Needle-like nano-selenium and preparation method thereof

Abstract

The invention belongs to the technical field of nano-selenium material preparation, and particularly discloses needle-like nano-selenium and a preparation method thereof. According to the method, a sodium selenite solution and an ascorbic acid solution are subjected to an oxidation-reduction reaction under the ultrasonic condition, the needle-like nano-selenium can be obtained, and the diameter of the needle-like nano-selenium is 20-100 nm. The preparation steps disclosed by the invention are simple and convenient to operate, the reaction can be carried out under the conditions of normal temperature and normal pressure, complicated equipment is not needed, and excessive auxiliaries such as a surfactant are not needed; and the shape and size of the needle-shaped nano-selenium can be effectively controlled through an ultrasonic-assisted technology, so that the needle-shaped nano-selenium can meet the requirements of various applications. By introducing ultrasonic waves, the speed of the reduction reaction is remarkably increased, the generation rate of nano-selenium is increased, and the preparation process is more efficient. The method is suitable for large-scale industrial production and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of nano-selenium materials, and particularly to a needle-shaped nano-selenium and a preparation method thereof. Background Art

[0002] Nano-selenium is a new type of nano-material with broad application prospects. Due to its unique physical and chemical properties, such as high antioxidant, antibacterial, and anti-cancer properties, it shows great potential in multiple fields. Especially in the medical field, nano-selenium, as a material with significant antioxidant activity and immune regulation function, has been widely studied and applied in cancer treatment, the development of anti-inflammatory drugs, and the prevention of chronic diseases. In addition, nano-selenium also plays an important role in the agricultural field. For example, as a plant nutrient fortifier, it can enhance the yield and stress resistance of crops; as a feed additive, it can improve the immunity and growth rate of animals; in the food industry, nano-selenium is used as a new type of functional food additive, which can extend the shelf life of food and improve the nutritional value of food.

[0003] Although nano-selenium has broad application prospects, how to control its morphology and size during the preparation process has always been a key technical challenge. The morphology and size of nano-materials have a significant impact on their physical and chemical properties. Therefore, it is crucial to precisely control these parameters during the preparation process. Although traditional preparation methods can produce spherical nano-selenium, it is often difficult to achieve morphological diversity and precise control of size, resulting in unstable material properties or difficulty in meeting specific application requirements.

[0004] Needle-shaped nano-selenium, due to its unique structure, exhibits excellent physical and chemical properties, especially showing great potential in the fields of agriculture, catalysis, drug carriers, and biosensing. For example, the needle-shaped structure helps improve the binding ability of nano-materials to plants and increases the utilization rate of nano-fertilizers; it can improve its bioavailability in the body, enhance its interaction with target cells, and improve the therapeutic effect of drugs. Therefore, developing an efficient and size-controllable preparation method for needle-shaped nano-selenium has important practical significance. It can not only promote the application of nano-selenium in existing fields but also potentially open up its use in more emerging fields. At the same time, through process optimization to achieve large-scale and low-cost production, it helps to accelerate the industrialization process of needle-shaped nano-selenium and further expand its market application scope. Summary of the Invention

[0005] In view of this, the present invention provides a needle-shaped nano-selenium and a preparation method thereof to solve the problems that the existing nano-selenium preparation methods are difficult to precisely control the morphology and that there are few reports on needle-shaped nano-selenium.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A preparation method of needle-shaped nano-selenium, comprising the following steps:

[0008] Perform an oxidation-reduction reaction on a sodium selenite solution and an ascorbic acid solution to obtain needle-shaped nano-selenium;

[0009] The oxidation-reduction reaction is carried out under ultrasonic conditions.

[0010] Preferably, the molar ratio of sodium selenite in the sodium selenite solution to ascorbic acid in the ascorbic acid solution is 1:2 to 10.

[0011] Preferably, the process of the oxidation-reduction reaction is to drop the sodium selenite solution into the ascorbic acid solution for reaction, and ultrasonic and stirring are maintained during the oxidation-reduction reaction.

[0012] Preferably, the dropping rate is 2 to 3 mL / min.

[0013] Preferably, the mass concentration of the sodium selenite solution is 2 g / L; the mass concentration of the ascorbic acid solution is 4.08 g / L.

[0014] Preferably, during the oxidation-reduction reaction, the ultrasonic frequency is 40 kHz, and the ultrasonic power is 500 to 1000 W;

[0015] The stirring rate is 3000 to 5000 rpm; the oxidation-reduction reaction time is 40 to 80 min.

[0016] Preferably, the diameter of the needle-shaped nano-selenium is 20 to 100 nm.

[0017] Preferably, when the ultrasonic power is 500 W, the diameter of the needle-shaped nano-selenium obtained is 90 to 100 nm; when the ultrasonic power is 750 W, the diameter of the needle-shaped nano-selenium obtained is 60 to 70 nm; when the ultrasonic power is 1000 W, the diameter of the needle-shaped nano-selenium obtained is 20 to 40 nm.

[0018] Another object of the present invention is to provide needle-shaped nano-selenium prepared by a preparation method of needle-shaped nano-selenium.

[0019] Through the above technical solutions, compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The preparation steps disclosed in the present invention are simple to operate, the reaction can be carried out under normal temperature and pressure conditions, without complex equipment, without unnecessary auxiliaries such as surfactants, simplifying the preparation process and reducing the production cost.

[0021] 2. The present invention can effectively control the morphology and size of needle-shaped nano-selenium through ultrasonic-assisted technology, so as to meet the requirements of various applications.

[0022] 3. The present invention uses ascorbic acid as a reducing agent, and the reaction process is mild and non-toxic, meeting the principles of green chemistry and contributing to environmental protection. The introduction of ultrasonic waves significantly accelerates the reduction reaction rate, increases the production rate of nano-selenium, and makes the preparation process more efficient. At the same time, due to the simple and easy implementation of the method of the present invention, the size and morphology of the product can be precisely controlled by adjusting process parameters, which is suitable for large-scale industrial production and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0024] Figure 1 SEM image of needle-shaped nano-selenium prepared in Example 1, Figure 1 where a in [the figure] is a 10,000-fold magnification image, Figure 1 and b in [the figure] is a 50,000-fold magnification image;

[0025] Figure 2 SEM image of needle-shaped nano-selenium prepared in Example 2, Figure 2 where a in [the figure] is a 10,000-fold magnification image, Figure 2 and b in [the figure] is a 50,000-fold magnification image;

[0026] Figure 3 SEM image of needle-shaped nano-selenium prepared in Example 3, Figure 3 where a in [the figure] is a 10,000-fold magnification image, Figure 3 and b in [the figure] is a 50,000-fold magnification image. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The present invention provides a method for preparing needle-shaped nano-selenium, which includes the following steps:

[0028] Perform an oxidation-reduction reaction on a sodium selenite solution and an ascorbic acid solution to obtain needle-shaped nano-selenium;

[0029] The oxidation-reduction reaction is carried out under ultrasonic conditions.

[0030] In the present invention, the molar ratio of sodium selenite in the sodium selenite solution to ascorbic acid in the ascorbic acid solution is 1:2 - 10, preferably 1:3 - 8, further preferably 1:4 - 6, and still further preferably 1:5.

[0031] In the present invention, the process of the redox reaction is to drop the sodium selenite solution into the ascorbic acid solution for reaction, and ultrasound and stirring are maintained during the redox reaction.

[0032] In the present invention, the dropping rate is 2 - 3 mL / min, specifically it can be 2.2 mL / min, 2.4 mL / min, 2.5 mL / min, 2.6 mL / min, 2.8 mL / min.

[0033] In the present invention, the mass concentration of the sodium selenite solution is 2 g / L; the mass concentration of the ascorbic acid solution is 4.08 g / L.

[0034] In the present invention, during the process of the redox reaction, the frequency of the ultrasound is 40 kHz, and the power of the ultrasound is 500 - 1000 W, specifically it can be 550 W, 600 W, 650 W, 700 W, 750 W, 800 W, 850 W, 900 W, 950 W.

[0035] In the present invention, the stirring rate is 3000 - 5000 rpm, specifically it can be 3200 rpm, 3500 rpm, 3800 rpm, 4000 rpm, 4200 rpm, 4500 rpm, 4800 rpm; the time of the redox reaction is 40 - 80 min, specifically it can be 45 min, 50 min, 55 min, 60 min, 65 min, 70 min, 75 min. The redox reaction still needs to react for a period of time after the dropping is completed. The defined time of the redox reaction includes the dropping time and the reaction time after the dropping is completed. Ultrasound and stirring are maintained during both of these two periods.

[0036] In the present invention, the diameter of the needle-shaped nano-selenium is 20 - 100 nm, specifically it can be 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm.

[0037] In the present invention, when the power of the ultrasound is 500 W, the diameter of the needle-shaped nano-selenium obtained is 90 - 100 nm; when the power of the ultrasound is 750 W, the diameter of the needle-shaped nano-selenium obtained is 60 - 70 nm; when the power of the ultrasound is 1000 W, the diameter of the needle-shaped nano-selenium obtained is 20 - 40 nm.

[0038] In the present invention, the diameter of the needle-shaped nano-selenium is negatively correlated with the power of the ultrasound. As the power of the ultrasound increases, the diameter of the needle-shaped nano-selenium gradually decreases.

[0039] In the present invention, after the redox reaction is completed, a separation and purification step is further included, specifically: the needle-shaped nano selenium produced is separated by precipitation-re-suspension, and then the product is centrifugally washed with deionized water multiple times to remove unreacted raw materials and by-products, and then dried to obtain pure needle-shaped nano selenium.

[0040] In the present invention, the number of centrifugal washing times is preferably 3 to 6, specifically it can be 3 times, 4 times, 5 times, or 6 times; the drying temperature is preferably 20 to 50 °C, specifically it can be 25 °C, 30 °C, 35 °C, 40 °C, or 45 °C.

[0041] The present invention also provides needle-shaped nano selenium prepared by a method for preparing needle-shaped nano selenium.

[0042] The needle-shaped nano selenium of the present invention is applicable to fields such as agriculture, catalysis, drug carriers, and biosensing.

[0043] Next, the technical solutions in the embodiments of the present invention will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0044] Example 1

[0045] (1) Material preparation

[0046] Sodium selenite (Na 2 SeO 3 ), ascorbic acid (C 6 H 8 O 6 ), deionized water.

[0047] (2) Preparation of oxidant solution

[0048] Take 0.2000 grams of sodium selenite and dissolve it in 100 milliliters of deionized water, stir until completely dissolved to obtain a sodium selenite solution.

[0049] (3) Preparation of reductant solution

[0050] Take 0.4080 grams of ascorbic acid and dissolve it in 100 milliliters of deionized water, stir until completely dissolved to obtain an ascorbic acid solution.

[0051] (4) Ultrasonic-assisted reduction reaction

[0052] Under normal temperature and pressure conditions, the sodium selenite solution in step (2) is added dropwise to the ascorbic acid solution in step (3) (the dropping rate is 2 mL / min), and the molar ratio of sodium selenite to ascorbic acid is 1:2. During the reaction process, ultrasonic waves with a frequency of 40 kHz are used for assistance, the ultrasonic power is set to 500 W, the ultrasonic time is 60 minutes, and at the same time, it is ensured that the reaction is carried out under stirring conditions, and the stirring rate is 4000 rpm. A reduction reaction occurs during this process to generate needle-shaped nano selenium.

[0053] (5) Product separation and purification

[0054] After the reaction is completed, the generated needle-shaped nano selenium product is purified by precipitation - resuspension. The product is centrifugally washed 4 times with deionized water to remove unreacted substances and by-products, and then dried at a low temperature of 40 °C to obtain pure needle-shaped nano selenium with a diameter of 90 - 100 nm.

[0055] Example 2

[0056] The difference between this example and Example 1 is only that the ultrasonic power is adjusted to 750 W, and pure needle-shaped nano selenium with a diameter of 60 - 70 nm is obtained.

[0057] Example 3

[0058] The difference between this example and Example 1 is only that the ultrasonic power is adjusted to 1000 W, and pure needle-shaped nano selenium with a diameter of 20 - 40 nm is obtained.

[0059] The SEM images of the needle-shaped nano selenium prepared in Examples 1 - 3 are shown in sequence as Figures 1 to 3 shown, and it can be seen from Figures 1 to 3 that the present invention has prepared needle-shaped nano selenium.

[0060] Comparative Example 1

[0061] The difference between this example and Example 1 is only that the ultrasonic power is adjusted to 0 W (without ultrasonic assistance), and spherical nano selenium is obtained.

[0062] Example 4

[0063] (1) Material preparation

[0064] Sodium selenite (Na 2 SeO 3 ), ascorbic acid (C 6 H 8 O 6 ), deionized water.

[0065] (2) Preparation of oxidant solution

[0066] Take 0.2000 g of sodium selenite and dissolve it in 100 mL of deionized water. Stir until completely dissolved to obtain a sodium selenite solution.

[0067] (3) Prepare a reducing agent solution

[0068] Take 1.0020 g of ascorbic acid and dissolve it in 100 mL of deionized water. Stir until completely dissolved to obtain an ascorbic acid solution.

[0069] (4) Ultrasonic-assisted reduction reaction

[0070] Under normal temperature and pressure conditions, gradually add the sodium selenite solution in step (2) dropwise to the ascorbic acid solution in step (3) (the dropping rate is 2.5 mL / min), and the molar ratio of sodium selenite to ascorbic acid is 1:5. During the reaction process, use ultrasonic waves with a frequency of 40 kHz for assistance, set the ultrasonic power to 800 W, and the ultrasonic time to 60 minutes. At the same time, ensure that the reaction is carried out under stirring conditions, and the stirring rate is 3500 rpm. A reduction reaction occurs during this process to generate needle-shaped nano-selenium.

[0071] (5) Product separation and purification

[0072] After the reaction is completed, purify the generated needle-shaped nano-selenium product by precipitation-resuspension. Centrifuge and wash the product 4 times with deionized water to remove unreacted substances and by-products, and then dry it at a low temperature of 40 °C to obtain pure needle-shaped nano-selenium.

[0073] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other.

[0074] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can 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 these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing needle-shaped nano-selenium, characterized in that: The steps include: The sodium selenite solution and the ascorbic acid solution are subjected to an oxidation-reduction reaction to obtain needle-shaped nano-selenium; The redox reaction is carried out under ultrasonic conditions.

2. The method for preparing needle-shaped nano-selenium according to claim 1, characterized in that: The molar ratio of the sodium selenite in the sodium selenite solution to the ascorbic acid in the ascorbic acid solution is 1:2-10.

3. The method for preparing needle-shaped nano-selenium according to claim 2, characterized in that: The process of the redox reaction is to drop the sodium selenite solution into the ascorbic acid solution for reaction, and maintain ultrasound and stirring during the redox reaction.

4. The method for preparing needle-shaped nano-selenium according to claim 3, characterized in that: The dropping rate is 2-3 mL / min.

5. The method for preparing needle-shaped nano-selenium according to any one of claims 1 to 4, characterized in that: The mass concentration of the sodium selenite solution is 2 g / L; the mass concentration of the ascorbic acid solution is 4.08 g / L.

6. The method for preparing needle-shaped nano-selenium according to claim 5, characterized in that: The frequency of ultrasound during the redox reaction is 40kHz, and the power of ultrasound is 500-1000W; The stirring rate is 3000-5000 rpm; the redox reaction time is 40-80 min.

7. The method for preparing needle-shaped nano-selenium according to claim 6, characterized in that: The diameter of the needle-shaped nano-selenium is 20-100 nm.

8. The method for preparing needle-shaped nano-selenium according to claim 5 or 6, characterized in that: When the ultrasonic power is 500W, the diameter of the needle-shaped nano-selenium is 90-100nm; when the ultrasonic power is 750W, the diameter of the needle-shaped nano-selenium is 60-70nm; when the ultrasonic power is 1000W, the diameter of the needle-shaped nano-selenium is 20-40nm.

9. The needle-shaped nano-selenium prepared by the method for preparing needle-shaped nano-selenium according to any one of claims 1 to 8.

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