Hydroxide-Source-Dependent Polymorphism and Phase Stability of Cobalt(II) Hydroxides in Diffusion-Driven Systems.

Hydroxides of cobalt(II) exist predominantly in two polymorphic forms, namely, the blue-green α-form [α-Co(OH)] and reddish β-form [β-Co(OH)]. These hydroxides have a layered structure with interlayer galleries of around 7 and 4 Å, respectively, for α- and β-Co(OH). In most of the previous studies, both the polymorphs were synthesized separately, and a few of them showed that the α-form gets converted to a thermodynamically more stable β-form via physical processes.

A Quasi Universal Matalon-Packter Law for a Periodically Precipitating System of Iron(II) Hydroxide Involving Volumes and Concentrations of the Invading Electrolyte.

The Matalon-Packter (MP) empirical law of periodically precipitating (Liesegang phenomenon) systems under non-equilibrium conditions describes the dependence of the periodicity (spacing coefficient) on the initial concentration of the outer electrolyte. We aim to present the MP law in a more generalized form using a realistic approach wherein mass transfer in the gel column plays a role instead of the initial concentrations. This work is an attempt to make such progress.

Cu(II)-Metallized Three-Layered Cu-8HQ Complex with Hierarchical Crystallite Morphologies Synthesized via Reaction-Diffusion.

Self-organization of regular band patterns of the precipitate via a reaction-diffusion (RD) framework is called Liesegang phenomenon. This non-equilibrium system is emerging as an efficient method for synthesizing materials with unique morphologies that may have desired properties. The formation of continuous precipitation inside a band with poor control over the shape and size of sparingly soluble salts has been well documented.

Precise Evaluation of Spatial Characteristics of Periodically Precipitating Systems via Measurement of RGB (Red, Green, and Blue) Values of Pattern Images.

In the present study, a method is described for precise determination of spatial characteristics of Liesegang bands formed by employing a classical 1D setup using a web-based free resource (https://www.ginifab.com/feeds/pms/color_picker_from_image.

Revert Banding in One-Dimensional Periodic Precipitation of the (AgNO + KBr) System in Agar Gel.

A periodically precipitating system wherein interband distance successively decreases is known as revert Liesegang banding. The phenomenon is rare, and the underlying mechanism is implicit. In the present paper, the Liesegang system comprising of AgNO and KBr as the outer and inner electrolyte pair showing revert banding in agar gel by employing a 1D experimental setup is studied under varying concentrations of participating species.