阅读说明：本技术 一种球形纳微米氧化铝的制备方法 (Preparation method of spherical nano-micron alumina ) 是由 车圆圆 杨柳 杨振 张耀洁 刘嘉琪 张志浩 于 2021-01-13 设计创作，主要内容包括：本发明公开了一种球形纳微米氧化铝的制备方法,包括以下步骤：将可溶性铝盐作为铝源溶于去离子水中,搅拌至溶解；分别加入分散剂和沉淀剂,混合搅拌；升温至90-200℃,恒温反应2-24小时；冷却至室温,经过洗涤、干燥和煅烧得到球形纳微米氧化铝粉末。本发明通过铝盐的水热沉淀生成了纳米氧化铝的前驱体,继而高温煅烧生成了的纳米氧化铝,生长过程可控,通过调控硫酸盐和硝酸盐的比例可控制产物的尺寸大小,合成的氧化铝尺寸分布窄,分散均匀,在涂料、化妆品、塑料和橡胶等作为添加剂具有很好的应用前景。(The invention discloses a preparation method of spherical nano-micron alumina, which comprises the following steps: dissolving soluble aluminum salt as an aluminum source in deionized water, and stirring until the soluble aluminum salt is dissolved; respectively adding a dispersant and a precipitator, mixing and stirring; heating to 90-200 ℃, and reacting for 2-24 hours at constant temperature; cooling to room temperature, washing, drying and calcining to obtain the spherical nano-micron aluminum oxide powder. According to the invention, the precursor of the nano-alumina is generated through the hydrothermal precipitation of the aluminum salt, and then the generated nano-alumina is calcined at high temperature, the growth process is controllable, the size of the product can be controlled by regulating the proportion of the sulfate and the nitrate, the size distribution of the synthesized alumina is narrow, the dispersion is uniform, and the nano-alumina has a good application prospect as an additive in coatings, cosmetics, plastics, rubber and the like.)

1. A preparation method of spherical nano-micron alumina is characterized by comprising the following steps:

(1) dissolving soluble aluminum salt as an aluminum source in deionized water, and stirring until the soluble aluminum salt is dissolved;

(2) respectively adding a dispersant and a precipitator, mixing and stirring;

(3) heating to 90-200 ℃, and reacting for 2-24 hours at constant temperature;

(4) cooling to room temperature, washing, drying and calcining to obtain the spherical nano-micron aluminum oxide powder.

2. The method for preparing spherical nano-micron alumina as claimed in claim 1, wherein the aluminum source in step 1 is aluminum sulfate octadecahydrate or aluminum nitrate nonahydrate or a mixture of the aluminum sulfate octadecahydrate and the aluminum nitrate nonahydrate.

3. The method for preparing spherical nano-micron alumina according to claim 1, wherein the concentration of aluminum ions in step 1 is 1mmol/L to 0.1 mol/L.

4. The method for preparing spherical nano-micron alumina as claimed in claim 1, wherein the dispersant in step 2 is polyethylene glycol or sodium polyacrylate.

5. The method for preparing spherical nano-micron alumina according to claim 1, wherein the precipitant in step 2 is formamide, ammonia water or urea.

6. The method for preparing spherical nano-micron alumina according to claim 1, wherein the molar ratio of the dispersant to the aluminum ions in step 2 is (20-2500):1, and the molar ratio of the precipitant to the aluminum ions is (0.5-30): 1.

7. The method for preparing spherical nano-micron alumina according to claim 1, wherein the stirring time in step 2 is 30min to 120 min.

8. The method for preparing spherical nano-micron alumina as claimed in claim 1, wherein the calcination temperature in step 4 is 600-1100 ℃, and the calcination time is 1-2 h.

Technical Field

The invention belongs to the technical field of materials, and particularly relates to a preparation method of spherical nano-micron alumina.

Background

Alumina is widely applied to many fields, such as ceramics, coatings, catalysts and polishing or grinding tools, and has a series of excellent properties of corrosion resistance, high temperature resistance, wear resistance, high strength and the like. The size, the shape and the dispersibility of the alumina nano particles have great influence on the forming and sintering processes of ceramics and even on the mechanical properties of materials. Spherical alumina powders have good forming and sintering properties and are often used in chip materials for printed ceramics, integrated circuits due to their high thermal conductivity, good flowability and high bulk density. In order to realize high-performance ceramics, it is essential to prepare spherical alumina particles with controllable size and good dispersion.

Although alumina nano-materials with different morphologies are reported successively, such as alumina fiber, flake alumina, nano-rod, etc., and the Synthesis methods are also many, including gas phase method, microwave method, reverse micro-emulsion method, liquid phase method, etc., although the literature of synthesizing alumina is available, such as Zhang et al (Synthesis of scientific Leaf Cluster Nanoallumlina by Solvothermal Approach), which uses aluminum nitrate and urea to heat in a reaction kettle to obtain white precipitate, and finally calcines to obtain alumina white powder, although the particle size is small, the nano-particles are nearly spherical and amorphous, and have agglomeration phenomenon, which affects the performance of composite materials, etc. King et al (Preparation and catalysis of Al)₂O₃Nanoparticles with dedocyclic ammonium bromide surfactant) is prepared by dispersing aluminum nitrate, urea and surfactant in water, heating to form colloid, further forming precursor white precipitate, and finally calcining at high temperature to obtain alumina. The synthesis of dispersed, size-controlled, spherical amorphous alumina particles remains a challenge.

Disclosure of Invention

The invention provides a method for preparing spherical nano-alumina by a mild homogeneous precipitation method, which has the advantages of simple process and lower cost and can prepare nano-to micron-sized spherical alumina powder.

In order to achieve the purpose, the technical scheme is as follows:

a preparation method of spherical nano-micron alumina comprises the following steps:

(1) dissolving soluble aluminum salt as an aluminum source in deionized water, and stirring until the soluble aluminum salt is dissolved;

(2) respectively adding a dispersant and a precipitator, mixing and stirring;

(3) heating to 90-200 ℃, and reacting for 2-24 hours at constant temperature;

(4) cooling to room temperature, washing, drying and calcining to obtain the spherical nano-micron aluminum oxide powder.

According to the scheme, the aluminum source in the step 1 is aluminum sulfate octadecahydrate or aluminum nitrate nonahydrate or the mixture of the aluminum sulfate octadecahydrate and the aluminum nitrate nonahydrate.

According to the scheme, the concentration of aluminum ions in the step 1 is 1mmol/L-0.1 mol/L.

According to the scheme, the dispersing agent in the step 2 is polyethylene glycol or sodium polyacrylate.

According to the scheme, the precipitator in the step 2 is formamide, ammonia water or urea.

According to the scheme, the molar ratio of the using amount of the dispersing agent to the aluminum ions in the step 2 is (20-2500):1, and the molar ratio of the using amount of the precipitating agent to the aluminum ions is (0.5-30): 1.

According to the scheme, the stirring time in the step 2 is 30-120 min.

According to the scheme, the calcining temperature in the step 4 is 600-1100 ℃, and the calcining time is 1-2 h.

In the reaction system, added precipitator is decomposed at a certain temperature to generate hydroxyl, and the hydroxyl and aluminum ions provided by aluminum salt generate homogeneous precipitation to obtain alumina precursor particles; the precipitation appears slowly at a low pH value, so that the precursor grows slowly and spherical particles with narrow particle size distribution are formed; finally, high temperature calcination is carried out to form alumina particles.

Compared with the prior art, the invention has the following beneficial effects:

the precursor of the nano-alumina is generated through the hydrothermal precipitation of aluminum salt, then the generated nano-alumina is calcined at high temperature, the growth process is controllable, the size of the product can be controlled by regulating the proportion of sulfate and nitrate, the size distribution of the synthesized alumina is narrow, the dispersion is uniform, and the nano-alumina has good application prospect as an additive in coatings, cosmetics, plastics, rubber and the like.

Drawings

FIG. 1: infrared image of the precursor obtained in example 1;

FIG. 2: example 1 infrared picture of alumina particles obtained after calcination;

FIG. 3: particle size distribution plot for alumina particles obtained in example 1;

FIG. 4: particle size distribution plot for alumina particles obtained in example 2;

FIG. 5: particle size distribution of alumina particles obtained in example 3.

Detailed Description

The following examples further illustrate the technical solutions of the present invention, but should not be construed as limiting the scope of the present invention.

Example 1

Weighing 0.076g of aluminum sulfate octadecahydrate and 0.064g of aluminum nitrate nonahydrate, adding into 400ml of deionized water, and fully stirring until the aluminum sulfate octadecahydrate and the aluminum nitrate nonahydrate are dissolved;

adding 4ml of polyethylene glycol 400, 0.8g of polyethylene glycol 6000 and 10ml of formamide into the solution, and stirring at room temperature for reaction for 120 min;

then reacting for 2h in an oil bath at 120 ℃ to obtain alumina precursor particles, wherein an infrared diagram of the alumina precursor particles is shown in figure 1;

cooling to room temperature, filtering, washing, drying the precipitate in an oven for 48h, and calcining at 600 deg.C for 2h to obtain spherical alumina particles with average particle diameter of 51 nm, whose infrared pattern is shown in FIG. 2; the particle size distribution of the resulting alumina particles is shown in FIG. 3.

Example 2

Weighing 0.0615g of aluminum sulfate octadecahydrate and 0.081g of aluminum nitrate nonahydrate, adding into 400ml of deionized water, and fully stirring until the aluminum sulfate octadecahydrate and the aluminum nitrate nonahydrate are dissolved;

then adding 10ml of polyethylene glycol 400, 2g of polyethylene glycol 6000 and 40ml of formamide into the solution, and stirring and reacting for 90min at room temperature;

then reacting for 2 hours in an oil bath pan at 200 ℃;

cooling to room temperature, filtering, washing, drying the precipitate in an oven for 48h, and calcining at 600 ℃ for 2h to obtain spherical alumina particles with the average particle size of 37 nm; the particle size distribution of the resulting alumina particles is shown in FIG. 4.

Example 3

Weighing 0.044g of aluminum sulfate octadecahydrate and 0.1g of aluminum nitrate nonahydrate, adding into 400ml of deionized water, and fully stirring until the aluminum sulfate octadecahydrate and the aluminum nitrate nonahydrate are dissolved;

then adding 5ml of polyethylene glycol 200, 1g of polyethylene glycol 6000 and 10ml of urea into the solution, and stirring and reacting for 60min at room temperature;

then reacting for 4 hours at 180 ℃ in an oil bath pan;

cooling to room temperature, filtering, washing, drying the precipitate in an oven for 48h, and calcining at 700 ℃ for 1h to obtain spherical alumina particles with the average particle size of 25 nm; the particle size distribution of the resulting alumina particles is shown in FIG. 5.

Example 4

Weighing 4.44g of aluminum sulfate octadecahydrate and 10.00g of aluminum nitrate nonahydrate to ensure that the concentration of aluminum ions is 0.1mol/L, adding the aluminum ions into 400ml of deionized water, and fully stirring the mixture until the aluminum ions are dissolved;

then adding 10ml of polyethylene glycol 200, 0.8g of polyethylene glycol 6000 and 100ml of urea into the solution, and stirring and reacting for 30min at room temperature;

then reacting for 12 hours in an oil bath pan at 150 ℃;

cooling to room temperature, filtering, washing, drying the precipitate in an oven for 48h, and then calcining at 800 ℃ for 2h to obtain spherical alumina particles with an average particle size of 1 micron.

Example 5

7.616g of aluminum sulfate octadecahydrate and 6.428g of aluminum nitrate nonahydrate are weighed to ensure that the concentration of aluminum ions is 0.1mol/L, and the weighed materials are added into 400ml of deionized water and fully stirred until the aluminum ions are dissolved;

adding 5ml of sodium polyacrylate and 10ml of urea into the solution, and stirring and reacting for 60min at room temperature;

then reacting for 12 hours in an oil bath pan at 130 ℃;

cooling to room temperature, filtering, washing, drying the precipitate in an oven for 48h, and then calcining at 800 ℃ for 2h to obtain spherical alumina particles with an average particle size of 2 microns.

Example 6

Weighing 0.332g of aluminum sulfate octadecahydrate, adding the weighed aluminum sulfate octadecahydrate into 400ml of deionized water, and fully stirring the mixture until the aluminum sulfate octadecahydrate is dissolved;

then adding 5ml of polyethylene glycol 400, 1g of polyethylene glycol 6000 and 10ml of ammonia water into the solution, and stirring and reacting for 90min at room temperature;

then reacting for 24 hours in an oil bath pan at 120 ℃;

cooling to room temperature, filtering, washing, drying the precipitate in an oven for 48h, and calcining at 900 ℃ for 1h to obtain spherical alumina particles with the average particle size of 120 nm.

Example 7

Weighing 0.375g of aluminum nitrate nonahydrate, adding into 400ml of deionized water, and fully stirring until the aluminum nitrate nonahydrate is dissolved;

then adding 10ml of polyethylene glycol 400, 2g of polyethylene glycol 6000 and 10ml of ammonia water into the solution, and stirring and reacting for 60min at room temperature;

then reacting for 24 hours at 90 ℃ in an oil bath pan;

cooling to room temperature, filtering, washing, drying the precipitate in an oven for 48h, and then calcining at 1100 ℃ for 1h to obtain spherical alumina particles with an average particle size of 20 nm.