Comparison of the Nucleation Parameters of Aqueous L-glycine Solutions in the Presence of L-arginine from Induction Time and Metastable-Zone-Width Data

Induction time and metastable-zone-width (MSZW) data for aqueous L-glycine solutions in the presence of L-arginine impurity were experimentally measured using a turbidity probe in this study. The nucleation parameters, including the interfacial free energy and pre-exponential nucleation factor, obtained from induction time data, were compared with those obtained from MSZW data. The influences of lag time on the nucleation parameters were examined for the induction time data. The effects of L-arginine impurity concentration on the nucleation parameters based on both the induction time and MSZW data were investigated in detail.

Determination of the Metastable Zone Width and Nucleation Parameters of Succinic Acid for Electrochemically Induced Crystallization

Electrified downstream processes for biotechnologically produced carboxylic acids reduce waste salt generation significantly and make biotechnological production ecologically and economically more attractive. In order to design, optimize, scale-up and control electrochemically induced crystallization processes, knowledge of the metastable zone width (MSZW) is essential. An optical observation approach of nucleation processes close to the electrode and determination of the MSZW is presented. This work presents a method for MSZW measurements for electrochemically induced pH-shift crystallization processes by monitoring the nucleation, the saturation pH value and saturation concentration for different current densities. The measured MSZWs for electrochemically induced pH-shift crystallization are narrow due to the foreign surface, gas bubbles and electrode surface, and rising current densities lead to even smaller MSZW. Nucleation parameters are estimated from MSWZ data, adapting the classical approach of Nývlt to electrochemically induced crystallization.

Hydration breaking and chemical ordering in a levitated NaCl solution droplet beyond the metastable zone width limit: evidence for the early stage of two-step nucleation

This work provides evidence for two-step nucleation in highly supersaturated bulk NaCl solution, using electrostatic levitation combined with Raman/X-ray scatterings.

Insight into the role of hydrochloric acid in the thermodynamics and nucleation kinetics behavior of Arbidol hydrochloride monohydrate from Metastable Zone Widths

In order to investigate the nucleation behavior of arbidol hydrochloride monohydrate (AHM) in the aqueous THF (Tetrahydrofuran) solutions, metastable zone width (MSZW) was experimentally determined via the polythermal method, and...

Kinetic origins of the metastable zone width in the manganese oxide Pourbaix diagram

The metastable zone width is the region on a phase diagram where a phase transformation is thermodynamically favored but kinetically hindered. Reaction conditions may need to be far beyond the Pourbaix phase diagram boundaries to initiate nucleation.

Recent progresses on the boron species in aqueous solution: structure, phase equilibria, metastable zone width (MZW) and thermodynamic model

The complexity of boron species in aqueous solution becomes the bottleneck in development of boron resources from brine. The concentrations of different boron species and transformation mechanism among boron species are mainly affected with the total boron concentration, temperatures, pH of the solution, and cations in the solution. The change trends for concentration of total boron in the complicated aqueous solution can be obtained with the phase equilibrium results, but the accurate concentration of boron species in the solution cannot be obtained. The metastable zone width (MZW) of borates and H3BO3 changed with the concentrations of impurity ions, the stirring rate, cooling rate, and original temperature for the saturated solution. The Pitzer model is the effective method to calculate the concentration of boron species. More thermodynamic data at temperatures below and above 298.15 K are needed for model parameterization. The main problems existed in the systems containing boron species were summarized, and the future development direction is also discussed. The progresses on boron species in the aqueous solution can provide fundamental data in the comprehensive exploitation of the brine boron resource.