Provider: Ingenta Connect Database: Ingenta Connect Content: application/x-research-info-systems TY - ABST AU - He, Xin-Kuai AU - Kim, Dongmin ShinWoo-Sik TI - Synthesis of Nanocrystals of Gadolinium Carbonate by Reaction Crystallization JO - Journal of Nanoscience and Nanotechnology PY - 2012-03-01T00:00:00/// VL - 12 IS - 3 SP - 2367 EP - 2373 N2 - The formation of nano-sized crystals of gadolinium carbonate via reaction crystallization was studied in a semi-batch crystallizer using gadolinium chloride and ammonium hydrogen carbonate as the reactants. The gadolinium carbonate crystals were formed by the aggregation of primary particles sized about 5 nm. Thereby, the crystallization parameters acting directly on the aggregation of the primary particles, such as the reactant concentrations, non-stoichiometry of the reactants, solution pH, acoustic energy, and agitation speed, were mechanistically investigated. As such, increasing the reactant concentrations enhanced the crystal size due to higher nucleation of the primary particles for the aggregation. Non-stoichiometric reactant concentrations resulted in a significant reduction of the crystal size, due to the adsorption of the excess species on the primary particles. Similarly, the surface charge of the primary particles depended on the solution pH. Thus, the crystal size was reduced when the pH deviated from the neutral point. The acoustic cavitation of the ultrasound was much more effective than the turbulent fluid motion of the agitation in inhibiting the primary particle aggregation. Thus, the crystal size was remarkably reduced, even at a low acoustic energy of 6 watts. UR - https://www.ingentaconnect.com/content/asp/jnn/2012/00000012/00000003/art00087 M3 - doi:10.1166/jnn.2012.5678 UR - https://doi.org/10.1166/jnn.2012.5678 ER -