Definition
A homogeneous disperser is a type of laboratory equipment used to evenly disperse solid particles or droplets in a continuous phase. It realizes the refinement and mixing of materials through mechanical action, and is widely used in chemical, food, coatings, new energy materials and environmental monitoring and other fields, aiming to obtain a stable and uniform dispersion system.
Principle
The homogeneous disperser is based on high-speed shear and turbulence effects to achieve dispersion. Its core component is a rotor-stator structure, which rotates at high speed driven by a motor to draw materials into the working chamber. In the narrow gap between the rotor and the stator, the material is subjected to strong shear, impact and hole effects, so that the agglomerated particles are broken and evenly dispersed in the medium. The whole process can be simplified into mechanical energy to interface energy, reducing the inhomogeneity of the system.
Measurement and evaluation methods
Dispersion is usually evaluated by particle size distribution and stability. Particle size analysis can be done using laser diffraction or dynamic light scattering to measure the size distribution of dispersed phase particles. Stability can be assessed by standing observation stratification time, centrifugal sedimentation experiments, or zeta potentiometry. For example, a higher zeta potential value (positive or negative) usually indicates that the dispersion system is more stable due to electrostatic repulsion. Dispersion uniformity can also be visually verified with the help of microscopic imaging.
Influencing factors
The dispersion effect is affected by multiple factors. Equipment parameters include rotor speed, rotor-stator clearance design, and processing time; The material characteristics include dispersed phase concentration, particle hardness, medium viscosity and interfacial tension. Process conditions such as temperature control, dosing sequence, and pre-mixing also play a role in the results. These factors need to be comprehensively adjusted in operation to achieve the expected dispersion.
Applications
In the chemical field, it is used for the dispersion of pigments in coatings; In the food industry, it is used in sauce emulsification and stabilization; When preparing new energy materials, it helps the uniform mixing of electrode slurry; In environmental testing, assist in sample preparation for representative analysis. In addition, homogeneous dispersers also play a role in the synthesis of cosmetics, ceramic slurries, and nanomaterials.
Key points of selection
The physical and chemical properties of the treated material, such as viscosity, corrosiveness, and solids content, should be considered when selecting the type. Choose the appropriate working capacity and model size according to the sample volume. Pay attention to the speed range, material resistance and temperature control function of the equipment. For samples that are prone to oxidation or sensitive, models with inert gas protection interfaces are available. In addition, the easy-to-clean design and compliance with relevant safety standards are important considerations.