What kind machine can dispersion Silicon dioxide powder?

What kind machine can dispersion Silicon dioxide powder?

Due to its high surface energy, titanium dioxide (TiO₂) powder easily forms stable aggregates through van der Waals forces and hydrogen bonds (especially nano-sized TiO₂). Direct use can reduce its optical, catalytic, and hiding properties, necessitating efficient dispersion through scientific methods. The following systematically introduces titanium dioxide powder dispersion solutions from four perspectives: core dispersion principles, specific dispersion methods (including operational details), key influencing factors, and application scenario adaptation.

1. Core Dispersion Principles
The essence of titanium dioxide dispersion is "breaking up aggregates to stabilize dispersed particles," requiring simultaneous solutions for two key issues:

Agglomerate structure disruption: Physical or chemical methods are used to overcome interparticle attractions (van der Waals forces, hydrogen bonds, and electrostatic attraction) to disassemble micron/nanoscale aggregates into primary particles.

Secondary agglomeration suppression: Surface modification or the addition of dispersants creates a "steric barrier" or "electrostatic repulsion layer" on the primary particle surface, preventing dispersed particles from re-adsorbing and agglomerating.

Do you know what kind machine can disperse the silicon dioxide powder?

Ultrasonic dispersion is a physical process that uses high-frequency sound wave energy (typically in the 20kHz-100kHz frequency range, beyond the range of human hearing) to break up material agglomerates and achieve uniform dispersion of particles or molecules. The core principle is the "cavitation effect" generated by sound waves in a liquid medium. This energy is transferred to the dispersed material, breaking down the forces that bind aggregates (such as van der Waals forces and hydrogen bonds), ultimately forming a stable, uniform dispersion.

1. Core Principle: Cavitation Effect
The essence of ultrasonic dispersion is the application of the "cavitation effect," a process that can be divided into three stages and is the core driving force of dispersion:

Cavitation bubble formation: When high-frequency sound waves propagate through a liquid, they periodically produce "compression zones" and "rarefaction zones." In the rarefaction zone (where pressure suddenly drops), tiny bubbles (or dissolved gases) in the liquid rapidly expand, forming invisible "cavitation bubbles."

Cavitation bubble collapse: When the sound wave propagates to the compression zone (where pressure suddenly rises), the expanding cavitation bubbles violently collapse within a very short time (on the order of microseconds), generating localized high temperatures (up to 5000K), high pressures (up to 1000atm), and intense microjets (with flow rates up to 100m/s).

Dispersion: The microjets of the collapsing cavitation bubbles exert strong impact and shear forces on the surrounding agglomerated particles, directly breaking up the agglomeration structure between the particles. Furthermore, the high temperature and high pressure environment weakens intermolecular forces, helping to achieve uniform dispersion at the molecular level. II. Key Elements of Ultrasonic Dispersion
To achieve efficient ultrasonic dispersion, the following four key elements must be controlled. Different parameter combinations directly affect the dispersion effect:

Element Category Key Parameter Impact on Dispersion
Ultrasonic System Frequency (20kHz-100kHz) Low frequency (20-40kHz): Cavitation bubble collapse energy is stronger, suitable for dispersing coarse particles (e.g., micron-sized particles); High frequency (>40kHz): Gener energy is more suitable for nanoparticles or sensitive systems (e.g., biomolecules).

Power Density (W/cm²) Too low power: Ineffective at breaking up agglomerates; too high power: May cause secondary agglomeration (localized overheating) or medium splashing. The power density must be adjusted according to the dispersion system.
Dispersion Medium Viscosity and Surface Tension: Low-viscosity and low-surface-tension media (e.g., water and ethanol) are more prone to cavitation and have higher dispersion efficiency. High-viscosity media (e.g., glycerol) require increased power to compensate for energy loss. Chemical Properties (Polar/Non-Polar): The medium must have good compatibility with the dispersed phase (e.g., particles) to prevent reagglomeration due to hydrophobic-hydrophilic repulsion (dispersants may be added to assist).

Dispersed Phase: Particle Size/Morphology: Micron-sized, blocky particles require higher cavitation energy; nano-sized, spherical particles are easier to disperse, but power must be controlled to prevent reagglomeration and resorption.

Initial Agglomeration: The more severe the initial agglomeration (e.g., hard agglomerates), the longer the dispersion time or the more appropriate dispersion method (coarse-crushing followed by fine-dispersion).
Operating Conditions: Dispersion Time: Too short: Incomplete dispersion; too long: May cause particle abrasion or medium temperature increase (requiring cooling and temperature control).

Temperature/Pressure: High temperatures reduce cavitation bubble stability (reduced collapse energy); high pressures inhibit cavitation bubble formation. Operation is typically performed at atmospheric pressure. III. Advantages and Limitations of Ultrasonic Dispersion

1. Core Advantages
High Dispersion Efficiency: Compared to traditional mechanical stirring (which relies on macroscopic shear forces), ultrasonic microfluidics can act on nanoscale aggregates, resulting in more thorough dispersion and shorter time (typically several minutes to tens of minutes).
Wide System Applicability: It can be used in liquid-solid (e.g., dispersing nanoparticles into water), liquid-liquid (e.g., preparing emulsions, such as oil-water emulsions), and even liquid-gas (e.g., preparing dissolved air in water) systems.

No Mechanical Contamination: The dispersion process relies on acoustic energy and does not require rotating parts (e.g., agitators). This avoids impurity contamination caused by mechanical wear and tear, making it suitable for high-purity systems (e.g., semiconductor materials and pharmaceutical preparations).

Flexible Operation: The equipment can be miniaturized (laboratory probe type) or industrialized (pipeline trough type), and parameters (frequency, power) can be adjusted in real time to meet the needs of different scenarios. 2. Major Limitations
High Energy Loss: High-frequency sound waves attenuate rapidly in high-viscosity media, requiring higher power to maintain the cavitation effect, resulting in high energy consumption.

Risk of Localized Overheating: If the high temperatures generated by the collapse of cavitation bubbles cannot be dissipated quickly, they may cause denaturation or decomposition of heat-sensitive substances (such as proteins and polymers).

High Equipment Cost: The manufacturing and maintenance costs of industrial-grade ultrasonic dispersion equipment (such as high-power tank ultrasonic machines) are higher than those of traditional mixing equipment.

Particle Selectivity: The dispersion effect may be limited for particles with high hardness and density (such as metal powders), necessitating the use of other methods (such as ball milling combined with ultrasonication). IV. Typical Application Scenarios
Due to its high efficiency, pollution-free, and precise performance, ultrasonic dispersion is widely used in various fields:

Materials Science: Nanomaterial Preparation (e.g., dispersing graphene into resins to create conductive composites, dispersing nano-titanium dioxide into coatings to enhance antibacterial properties);

Biomedicine: Pharmaceutical Preparation (e.g., dispersing poorly soluble drug particles into nanosuspensions to improve absorption), Cell Dispersion (facilitating the extraction of intracellular proteins/nucleic acids, essentially "cellular-level dispersion");
Coatings and Inks: Pigment Dispersion (e.g., dispersing carbon black and titanium dioxide into resins to prevent coating delamination and improve color uniformity);

Food Industry: Emulsion Preparation (e.g., dispersing nano-sized cream into milk to enhance taste, or preparing stable probiotic emulsions to extend shelf life);
Environmental Management: Wastewater Treatment (dispersing flocculant particles into nano-scale to increase contact area with pollutants and enhance flocculation);

Electronics Industry: Semiconductor Paste Preparation (e.g., dispersing silver nanoparticles into organic carriers for chip conductive paste to ensure uniform conductivity). V. Common Equipment Types

Depending on the application scenario, ultrasonic dispersion equipment is primarily divided into two categories:

Probe-type ultrasonic dispersers (immersion): These are based on an ultrasonic probe (made of titanium alloy, transmitting sound waves) that is directly immersed in the dispersion system, concentrating the energy and making them suitable for small laboratory sample batches (e.g., 10mL-1L) or high-viscosity systems.

Trough-type ultrasonic dispersers (non-immersion): The ultrasonic transducer is mounted on the wall of the reaction tank, transmitting sound waves through the tank wall into the medium. These dispersers are suitable for industrial continuous production (e.g., assembly line processing, with single-time processing volumes of up to hundreds of liters), are free of probe wear, and are easy to clean.

In summary, ultrasonic dispersion is a fine dispersion technology based on the cavitation effect. Its core value lies in addressing the challenges of nano-agglomeration and high-purity dispersion, which are difficult to address with traditional methods. It has become an indispensable key process in the materials, pharmaceutical, and food industries.