Basic copper chloride microspheres with micro-nano structure and preparation method and application thereof

Abstract

The present invention belongs to the technical field of inorganic material manufacturing, and discloses a micro-nanostructured basic copper chloride microsphere, and a preparation method and application thereof. The basic copper chloride microsphere is prepared by dispersing calcite precursor crystals in a copper chloride solution, reacting at 30-80°C, filtering the obtained precipitate, washing with ultrapure water and ethanol, and vacuum drying; the basic copper chloride microsphere is formed by assembling basic copper chloride with a surface morphology of nano shuttle, nanorod or nanosheet. The method can obtain basic copper chloride microspheres with different surface assembly structures by changing the copper chloride concentration, reaction temperature and reaction time. The raw materials of the present invention are easy to obtain, the process is simple, the reaction conditions are mild, and there is no pollution. The obtained micro-nanostructured basic copper chloride microsphere has good antibacterial properties, can be widely used in the field of biomedical materials, can be used as a copper source supply for pig feed, and can be used as a precursor phase for synthesizing copper oxide.

Description

Technical Field

[0001] The invention belongs to the technical field of inorganic material manufacturing, and in particular relates to basic copper chloride microspheres with a micro-nano structure, and a preparation method and application thereof. Background Art

[0002] Copper is an essential trace element for the human body. It has an important influence on the development and function of hair, skin, bones and other tissues. Copper deficiency can cause anemia, hair abnormalities, bone and arterial abnormalities, and even brain disorders. Due to its high copper content (about 58%), basic copper chloride can easily and quickly dissolve in the intestines of animals to release copper ions and supplement copper elements. It is now used as a feed additive. Compared with copper sulfate, basic copper chloride has higher biological effectiveness and biosafety than copper sulfate. In addition, the amount of copper used is 25-30% less than that of copper sulfate, which not only reduces feed costs, but also greatly reduces the pollution of copper excretion to the environment.

[0003] The traditional process is to use copper-containing wastewater as raw material, add alkaline substances, and react at a certain pH value to obtain basic copper chloride. The process is cumbersome, and the synthesized basic copper chloride has uneven particle size and irregular morphology. Patents CN105964281A and CN111642633A disclose methods for synthesizing flaky and microspherical basic copper chloride, and the morphology and particle size of the obtained products are uniform, but the basic copper chloride crystals with flaky structure need to use sodium fluoride, a more dangerous drug, and the reaction time is long and the reaction temperature is high, which is more dangerous; the microspherical structure basic copper chloride needs to be synthesized in a mixed solvent of ethanol-water above 90%, and the solution selection is complex, the waste liquid ethanol content is high, and the cost of processing is high. Therefore, it is necessary to explore process conditions, synthesize basic copper chloride crystals with uniform size and novel structure, to achieve special purposes. Summary of the invention

[0004] In order to solve the above-mentioned deficiencies and disadvantages of the prior art, the primary purpose of the present invention is to provide a basic copper chloride microsphere with a micro-nano structure.

[0005] Another object of the present invention is to provide a method for preparing the above-mentioned basic copper chloride microspheres with micro-nano structure.

[0006] Another object of the present invention is to provide an application of the above-mentioned micro-nanostructured basic copper chloride microspheres.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A basic copper chloride microsphere with a micro-nano structure. The basic copper chloride microsphere is prepared by dispersing a calcite precursor crystal in a copper chloride solution, reacting at 30-80°C, filtering the obtained precipitate, washing with ultrapure water and ethanol, and vacuum drying. The basic copper chloride microsphere is formed by assembling basic copper chloride with a surface morphology of nano shuttle, nanorod or nanosheet.

[0009] Preferably, the particle size of the basic cupric chloride microspheres is 1 to 3 μm.

[0010] Preferably, the concentration of the calcite precursor crystals in the copper chloride solution is 0.1 to 0.5 g / mL; the concentration of the copper chloride solution is 5 to 100 mmol / L.

[0011] Preferably, the calcite precursor crystal is prepared by adding a sodium carbonate solution dropwise into a calcium chloride solution and reacting at 60-100°C.

[0012] More preferably, the concentrations of the calcium chloride solution and the sodium carbonate solution are the same, both of which are 0.2-0.7 mol / L.

[0013] The method for preparing the micro-nanostructured basic copper chloride microspheres comprises the following steps:

[0014] S1. Add calcium chloride and sodium carbonate into ultrapure water respectively, stir and fully dissolve; then add the sodium carbonate solution dropwise into the calcium chloride solution, react at 60-100°C to generate calcite precursor crystals;

[0015] S2. Disperse the calcite precursor crystals in a copper chloride solution, react at 30-80° C., filter the obtained precipitate, wash with ultrapure water and ethanol, and vacuum dry to obtain basic copper chloride microspheres with micro-nano structures.

[0016] Preferably, the reaction time in step S1 is 8 to 12 hours.

[0017] Preferably, the reaction time in step S2 is 20 to 120 min, the vacuum drying temperature is 30 to 70° C., and the vacuum drying time is 12 to 24 h.

[0018] The micro-nano structured basic copper chloride microspheres are used in antibacterial, pig feed or the preparation of copper oxide.

[0019] Preferably, the antibacterial bacteria are Escherichia coli and / or Staphylococcus aureus.

[0020] In the present invention, the calcite precursor crystal is used as a dissolution regulator. During the reaction, the calcite precursor crystal is dissolved in the acidic solution of copper chloride. Due to the OH generated by water ionization, - Binds free Cu in solution 2+and Cl - Basic copper chloride crystals are generated, and microspheres formed by the assembly of nanostructures with different structures are produced. In the method of the present invention, the temperature, reaction time, and copper chloride concentration will affect the dissolution of the calcite precursor crystals and the generation of OH - rate, thereby affecting the formation of assembly units and microsphere structure.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The basic copper chloride microspheres of the present invention have good copper ion release ability, can destroy the cell membrane structure of bacteria, and show good bactericidal ability. They are an effective feed copper source additive. In addition, they can effectively kill bacteria and treat tissue infections.

[0023] 2. The present invention can obtain basic copper chloride microspheres of different assemblies by controlling simple conditions. The preparation method is simple, the raw materials are cheap, no organic solvent is required, no complicated high-temperature and high-pressure equipment is required, the product has no side effects, the reaction does not require a strong acid or strong alkali environment, the equipment requirements are low, and it is suitable for large-scale production.

[0024] 3. The basic copper chloride microspheres of the present invention are easily converted into copper hydroxide or copper oxide in an alkaline environment. Using basic copper chloride microspheres of different assemblies as precursors, copper oxide nanoparticles with different structures can be prepared, thereby increasing their application range. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The scanning electron microscope images (ab), X-ray diffraction pattern (c) and infrared spectrum (d) of the calcite precursor crystal prepared in Example 1.

[0026] Figure 2 is the pH value of CuCl2 solution with different concentrations in Example 2.

[0027] Figure 3 The X-ray diffraction patterns of the calcite precursor crystals of Example 2 are regulated by dissolution in CuCl2 solutions of different concentrations.

[0028] Figure 4 This is the infrared spectrum of the dissolution regulation of the calcite precursor crystal of Example 2 in CuCl2 solutions of different concentrations.

[0029] Figure 5 The scanning electron microscope images of the dissolution regulation of the calcite precursor crystals of Example 2 in CuCl2 solutions of different concentrations.

[0030] Figure 6 The scanning electron microscope images of the calcite precursor crystals of Example 3 reacted in CuCl2 solution for different reaction times.

[0031] Figure 7 The scanning electron microscope images of the calcite precursor crystals of Example 4 reacting in a CuCl2 solution at different temperatures.

[0032] Figure 8 Transmission electron microscope images of the calcite precursor crystals of Example 4 reacting in a CuCl2 solution at different temperatures.

[0033] Fig. 9 This is the absorbance diagram of copper ions released by basic cupric chloride microspheres of different concentrations in Example 5.

[0034] Fig.10 This is a quantitative graph of the antibacterial rate of the basic copper chloride microspheres of Example 5 against Escherichia coli and Staphylococcus aureus.

[0035] Fig.11 This is a diagram of the agar plating method of basic copper chloride microspheres against Escherichia coli and Staphylococcus aureus in Example 5.

[0036] Fig.12 This is a scanning electron microscope image of the basic cupric chloride microspheres of Example 6 against Escherichia coli and Staphylococcus aureus. DETAILED DESCRIPTION

[0037] The content of the present invention is further described below in conjunction with specific examples, but it should not be construed as limiting the present invention. If not specifically indicated, the technical means used in the examples are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0038] Example 1

[0039] 1. Weigh 27.75 g of CaCl2 and add it to 500 mL of ultrapure water. Dissolve it by magnetic stirring to obtain a 0.5 M (mol / L) CaCl2 solution.

[0040] 2. Weigh 26.5 g Na2CO3 and add it to 500 mL ultrapure water. Stir magnetically to dissolve it to obtain a 0.5 M Na2CO3 solution.

[0041] 3. Use a dropping funnel to drip the Na2CO3 solution in step 2 into the CaCl2 solution in step 1 at a constant rate, stir at room temperature for 30 minutes, place the above solution in an oven at 80°C to react for 12 hours, filter with filter paper, wash with anhydrous ethanol and water three times each, and vacuum dry to obtain calcite precursor crystals.

[0042] Figure 1 The scanning electron microscope images (ab), X-ray diffraction pattern (c) and infrared spectrum (d) of the calcite precursor crystal prepared in Example 1. Figure 1It can be seen from the PDF card #47-1743 that in addition to the (104) crystal plane, (11-3), (112) and (110) crystal planes can also be seen, indicating that a polycrystalline material structure is synthesized under this condition. The scanning electron microscopy results show that the size of the calcite precursor crystal is 5-6μm, and the six faces of the crystal are clearly visible. Due to the unevenness of the crystal growth process, some crystals have surface steps. FT-IR results show that CO3 2- The vibration peaks appear at 1394, 875 and 712 cm -1 , and also shows that no other impurity phases are produced.

[0043] Example 2

[0044] 1. Weigh CuCl2 and dissolve it in ultrapure water to prepare CuCl2 solutions of different concentrations, which are 5mM, 10mM, 20mM, 50mM and 80mM respectively.

[0045] 2. Weigh 0.2 g of the calcite precursor crystals prepared in Example 1 and disperse them in 60 mL of the CuCl2 solution of different concentrations prepared in step 1, and react at 70° C. for 1 h. Filter with filter paper, wash with anhydrous ethanol and water three times each, and dry at 30-70° C. for 12-24 h to obtain basic copper chloride microspheres.

[0046] Figure 2 is the pH value of the CuCl2 solution with different concentrations in Example 2. The copper chloride solution is acidic, which is conducive to the dissolution of the calcite precursor crystals and consumes H + The solution ionizes more OH - , at this time Cu 2+ Combined OH - And the free Cl in the solution - , converted into basic copper chloride microspheres. Figure 3 The X-ray diffraction patterns of the calcite precursor crystals of Example 2 are regulated by dissolution in CuCl2 solutions of different concentrations. Figure 3 It can be seen that the standard PDF card of basic copper chloride microspheres (Cu2(OH)3Cl, JCPDS#25-0269) has main diffraction peaks at 16.28°, 32.23° and 39.69°, and the corresponding crystal planes are (-110), (-312) and (-222), respectively. As the concentration of CuCl2 increases, the calcite precursor crystals gradually dissolve, the (104) crystal plane diffraction intensity gradually decreases, and the (-110) and (-312) crystal plane diffraction intensities of the basic copper chloride microspheres gradually increase. When the CuCl2 concentration reaches 50mM, the (104) crystal plane disappears. At this concentration, the calcite precursor crystals are completely dissolved, and all basic copper chloride microspheres are generated. Figure 4 The infrared spectra of the calcite precursor crystals of Example 2 are adjusted by dissolution in CuCl2 solutions of different concentrations. Figure 4 It can be seen that CO3 2- At 1394, 875 and 712 cm -1 The absorption peak weakened with the increase of CuCl2 concentration and disappeared at 50mM. -1 The -OH vibration peak of basic copper chloride microspheres appeared at 986, 956, 917 and 846 cm -1 The Cu-OH absorption peak appeared at Figure 5 The scanning electron microscope images of the dissolution control of the calcite precursor crystals in Example 2 in CuCl2 solutions of different concentrations. Among them, (a1)-(e1) are respectively the basic copper chloride microspheres produced when the CuCl2 concentration is 5, 10, 20, 50 and 80 mM, and (a2)-(e2) are respectively the above-mentioned partial enlarged images. Figure 5 It can be seen that the synthesized basic cupric chloride microspheres are microspheres assembled from nano-block-shaped basic cupric chloride, and the particle size is 1 to 3 μm.

[0047] Example 3

[0048] The difference from Example 2 is that the CuCl2 concentration is fixed at 20 mM, the reaction temperature is 70°C, the reaction times are 20 min, 40 min and 2 h respectively, and the rest is the same as Example 2, thereby obtaining basic copper chloride microspheres with different assembly structures on the surface.

[0049] Figure 6 The scanning electron microscope images of the basic copper chloride microspheres formed at different reaction times in Example 3. Among them, (a1)-(c1) are basic copper chloride microspheres formed at reaction times of 20min, 40min and 2h, respectively, and (a2)-(c2) are partial enlargements of the above. Figure 6 It can be seen that the surface assembled particles of basic copper chloride microspheres are composed of irregular blocks ( Figure 6 a and b) to a rod-like structure ( Figure 6 c), contrast Figure 5 c The reaction temperature is 1h. As the reaction time increases, the nanostructure of the microsphere surface changes from nano-block-like basic copper chloride to nano-rod-like basic copper chloride.

[0050] Example 4

[0051] The difference from Example 2 is that the CuCl2 concentration is fixed at 20 mM, the reaction time is fixed at 1 h, the reaction temperature is 37°C and 50°C, and the rest is the same as Example 2, and basic copper chloride microspheres with shuttle-shaped and nanosheet assembly structures on the surface are obtained.

[0052] Figure 7The scanning electron micrographs of basic copper chloride microspheres formed at different reaction temperatures in Example 4. (a) and (c) are basic copper chloride microspheres formed at reaction temperatures of 37°C and 50°C, respectively, and (b) and (d) are partial enlarged views of the microspheres. Figure 8 The transmission electron microscope photos of the basic copper chloride microspheres formed at different reaction temperatures in Example 4. Among them, (a1)-(a3) are basic copper chloride microspheres produced by reaction at 37°C, (b1)-(b3) are basic copper chloride microspheres produced by reaction at 50°C, and (c1)-(c3) are basic copper chloride microspheres produced by reaction at 70°C. (c2) is a partial enlarged view of (c1), and (c3) is a partial enlarged view of (c2). Figure 7 and 8 It can be seen that as the temperature increases, the surface assembled particles of basic copper chloride microspheres change from a spindle structure ( Figure 7 a and 8a, 37°C) to the nanosheets ( Figure 7 Medium b and Figure 8 b, 50℃) and nanocube transformation ( Figure 5 Medium c and Figure 8 c, 80°C), the reaction temperature affects the chemical reaction rate because microspheres with different assemblies will be produced.

[0053] Example 5 Antibacterial Activity Test of Basic Copper Chloride Microspheres

[0054] 1. Weigh 10 mg of the basic copper chloride microspheres generated by the 20 mM CuCl2 in Example 2, react at 70°C for 1 hour, and sterilize under ultraviolet light for 12 hours;

[0055] 2. The basic copper chloride microspheres were prepared into powder dispersions of 0.2, 0.5, 0.7, 1 and 2 mg / mL using nutrient broth, and placed in a shaker at 37°C and 100 rpm for 18 hours to allow the copper ions to be fully released, and copper ion extracts of different concentrations were prepared;

[0056] 3. Escherichia coli (ATCC 8739, E. coli) and Staphylococcus aureus (ATCC 6538P, S. aureus) were cultured in nutrient broth to allow the bacteria to proliferate. After a specified period of time, the bacterial solution was taken out and its absorbance at 600 nm was detected. The number of bacteria was calculated and diluted to 1×10 6 CFU / mL;

[0057] 4. Add 10 μL of the diluted bacterial solution in step 3 to the copper ion extraction solution in step 2, and incubate on a constant temperature shaker at 220 rpm and 37 ° C for 2 hours; then take 10 μL of the incubated solution and drop it on the agar plate, spread it evenly with a bacterial stick to allow the bacteria to differentiate evenly on the entire agar plate, incubate in a 37 ° C incubator for 12 to 18 hours, and then take out and observe the number of colonies on the agar plate.

[0058] 5. Add bacterial stock solution to the copper ion leaching solution in step 2 so that the bacterial count of the final solution is 1×10 6 CFU / mL, incubate on a shaker for 16-17 hours, then detect the absorbance value of the solution at 600nm, and the final antibacterial rate is calculated according to the following formula:

[0059]

[0060] Among them, A bo is the absorbance value of the blank group at 600 nm, A bi is the absorbance value of the experimental group, A cu It is the absorbance value of the solution corresponding to the experimental group without adding bacterial solution.

[0061] In order to detect the release of copper ions in basic copper chloride microspheres, the above-mentioned leaching solution was taken and the absorbance value of the solution at 600nm was detected, wherein the absorbance of the nutrient broth was the blank background value, and the absorbance value of the copper ions in the solution was obtained by subtracting the blank group from the solution of each group. Fig. 9 This is the absorbance diagram of copper ions released by basic copper chloride microspheres of different concentrations in Example 5. Fig. 9 It can be seen that with the increase of the concentration of basic copper chloride microspheres, the color of the solution gradually deepened. The release of copper ions within 1 mg / mL almost increased linearly. There was a significant increase in the release of copper ions from 1 mg / mL to 2 mg / mL. The absorbance value of 3 mg / mL and above solutions remained almost unchanged, indicating that the release of copper ions in solutions with a concentration of more than 3 mg / mL reached a dynamic equilibrium process. 2+ The concentration reached an extreme value.

[0062] Fig.10 This is a quantitative graph of the antibacterial rate of the basic copper chloride microspheres of Example 5 against Escherichia coli and Staphylococcus aureus. Fig.11 The results of the agar plating method of basic copper chloride microspheres against Escherichia coli and Staphylococcus aureus in Example 5 are shown in Figure 5. (a) is Staphylococcus aureus, and (b) is Escherichia coli. Fig.10 and 11 It can be seen that the antibacterial rate of basic copper chloride microspheres against Staphylococcus aureus S.aureus and Escherichia coli E.coli exceeds 50%. When the concentration of basic copper chloride microspheres is 0.7 mg / mL, the bactericidal rate is close to 80%. When the concentration of basic copper chloride microspheres is 1 mg / mL, the bactericidal rate is above 90%. When the concentration of basic copper chloride microspheres is 2 mg / mL and 3 mg / mL, the copper ion concentration is too high, the bacteria have been completely killed, and the presence of bacteria cannot be seen on the agar plate.

[0063] Example 6 Bacterial morphology observation

[0064] 1. This example is consistent with steps 1-3 in Example 5. In Example 6, the extraction concentration of basic copper chloride microspheres is 1 mg / mL. After the bacterial solution and the extraction solution are incubated together, centrifuge at 10,000 rpm for 3 minutes, remove the upper solution, add PBS to wash 2-3 times, and then add 4% paraformaldehyde fixative to fix overnight at 4°C; after fixation, centrifuge and wash 2-3 times with PBS to remove the fixative;

[0065] 2. Dehydrate with ethanol gradient, with each gradient interval of 15 minutes. The ethanol concentrations for dehydration are 30%, 50%, 75%, 90%, 99%, and 100%, of which 100% dehydration is performed twice. Then drop the bacterial solution on a clean silicon wafer and dry it naturally overnight. Then observe the morphology of the bacteria with SEM.

[0066] Fig.12 The following are scanning electron microscope images of the basic copper chloride microspheres against Escherichia coli and Staphylococcus aureus in Example 6. (a) and (c) are the normal structures of Staphylococcus aureus and Escherichia coli, respectively, and (b) and (d) are the structures of Staphylococcus aureus and Escherichia coli after adding basic copper chloride microspheres. It can be seen that the normal bacterial structure is intact ( Fig.12 In a and c), after adding the extraction solution, the cell membrane of Staphylococcus aureus S.aureus has been broken, without its bacterial structure, and the contents have flowed out; the surface of E.coil E.coil is severely wrinkled, and a pit structure appears on its surface, showing that the basic cupric chloride microspheres destroy the structure of E.coli and Staphylococcus aureus, indicating that the basic cupric chloride microspheres have good bactericidal properties.

[0067] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for preparing basic copper chloride microspheres with micro-nano structure, characterized in that: The steps include: S1. Add calcium chloride and sodium carbonate into ultrapure water respectively and stir to fully dissolve; then add the sodium carbonate solution dropwise into the calcium chloride solution and react at 60-100℃ for 8-12 hours to generate calcite precursor crystals; S2. Disperse calcite precursor crystals in a copper chloride solution, react at 30-80°C, filter the obtained precipitate, wash with ultrapure water and ethanol, and vacuum dry to obtain micro-nanostructured basic copper chloride microspheres, wherein the concentration of the calcite precursor crystals in the copper chloride solution is 0.1-0.5 g / mL; the concentration of the copper chloride solution is 5-100 mmol / L; the basic copper chloride microspheres are assembled from basic copper chloride with a surface morphology of nano-shuttle, nano-rod or nano-sheet.

2. The method for preparing the micro-nanostructured basic copper chloride microspheres according to claim 1, characterized in that: The concentrations of the calcium chloride solution and the sodium carbonate solution in step S1 are the same, both of which are 0.2-0.7 mol / L.

3. The method for preparing the micro-nanostructured basic copper chloride microspheres according to claim 1, characterized in that: The reaction time in step S2 is 20-120 min, the vacuum drying temperature is 30-70° C., and the vacuum drying time is 12-24 h.

4. The method for preparing the micro-nanostructured basic copper chloride microspheres according to claim 1, characterized in that: The particle size of the basic cupric chloride microspheres in step S2 is 1-3 μm.

5. A basic copper chloride microsphere with a micro-nano structure, characterized in that: The basic copper chloride microspheres are prepared by the method described in any one of claims 1 to 4.

6. Use of the basic copper chloride microspheres with micro-nano structure as claimed in claim 5 in antibacterial, pig feed or preparation of copper oxide.

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