Related Experiment Video
Updated: Nov 27, 2025
09:52
Optimizing the Growth of Endothiapepsin Crystals for Serial Crystallography Experiments
Published on: February 4, 2021
2.6K
Anisotropic Nucleation, Growth and Ripening under Stirring-A Phenomenological Model.
Andriy Gusak1, Yaroslav Huriev1, Jürn W P Schmelzer2
1Department of Physics, Cherkasy National University, 18000 Cherkasy, Ukraine.
Entropy (Basel, Switzerland)
|December 8, 2020
Summary
Intensive stirring in water drives anisotropic formation of elongated metal-oxide aggregates. Elongation is most pronounced during the ripening stage of aggregate formation.
Area of Science:
- Materials Science
- Physical Chemistry
- Chemical Engineering
Background:
- Metal-oxide aggregate formation is crucial in various industrial processes.
- Understanding aggregate morphology, such as elongation, impacts material properties.
- Existing models often simplify aggregation kinetics, particularly under dynamic conditions.
Purpose of the Study:
- To analyze the anisotropic formation of elongated metal-oxide aggregates in water.
- To model aggregate formation under intensive stirring using kinetic equations.
- To identify the key stage where aggregate elongation is maximized.
Main Methods:
- Formulation of basic kinetic equations for open systems.
- Analysis of homogeneous nucleation, independent growth, and ripening stages.
- Modeling aggregation kinetics under external influence, specifically stirring intensity.
Main Results:
- Anisotropic formation of elongated metal-oxide aggregates observed.
- Kinetic equations developed for open systems with stirring.
- Stirring intensity identified as the primary process-governing parameter.
- Maximum aggregate elongation occurs during the ripening stage.
Conclusions:
- The ripening stage is critical for achieving significant aggregate elongation.
- Ballistically mediated aggregation kinetics provide a framework for understanding this process.
- Stirring intensity is a key factor in controlling aggregate morphology.
Related Concept Videos
01:25Crystal Growth: Principles of Crystallization
3.9K
Crystallization is a phase transformation process in which crystals are precipitated from a supersaturated solution or formed from other sources. During crystallization, atoms or molecules arrange themselves into a well-defined, rigid crystal lattice to minimize energy.
Initiating crystallization involves manipulating the concentration of the solute and the temperature of the solution. Since crystal growth occurs when the ratio of concentration and solubility of the solute in the solvent...
Initiating crystallization involves manipulating the concentration of the solute and the temperature of the solution. Since crystal growth occurs when the ratio of concentration and solubility of the solute in the solvent...
3.9K
01:04Anionic Chain-Growth Polymerization: Mechanism
2.3K
The mechanism for anionic chain-growth polymerization involves initiation, propagation, and termination steps. In the initiation step, a nucleophilic anion, such as butyl lithium, initiates the polymerization process by attacking the π bond of the vinylic monomer. As a result, a carbanion, stabilized by the electron‐withdrawing group, is generated. The resulting carbanion acts as a Michael donor in the propagation step and attacks the second vinylic monomer, which acts as a Michael...
2.3K
01:10Recrystallization: Solid–Solution Equilibria
1.7K
Recrystallization is a purification technique used to separate impurities from solid compounds. In this technique, no chemical reactions occur. Instead, it exploits physical properties only, specifically, the solubility differences between the desired compound and impurities, either at a single temperature or at different temperatures, and under other selected conditions. The solid-solution equilibrium (solubility equilibrium) of each component in the solution represents a binary phase...
1.7K
01:12Precipitation Processes
2.9K
The experimental conditions in a gravimetric analysis should be optimized to maximize the particle size and purity of the obtained precipitate. Ideally, the concentration of the precipitating reagent should be low with effective stirring to maintain low relative supersaturation for the growth of large crystals. In homogeneous precipitation, the precipitant is slowly generated by a chemical reaction in the solution to avoid local reagent excesses. For example, urea decomposes gradually to...
2.9K
01:09Radical Chain-Growth Polymerization: Mechanism
3.1K
The radical chain-growth polymerization mechanism consists of three steps: initiation, propagation, and termination of polymerization. The polymerization initiates when a free radical generated from the radical initiator adds to the unsaturated bond in the monomer. The unpaired electron of the free radical and one π electron in the unsaturated bond creates a σ bond between the free radical and the monomer. As a result, the other π electron in the unsaturated bond converts this species into...
3.1K
01:03Step-Growth Polymerization: Overview
4.1K
Step-growth or condensation polymerization is a stepwise reaction of bi or multifunctional monomers to form long-chain polymers. As all the monomers are reactive, most of the monomers are consumed at the early stages of the reaction to form small chains of reactive oligomers, which then combine to form long polymer chains in the late stages. Hence, the reaction has to proceed for a long time to achieve high molecular weight polymers.
Many natural and synthetic polymers are produced by...
Many natural and synthetic polymers are produced by...
4.1K