Effects of Preferential Incorporation of Carboxylic Acids on the Crystal Growth and Physicochemical Properties of Aragonite

Abstract

The preferential incorporation of carboxylic acids into aragonite and its effects on the crystal growth and physicochemical properties of aragonite were systematically investigated using a seeded co-precipitation system with different carboxylic acids (citric, malic, acetic, glutamic, and phthalic). Aragonite synthesized in the presence of citric and malic acids showed a remarkable decrease in the crystallinity and size of crystallite, and the retardation of crystal growth distinctively changed the crystal morphology. The contents of citric acid and malic acid in the aragonite samples were 0.65 wt % and 0.19 wt %, respectively, revealing that the changes in the physicochemical properties of aragonite were due to the preferential incorporation of such carboxylic acids. Speciation modeling further confirmed that citric acid with three carboxyl groups dominantly existed as a metal–ligand, (Ca–citrate)−, which could have a strong affinity toward the partially positively charged surface of aragonite. This indicates why citric acid was most favorably incorporated among other carboxylic acids. Our results demonstrate that the number of carboxyl functional groups strongly affects the preferential incorporation of carboxylic acids into aragonite; however, it could be suppressed by the presence of other functional groups or the structural complexity of organic molecules.

Feasible calcium carbonate polymorphs synthesis from natural corallines and their potential gelling role in hydraulic fracturing application

“…Calcium carbonates are characterized by their abundance which comprises three crystalline polymorphs. (i.e., aragonite, calcite, and vaterite) [3,4] The thermodynamics viewpoint reveals the highest stability of the rhombohedral calcite phase and the reduced stability of the hexagonal vaterite phase [5]. The calcium carbonates might be presented to production using numerous methods and chemical precursors such as the sonochemical approach [6], co-precipitation [7], and microwave-aided procedure [8].…”

Regulation of Calcite Morphology by Low‐Molecular‐Weight Organic Acids: Alcohol Hydroxyl and Carboxyl Matters

“…Similarly, it has been confirmed by NMR, TG and FI-IR that citrate could incorporate into the calcite lattice. [33][34][35] CA in the growth solutions can chelate with Ca 2+ to from metal-citrate complex, the predominance of the negatively charged complex show strong affinity to the calcite surface and finally coprecipitated with supersaturated calcite solution.…”