In this work, stable aqueous suspensions of nano-boehmite were developed through a hybrid wet-chemical route that uses hyperbranched dendritic poly(ethylene)imine (PEI) as template material for boehmite formation aiming at the development of a deagglomerated α-alumina nanopowder after calcination. The method involves firstly the interaction between the Al precursor and PEI followed by the hydrolysis and polycondensation reactions. The study was aiming to investigate the effect of solids content and pH during reactions on both the stability of the final suspension and the morphology of the resulting nanocrystals. For this purpose, the suspensions were evaluated through viscosity measurements, zeta potential analyses, FT-IR, DLS and sedimentation studies, whereas after the proper centrifugation, drying, and calcination steps, the as-received nanocrystals were evaluated through SEM, TEM and XRD studies. In addition, the boehmite nanopowder was studied using Thermogravimetric and Differential Thermal Analysis, whereas its sinterability was evaluated by dilatometric measurements. The investigation showed that the conditions employed affect greatly both the morphology of nanocrystals as well as the dispersion and the stability of the suspensions. The boehmite suspension with the optimum dispersion and stability can lead, after calcination at 1050°C, to a fine deagglomerated α-alumina nanopowder with a mean size at about 10 nm.

中文翻译：

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湿法合成纳米分散勃姆石的α-氧化铝纳米球

在这项工作中，通过混合湿化学路线开发了纳米勃姆石的稳定水悬浮液，该路线使用超支化树枝状聚（乙烯）亚胺（PEI）作为勃姆石形成的模板材料，旨在开发一种解聚的 α-氧化铝纳米粉末。煅烧。该方法首先涉及铝前体和 PEI 之间的相互作用，然后是水解和缩聚反应。该研究旨在研究反应过程中固体含量和 pH 值对最终悬浮液的稳定性和所得纳米晶体形态的影响。为此，悬浮液通过粘度测量、zeta 电位分析、FT-IR、DLS 和沉降研究进行评估，而在适当的离心、干燥和煅烧步骤之后，通过 SEM、TEM 和 XRD 研究评估了原样的纳米晶体。此外，使用热重分析和差热分析研究了勃姆石纳米粉末，而通过膨胀测量来评估其可烧结性。研究表明，所采用的条件极大地影响纳米晶体的形态以及悬浮液的分散和稳定性。具有最佳分散性和稳定性的勃姆石悬浮液在 1050°C 煅烧后可产生平均尺寸约为 10 nm 的精细解聚 α-氧化铝纳米粉末。研究表明，所采用的条件极大地影响纳米晶体的形态以及悬浮液的分散和稳定性。具有最佳分散性和稳定性的勃姆石悬浮液在 1050°C 煅烧后可产生平均尺寸约为 10 nm 的精细解聚 α-氧化铝纳米粉末。研究表明，所采用的条件极大地影响纳米晶体的形态以及悬浮液的分散和稳定性。具有最佳分散性和稳定性的勃姆石悬浮液在 1050°C 煅烧后可产生平均尺寸约为 10 nm 的精细解聚 α-氧化铝纳米粉末。