Cuprous oxide, a preparation method and application thereof

Abstract

The application discloses cuprous oxide and a preparation method and application thereof, and relates to the technical field of cuprous oxide, in particular to a preparation method of cuprous oxide, which comprises the following steps: adding an alkali solution with a mass of m1 into a copper source solution, and reacting at a reaction temperature of T1 to obtain a first solution; then adding an alkali solution with a mass of m2 and a saccharide reducing agent into the first solution, and reacting at a reaction temperature of T2 to obtain a second solution, wherein T1 < T2, m2 <= m1; and sequentially performing filtration treatment and drying treatment on the precipitate in the second solution, so as to obtain the cuprous oxide. The preparation method of the cuprous oxide can effectively intervene in the particle size of the cuprous oxide by controlling the temperature in stages, so that the cuprous oxide particles with nanoscale small size are finally obtained, the bioavailability is relatively high, the cuprous oxide can be more effectively absorbed and utilized by animals, and the waste and excretion of copper are reduced.

Description

Technical Field

[0001] This invention belongs to the field of feed additives, and particularly relates to a copper feed additive, its preparation method, and its application. Background Technology

[0002] Copper is an essential trace element for animals to maintain life. A deficiency can impair hematopoiesis, leading to anemia. Furthermore, copper participates in the formation of lysyl oxidase, an enzyme responsible for maintaining the strength and elasticity of bones, blood vessels, and cartilage; copper deficiency results in brittle bones and increased susceptibility to fractures. In addition, copper helps animals resist disease by forming antioxidant enzymes such as copper-zinc superoxide dismutase and is crucial for maintaining normal reproductive function.

[0003] Existing copper sulfate feed additives are easily antagonized by phytic acid, calcium, magnesium and other components in the feed, resulting in low absorption rates. Some copper may be excreted in the form of insoluble salts. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies and defects mentioned in the background art above, and to provide cuprous oxide and its preparation method and application, aiming to solve the problem of low absorption rate of related copper feed additives.

[0005] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows:

[0006] A method for preparing cuprous oxide includes the following steps: adding an alkaline solution of mass m1 to a copper source solution and reacting at a reaction temperature T1 to obtain a first solution; then adding an alkaline solution of mass m2 and a sugar reducing agent to the first solution and reacting at a reaction temperature T2 to obtain a second solution, wherein T1 < T2 and m2 ≤ m1; and sequentially filtering and drying the precipitate in the second solution to obtain cuprous oxide.

[0007] In the above preparation method, preferably, in the process of preparing the first solution, the molar ratio of the copper source solution to the alkaline solution is 1:1.5-2.5, and in the process of preparing the second solution, the molar ratio of the sugar reducing agent to the alkaline solution is 1:0.5-1.5.

[0008] In the above preparation method, preferably, 1≤m1 / m2≤4, and 35℃≤T1≤45℃, 70℃<T2<80℃.

[0009] In the above preparation method, preferably, the copper source is copper sulfate, the alkaline solution is sodium hydroxide solution, and the sugar reducing agent is any one of glucose, fructose, galactose, maltose, and lactose.

[0010] In the above preparation method, preferably, the first solution contains copper hydroxide precipitate, and the copper hydroxide precipitate is spherical.

[0011] In the above preparation method, preferably, the particle size of the copper hydroxide precipitate is 500-800 nm.

[0012] As a general technical concept, the present invention also provides a cuprous oxide, which is prepared by the method of any one of claims 1-6.

[0013] Preferably, the cuprous oxide is spherical and has a particle size of 400-600 nm.

[0014] Preferably, in the cuprous oxide described above, the mass content of copper in the cuprous oxide is ω > 87%.

[0015] As a general technical concept, the present invention also provides an application of the above-mentioned cuprous oxide in animal feed.

[0016] Compared with the prior art, the advantages of the present invention are as follows: The method for preparing cuprous oxide provided by this invention involves adding alkali in batches during the preparation process, which helps maintain the pH stability of the entire reaction system. Adding all the alkali solution at once will cause drastic local pH fluctuations, leading to side reactions and the formation of byproducts such as copper oxide, reducing the purity of the cuprous oxide product. Furthermore, it will cause the copper hydroxide precipitate in the first solution to form too quickly, resulting in cuprous oxide particles of varying sizes and irregular shapes. In addition, the method for preparing cuprous oxide provided by this invention, through staged temperature control, can effectively control the cuprous oxide particle size, ultimately obtaining nanoscale cuprous oxide particles. Compared to copper sulfate, nanoscale cuprous oxide has a high specific surface area, and these particles can more easily enter cells through mechanisms such as phagocytosis, resulting in higher bioavailability and more effective absorption and utilization by animals, reducing copper waste and excretion. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figures 1-4 The image shows an electron microscope image of cuprous oxide prepared in Example 1.

[0019] Figures 5-8The image shows an electron microscope image of the cuprous oxide prepared in Example 2. Detailed Implementation

[0020] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0021] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0022] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0023] This invention provides a method for preparing cuprous oxide, comprising the following steps: S1: Add an alkaline solution of mass m1 to the copper source solution and react at a reaction temperature T1 to obtain the first solution; S2: Add an alkaline solution with a mass of m2 and a sugar reducing agent to the first solution, and react at the reaction temperature T2 to obtain the second solution, satisfying: T1 < T2, m2 ≤ m1; S3: The precipitate in the second solution is filtered and dried sequentially to obtain cuprous oxide.

[0024] In some embodiments, the first solution in S1 contains a copper hydroxide precipitate, and the copper hydroxide precipitate is spherical.

[0025] More specifically, the particle size of the copper hydroxide precipitate is 500-800 nm.

[0026] In some embodiments, the copper source in S1 is copper sulfate pentahydrate, the alkaline solution in S1 and S2 is sodium hydroxide solution, and the sugar reducing agent in S2 is any one of glucose, fructose, galactose, maltose, and lactose.

[0027] In some embodiments, during the preparation of the first solution in S1, the molar ratio of copper sulfate pentahydrate to sodium hydroxide is 1:2.

[0028] It should be noted that the chemical reaction equation between copper sulfate pentahydrate and sodium hydroxide solution in S1 is as follows: .

[0029] In some embodiments, during the preparation of the second solution in S2, the molar ratio of the sugar reducing agent to sodium hydroxide is 1:1.

[0030] It should be noted that the chemical reaction equation in S2 during the preparation of the second solution is: .

[0031] In some embodiments, 1 ≤ m1 / m2 ≤ 4.

[0032] More specifically, m1 / m2 = 4.

[0033] In some embodiments, 35℃≤T1≤45℃, 70℃<T2<80℃.

[0034] More specifically, T1 = 40℃, T2 = 75℃.

[0035] It is understood that the preparation method of cuprous oxide provided by the present invention involves two steps: the first step is the reaction of copper sulfate pentahydrate with sodium hydroxide to generate a copper hydroxide precursor precipitate, and the second step is the reaction of copper hydroxide with sodium hydroxide and a sugar reducing agent to generate a cuprous oxide precipitate.

[0036] It should be further noted that adding sodium hydroxide in batches during the preparation process helps maintain the pH stability of the entire reaction system. Adding all the sodium hydroxide at once will cause drastic local pH fluctuations, leading to side reactions and the formation of byproducts such as copper oxide, reducing the purity of the cuprous oxide product. Furthermore, it causes the copper hydroxide precipitate to form too quickly in the first step of the reaction, resulting in cuprous oxide particles of varying sizes and irregular shapes. In addition, the reaction temperature of copper sulfate pentahydrate with sodium hydroxide is lower than that of copper hydroxide with sodium hydroxide and glucose; therefore, staged temperature control can effectively influence the cuprous oxide particle size.

[0037] More specifically, by using less sodium hydroxide in the first step of the reaction than in the second step, the morphology of the product can be controlled to be spherical. Furthermore, the synthesis temperature of the copper hydroxide precursor precipitate in the first reaction allows for control over the particle size of the copper hydroxide precursor precipitate to the submicron level, thus ensuring that the cuprous oxide produced after subsequent reduction is also submicron in size.

[0038] Compared to copper sulfate, nano-sized cuprous oxide has a high specific surface area, and nano-sized cuprous oxide particles can more easily enter cells through mechanisms such as phagocytosis, resulting in higher bioavailability. It can be more effectively absorbed and utilized by animals, reducing copper waste and excretion.

[0039] In some embodiments, the filtration process in S3 specifically involves vacuum filtration using a filter membrane with a pore size of 15-20 mesh.

[0040] In some embodiments, the S3 drying process specifically involves drying at 105°C for 30 minutes in a ventilated oven.

[0041] Example 1: A cuprous oxide and its preparation method, the preparation method comprising the following steps: The water bath was set to 40℃. 50g of copper sulfate pentahydrate was weighed into a 1L beaker and dissolved in 250g of water. 16g of sodium hydroxide was weighed and dissolved in 250g of water. The sodium hydroxide solution was slowly added dropwise into the reaction beaker and allowed to precipitate for 10 minutes. 24g of glucose was weighed and added to the reaction beaker and stirred until homogeneous. The temperature was raised to 75℃. 4g of sodium hydroxide was weighed and dissolved in 150g of water. The solution was slowly added dropwise into the reaction beaker and allowed to react for 30 minutes. The slurry turned brick red. After filtration and drying, 14.2g of brick red product (purity approximately 98%) was obtained.

[0042] Figures 1-4 All images are electron microscope images of the products of Example 1. The electron microscope shows that the sample particle size is about 200-500 nm, which meets the requirements. The smaller the particle size, the lighter the color.

[0043] Comparative Example 1: A cuprous oxide and its preparation method, the preparation method comprising the following steps: The water bath was set to 75℃. 50g of copper sulfate pentahydrate was weighed into a 1L beaker and dissolved in 250g of water. 16g of sodium hydroxide was weighed and dissolved in 250g of water. The sodium hydroxide solution was slowly added dropwise into the reaction beaker and allowed to precipitate for 10 minutes. 24g of glucose was weighed and added to the reaction beaker and stirred until homogeneous. 4g of sodium hydroxide was weighed and dissolved in 150g of water. The solution was slowly added dropwise into the reaction beaker and allowed to react for 30 minutes. The mixture was filtered and dried to obtain 14.1g of a brick-red product.

[0044] Figures 5-8 All images are electron microscope (EM) images of the products of Example 2. The electron microscope shows that the particle size of the sample is about 3-6 micrometers, which is larger than the particle size of the sample obtained in Example 1, and the sample morphology is square.

[0045] Comparative Example 2: A cuprous oxide and its preparation method, the preparation method comprising the following steps: The water bath was set to 40℃. 50g of copper sulfate pentahydrate was weighed into a 1L beaker and dissolved in 250g of water. 16g of sodium hydroxide was weighed and dissolved in 250g of water. The sodium hydroxide solution was slowly added dropwise into the reaction beaker and allowed to precipitate for 10 minutes. 24g of glucose was weighed and added to the reaction beaker and stirred until homogeneous. 4g of sodium hydroxide was weighed and dissolved in 150g of water. The solution was slowly added dropwise into the reaction beaker and allowed to react for 30 minutes. The slurry turned blue. After filtration and drying, 17.7g of blue product was obtained.

[0046] In Comparative Example 2, the reaction temperature in the second step was too low, the reduction reaction was incomplete, and most of the product was copper hydroxide, with cuprous oxide not being completely formed.

[0047] Example 2: A cuprous oxide and its preparation method, the preparation method comprising the following steps: The water bath was set to 45℃. 50g of copper sulfate pentahydrate was weighed into a 1L beaker and dissolved in 250g of water. 16g of sodium hydroxide was weighed and dissolved in 250g of water. The sodium hydroxide solution was slowly added dropwise into the reaction beaker and allowed to precipitate for 10 minutes. 24g of glucose was weighed and added to the reaction beaker and stirred until homogeneous. The temperature was raised to 75℃. 4g of sodium hydroxide was weighed and dissolved in 150g of water. The solution was slowly added dropwise into the reaction beaker and allowed to react for 30 minutes. The slurry turned brick red. After filtration and drying, 14.2g of brick red product (purity approximately 98%) was obtained.

[0048] Example 3: A cuprous oxide and its preparation method, the preparation method comprising the following steps: The water bath was set to 35℃. 50g of copper sulfate pentahydrate was weighed into a 1L beaker and dissolved in 250g of water. 16g of sodium hydroxide was weighed and dissolved in 250g of water. The sodium hydroxide solution was slowly added dropwise into the reaction beaker and allowed to precipitate for 10 minutes. 24g of glucose was weighed and added to the reaction beaker and stirred until homogeneous. The temperature was raised to 75℃. 4g of sodium hydroxide was weighed and dissolved in 150g of water. The solution was slowly added dropwise into the reaction beaker and allowed to react for 30 minutes. The slurry was brick red in color. After filtration and drying, 14.13g of brick red product (purity approximately 98%) was obtained.

[0049] Example 4: A cuprous oxide and its preparation method, the preparation method comprising the following steps: The water bath was set to 40℃. 50g of copper sulfate pentahydrate was weighed into a 1L beaker and dissolved in 250g of water. 8g of sodium hydroxide was weighed and dissolved in 250g of water. The sodium hydroxide solution was slowly added dropwise into the reaction beaker and allowed to precipitate for 10 minutes. 24g of glucose was weighed and added to the reaction beaker and stirred until homogeneous. The temperature was raised to 75℃. 8g of sodium hydroxide was weighed and dissolved in 150g of water. The solution was slowly added dropwise into the reaction beaker and allowed to react for 30 minutes. The slurry was brick red in color. After filtration and drying, 14.25g of brick red product (purity approximately 98%) was obtained.

[0050] Example 5: A cuprous oxide and its preparation method, the preparation method comprising the following steps: The water bath was set to 40℃. 50g of copper sulfate pentahydrate was weighed into a 1L beaker and dissolved in 250g of water. 15g of sodium hydroxide was weighed and dissolved in 250g of water. The sodium hydroxide solution was slowly added dropwise into the reaction beaker and allowed to precipitate for 10 minutes. 24g of glucose was weighed and added to the reaction beaker and stirred until homogeneous. The temperature was raised to 75℃. 5g of sodium hydroxide was weighed and dissolved in 150g of water. The solution was slowly added dropwise into the reaction beaker and allowed to react for 30 minutes. The slurry turned brick red. After filtration and drying, 14.17g of brick red product (purity approximately 98%) was obtained.

[0051] Comparative Example 3: A cuprous oxide and its preparation method, the preparation method comprising the following steps: The water bath was set to 40℃. 50g of copper sulfate pentahydrate was weighed into a 1L beaker and dissolved in 250g of water. 20g of sodium hydroxide was weighed and dissolved in 250g of water. The sodium hydroxide solution was slowly added dropwise into the reaction beaker and allowed to precipitate for 10 minutes. 24g of glucose was weighed and added to the reaction beaker and stirred until homogeneous. The temperature was raised to 75℃, and 150g of water was added and dissolved completely. The solution was then slowly added dropwise into the reaction beaker and allowed to react for 30 minutes. The slurry was black. After filtration and drying, 15.7g of black product was obtained.

[0052] The 15.7g product in Comparative Example 3 contained some black copper oxide.

[0053] Comparative Example 4: A cuprous oxide and its preparation method, the preparation method comprising the following steps: The water bath was set to 40℃. 50g of copper sulfate pentahydrate was weighed into a 1L beaker and dissolved in 250g of water. 17g of sodium hydroxide was weighed and dissolved in 250g of water. The sodium hydroxide solution was slowly added dropwise into the reaction beaker and allowed to precipitate for 10 minutes. 24g of glucose was weighed and added to the reaction beaker and stirred until homogeneous. The temperature was raised to 75℃. 3g of sodium hydroxide was weighed and dissolved in 150g of water. The solution was slowly added dropwise into the reaction beaker and allowed to react for 30 minutes. The slurry turned black. After filtration and drying, 14.7g of product was obtained.

[0054] In Comparative Example 4, a portion of the 14.7g product was black copper oxide.

[0055] Comparative Example 5: A cuprous oxide and its preparation method, the preparation method comprising the following steps: The water bath was set to 75℃. 50g of copper sulfate pentahydrate was weighed into a 1L beaker and dissolved in 250g of water. 16g of sodium hydroxide was weighed and dissolved in 250g of water. The sodium hydroxide solution was slowly added dropwise into the reaction beaker and allowed to precipitate for 10 minutes. 24g of glucose was weighed and added to the reaction beaker and stirred until homogeneous. The temperature was lowered to 40℃. 4g of sodium hydroxide was weighed and dissolved in 150g of water. The solution was slowly added dropwise into the reaction beaker and allowed to react for 30 minutes. The slurry turned blue. After filtration and drying, 18.0g of blue product was obtained.

[0056] In Comparative Example 5, the reaction temperature in the second step was too low, resulting in incomplete reduction and the formation of most of the copper hydroxide, with less cuprous oxide being formed.

[0057] The performance data of the above embodiments and comparative examples are shown in Table 1 below: Table 1: Performance data of examples and comparative examples

[0058] In the table above, the determination of copper content refers to GB / T13885-2017 Determination of calcium, copper, iron, magnesium, manganese, potassium, sodium and zinc content in feed, using atomic absorption spectrometry.

[0059] This invention also provides an application of cuprous oxide in Example 1 above. Cuprous oxide is used as an additive in animal feed and has all the beneficial effects of cuprous oxide in any of Examples 1 above, which will not be elaborated here.

[0060] Furthermore, cuprous oxide is used as an additive in growing-finishing pig feed, and the amount added per ton of feed is 100ppm-200ppm based on the copper content in cuprous oxide.

[0061] To better illustrate the effect of adding the above-mentioned cuprous oxide to the feed of growing-finishing pigs on the growth performance of growing-finishing pigs, the cuprous oxide prepared in Examples 1 and 5 was used in a feeding experiment on growing-finishing pigs: Test materials Treatment Group 1: Copper sulfate (containing 25% copper), purchased from the market.

[0062] Treatment group 2: Cuprous oxide (20 micrometers), purchased from the market.

[0063] Treatment group 3: Cuprous oxide (500-800 nm), prepared in Example 6.

[0064] Treatment group four: Cuprous oxide (200-500 nm), prepared in Example 1.

[0065] Experimental Design The experiment was conducted in two batches. The first batch consisted of 60 healthy Duroc-Landrace-Landrace-Large White crossbred piglets (approximately 28 kg in weight) with the same genetic background. These piglets were randomly assigned to 12 pens, with 5 piglets per pen. Pigs with larger or smaller weights were excluded from the experiment, and the weights were kept consistent across replicates. Each of the 12 pens was randomly assigned to one of four treatments, with three replicates per treatment. Each treatment was fed the appropriate experimental feed. The pigs were weighed on the morning of the fifth day to begin the formal experiment. The experiment lasted 28 days, and feeding and management were conducted according to standard procedures.

[0066] The second batch of experiments selected approximately 48 Duroc-Landrace-Large White crossbred growing-finishing pigs (weighing 40-50 kg) with healthy genetic backgrounds. These pigs were randomly assigned to 12 pens, with 4 pigs per pen. The replicates were of roughly the same weight, and the number of males was equal to that of females. The 12 pens were randomly divided into 4 treatments, with 3 replicates per treatment. The pigs were fed the corresponding experimental feed. On the morning of the 5th day, the pigs were weighed to begin the formal experiment. Feeding and management were carried out according to standard procedures.

[0067] Experimental diets and feeding management The experimental pig diet was formulated according to the NRC (1998) swine nutrition standards. Powdered feed was used, supplemented manually. The pigsties were arranged in double rows, fed three times a day, with free access to water. The pens were well-ventilated, and immunization and deworming were completed before the experiment.

[0068] Table 2: Experimental Groups for Different Copper Sources

[0069] Determination of production performance in experimental pigs Growth rate: Pigs were weighed by pen at the beginning and end of the experiment (1 month), on an empty stomach, before which they were fasted the night before. The average daily gain (ADG) of the experimental pigs was calculated.

[0070] Feed intake and feed conversion efficiency: Accurately record the feed consumption of each pig pen, and calculate the average daily feed intake (ADFI) and feed conversion ratio (total feed consumption / total weight gain) on a pen (repeated) basis.

[0071] Observe and compare the skin color and hair growth of each treatment weekly, take photos and archive them. The hair color is rated on a 5-point scale: very good color, 5 points; good, 4 points; average, 2 points; poor, 2 points; very poor, 1 point.

[0072] The specific structure is shown in Table 3 below.

[0073] Table 3: Effects of different copper sources on the production performance of growing-finishing pigs

[0074] As shown in Table 3, compared with treatment group 1 which was supplemented with copper sulfate, the average daily weight gain increased by about 60 grams per day (an increase of 7.28%) when the diet was supplemented with cuprous oxide of 200-500 nm, which was significantly better than treatment group 1 and treatment group 2.

Claims

1. A method for preparing cuprous oxide, characterized in that, The process includes the following steps: adding an alkaline solution of mass m1 to a copper source solution and reacting at a reaction temperature T1 to obtain a first solution; then adding an alkaline solution of mass m2 and a sugar reducing agent to the first solution and reacting at a reaction temperature T2 to obtain a second solution, wherein T1 < T2 and m2 ≤ m1; and then filtering and drying the precipitate in the second solution to obtain cuprous oxide.

2. The preparation method according to claim 1, characterized in that, In the preparation of the first solution, the molar ratio of the copper source solution to the alkaline solution is 1:1.5-2.

5. In the preparation of the second solution, the molar ratio of the sugar reducing agent to the alkaline solution is 1:0.5-1.

5.

3. The preparation method according to claim 1, characterized in that, 1≤m1 / m2≤4, and 35℃≤T1≤45℃, 70℃<T2<80℃.

4. The preparation method according to claim 1, characterized in that, The copper source is copper sulfate, the alkaline solution is sodium hydroxide solution, and the sugar reducing agent is any one of glucose, fructose, galactose, maltose, and lactose.

5. The preparation method according to claim 1, characterized in that, The first solution contains copper hydroxide precipitate, which is spherical.

6. The preparation method according to claim 1, characterized in that, The particle size of the copper hydroxide precipitate is 500-800 nm.

7. A cuprous oxide, characterized in that, The cuprous oxide is prepared by the method of any one of claims 1-6.

8. The cuprous oxide according to claim 7, characterized in that, The cuprous oxide is spherical, and the particle size of the cuprous oxide is 400-600 nm.

9. The cuprous oxide according to claim 7, characterized in that, The copper content ω in the cuprous oxide is greater than 87%.

10. The use of cuprous oxide prepared by any one of claims 1-6 or cuprous oxide prepared according to any one of claims 7-9 in animal feed.

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