Synthesis Mechanism: Crystal Growth and Nucleation

Study of the synthesis and crystallization kinetics of magnesium hydroxide

“…An induction period in chemical kinetics is the initial slow stage of a chemical reaction, which refers to an interval between an initial formation of supersaturated solution and the appearance of precipitate. The induction period can be defined as [9,21,22], …”

Fractal MTW Zeolite Crystals: Hidden Dimensions in Nanoporous Materials

“…Theabove conceptual evolution model of spiral structure of MTW also can be adopt to interpret those in the nanoporous materials with different topology.F or ak nown screw dislocation, there must be an ucleation in the plane and as pread along the vertical direction in the crystal, which involves the two collaborative growth behaviors along the two different dimensions.Aspreviously reported spirals in nanoporous systems,s uch as LTA [7,14] (Supporting Information, Figure S52, Table S8), CHA/AEI, [15] STA-7 (SAV), [16] ZnPO 4 -Sodalite,a nd ZnPO 4 -Faujasite, [17] 3D spiral terraces are considered here to be defined by three crucial parameters: spiral pitch h,s crew angle q,a nd spatial angle y. ForL TA zeolite,t he above two angles are 908 8 and 08 8,r espectively.I n the each corner of the LTAsquare spiral terrace,the adjacent segments rotate about 908 8 and fuse into the bulky crystal owing to the identical atomic arrangement in the (010) and (001) planes.Itworth noting that other nanoporous materials with ah igh level of symmetry always fuse into their bulky crystal and leave aspiral terrace on the surface owing to the overlap of two dimensions,w hich may explain that why we seldom capture the screw dislocation structure in the nanoporous system. [7,18] In MTW zeolite with lower symmetry (C2/ c), the three parameters are determined as spiral pitch: 1.2 nm, screw angle:6 7.98 8 with spatial angle:2 0.38 8,a nd the layer by layer stacked branches aggregate into ap ine-treelike,s piral contour on the original hexagonal plane.I n contrast to the regular spiral terrace on the flat zeolite surface, [13][14][15][16] it is hard to obtain the regular spiral step height on the highly dendritic surface structure of MTW (equal to the Burgers vector along the vertical direction) by atomic force microscopy,but the spiral patterns and hillocks can still be clearly recognized.…”

Human Cartilage Homogenates Influence the Crystallization of Monosodium Urate and Inflammatory Response to Monosodium Urate Crystals: A Potential Link Between Osteoarthritis and Gout

“…However, we observed the formation of tight MSU crystal bow‐like structures under control conditions without any additional tissue or factors. The formation of bow‐like structures is indicative of an adhesive mechanism of crystal growth, typical of what is seen under conditions of high supersaturation, in which rapid crystal growth leads to morphologic instability at the crystal tip . Thereafter, individual crystals take on a strongly anisotropic needle shape, growing rapidly around the existing nucleus, resulting in spherulitic (bow‐like) crystal aggregates .…”