Preparation method for boehmite nanocrystal

Abstract

The invention discloses a preparation method for boehmite nanocrystal. The preparation method comprises the following steps: S1: adding aluminium hydroxide powder into water to obtain a first mixed system, wherein the mass ratio of the aluminium hydroxide powder to the water is (0.2:1)-(0.8:1) in the first mixed system; S2: regulating the pH (Potential of Hydrogen) value of the first mixed system to 6-10, and obtaining a second mixed system; S3: carrying out hydrothermal reaction on the second mixed system at the temperature which is not lower than 170 DEG C for 7-10h to obtain a third mixed system; S4: carrying out cooling and solid-liquid separation on the third mixed system, wherein a solid phase is washed and dried to obtain the boehmite nanocrystal. The preparation method disclosed by the invention has the advantages of simpleness in operation, moderate condition, low cost and environment protection and conforms to a green development requirement, and no abundant acid-base wastes are generated. In addition, the obtained boehmite nanocrystal has the advantages of good crystallinity, controllable morphology, good dispersibility, high purity and the like.

Description

Technical field [0001] The invention belongs to the technical field of nano powder material preparation, and specifically relates to a method for preparing boehmite nanocrystals. Background technique [0002] In addition to being used as a template and adsorbent, aluminum hydroxide (Al 2 O 3 ·NH 2 O) It can also be used as a precursor to prepare various high-performance alumina powders and high-quality ceramic products. According to the different water content in aluminum hydroxide, it can generally be divided into aluminum hydroxide monohydrate (that is, n is 1) and aluminum hydroxide trihydrate (that is, n is 3); among them, aluminum hydroxide can also be Divided into boehmite (γ-AlOOH), pseudoboehmite (psendoboehmite) and diaspore (diaspora, α-AlOOH), and aluminum trihydrate can also be divided into gibbsite (Gibbsite, γ-AlOOH) -Al(OH) 3 ), Bayerite, α-Al(OH) 3 ), nordstrandite and doyleite. [0003] Because the alumina prepared by boehmite can maintain the consistency of size...

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Problems solved by technology

In addition, although the commonly used aluminum hydroxide powder prepared by the replacement reaction of aluminum metal and water is low in cost and simple in method, the powder is usually boehmite (γ-AlOOH) and gibbsite. (γ-Al(OH) 3 ), and the powder size is very large, there are many hard agglomerates, which greatly limits the application of this aluminum hydroxide powder

[0004] Although there are a large number of related reports on boehmite with different shapes, these methods not only have complex preparation processes, but also require a large number of auxiliary agents such as template agents, surfactants, and acid-base reagents, resulting in high preparation costs and environmental pollution. The prepared boehmite nanocrystals have problems such as uneven particle size, poor dispersion, poor crystallinity, and low purity.

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