Method for preparing nano-silver particles with uniform particle size by using halogen-free eutectic solvent to assist oleylamine
Through the combination of halogen-free eutectic solvent and oleamine, the problem of halogen ions affecting nanosilver particle size and morphology is solved, and the preparation of nanosilver particles with uniform particle size and good dispersion is achieved, reducing production costs, and suitable for industrial use Production and biochemical medical applications.
Patent Information
- Application Number
- CN202411315506.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-20
- Publication Date
- 2024-12-31
AI Technical Summary
In the prior art, when preparing nano silver particles, the eutectic solvent often contains halide ions, which affects the particle size and morphology of silver powder. High-cost electrochemical methods are not suitable for large-scale industrial production.
The halogen-free hydrogen bond acceptor is used to mix with the hydrogen bond donor to form a low eutectic solvent, and use oleamine as the reducing agent and dispersant to prepare nanosilver particles by heating the reactor to avoid interference from halogen ions and reduce production costs.
It has achieved the preparation of spherical nanosilver particles with uniform particle size and good dispersion, which is low in cost and strong controllability, suitable for large-scale industrial production, and can be widely used in biochemical and medical antibacterial materials.
Smart Images
Figure CN119216598A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of silver particle preparation, and particularly relates to a method for preparing nano silver particles with uniform particle size by using a halogen-free deep eutectic solvent as an aid of oleylamine. Background Art
[0002] In recent years, metal nanoparticles, especially gold and silver, have attracted great research interest due to their potential applications in nanoelectronics, nanooptics, catalysis, biology, etc. At present, the method of preparing nanosilver based on deep eutectic solvents uses choline chloride as the hydrogen bond acceptor (HBA), and the presence of halogen ions will have a certain effect on the particle size and morphology of silver powder.
[0003] The chemical reduction method based on low eutectic solvents can realize the preparation of nano-scale and submicron-scale particles. The patent with publication number CN118106504A discloses a method and application of low eutectic solvent-assisted preparation of metal nanocatalysts. This method uses low eutectic solvent oil bath heating to prepare nano cobalt-based catalysts; the patent with publication number CN116463685A discloses a method of synthesizing silver particles using low eutectic solvent-based electrolyte. Although this method uses low eutectic solvent as electrolyte and electrochemical method to synthesize silver particles, this technical route has the disadvantage of high cost and is not suitable for large-scale industrial production; the patent with publication number CN116768196A discloses a method of preparing carbon nanotubes using low eutectic solvents. Although it uses microwave heating in low eutectic solvents, Carbon nanotubes were prepared, but the low eutectic solvent used contained chloride / bromide ions, which was not conducive to the preparation of nano silver; the patent with publication number CN118547026A disclosed a method for enzymatically catalyzing the synthesis of glucose laurate in a low eutectic solvent. Although cyclohexanone-lauric acid was used as the low eutectic solvent and glucose laurate was synthesized by the enzymatic method of glucose ester, it adopted a common heating method, which was not conducive to uniform heating during the preparation process and was not conducive to controlling the morphology of the product; the patent with publication number CN110182860B disclosed a method for preparing nano nickel-sulfur compounds by a one-step synthesis method using a low eutectic solvent. The low eutectic solvent used contained halogen ions, which would have a certain effect on the particle size and morphology of the silver powder.
[0004] Therefore, how to propose a method for preparing nanosilver particles with uniform particle size is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention
[0005] In view of this, an object of the present invention is to provide a method for preparing silver nanoparticles with uniform particle size by using oleylamine assisted by a halogen-free deep eutectic solvent.
[0006] In order to achieve the above object, the present invention adopts the following technical solution:
[0007] A method for preparing nano silver particles with uniform particle size using oleylamine assisted by a halogen-free deep eutectic solvent comprises the following steps:
[0008] (1) A halogen-free hydrogen bond acceptor (HBA) and a hydrogen bond donor (HBD) are mixed in a certain proportion and heated and stirred for a certain period of time to synthesize a halogen-free deep eutectic solvent with a certain viscosity and fluidity;
[0009] (2) adding a certain amount of silver salt into a beaker, adding a certain amount of a deep eutectic solvent, and finally adding a certain amount of oleylamine into the beaker at room temperature and stirring for a certain period of time;
[0010] (3) placing the mixture in a reaction vessel, heating it at a certain temperature for a certain time, and after the reaction is completed, washing it three times by centrifugation with acetone, and finally dispersing it in ethanol to obtain nanosilver particles.
[0011] It should be noted that, since the reducing agents that are easily soluble in the deep eutectic solvent include alcohols and amines, the present invention considers using oleylamine as a reducing agent to prepare nanosilver. The nanosilver particles prepared by the present invention use a halogen-free deep eutectic solvent, oleylamine as a reducing agent and a dispersant, and prepare spherical nanosilver particles with a particle size of 5-15nm.
[0012] Preferably, in step (1), the hydrogen bond acceptor (HBA) is choline bitartrate or choline nitrate, and the hydrogen bond donor (HBD) is N,N-dimethylurea, maleic acid, D + At least one of glucose, acrylamide, oxalic acid and ethylene glycol, wherein the molar ratio of the halogen-free hydrogen bond acceptor (HBA) to the hydrogen bond donor (HBD) is 1:1-1:3.
[0013] Preferably, in step (1), the heating temperature is 100-130° C., and the stirring time is 1-3 h.
[0014] Preferably, in step (2), the silver salt is one of silver nitrate, silver carbonate and silver trifluoromethanesulfonate.
[0015] Preferably, the amount of the low eutectic solvent added is 200-2000 times the mass of the silver salt added, and the amount of oleylamine added is 20-30 times the mass of the silver salt added.
[0016] Specifically, in step (2), the amount of the silver salt added is 0.5-1.5 mmol, the amount of the low eutectic solvent added is 10-100 g, and the amount of oleylamine added is 5-30 mmol.
[0017] Preferably, in step (2), the stirring time is 1-5 min.
[0018] Preferably, in step (3), the heating reaction temperature is 100-180° C., and the heating reaction time is 1-3 h.
[0019] Compared with the prior art, the present invention has the following beneficial effects:
[0020] (1) The method of the present invention abandons the traditional solvent of the liquid phase chemical reduction method and adopts a low eutectic solvent as the solvent. The provided low eutectic solvent does not contain halogen ions, thereby eliminating the interference of halogen ions on the morphology of nanosilver. The prepared silver particles can adjust the particle size distribution of nanosilver according to the type of the low eutectic solvent and the amount of key active substances used.
[0021] (2) The low eutectic solvent is a low eutectic mixture composed of a certain stoichiometric ratio of hydrogen bond acceptors (HBA) and hydrogen bond donors (HBD). It has the characteristics of low cost, non-toxicity, low eutectic point, and high thermal stability. It is an ideal new reaction medium and has a certain viscosity. It has an inhibitory effect on the growth and agglomeration of nanosilver, making the prepared nanosilver particle size distribution narrower, with good dispersion and regular spherical shape. It can be stored at room temperature and can be widely used in biochemical and medical antibacterial materials.
[0022] (3) The method of the present invention conducts exploratory experiments on different types of low eutectic solvents. The low eutectic solvent can be structurally modified and designed according to the application requirements of the silver powder. It is determined that the silver salt and dispersant used can be evenly dispersed in the low eutectic solvent during the preparation process and have good solubility.
[0023] (4) The method of the present invention replaces the electrolysis method with heating in a reactor and adopts oleylamine which is easily soluble in a low eutectic solvent as a reducing agent and a dispersant, thereby reducing the production cost, achieving uniform heating of the solute, and making the nanosilver homogeneous generated and grown, and the entire reaction is more controllable. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.
[0025] Figure 1 This is a transmission electron microscope image of nanosilver prepared in Example 1.
[0026] Figure 2 This is a transmission electron microscope image of nanosilver prepared in Comparative Example 1. DETAILED DESCRIPTION
[0027] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0028] The word "embodiment" used here as an "exemplary" does not necessarily mean that any embodiment described is superior to or better than other embodiments. Unless otherwise specified, the performance index tests in the embodiments of this application are performed using conventional test methods in the art. It should be understood that the terms described in this application are only used to describe specific implementation methods and are not used to limit the content disclosed in this application.
[0029] Unless otherwise specified, the technical and scientific terms used in this document have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs; other experimental methods and technical means not specifically specified in this application refer to experimental methods and technical means commonly used by ordinary technicians in this field.
[0030] In order to better illustrate the content of the present application, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In the embodiments, some methods, means, instruments, equipment, etc. well known to those skilled in the art are not described in detail in order to highlight the main purpose of the present application.
[0031] Under the premise of no conflict, the technical features disclosed in the embodiments of the present application can be combined arbitrarily, and the resulting technical solutions belong to the contents disclosed in the embodiments of the present application.
[0032] The invention discloses a method for preparing nano silver particles with uniform particle size by using oleylamine assisted by a halogen-free deep eutectic solvent.
[0033] In order to better understand the present invention, the present invention is further specifically described below through the following examples, but it should not be understood as a limitation of the present invention. Some non-essential improvements and adjustments made by technicians in this field based on the above invention content are also considered to fall within the protection scope of the present invention.
[0034] Example 1
[0035] (1) Choline bitartrate and N,N-dimethylurea were mixed in a molar ratio of 1:2 and heated at 130°C for 2 hours to synthesize a choline bitartrate-N,N-dimethylurea based low eutectic solvent.
[0036] (2) 0.5 mmol of silver nitrate was added to a beaker, and 50 g of choline bitartrate-N,N-dimethylurea-based low eutectic solvent was added. Finally, 10 mmol of oleylamine was added to the beaker at room temperature and stirred for 2 min.
[0037] (3) The mixture was placed in a reaction kettle and heated at 120° C. for 2 h. After the reaction was completed, the mixture was washed three times by centrifugation with acetone and finally dispersed in ethanol to obtain spherical silver nanoparticles with an average particle size of 8.3 nm.
[0038] Example 2
[0039] (1) Choline bitartrate and maleic acid are mixed in a molar ratio of 1:1 and heated at 130° C. for 2 h to synthesize a choline bitartrate-maleic acid-based deep eutectic solvent.
[0040] (2) 1.5 mmol of silver nitrate was added to a beaker, 40 g of choline bitartrate-maleic acid-based low eutectic solvent was added, and finally 25 mmol of oleylamine was added to the beaker at room temperature and stirred for 2 min;
[0041] (3) The mixture was placed in a reaction kettle and heated at 140° C. for 2.5 h. After the reaction was completed, the mixture was washed three times by centrifugation with acetone and finally dispersed in ethanol to obtain spherical nanosilver particles with an average particle size of 12.7 nm.
[0042] Example 3
[0043] (1) Choline nitrate and ethylene glycol are mixed in a molar ratio of 1:1 and heated at 130° C. for 2 h to synthesize a choline nitrate-ethylene glycol-based low eutectic solvent.
[0044] (2) 1 mmol of silver nitrate was added to a beaker, 60 g of choline nitrate-ethylene glycol-based low eutectic solvent was added, and finally 10 mmol of oleylamine was added to the beaker at room temperature and stirred for 2 min;
[0045] (3) The mixture was placed in a reaction kettle and heated at 150° C. for 1.5 h. After the reaction was completed, the mixture was washed three times by centrifugation with acetone and finally dispersed in ethanol to obtain spherical silver nanoparticles with an average particle size of 7.9 nm.
[0046] Example 4
[0047] (1) Choline bitartrate and D + Glucose was mixed in a 1:1 molar ratio and heated at 130°C for 3 h to synthesize choline bitartrate-D + Glucose based deep eutectic solvent.
[0048] (2) Add 1.5 mmol of silver nitrate to a beaker and 30 g of choline bitartrate-D +Glucose-based deep eutectic solvent, finally, 10 mmol of oleylamine was added to the beaker at room temperature and stirred for 2 min;
[0049] (3) The mixture was placed in a reaction kettle and heated at 160° C. for 3 h. After the reaction was completed, the mixture was washed three times by centrifugation with acetone and finally dispersed in ethanol to obtain spherical nanosilver particles with an average particle size of 11.7 nm.
[0050] Example 5
[0051] (1) Choline bitartrate and ethylene glycol are mixed in a molar ratio of 1:1 and heated at 120° C. for 2 h to synthesize a choline bitartrate-ethylene glycol-based deep eutectic solvent.
[0052] (2) 1.5 mmol of silver trifluoromethanesulfonate was added to a beaker, 50 g of choline bitartrate-ethylene glycol-based low eutectic solvent was added, and finally 26 mmol of oleylamine was added to the beaker at room temperature and stirred for 1 min;
[0053] (3) The mixture was placed in a reaction kettle and heated at 150° C. for 2 h. After the reaction was completed, the mixture was washed three times by centrifugation with acetone and finally dispersed in ethanol to obtain spherical silver nanoparticles with an average particle size of 12.1 nm.
[0054] Example 6
[0055] (1) Choline bitartrate and ethylene glycol are mixed in a molar ratio of 1:1 and heated at 120° C. for 2 h to synthesize a choline bitartrate-ethylene glycol-based deep eutectic solvent.
[0056] (2) 1 mmol of silver nitrate was added to a beaker, 50 g of choline bitartrate-ethylene glycol-based low eutectic solvent was added, and finally 23 mmol of oleylamine was added to the beaker at room temperature and stirred for 2 min;
[0057] (3) The mixture was placed in a reaction kettle and heated at 170° C. for 1 h. After the reaction was completed, the mixture was washed three times by centrifugation with acetone and finally dispersed in ethanol to obtain spherical silver nanoparticles with an average particle size of 8.4 nm.
[0058] In order to further demonstrate the beneficial effects of the present invention and to better understand the present invention, the following comparative examples are used to further illustrate the technical features disclosed in the present invention, but they should not be construed as limiting the present invention. Other improvements made by those skilled in the art based on the above invention content without inventive work are also considered to fall within the scope of protection of the present invention.
[0059] Comparative Example 1
[0060] (1) Choline chloride and ethylene glycol are mixed in a molar ratio of 1:1 and heated at 130° C. for 2 h to synthesize a choline chloride-ethylene glycol-based deep eutectic solvent.
[0061] (2) 0.5 mmol of silver nitrate was added to a beaker, 50 g of choline chloride-ethylene glycol-based low eutectic solvent was added, and finally 10 mmol of oleylamine was added to the beaker at room temperature and stirred for 2 min;
[0062] (3) The mixture was placed in a reaction vessel and heated at 120° C. for 2 h. After the reaction was completed, it was washed three times by centrifugation with acetone and finally dispersed in ethanol to obtain silver nanoparticles, but the sphericity was not high.
[0063] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for preparing nano silver particles with uniform particle size using oleylamine assisted by a halogen-free deep eutectic solvent, characterized in that: The following steps are involved: (1) mixing a halogen-free hydrogen bond acceptor (HBA) and a hydrogen bond donor (HBD) and heating and stirring them to synthesize a halogen-free deep eutectic solvent; (2) adding the halogen-free low eutectic solvent synthesized in step (1) to the silver salt, adding oleylamine at room temperature and stirring to obtain a mixture; (3) heating the mixture obtained in step (2) to react, centrifuging and washing after the reaction is completed, and finally dispersing it in ethanol to obtain spherical silver nanoparticles with uniform particle size.
2. The method for preparing nano silver particles with uniform particle size using oleylamine assisted by a halogen-free deep eutectic solvent according to claim 1, characterized in that: In step (1), the hydrogen bond acceptor (HBA) is choline bitartrate or choline nitrate, and the hydrogen bond donor (HBD) is N,N-dimethylurea, maleic acid, D + At least one of glucose, acrylamide, oxalic acid and ethylene glycol, wherein the molar ratio of the halogen-free hydrogen bond acceptor (HBA) to the hydrogen bond donor (HBD) is 1:1-1:
3.
3. The method for preparing nano silver particles with uniform particle size using oleylamine assisted by a halogen-free deep eutectic solvent according to claim 1, characterized in that: In step (1), the heating temperature is 100-130° C., and the stirring time is 1-3 h.
4. The method for preparing nano silver particles with uniform particle size using oleylamine assisted by a halogen-free deep eutectic solvent according to claim 1, characterized in that: In step (2), the silver salt is silver nitrate, silver carbonate or silver trifluoromethanesulfonate.
5. The method for preparing nano silver particles with uniform particle size using oleylamine assisted by a halogen-free deep eutectic solvent according to claim 1 or 4, characterized in that: The amount of the low eutectic solvent added is 200-2000 times the mass of the silver salt added, and the amount of oleylamine added is 20-30 times the mass of the silver salt added.
6. The method for preparing nano silver particles with uniform particle size using oleylamine assisted by a halogen-free deep eutectic solvent according to claim 5, characterized in that: The amount of the silver salt added is 0.5-1.5 mmol, the amount of the low eutectic solvent added is 10-100 g, and the amount of the oleylamine added is 5-30 mmol.
7. The method for preparing nano silver particles with uniform particle size using oleylamine assisted by a halogen-free deep eutectic solvent according to claim 1, characterized in that: In step (2), the stirring time is 1-5 min.
8. The method for preparing nano silver particles with uniform particle size using oleylamine assisted by a halogen-free deep eutectic solvent according to claim 1, characterized in that: In step (3), the heating reaction temperature is 100-180° C., and the heating reaction time is 1-3 h.