Composite carbon cloth modification process for directionally promoting deposition of electrolytic calcium phosphate

Abstract

The invention discloses a composite carbon cloth modification process for directionally promoting deposition of electrolytic calcium phosphate, which comprises the following steps: S1, immersing carbon cloth into an electroplating solution, applying a constant voltage of-1.2 V, and depositing in a water bath at 80 DEG C for 40 minutes to obtain a vertical ZnO nanoneedle; s2, taking out the carbon cloth from the electroplating solution, immersing the carbon cloth into a citric acid solution or an ethanol solution, and refluxing at 80 DEG C for 2 hours; s3, washing the carbon cloth with deionized water, and then carrying out vacuum drying at 60 DEG C; s4, immersing the carbon cloth subjected to carboxylation modification into a pre-polymerization solution; s5, eluting the carbon cloth by using a 0.5 M EDTA (Ethylene Diamine Tetraacetic Acid) solution; s6, immersing the carbon cloth into a mixed solution of the LDH precursor and urea, and carrying out hydrothermal reaction at 120 DEG C for 8 hours to generate an MgAl-LDH coating; s7, immersing the carbon cloth into the intercalation liquid, and carrying out ion exchange for 24 hours at the temperature of 60 DEG C; s8, washing the carbon cloth with deionized water, and drying and curing at 80 DEG C; the method has the advantage of promoting calcium phosphate deposition.

Description

Technical Field

[0001] The invention belongs to the technical field of composite carbon cloth modification, and relates to a composite carbon cloth modification process for directionally promoting electrolytic calcium phosphate deposition. Background Art

[0002] At present, carbon cloth, as a flexible, highly conductive substrate material widely used in sensors, filtration, energy storage and other fields, has attracted more and more attention for its surface functionalization modification. Traditional surface modification methods mainly focus on simple physical adsorption or chemical modification, which makes it difficult to achieve directional mineralization control under low supersaturation conditions, making it difficult to balance biocompatibility, stability and selectivity in the fields of biomedicine, industrial water treatment and seawater desalination. Especially in the process of high-purity calcium phosphate deposition, it is often due to competing ions (such as Mg 2+ ) which results in a reduction in the purity and stability of the target sediment, while the durability and dissolution resistance of the sediment layer need to be improved;

[0003] To overcome the limitations of traditional technologies, scholars in this field have attempted to construct multi-level functionalized surfaces using electrochemical deposition and molecular imprinting techniques. However, single ZnO nanostructures or direct organic molecule modifications often cannot simultaneously achieve high specific surface area, specific calcium ion capture, and persistent regulation of the local alkaline environment. On the other hand, layered double hydroxides (LDHs) have the characteristic of regulated release of 0H-, but traditional coatings are easily ineffective in actual operation due to erosion by ions in the environment. Summary of the Invention

[0004] In view of the above problems, the present invention proposes a composite carbon cloth modification process for directionally promoting the deposition of electrolytic calcium phosphate, which effectively solves the problems in the prior art.

[0005] In order to achieve the above-mentioned object, the technical solution adopted by the present invention is as follows: a composite carbon cloth modification process for directionally promoting electrolytic calcium phosphate deposition comprises the following steps:

[0006] S1, immerse the carbon cloth in the electroplating solution, apply a constant voltage of -1.2V, and deposit in an 80℃ water bath for 40 minutes to form vertical ZnO nanoneedles on the carbon cloth;

[0007] S2, after removing the carbon cloth from the electroplating solution, immerse it in a citric acid solution or an ethanol solution and reflux it at 80°C for 2 hours to form carboxyl (-COOH) modification on the surface of the nanoneedles;

[0008] S3, rinsing the carbon cloth treated in step S2 with deionized water, and then vacuum drying at 60° C. to obtain a carboxyl-modified carbon cloth;

[0009] S4, immersing the carboxyl modified carbon cloth in a prepolymerization solution, and polymerizing it at 60° C. for 6 hours under nitrogen protection, so that the polymer is firmly deposited on the surface of the carbon cloth;

[0010] S5. After the polymerization is completed, the carboxyl modified carbon cloth is eluted with 0.5M ethylenediaminetetraacetic acid solution to remove Ca 2+ , thereby forming an imprinted structure with specific holes in the polymer layer, and obtaining a carbon cloth with a calcium ion imprinted polymer layer;

[0011] S6, immersing the carbon cloth with the calcium ion imprinted polymer layer in a mixture of LDH precursor and urea, and hydrothermally reacting it at 120° C. for 8 hours to obtain a carbon cloth with a MgAl-LDH coating;

[0012] S7, immerse the carbon cloth with MgAl-LDH coating in the intercalation solution and perform ion exchange at 60℃ for 24 hours to make PO4 3- Intercalate into the LDH interlayer structure together with phytic acid;

[0013] S8. Rinse the carbon cloth with the MgAl-LDH coating after the treatment in step S7 with deionized water, and dry and solidify it at 80° C. to obtain a carbon cloth with an LDH@phytic acid composite coating.

[0014] Furthermore, the electroplating solution in step S1 is a mixed solution of 0.1M Zn(NO3)2·6H2O and 0.05M hexamethylenetetramine (HMTA).

[0015] Furthermore, the concentration of the citric acid solution in step S1 is 0.2M.

[0016] Furthermore, the prepolymer solution in step S4 comprises a mixture of 5 mL of imprinting monomer methacrylic acid, 20 mL of cross-linking agent ethylene glycol dimethacrylate, 10 mL of 0.1 M solution of 0.1 M CaCl2 solution, and 0.1 g of initiator ammonium persulfate.

[0017] Furthermore, the LDH precursor solution in step S6 is a mixture of 0.1M Mg(NO3)2 and 0.05M Al(NO3)3.

[0018] Furthermore, the urea concentration of the urea mixed solution in step S6 is 0.5M.

[0019] Furthermore, the intercalation solution in step S7 is 0.3M Na2HPO4+0.1M phytic acid (C0H 18 O 24 P5) mixed.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention provides abundant calcium ion specific binding sites at low supersaturation by ZnO nanoneedles and carboxylation treatment, effectively promoting heterogeneous nucleation of calcium phosphate; and realizes Ca ion imprinting polymer layer. 2+ selective capture and exclusion of Mg 2+ Competitive ions; sustained release of OH through LDH@phytic acid composite coating - Regulating the local micro-alkaline environment not only further promotes the directional deposition process, but also the PO-Mg bond formed after the participation of phytic acid in the co-intercalation greatly improves the anti-dissolution performance of the coating. DETAILED DESCRIPTION

[0022] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0023] A composite carbon cloth modification process for directionally promoting electrolytic calcium phosphate deposition comprises the following steps:

[0024] S1, immerse the carbon cloth in the electroplating solution, apply a constant voltage of -1.2V, and deposit in an 80℃ water bath for 40 minutes to form vertical ZnO nanoneedles on the carbon cloth;

[0025] S2, after removing the carbon cloth from the electroplating solution, immerse it in a citric acid solution or an ethanol solution and reflux it at 80°C for 2 hours to form carboxyl (-COOH) modification on the surface of the nanoneedles;

[0026] S3, rinsing the carbon cloth treated in step S2 with deionized water, and then vacuum drying at 60° C. to obtain a carboxyl-modified carbon cloth;

[0027] S4, immersing the carboxyl modified carbon cloth in a prepolymerization solution, and polymerizing it at 60° C. for 6 hours under nitrogen protection, so that the polymer is firmly deposited on the surface of the carbon cloth;

[0028] S5. After the polymerization is completed, the carboxyl modified carbon cloth is eluted with 0.5M EDTA solution to remove Ca 2+ , thereby forming an imprinted structure with specific holes in the polymer layer, and obtaining a carbon cloth with a calcium ion imprinted polymer layer;

[0029] S6, immersing the carbon cloth with the calcium ion imprinted polymer layer in a mixture of LDH precursor and urea, and hydrothermally reacting it at 120° C. for 8 hours to obtain a carbon cloth with a MgAl-LDH coating;

[0030] S7, immerse the carbon cloth with MgAl-LDH coating in the intercalation solution and perform ion exchange at 60℃ for 24 hours to make PO4 3- Intercalate into the LDH interlayer structure together with phytic acid;

[0031] S8. Rinse the carbon cloth with the MgAl-LDH coating after the treatment in step S7 with deionized water, and dry and solidify it at 80° C. to obtain a carbon cloth with an LDH@phytic acid composite coating.

[0032] In this embodiment, the electroplating solution in step S1 is a mixed solution of 0.1 M Zn(NO 3 ) 2 ·6H 2 O and 0.05 M hexamethylenetetramine (HMTA).

[0033] In this embodiment, the concentration of the citric acid solution in step S1 is 0.2M.

[0034] In this embodiment, the prepolymer solution in step S4 includes 5 mL of imprinting monomer methacrylic acid, 20 mL of cross-linking agent ethylene glycol dimethacrylate, 10 mL of 0.1 M solution of 0.1 M CaCl2 solution, and 0.1 g of initiator ammonium persulfate.

[0035] In this embodiment, the LDH precursor solution in step S6 is a mixture of 0.1 M Mg(NO 3 ) 2 and 0.05 M Al(NO 3 ) 3 .

[0036] In this embodiment, the urea concentration of the urea mixed solution in step S6 is 0.5M.

[0037] In this embodiment, the intercalation solution in step S7 is 0.3M Na2HPO4+0.1M phytic acid (C0H 18 O 24 P5) mixed.

[0038] In this embodiment, LDH is the abbreviation of Layered Double Hydroxides, also known as hydrotalcite compounds, which is an inorganic material with a unique layered structure. Its special properties enable it to achieve a sustained release function regulated by an alkaline environment.

[0039] In this embodiment, the ethylenediaminetetraacetic acid solution is also called EDTA solution.

[0040] In this example, MgAl-LDH (magnesium aluminum layered double hydroxide) is used for the following key functions:

[0041] 1. Continuously release OH- to create an alkaline microenvironment.

[0042] · Alkalinity source: hydroxyl groups (OH - ) slowly hydrolyzes in solution, releasing OH - ion.

[0043] Dynamic regulation: Mg 2+ and Al 3+ The hydrolysis reaction:

[0044]

[0045]

[0046] Synergistic effect: After the Mg / Al ratio is optimized, the overall performance is the continuous release of 0H-, which stabilizes the local pH at 8.8-9.2 and promotes the deposition of calcium phosphate (Ca3(PO4)2).

[0047] 2. Inhibit the dissolution of calcium phosphate

[0048] Phytic Acid Synergistic Effect:

[0049] The hexaphosphate group of phytic acid interacts with the Mg in the LDH layer. 2+ A strong coordination bond (PO-Mg) is formed to stabilize the interlayer structure.

[0050] Free phytic acid molecules chelate Ca in the solution 2+ , reducing the concentration of free calcium and inhibiting the dissolution of deposited calcium phosphate (solubility product regulation).

[0051] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A composite carbon cloth modification process for directional promotion of electrolytic calcium phosphate deposition, characterized in that: The steps include: S1, immerse the carbon cloth in the electroplating solution, apply a constant voltage of -1.2V, and deposit in an 80℃ water bath for 40 minutes to form vertical ZnO nanoneedles on the carbon cloth; S2, after removing the carbon cloth from the electroplating solution, immerse it in a citric acid solution or an ethanol solution and reflux it at 80°C for 2 hours to form carboxyl (-COOH) modification on the surface of the nanoneedles; S3, rinsing the carbon cloth treated in step S2 with deionized water, and then vacuum drying at 60° C. to obtain a carboxyl-modified carbon cloth; S4, immersing the carboxyl modified carbon cloth in a prepolymerization solution, and polymerizing it at 60° C. for 6 hours under nitrogen protection, so that the polymer is firmly deposited on the surface of the carbon cloth; S5. After the polymerization is completed, the carboxyl modified carbon cloth is eluted with 0.5M ethylenediaminetetraacetic acid solution to remove Ca 2+ , thereby forming an imprinted structure with specific holes in the polymer layer, and obtaining a carbon cloth with a calcium ion imprinted polymer layer; S6, immersing the carbon cloth with the calcium ion imprinted polymer layer in a mixture of LDH precursor and urea, and hydrothermally reacting it at 120° C. for 8 hours to obtain a carbon cloth with a MgAl-LDH coating; S7, immerse the carbon cloth with MgAl-LDH coating in the intercalation solution and perform ion exchange at 60℃ for 24 hours to make PO4 3- Intercalate into the LDH interlayer structure together with phytic acid; S8. Rinse the carbon cloth with the MgAl-LDH coating after the treatment in step S7 with deionized water, and dry and solidify it at 80° C. to obtain a carbon cloth with an LDH@phytic acid composite coating.

2. The composite carbon cloth modification process for directional promotion of electrolytic calcium phosphate deposition according to claim 1, characterized in that: The electroplating solution in step S1 is a mixed solution of 0.1M Zn(NO3)3·6H2O and 0.05M hexamethylenetetramine (HMTA).

3. The composite carbon cloth modification process for directional promotion of electrolytic calcium phosphate deposition according to claim 1, characterized in that: The concentration of the citric acid solution in step S1 is 0.2M.

4. The composite carbon cloth modification process for directional promotion of electrolytic calcium phosphate deposition according to claim 1, characterized in that: The prepolymer solution in step S4 includes 5 mL of imprinting monomer methacrylic acid, 20 mL of cross-linking agent ethylene glycol dimethacrylate, 10 mL of 0.1 M solution of 0.1 M CaCl2 solution, and 0.1 g of initiator ammonium persulfate.

5. The composite carbon cloth modification process for directional promotion of electrolytic calcium phosphate deposition according to claim 1, characterized in that: The LDH precursor solution in step S6 is a mixture of 0.1M Mg(NO3)2 and 0.05M Al(NO3)3.

6. The composite carbon cloth modification process for directionally promoting electrolytic calcium phosphate deposition according to claim 1, characterized in that: The urea concentration of the urea mixed solution in step S6 is 0.5M.

7. The composite carbon cloth modification process for directional promotion of electrolytic calcium phosphate deposition according to claim 1, characterized in that: The intercalation solution in step S7 is 0.3M Na2HPO4+0.1M phytic acid (C3H 18 O 24 P. ) mixed.