Preparation method of alpha-Al2O3 nanoparticles

Abstract

The invention discloses a method for preparing alpha-Al2O3 nanoparticles. The method comprises the following steps that 1, water-soluble ferric salt and water-soluble aluminium salt are dissolved in deionized water according to a molar ratio of ferric ions to aluminium ions of 0-1; 2, a (NH4)2.CO3 solution with the concentration of 1-4 mol/L is added into a mixture in the step (1) dropwise, and after sol is generated, dropping adding is stopped immediately; 3, the sol is aged at a room temperature to prepare gel; 4, the gel is placed in an oven for drying to prepare a precursor; 5, the precursor is calcined with a heating rate of 1-3 DEG C/min at 600-850 DEG C to obtain an alpha-Fe2O3/alpha-Al2O3 nanometer compound; 6, acid washing is conducted on the alpha-Fe2O3/alpha-Al2O3 nanometer compound material to remove alpha-Fe2O3 particles to obtain the alpha-Al2O3 nanoparticles. According to the method for preparing the alpha-Al2O3 nanoparticles, the calcination temperature is reduced, energy consumption is reduced, and the operation steps are simple.

Description

technical field [0001] The invention relates to the field of inorganic nanomaterials, in particular to a method for preparing ultrafine α-Al at low temperature by using an inorganic salt hydrolysis method 2 o 3 particle method. Background technique [0002] Due to the size of its structural unit between 1-100nm, the physical and chemical properties of nanomaterials have undergone great changes, showing many special properties different from those of the substance in the bulk state. α-Al 2 o 3 is al 2 o 3 It is an important basic material. Due to its excellent physical and chemical properties such as high hardness, high dielectric properties, corrosion resistance, oxidation resistance, good thermal stability, and good insulation, nano-α-Al 2 o 3 It is widely used in various fields such as high-temperature ceramics, biomedical ceramics, electronic and information materials, coating materials, optical materials, and catalytic materials. [0003] Al 2 o 3 The size, di...

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Problems solved by technology

The commonly used mechanical ball milling method: this method has the advantages of simple manufacturing process, low cost and high output, but the prepared nanoparticles have disadvantages such as uneven size, easy introduction of impurities and pollution, etc.

Sol-gel method: This method can prepare high-purity, small-sized, and highly active particles at relatively low temperatures, but the price of raw materials is high and the process is long. The organic solvents commonly used are toxic, and dispersants or surfactants need to be added agent, there is environmental pollution during the debinding process

Chemical precipitation method: the process is simple, the cost is low, and it is suitable for industrial production, but the dispersion is poor, there are serious hard agglomeration problems, and the filtration and washing process of the precipitate is relatively difficult

Organic salt hydrolysis method: can obtain uniform and fine α-Al 2 o 3 Nanoparticles, but this method is difficult to operate, the equipment is expensive, and it is not easy to realize industrial production

[0005] The patent "Preparation Method of Completely Dispersed Alumina Nanoparticles" (CN 103570049 A) ​​uses chemical precipitation method and adds a large amount of auxiliary phase in the process of preparing the precursor to effectively reduce the Al 2 o 3 The phase transition temperature when transforming from the transition phase to the α phase reduces the formation of hard agglomerates, but it needs to add a large amount of precipitant and auxiliary phase, and the filtration and washing process of the precipitate is quite complicated, which is not conducive to industrial production

[0006] The patent "a preparation method of monodisperse nano α-alumina particle powder" (CN 1948155A) adds a water-soluble salt auxiliary phase to the aluminum salt solution, and then adds α-alumina seeds and hydrophilic Monodisperse nano-α-alumina particles were prepared at 950-1100°C, but a large amount of isolation phase and more expensive surfactants need to be added during the preparation process, and the calcination temperature is high and energy consumption is large

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