Effects of Cation on the Morphology of Boehmite Precipitated from Alkaline Solutions by Adding Gibbsite as Seed

Abstract

Regulation of boehmite morphology is important for improving its performance in applications. In this paper, the dependence of boehmite morphology on cation ions was studied by XRD, SEM, TEM, FTIR, and zeta-potential, together with calculation of ion degree of association. Boehmite was respectively precipitated from sodium, potassium, lithium, or barium alkaline solution by adding gibbsite as seed at 180 °C for 2 h. Cation concentration and species determined the boehmite morphology. Increase in cation concentration or precipitation in K+, Na+, Li+, and Ba2+ alkaline solution correspondingly precipitated rhombic, hexagonal, and elliptical morphology for boehmite. Al­(OH)4 – was predominantly found in filtrate solution by Raman spectra, whereas red shift of FTIR was observed in alkaline solution containing Ba2+, Li+, Na+, and K+ cations. The degree of association of M n+[Al­(OH)4 –] n n− increased in the following order: Ba2+[Al­(OH)4 –]2 > Li+Al­(OH)4 – > K+Al­(OH)4 – > Na+Al­(OH)4 – in the same concentration of cation solution. This finding agreed with the variations in FTIR change and zeta potential. Meanwhile, increasing cation and Al­(OH)4 – concentration or precipitation in lithium or barium alkaline solution caused the (202) facet of boehmite to gradually disappear and the (200) facet to be exposed. Therefore, the selective adsorption of ion pairs on the (202) and (200) facet of boehmite mainly accounted for the boehmite morphology.

Effect of SDBS on Crystallization Behavior of Pseudoboehmite

“…Li et al prepared ammonium persulfate crystals with a lower aspect ratio by altering the crystal face growth rate through the selective adsorption of sodium dodecylbenzene sulfonate (SDBS) on the crystal face of ammonium persulfate. Liu et al explored the effect of adsorption on the growth rate of the crystal surface by precipitating boehmite in different cation solutions such as sodium, potassium, lithium, and barium. Sun et al added SDBS during the cooling and crystallization process of an aluminum sulfate solution to inhibit the nucleation process in the reaction stage and promote crystal growth.…”

Al‐Li Alloy Chemical Milling Waste Solution Synthesis of γ‐AlOOH Bundles for Cr(VI) Rapid Adsorption

“…However, it is difficult to find the right treatment due to its high alkalinity, high viscosity and complex physical properties . Currently, the Al recovery is main trend of wastewater treatment of AlCM, and the seed crystal crystallization method represents a mainstream strategy for aluminum resource recovery . Unfortunately, it exhibits some drawbacks such as the long reaction time, low recycling efficiency and low economic value.…”

“…[1][2] Currently, the Al recovery is main trend of wastewater treatment of AlCM, and the seed crystal crystallization method represents a mainstream strategy for aluminum resource recovery. [3][4][5] Unfortunately, it exhibits some drawbacks such as the long reaction time, low recycling efficiency and low economic value. Consequently, there is need for further research on the technology to comprehensively utilize AlCM to increase revenue while minimizing the impact on the environment.…”

“…As for the reason that micro-morphology of γ-AlOOH is extremely important for its application. Recently, γ-AlOOH with different morphologies, such as nanorods, [7] nanofibers, [15][17] flowerlike, [9][11][20][21] lamellar, [22] nanosheets, [23] rhombic, [5] hexagon, [5] olive-like, [5] ribbon-like, [24] leaf-like, [25] cantaloupelike [26] and microspheres, [21][27-30] have been prepared by the high-temperature above (> 100 °C) and high-pressure hydrothermal method, [31] cationic-anionic double hydrolysis method [32] or microemulsion-gel method under the action of surfactants. Furthermore, the regulation of γ-AlOOH morphology has been achieved through controlling added cation concentration and species [5] or adjusting the molar ratios of Al 3 + /AlO 2À .…”

“…Recently, γ-AlOOH with different morphologies, such as nanorods, [7] nanofibers, [15][17] flowerlike, [9][11][20][21] lamellar, [22] nanosheets, [23] rhombic, [5] hexagon, [5] olive-like, [5] ribbon-like, [24] leaf-like, [25] cantaloupelike [26] and microspheres, [21][27-30] have been prepared by the high-temperature above (> 100 °C) and high-pressure hydrothermal method, [31] cationic-anionic double hydrolysis method [32] or microemulsion-gel method under the action of surfactants. Furthermore, the regulation of γ-AlOOH morphology has been achieved through controlling added cation concentration and species [5] or adjusting the molar ratios of Al 3 + /AlO 2À . [32] Previous studies have shown that nano γ-AlOOH used as a sorbent exhibits good adsorption properties for organic dyes (Congo red, [28][29] methylene blue [30] ).…”