Effects of different carboxyl additives on the growth habits of hemihydrate gypsum crystals

Recent progress on strategies for the enhancement of crystal growth process

“…From the perspective of molecular weight, additives can be mainly divided into three categories: additives with small molecular weight (such as surfactants and salts), additives with large molecular weight (such as protein and polymers), and special additives, also named “tailor-made additives” (some compounds similar in structure to solute molecules). 37–42…”

“…From the perspective of molecular weight, additives can be mainly divided into three categories: additives with small molecular weight (such as surfactants and salts), additives with large molecular weight (such as protein and polymers), and special additives, also named "tailor-made additives" (some compounds similar in structure to solute molecules). [37][38][39][40][41][42] Krishnamoorthi and Karuppannan 43 found that the addition of borax and EDTA could grow ammonium dihydrogen phosphate crystals with a large size, good quality, and excellent transparency in a short period. This is because the addition of three additives (borax, EDTA, and borax-EDTA mixture) could enhance supersaturation and metastable zone width and inhibit the activity of metal ions, thus increasing the growth rate, reducing the secondary nucleation and improving the growth rate along the directions of (0 1 0) and (1 0 0).…”

Effect of mixed cation acetate electrolyte on synthesis of α‐hemihydrate gypsum from phosphogypsum

“…In previous studies, a very small amount of crystal modifier was added to the electrolyte solution to control the morphology of the crystal, so that the aspect ratio of the crystal was controlled in a lower range. 16,20,25,35 However, in this study, α-HH was prepared by acetate solution from PG. Acetate solution can not only be used as an electrolyte solution from PG to prepare α-HH by atmospheric hydrothermal synthesis but also the carboxyl group of acetate can be adsorbed on the top surface of α-HH crystal and inhibit the growth of the top surface, which can play a role in regulating crystal type without adding additional crystal modifier.…”

“…These unpaired electrons could form a coordination bond with the empty orbital of metal ions, including the aforementioned Ca 2+ cation on the top surface of a growing α-HH, therefore playing the role of regulating the crystal morphology of α-HH. 35 In a high-concentration acetic acid solution, a large number of carboxyl groups can also be complexed with metal impurities in the solution, 36,37 which is conducive to their removal. At present, the electrolyte solution used is mostly chloride solution, among which Cl − is a commonly used counterion due to its high solubility in water.…”

Structure‐Induced Enhanced Dissolving Properties of Mg(OH)2 Prepared by Glycine‐Assisted MgO Hydration

“…[18,19] Similar phenomena of adsorption-induced crystal growth were observed in the synthesis of other materials as well. [20,21] Meanwhile, Mg(OH) 2 with a unique structure is frequently claimed to exhibit distinct adsorption properties. [22,23] However, little attention has been paid to the correlation between dissolving properties and the morphology of the hydration products.…”