School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, 205 Luoshi Road, Wuhan 430070, PR China; School of Chemistry and Chemical Engineering, Guangzhou University, 230 Wai Huan Xi Road, Guangzhou Higher Education Mega Center, Guangzhou 510006, China.
School of Chemistry and Chemical Engineering, Guangzhou University, 230 Wai Huan Xi Road, Guangzhou Higher Education Mega Center, Guangzhou 510006, China; School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450002, PR China.
J Colloid Interface Sci. 2021 Feb 1;583:128-138. doi: 10.1016/j.jcis.2020.09.004. Epub 2020 Sep 16.
A series of boehmite microspheres with highly effective adsorption performance for Congo red (CR) were successfully prepared via amides assisted hydrothermal method at 180 °C. Effects of dosages and hydrolysates of N,N-dimethylformamide (DMF), amides species including DMF, N-methylformamide (MF) and formamide (FA), and reaction times on their physicochemical properties were studied in detail. It was found that increase on their crystallinity and shell thickness results from the different hydrolysis rates of the amides; amorphous alumina hydrate, boehmite core-shell structure and hollow microspheres were obtained at hydrothermal times of 60, 140 and 360 min, respectively due to the Ostwald ripening. Especially, dimethylamine (DMA) as a hydrolysate of DMF, can effectively regulate the morphologies of the boehmites together with the sulfate ions, and make their pore sizes distribution (PSD) centering at 3-4 nm. Importantly, the boehmite microspheres with specific surface area of 221.3 m/g shows the maximum adsorption capacity of 847.5 mg/g for CR calculated from Langmuir isotherm model, and its adsorption amount reached a high value of 484.1 mg/g at 60 min due to the mentioned PSD. This template-free hydrothermal method using DMF as precipitant provides an alternative approach for preparing high-performance hydrated alumina for environmental applications.
通过酰胺辅助水热法在 180°C 下成功制备了一系列具有高效刚果红（CR）吸附性能的拟薄水铝石微球。详细研究了 DMF 的用量和水解产物、酰胺种类（包括 DMF、N-甲基甲酰胺（MF）和甲酰胺（FA））以及反应时间对其物理化学性质的影响。结果表明，酰胺水解速率的不同导致其结晶度和壳层厚度增加；水热时间分别为 60、140 和 360 min 时，得到无定形氧化铝水合物、拟薄水铝石核壳结构和空心微球，这是由于奥斯特瓦尔德熟化所致。特别地，DMF 的水解产物二甲胺（DMA）与硫酸根离子一起可以有效地调节拟薄水铝石的形态，并使它们的孔径分布（PSD）集中在 3-4nm 处。重要的是，比表面积为 221.3 m/g 的拟薄水铝石微球对 CR 的最大吸附容量为 847.5mg/g，根据 Langmuir 等温模型计算，其吸附量在 60min 时达到 484.1mg/g 的高值，这归因于所述 PSD。这种以 DMF 为沉淀剂的无模板水热法为环境应用制备高性能水合氧化铝提供了一种替代方法。
