Method for preparing catechol-furfuryl-based resin nanospheres with a surface capable of loading silver nanoparticles and having a lychee-like concave-convex structure

Abstract

The present application relates to a kind of preparation method of catechol-furfuryl resin nanosphere with surface having lychee-like concave-convex structure capable of loading silver nanoparticles, belong to biomass-based nanomaterial preparation technology related field, comprising: (1) catechol, ammonia is added to the mixed solution of ethanol and water and mixed uniformly, after adding appropriate amount of furfuryl, hydrothermal reaction is carried out, and ABR is obtained after centrifugal drying (hereinafter referred to as ABR);(2) different concentrations of silver ammonia solution are added to the surface of ABR to load silver, and form ABR@Ag composite material.By adjusting the molar ratio of furfuryl and catechol and the addition amount of ammonia in step (1), the particle size and surface roughness of ABR resin ball can be controlled, and the surface pore size and specific surface area of ABR can be controlled, and preferably a resin ball with lychee-like concave-convex structure on the surface can be obtained, which shows excellent performance in subsequent silver nanoparticle loading (loading capacity is nearly 30%), and has potential application value.

Description

Technical Field

[0001] This invention belongs to the field of biomass-based nanomaterial preparation technology, specifically relating to a method for preparing catechol-furfural-based resin nanospheres with a lychee-like uneven structure on the surface that can support silver nanoparticles. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Phenolic resins have been widely used in the preparation of composite matrices, adhesives, insulation materials, and fireproofing materials due to their simple preparation methods, low cost, high thermal stability, and strong environmental adaptability. Recently, phenolic resin materials with nanoscale structures have further expanded their application areas due to their ultra-high specific surface area. However, the synthesis of phenolic resin spheres often requires the use of toxic phenol and formaldehyde as crosslinking monomers. Formaldehyde, in particular, is listed as a carcinogen by the International Agency for Research on Cancer (IARC) of the World Health Organization, making its use highly questionable. Finding reagents that can replace formaldehyde and exploring green preparation methods for resin micro / nanospheres have become major concerns in this industry. Currently, researchers have attempted to use glyoxal and glutaraldehyde to replace formaldehyde in the preparation of resin micro / nanospheres; however, their high price and low crosslinking efficiency have slowed down related research progress. Furfural, as a common platform chemical, has potential application value and is considered an ideal material to replace formaldehyde in the preparation of resin nanomaterials; however, related research is rarely reported.

[0004] In previous research, the inventors developed methods for in-situ reduction of ultra-small and high-density silver nanoparticles on the surface of phenolic resin microspheres using tannic acid coating and for controlling the morphology and size of phenolic resin micro / nanospheres through tannic acid doping, which greatly improved the loading of Ag NPs. However, these methods still require the use of the toxic and carcinogenic chemical formaldehyde, and the surface morphology of the resin spheres obtained by these methods is uniform, limiting the application range of the resin spheres. Meanwhile, a high-yield, environmentally friendly method for preparing resin micro / nanospheres with high specific surface area has yet to be found in the industry. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention develops a method for preparing catechol-furfural-based resin nanospheres with a lychee-like uneven surface structure capable of supporting silver nanoparticles. This technology is the first to replace formaldehyde with furfural for loading resin nanospheres and the first to prepare resin nanospheres with a lychee-like morphology. These resin nanospheres are environmentally friendly and show potential application value in the process of loading silver nanoparticles.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for preparing catechol-furfural resin nanospheres capable of supporting silver nanoparticles with a lychee-like uneven surface structure, comprising:

[0008] Catechol and ammonia solution are mixed into an ethanol solution to obtain a mixed solution;

[0009] After ultrasonic treatment of the mixture solution, furfural solution was added, and the reaction was carried out at 160-165℃ for 7-7.2 h. The product was washed, centrifuged, and dried to obtain ABR nanospheres.

[0010] Ag nanoparticles were synthesized on the ABR nanospheres using silver ammonia solution as Ag precursor solution to obtain ABR@Ag composite material.

[0011] The molar ratio of furfural to catechol is 4-6:1.

[0012] This invention provides a method for preparing lychee-shaped furfural resin nanospheres loaded with silver nanoparticles. This invention is the first to report a method for preparing uniform and controllable formaldehyde-free phenolic resin nanospheres using furfural and catechol. Furthermore, by controlling the molar ratio of furfural and catechol and the amount of ammonia added, a furfural resin nanosphere with a lychee-shaped uneven structure was successfully obtained, with a yield of over 69%. This has theoretical significance and practical value for expanding the application of resin nanospheres, and is expected to show application prospects in cutting-edge fields such as electrochemistry, sensing, catalysis, and pharmaceuticals.

[0013] In a second aspect, the present invention provides catechol-furfural resin nanospheres with a lychee-like uneven structure on the surface, which can be prepared by the above method and are capable of supporting silver nanoparticles.

[0014] A third aspect of the present invention provides the application of the above-described catechol-furfural-based resin nanospheres in the fields of electrochemistry, sensing, catalysis, and pharmaceuticals.

[0015] Beneficial effects of the present invention

[0016] (1) Furfural used in this invention is a common platform chemical that can be obtained from agricultural product residues such as corn, wheat and sugarcane, and has potential practical value. Furfural has double bonds and aldehyde functional groups on its furan ring, and its activity is high, which can ensure that the resin balls undergo good cross-linking and curing. The yield of the resin balls formed by it is much higher than that of formaldehyde. Using it to replace formaldehyde in the preparation of resin micro and nanospheres is in line with the concept of green environmental protection.

[0017] (2) By optimizing the operating conditions, the present invention can control the molar ratio of furfural and catechol and the amount of ammonia added. Preferably, when the molar ratio of furfural and catechol is 6:1 and the amount of ammonia added is 1.5 mL, resin nanospheres with a surface texture resembling lychee can be obtained. The specific surface area of ​​these nanospheres is significantly higher than that of common resin spheres, which is of great significance for their subsequent applications. On the one hand, the surface with a lychee-like texture can expose more phenolic hydroxyl groups and aromatic rings, which can ionize more negative ions, increase the surface charge of the resin spheres, and subsequently improve the stability of the resin spheres. On the other hand, the presence of more phenolic hydroxyl groups can better adsorb, reduce, and chelate silver nanoparticles, thereby improving their catalytic activity in subsequent applications.

[0018] (3) The ABR@Ag composite functional material prepared by this invention has high catalytic activity and has potential application prospects in the field of catalytic degradation of dye wastewater. Furthermore, based on the structural characteristics of ABR@Ag, it can be inferred that this composite nanosphere can also be used to load other precious metals, such as gold, platinum, and rhodium. In addition, this material can also be used to prepare various functional composite materials, endowing them with many properties, such as enhanced antibacterial ability, and has very broad commercial prospects.

[0019] (4) The processing method of the present invention is simple, practical and easy to promote. Attached Figure Description

[0020] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. Exemplary embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0021] Figure 1 This is a technical roadmap of the present invention;

[0022] Figure 2 This is a scanning electron microscope image of ABR nanospheres prepared with different molar ratios of furfural and catechol and different amounts of ammonia water obtained in this invention.

[0023] Figure 3 These are scanning electron microscope and energy dispersive spectroscopy (EDS) images of ABR@Ag silver nanospheres obtained in Example 2 of this invention.

[0024] Figure 4 The silver content and particle size of ABR@Ag obtained in Example 2 of this invention are shown. Detailed Implementation

[0025] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0026] A method for preparing catechol-furfural resin nanospheres with a lychee-like uneven surface capable of supporting silver nanoparticles includes the following actual preparation steps:

[0027] Step 1: Preparation of litchi-shaped furfural resin nanospheres, i.e., preparation of ABR.

[0028] 0.6 g of catechol and 1.5 mL of ammonia solution (25 wt.%) were mixed in an ethanol solution (120 mL deionized water and 60 mL ethanol). The prepared mixture was sonicated at room temperature (10 min), and then 3.0 mL of furfural solution was added to the above solution. Subsequently, the mixture was transferred to a Teflon-sealed autoclave and reacted at 160 °C for 7 h. Finally, after washing several times with deionized water and ethanol, centrifuging, and drying, ABR nanospheres were obtained (molar ratio of furfural to catechol 6:1, ammonia added 1.5 mL).

[0029] Step 2: Loading of silver nanoparticles, i.e., preparation of ABR@Ag.

[0030] Ag nanoparticles were synthesized on ABR nanospheres using silver ammonia solution as the Ag precursor solution. The silver ammonia solution was obtained by adding 5.0 wt.% ammonia solution to a silver nitrate solution of a certain concentration (50 mL) until all the brown precipitate was dissolved. Next, the prepared ABR nanospheres (100 mg) were added to the above silver ammonia solution, and the mixture was stirred at 300 rpm for 3 h at room temperature. After in-situ reduction, the ABR@Ag composite material was repeatedly washed with ethanol and deionized water, centrifuged repeatedly at 10000 rpm for 5 min, and then the ABR@Ag composite material was collected and dried under vacuum. The resulting composite sample is referred to as ABR@Ag in this invention. x Wherein, the subscript x represents the concentration of the silver nitrate solution (x = 1, 3, and 10 mg / mL). -1 ).

[0031] In some embodiments, the molar ratio of furfural to catechol is 6:1.

[0032] In some embodiments, the concentration of the ammonia solution is 20 wt.% to 25 wt.%, and the amount added is 1.2 to 2 mL.

[0033] In some embodiments, the concentration of the ammonia solution is 25 wt.%, and the amount added is 1.5 mL.

[0034] In some embodiments, the volume ratio of water to ethanol in the aqueous ethanol solution is 2:1.

[0035] In some embodiments, the ultrasonic treatment time is 10 to 15 minutes.

[0036] In some embodiments, the washing process involves washing several times with water and ethanol, respectively.

[0037] In some embodiments, the specific steps for synthesizing Ag nanoparticles on the ABR nanospheres include: adding the ABR nanospheres to the above-mentioned silver ammonia aqueous solution, stirring the mixed solution at room temperature to perform in-situ reduction, obtaining the ABR@Ag composite material, washing, centrifuging, and drying to obtain the final product.

[0038] In some embodiments, the concentration of the silver nitrate solution is 1–10 mg / mL.

[0039] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are explanations of the present invention and not limitations thereof.

[0040] Example 1

[0041] Step 1: Preparation of litchi-shaped furfural resin nanospheres, i.e., preparation of ABR.

[0042] 0.6 g of catechol and 1.2 mL of ammonia solution (25 wt.%) were mixed in an ethanol solution (120 mL deionized water and 60 mL ethanol). The prepared mixture was sonicated at room temperature (10 min), and then 3.0 mL of furfural solution was added to the above solution. Subsequently, the mixture was transferred to a Teflon-sealed autoclave and reacted at 160 °C for 7 h. Finally, after washing several times with deionized water and ethanol, centrifuging, and drying, ABR nanospheres were obtained with a yield of 38% (molar ratio of furfural to catechol 6:1, and ammonia added 1.2 mL).

[0043] Step 2: Loading of silver nanoparticles, i.e., preparation of ABR@Ag.

[0044] Ag nanoparticles were synthesized on ABR nanospheres using silver ammonia solution as the Ag precursor solution. The silver ammonia solution was prepared by adding solutions at concentrations of 1, 3, and 10 mg / mL. -1 A 5.0 wt.% ammonia solution was added to a 50 mL silver nitrate solution until all the brown precipitate was dissolved. Next, 100 mg of the prepared ABR nanospheres were added to the aforementioned silver ammonia solution, and the mixture was stirred at 300 rpm for 3 h at room temperature. After in-situ reduction, the ABR@Ag composite material was repeatedly washed with ethanol and deionized water, centrifuged repeatedly at 10000 rpm for 5 min, and then the ABR@Ag composite material was collected and dried under vacuum. The resulting composite sample is referred to as ABR@Ag in this invention. x Wherein, the subscript x represents the concentration of the silver nitrate solution (x = 1, 3, and 10 mg / mL). -1 ).

[0045] Example 2

[0046] Step 1: Preparation of litchi-shaped furfural resin nanospheres, i.e., preparation of ABR.

[0047] 0.6 g of catechol and 1.5 mL of ammonia solution (25 wt.%) were mixed in an ethanol solution (120 mL deionized water and 60 mL ethanol). The prepared mixture was sonicated at room temperature (10 min), and then 3.0 mL of furfural solution was added to the above solution. Subsequently, the mixture was transferred to a Teflon-sealed autoclave and reacted at 160 °C for 7 h. Finally, after washing several times with deionized water and ethanol, centrifuging, and drying, ABR nanospheres were obtained with a yield of 69% (molar ratio of furfural to catechol 6:1, and ammonia added in the amount of 1.5 mL).

[0048] Step 2: Loading of silver nanoparticles, i.e., preparation of ABR@Ag.

[0049] Ag nanoparticles were synthesized on ABR nanospheres using silver ammonia solution as the Ag precursor solution. The silver ammonia solution was prepared by adding solutions at concentrations of 1, 3, and 10 mg / mL. -1 A 5.0 wt.% ammonia solution was added to a 50 mL silver nitrate solution until all the brown precipitate was dissolved. Next, 100 mg of the prepared ABR nanospheres were added to the aforementioned silver ammonia solution, and the mixture was stirred at 300 rpm for 3 h at room temperature. After in-situ reduction, the ABR@Ag composite material was repeatedly washed with ethanol and deionized water, centrifuged repeatedly at 10000 rpm for 5 min, and then the ABR@Ag composite material was collected and dried under vacuum. The resulting composite sample is referred to as ABR@Ag in this invention. x Wherein, the subscript x represents the concentration of the silver nitrate solution (x = 1, 3, and 10 mg / mL). -1 ).

[0050] Example 3

[0051] Step 1: Preparation of litchi-shaped furfural resin nanospheres, i.e., preparation of ABR.

[0052] 0.6 g of catechol and 2.0 mL of ammonia solution (25 wt.%) were mixed in an ethanol solution (120 mL deionized water and 60 mL ethanol). The prepared mixture was sonicated at room temperature (10 min), and then 3.0 mL of furfural solution was added to the above solution. Subsequently, the mixture was transferred to a Teflon-sealed autoclave and reacted at 160 °C for 7 h. Finally, after washing several times with deionized water and ethanol, centrifuging, and drying, ABR nanospheres were obtained with a yield of 50% (molar ratio of furfural to catechol 6:1, and ammonia added in the amount of 2.0 mL).

[0053] Step 2: Loading of silver nanoparticles, i.e., preparation of ABR@Ag.

[0054] Ag nanoparticles were synthesized on ABR nanospheres using silver ammonia solution as the Ag precursor solution. The silver ammonia solution was prepared by adding solutions at concentrations of 1, 3, and 10 mg / mL. -1 A 5.0 wt.% ammonia solution was added to a 50 mL silver nitrate solution until all the brown precipitate was dissolved. Next, 100 mg of the prepared ABR nanospheres were added to the aforementioned silver ammonia solution, and the mixture was stirred at 300 rpm for 3 h at room temperature. After in-situ reduction, the ABR@Ag composite material was repeatedly washed with ethanol and deionized water, centrifuged repeatedly at 10000 rpm for 5 min, and then the ABR@Ag composite material was collected and dried under vacuum. The resulting composite sample is referred to as ABR@Ag in this invention. x Wherein, the subscript x represents the concentration of the silver nitrate solution (x = 1, 3, and 10 mg / mL). -1 ).

[0055] Example 4

[0056] Step 1: Preparation of litchi-shaped furfural resin nanospheres, i.e., preparation of ABR.

[0057] 0.6 g of catechol and 1.5 mL of ammonia solution (25 wt.%) were mixed in an ethanol solution (120 mL deionized water and 60 mL ethanol). The prepared mixture was sonicated at room temperature (10 min), and then 2.0 mL of furfural solution was added to the above solution. Subsequently, the mixture was transferred to a Teflon-sealed autoclave and reacted at 160 °C for 7 h. Finally, after washing several times with deionized water and ethanol, centrifuging, and drying, ABR nanospheres were obtained with a yield of 26% (molar ratio of furfural to catechol 4:1, and ammonia added in 1.5 mL).

[0058] Step 2: Loading of silver nanoparticles, i.e., preparation of ABR@Ag.

[0059] Ag nanoparticles were synthesized on ABR nanospheres using silver ammonia solution as the Ag precursor solution. The silver ammonia solution was prepared by adding solutions at concentrations of 1, 3, and 10 mg / mL. -1 A 5.0 wt.% ammonia solution was added to a 50 mL silver nitrate solution until all the brown precipitate was dissolved. Next, 100 mg of the prepared ABR nanospheres were added to the aforementioned silver ammonia solution, and the mixture was stirred at 300 rpm for 3 h at room temperature. After in-situ reduction, the ABR@Ag composite material was repeatedly washed with ethanol and deionized water, centrifuged repeatedly at 10000 rpm for 5 min, and then the ABR@Ag composite material was collected and dried under vacuum. The resulting composite sample is referred to as ABR@Ag in this invention. x Wherein, the subscript x represents the concentration of the silver nitrate solution (x = 1, 3, and 10 mg / mL). -1 ).

[0060] Example 5

[0061] Step 1: Preparation of litchi-shaped furfural resin nanospheres, i.e., preparation of ABR.

[0062] 0.6 g of catechol and 1.5 mL of ammonia solution (25 wt.%) were mixed in an ethanol solution (120 mL deionized water and 60 mL ethanol). The prepared mixture was sonicated at room temperature (10 min), and then 2.5 mL of furfural solution was added to the above solution. Subsequently, the mixture was transferred to a Teflon-sealed autoclave and reacted at 160 °C for 7 h. Finally, after washing several times with deionized water and ethanol, centrifuging, and drying, ABR nanospheres were obtained with a yield of 55% (molar ratio of furfural to catechol 5:1, and ammonia added in 1.5 mL).

[0063] Step 2: Loading of silver nanoparticles, i.e., preparation of ABR@Ag.

[0064] Ag nanoparticles were synthesized on ABR nanospheres using silver ammonia solution as the Ag precursor solution. The silver ammonia solution was prepared by adding solutions at concentrations of 1, 3, and 10 mg / mL. -1 A 5.0 wt.% ammonia solution was added to a 50 mL silver nitrate solution until all the brown precipitate was dissolved. Next, 100 mg of the prepared ABR nanospheres were added to the aforementioned silver ammonia solution, and the mixture was stirred at 300 rpm for 3 h at room temperature. After in-situ reduction, the ABR@Ag composite material was repeatedly washed with ethanol and deionized water, centrifuged repeatedly at 10000 rpm for 5 min, and then the ABR@Ag composite material was collected and dried under vacuum. The resulting composite sample is referred to as ABR@Ag in this invention. xWherein, the subscript x represents the concentration of the silver nitrate solution (x = 1, 3, and 10 mg / mL). -1 ).

[0065] Figure 2 These are scanning electron microscope (SEM) images of ABR nanospheres prepared with different molar ratios of furfural and catechol and different amounts of ammonia added, obtained in Examples 1-5 of this invention. It can be seen that within the range of a molar ratio of furfural to catechol of 4-6:1 and an amount of ammonia added of 1.2-2 mL, ABR nanospheres with a surface texture resembling lychee were prepared.

[0066] Figure 3 These are scanning electron microscope and energy dispersive spectroscopy (EDS) images of ABR@Ag silver nanospheres obtained in Example 2 of this invention.

[0067] Figure 4 The silver content and particle size of ABR@Ag obtained in Example 2 of this invention are shown.

[0068] Therefore, the average particle size of the ABR@Ag composite material of the present invention is 19.7 to 20.8 mm, and the maximum loading is 29.1 (wt.%).

[0069] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing catechol-furfural-based resin nanospheres with a lychee-like uneven surface structure capable of supporting silver nanoparticles, characterized in that, The method comprises the following steps: mixing catechol and an ammonia solution into an aqueous ethanol solution to obtain a mixture solution; after ultrasonic treatment of the mixture solution, adding a furfural solution, reacting at 160-165 DEG C for 7-7.2 h, washing, centrifuging and drying the product to obtain ABR nanospheres; synthesizing Ag nanoparticles on the ABR nanospheres by using a silver ammine solution as an Ag precursor solution to obtain ABR@Ag composite materials; wherein the molar ratio of furfural to catechol is 6:1; the concentration of the ammonia solution is 25 wt.% and the addition amount is 1.5 mL.

2. The method for preparing catechol-furfuryl-based resin nanospheres having a surface capable of loading silver nanoparticles and having a lychee-shaped concave-convex structure according to claim 1, characterized by, in the aqueous ethanol solution, the volume ratio of water to ethanol is 2:

1.

3. The method for preparing catechol-furfuryl-based resin nanospheres having a surface capable of loading silver nanoparticles and having a lychee-shaped concave-convex structure according to claim 1, characterized by, the ultrasonic treatment time is 10-15 min.

4. The method for preparing catechol-furfuryl-based resin nanospheres having a surface capable of loading silver nanoparticles and having a lychee-shaped concave-convex structure according to claim 1, characterized by, the washing is performed by using water and ethanol for several times respectively.

5. The method for preparing catechol-furfuryl-based resin nanospheres having a surface capable of loading silver nanoparticles and having a lychee-shaped concave-convex structure according to claim 1, characterized by, the specific steps for synthesizing Ag nanoparticles on the ABR nanospheres include: adding the ABR nanospheres into the above silver ammine solution, stirring the mixture solution at room temperature for in-situ reduction to obtain ABR@Ag composite materials, and then washing, centrifuging and drying to obtain the product; the concentration of the silver nitrate solution used for preparing the silver ammine solution is 1-10 mg / mL.

6. The catechol-furfural-based resin nanospheres with a surface capable of loading silver nanoparticles and having a lychee-like concave-convex structure, which are prepared by the method of any one of claims 1-5.

7. The catechol-furfural-based resin nanospheres of claim 6 in the fields of electrochemistry, sensing, catalysis and medical drugs.

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