preservation of core specimens.
[0075] Table 1 Effect of mildew and algaecide on core color
[0076]
[0077] 2. Long-term preservation capability
[0078] The core display specimens prepared by the present invention will be placed in the corridor of the new building of the Institute of Earth Environment of the Chinese Academy of Sciences for long-term display. The display lighting is sunlight and ordinary LED lights. The light source contains ultraviolet rays. Long-term irradiation will cause the transparent epoxy resin to turn yellow. It is necessary to introduce a light stabilizer to improve the anti-ultraviolet aging ability of the transparent epoxy resin. The performance of the light stabilizer in improving the anti-light aging ability of the transparent epoxy resin is tested using a spectrophotometer.
[0079] a. Test method: Use transparent epoxy resin + 1% Good UV-1500, transparent epoxy resin + 1% Good UV-962, and transparent epoxy resin to make cubes of 70*70*20mm respectively, put them into the UV aging box and use UVA-351 spectrum irradiation to simulate sunlight filtered by glass, age at 30℃ for 24 hours, and use a spectrocolorimeter to measure the color difference value of each resin block before and after aging.
[0080] b. Results and Discussion
[0081] It can be seen from Table 2 that the addition of UV absorbers has little effect on the color of transparent epoxy resin, among which Goode UV-1500 has the smallest color difference before and after light aging, indicating that adding 1% of Goode UV-1500 can improve the light aging resistance of epoxy resin, so that the core display specimens can be preserved for a long time in indoor daylight environment.
[0082] Table 2 Effect of UV absorber on the light aging resistance of transparent epoxy resin
[0083]
[0084] In summary, through understanding the physical, chemical and biological properties of the core, analyzing the display purpose and display environment, and combining the verification results of the trial production plan, we have made reasonable adjustments to the trial production plan. When using transparent epoxy resin to embed and fix the core, a certain amount of light stabilizer is added to the epoxy resin, which improves the ability of the transparent epoxy resin to resist light aging and extends the healthy life of the core display specimens in an environment dominated by natural light at room temperature for long-term preservation.
[0085] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.
Claims
1. A method for preparing a loess core display specimen, characterized in that: The following steps are involved: At 15-25° C. and 40%-60% humidity, the loess core is sequentially infiltrated with a hydrogen peroxide solution and a dodecyl dimethyl benzyl ammonium chloride solution to obtain a pretreated loess core; Embedding the pretreated loess core with epoxy resin and curing the resin to obtain an embedded core; The embedded core is ground and polished to obtain a loess core display specimen.
2. The method for preparing a loess core display specimen according to claim 1, characterized in that: The mass concentration of the hydrogen peroxide solution is 20% to 30%.
3. The method for preparing a loess core display specimen according to claim 2, characterized in that: The time for the hydrogen peroxide solution immersion treatment is 24 to 30 hours.
4. The method for preparing a loess core display specimen according to claim 1, characterized in that: The mass concentration of the dodecyl dimethyl benzyl ammonium chloride solution is 40% to 50%.
5. The method for preparing a loess core display specimen according to claim 4, characterized in that: The time for the infiltration treatment with the dodecyl dimethyl benzyl ammonium chloride solution is 24 to 30 hours.
6. The method for preparing a loess core display specimen according to claim 1, characterized in that: The epoxy resin has a Gardner color number of ≤1.
7. The method for preparing a loess core display specimen according to claim 1, characterized in that: After curing, the thickness of the epoxy resin on the cross section of the loess core is 3 to 5 mm.
8. The method for preparing a loess core display specimen according to claim 5, characterized in that: During grinding, 160 mesh, 240 mesh, 360 mesh, 600 mesh, 800 mesh, 1200 mesh and 2000 mesh sandpaper are used to grind the surface of the embedded core for 5 to 10 minutes respectively.
9. The method for preparing a loess core display specimen according to claim 1, characterized in that: After being infiltrated with a hydrogen peroxide solution, the loess core is left to dry and then infiltrated with a dodecyl dimethyl benzyl ammonium chloride solution.
10. The method for preparing a loess core display specimen according to claim 1, characterized in that: After being infiltrated with a hydrogen peroxide solution, the cross section of the loess core is leveled.