Method for in-situ removal of chlorine ions from surface of bronze by plasma oxidation-reduction
By forming an oxide layer on the surface of bronze artifacts using a plasma oxidation-reduction method and then reducing it to a metallic state, the problem of chloride ion corrosion on the surface of bronze artifacts was solved, a stable protective film was formed, and rapid and efficient corrosion protection was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HEFEI INSTITUTE OF PHYSICAL SCIENCE CHINESE ACADEMY OF SCIENCES
- Filing Date
- 2023-08-25
- Publication Date
- 2026-05-19
AI Technical Summary
Existing technologies are unable to quickly and effectively remove chloride ions from the surface of bronze artifacts, making corrosion problems difficult to solve. Conventional methods are time-consuming, and single-gas low-temperature plasma treatment is not very effective.
The plasma oxidation-reduction method is adopted, which forms an oxide layer on the surface of bronze and reduces it to a metallic state. Then, a stable protective film is formed by plasma treatment with oxidizing and reducing gases.
It achieves rapid and efficient removal of chloride ions from the surface of bronze artifacts, forming a stable protective layer, thus solving the corrosion problem of bronze artifacts. It has the advantages of being non-contact, non-corrosive, and environmentally friendly.
Smart Images
Figure CN117328075B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of bronze technology, and specifically to a method for in-situ removal of chloride ions from the surface of bronze artifacts using plasma oxidation-reduction. Background Technology
[0002] Bronze artifacts are an important part of traditional Chinese culture. Due to the influence of underground and post-excavation environments, they have suffered varying degrees of corrosion. Greenish powdery rust is crucial for the preservation of bronze artifacts. Its main component is basic copper chloride, and the corrosion mechanism is as follows: oxygen, chloride ions, and water in the environment react with copper in the bronze through electrochemical corrosion, successively forming layers of basic copper carbonate, cuprous oxide, and cuprous chloride on the surface of the bronze artifact. Hydrochloric acid is produced during the reaction, continuously expanding the cuprous chloride layer inside the bronze artifact. Simultaneously, with the penetration of oxygen and moisture, cuprous oxide and cuprous chloride are continuously converted into basic copper chloride. Basic copper chloride itself is a loose powder that easily absorbs oxygen and moisture. Thus, "powdery rust" can continuously form, causing the artifact to decay and develop perforations.
[0003] A common method for removing powdery rust from bronze artifacts is to convert the CuCl present on the bronze artifacts—the root cause of "bronze disease"—into a Cl-free form. - Stable products, such as Cu₂O or CuCO₃·Cu(OH)₂, are formed. Bronze artifacts are corroded by immersion in an aqueous solution of sodium sesquicarbonate (NaCO₃·NaHCO₃·2H₂O), using the CO₃²⁻ in the solution. 2- Replace Cl in bronzeware - It can convert Cl - The chloride ions are displaced, forming stable copper carbonates. However, in practical applications, this method is time-consuming, requiring two to three years to remove the chloride ions from the container. - The chloride ions are displaced. Therefore, a faster method is needed to remove chloride ions from the surface of bronze artifacts in situ, thereby stabilizing the bronze artifacts.
[0004] The prior art discloses a method for stabilizing bronze artifacts using low-temperature plasma surface effects, which selects atmospheres such as argon, ammonia, oxygen, carbon dioxide and nitrogen for the experiment. However, it only uses a single gas, and the effect is not good (Research on the stabilizing effect of low-temperature plasma surface effects on "powdery rust" of bronze artifacts, Zhengzhou University, Shang Zeya). Summary of the Invention
[0005] The technical problem to be solved by the present invention is to provide an efficient method for stabilizing bronze artifacts in situ.
[0006] The present invention solves the above-mentioned technical problems through the following technical means:
[0007] A method for in-situ removal of chloride ions from the surface of bronze artifacts using plasma oxidation-reduction includes the following steps:
[0008] S1. Place the bronze artifact to be processed into the reaction chamber of the plasma device;
[0009] S2. An oxidizing gas is added to the reaction chamber of the plasma device to form a plasma environment for plasma treatment of the bronze, causing a plasma oxidation reaction on the surface of the bronze and forming an oxide layer on the surface of the bronze.
[0010] S3. Replace the oxidizing gas in the reaction chamber of the plasma device with a reducing gas to form a plasma environment for plasma treatment of the bronze artifact, causing a plasma reduction reaction on the surface of the bronze artifact and reducing the surface oxide layer to a metallic state.
[0011] Preferably, in S1, the surface of the bronze artifact to be treated is cleaned and then placed into the plasma reaction chamber.
[0012] Preferably, in S1, the plasma device is a radio frequency plasma device.
[0013] Preferably, in S2, the oxidizing gas includes a mixture of oxygen and an inert gas, oxygen, ozone, and one or more mixtures of air.
[0014] Preferably, in S3, the reducing gas includes one or more of the following: a mixture of hydrogen and argon, hydrogen, and ammonia.
[0015] Preferably, in S2 and S3, during the plasma treatment of the bronze artifact, the temperature in the reaction chamber is 50℃~200℃, the pressure is 0.1~10Pa, and the treatment time is 1~120min.
[0016] Preferably, in S2 and S3, the gas flow rate is 100-400 mL / min.
[0017] Preferably, in S2 and S3, the power is 150W during the plasma treatment of the bronze artifact.
[0018] Preferably, steps S2 and S3 are repeated to remove chloride ions from the surface of the bronze until a stable protective layer is formed on the surface of the bronze.
[0019] The advantages of this invention are:
[0020] The basic principle of this invention is to first form a stable oxide layer on the surface of bronze artifacts using plasma oxidation technology, and then reduce the oxide layer to metal using plasma reduction technology, thereby removing chloride ions from the surface of the bronze artifacts. This invention employs plasma treatment, through oxidation and reduction, to remove chloride ions from the surface of bronze artifacts. - This method forms a stable protective film on the surface of bronze artifacts, fundamentally solving the corrosion problem. The equipment used is simple and easy to operate, and compared to conventional chemical methods, it has advantages such as being non-contact, non-corrosive, highly efficient, and environmentally friendly, making it highly valuable for bronze artifact restoration. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the radio frequency plasma reaction device in Embodiment 1 of the present invention;
[0022] Figure 2 This is a graph showing the change in the surface color of a real cultural relic over time after copper foil was treated with O2 radio frequency plasma and Ar / H2 mixed gas radio frequency plasma in Embodiment 1 of the present invention.
[0023] Figure 3 In Embodiment 1 of this invention, the Cl in the Cu2(OH)3Cl corrosion layer on the surface of copper foil and real cultural relics is treated with O2 radio frequency plasma. - With the original copper foil, the surface of the real cultural relic Cl - The graph showing the change of EDS atomic ratio quantification results with processing time;
[0024] Figure 4 In Embodiment 1 of this invention, the Cl in the Cu2(OH)3Cl corrosion layer on the surface of copper foil and real cultural relics is treated with Ar / H2 radio frequency plasma. - With the original copper foil, the surface of the real cultural relic Cl - The graph shows the change of EDS atomic ratio quantification results with processing time. Detailed Implementation
[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, 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.
[0026] Unless otherwise specified, all test materials and reagents used in the following examples are commercially available.
[0027] Unless otherwise specified in the embodiments, the techniques or conditions described in the literature in this field or in accordance with the product manual may be followed.
[0028] Example 1
[0029] A copper foil with a uniform Cu2(OH)3Cl layer grown on its surface and a real cultural relic were used as research objects and placed in a radio frequency plasma reaction chamber, such as... Figure 1 As shown, O2 was used as an oxidizing reaction gas to treat copper foil and real cultural relics. The specific steps included: placing the cleaned copper foil and real cultural relics in a radio frequency plasma reaction chamber, introducing O2 into the reaction chamber for plasma treatment, setting the O2 gas flow rate to 400 mL / min, the discharge power to 150 W, the reaction chamber temperature to 100-300℃, the pressure to 10 Pa, and varying the O2 plasma discharge time to 5-25 min, thereby exploring the treatment effect of different plasma discharge times on copper foil and real cultural relics.
[0030] Copper foil and the color and surface Cl of real cultural relics - The change in concentration with reaction time is as follows: Figure 2 and 3 As shown; by Figure 2 It is known that as the O2 plasma treatment time increases, the copper foil and the actual artifacts change from blue-green to brownish-yellow. Figure 3 The quantitative results of EDS atomic ratio analysis on the sample surface show that the Cl content of copper foil and the surface of real cultural relics is higher. - The content of [unspecified substance] was significantly reduced, indicating that oxygen plasma treatment can effectively remove Cl from the surface of bronze artifacts. - .
[0031] Copper foil treated with O2 plasma and real cultural relics were used as research objects and placed in a radio frequency plasma reaction chamber. Subsequently, an Ar / H2 mixture (Ar to H2 volume ratio of 95:5) was used as a reducing gas to treat the copper foil and real cultural relics. The specific steps included: placing the copper foil and real cultural relics in the radio frequency plasma reaction chamber, introducing the Ar / H2 mixture into the chamber for plasma treatment, setting the Ar / H2 mixture flow rate to 100 mL / min, the discharge power to 150 W, the chamber temperature to 100-300℃, the pressure to 10 Pa, and varying the Ar / H2 plasma discharge time from 10 to 120 min to investigate the treatment effects of different plasma discharge times on the copper foil and real cultural relics.
[0032] Copper foil and the color and surface Cl of real cultural relics - The change in concentration with reaction time is as follows: Figure 2 and 4 As shown; by Figure 2It can be seen that as the Ar / H2 mixed gas plasma treatment time is extended, the copper foil and the real cultural relics change from brownish-yellow to blackish-red. Figure 4 Cl in the Cu2(OH)3Cl corrosion layer on the surface of the copper foil after Ar / H2 treatment and the real cultural relic. - With the original copper foil, the surface of the real cultural relic Cl - The graph showing the change of EDS atomic ratio quantification results with processing time is presented by... Figure 4 The results show that the Cl content on the copper foil and the surface of the real artifact... - The content of Cl- decreased further, indicating that Ar / H2 plasma reduction can further remove Cl- from the surface of bronze artifacts. - .
[0033] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for in-situ removal of chloride ions from the surface of bronze artifacts using plasma oxidation-reduction, characterized in that: Includes the following steps: S1. Place the bronze artifact to be processed into the reaction chamber of the plasma device; S2. An oxidizing gas is added to the reaction chamber of the plasma device to form a plasma environment for plasma treatment of the bronze, causing a plasma oxidation reaction on the surface of the bronze and forming an oxide layer on the surface of the bronze. S3. Replace the oxidizing gas in the reaction chamber of the plasma device with a reducing gas to form a plasma environment for plasma treatment of the bronze, so that the surface of the bronze will undergo a plasma reduction reaction and reduce the surface oxide layer to a metallic state. In S2 and S3, the gas flow rate is 100~400 mL / min, and the treatment time is 1~120 min.
2. The method for in-situ removal of chloride ions from the surface of bronze artifacts using plasma oxidation-reduction as described in claim 1, characterized in that: In S1, the surface of the bronze artifact to be processed is cleaned and then placed into the plasma reaction chamber.
3. The method for in-situ removal of chloride ions from the surface of bronze artifacts using plasma oxidation-reduction as described in claim 1, characterized in that: In S1, the plasma device is a radio frequency plasma device.
4. The method for in-situ removal of chloride ions from the surface of bronze artifacts using plasma oxidation-reduction as described in claim 1, characterized in that: In S2, the oxidizing gas includes a mixture of oxygen and an inert gas, oxygen, ozone, and one or more mixtures of air.
5. The method for in-situ removal of chloride ions from the surface of bronze artifacts using plasma oxidation-reduction as described in claim 1, characterized in that: In S3, the reducing gas includes one or more of the following: a mixture of hydrogen and argon, hydrogen, and ammonia.
6. The method for in-situ removal of chloride ions from the surface of bronze artifacts using plasma oxidation-reduction according to any one of claims 1-5, characterized in that: In S2 and S3, during the plasma treatment of bronze artifacts, the temperature in the reaction chamber was 50℃~200℃, the pressure was 0.1~10Pa, and the treatment time was 120min.
7. The method for in-situ removal of chloride ions from the surface of bronze artifacts using plasma oxidation-reduction according to any one of claims 1-5, characterized in that: In S2 and S3, the gas flow rate is 400 mL / min.
8. The method for in-situ removal of chloride ions from the surface of bronze artifacts using plasma oxidation-reduction according to any one of claims 1-5, characterized in that: In S2 and S3, the power is 150W during the plasma treatment of bronze artifacts.
9. The method for in-situ removal of chloride ions from the surface of bronze artifacts using plasma oxidation-reduction according to any one of claims 1-5, characterized in that: It also includes repeating S2 and S3 to remove chloride ions from the surface of the bronze until a stable protective layer is formed on the surface of the bronze.