Application Of Ultrasonic Atomization Spraying in The Preparation Of Nanomaterials?

Ultrasonic atomization spraying (UAS) is a technology that uses ultrasonic vibration to break liquid raw materials into micron/nanometer-sized droplets, which are then transported to a substrate or reaction zone via a carrier gas. Nanomaterials are then prepared through drying, sintering, or chemical reactions. Its core advantages lie in the uniform droplet size (down to 1-10 μm), precise and controllable coating thickness (nm-μm level), no mechanical damage, and high raw material utilization. It has been widely applied in the preparation of nanofilms, nanopowders, and nanocomposite materials, and is particularly suitable for high-end fields such as precision electronics, new energy, and biomedicine.

 

1. Nanofilm Fabrication (Most Mainstream Application)

Application Scenarios:

◆Semiconductor/Electronic Devices: Conductive nanofilms (e.g., ITO, graphene, carbon nanotube films), insulating films, photoresist coatings;

◆New Energy: Lithium-ion battery electrode films (nanosilicon, lithium iron phosphate coatings), fuel cell proton exchange membranes (Nafion film modification), solar cell light absorption layers (quantum dot films);

◆Functional Coatings: Transparent heat-insulating films (nanoTiO₂, ZrO₂ coatings), antibacterial films (nanosilver, zinc oxide coatings), self-cleaning films (nanoSiO₂ hydrophobic coatings).

Technical Advantages:

◆ Excellent Film Uniformity: Uniform droplet size avoids coating defects (such as pinholes and cracks) caused by "droplet aggregation" in traditional spraying;

◆ Precise and Controllable Thickness: Nanoscale to micrometer-scale coating thickness (e.g., 10 nm-5 μm) can be achieved by adjusting the atomization frequency (20-180 kHz), liquid flow rate (0.1-10 mL/min), and spraying time;

◆ Low-Temperature Preparation: Low kinetic energy when droplets impact the substrate allows for preparation at room temperature or medium to low temperatures (<200℃), making it suitable for flexible substrates (such as PET, PI films) or thermosensitive materials (such as biomacromolecules, quantum dots).

Typical Cases:

◆Graphene Transparent Conductive Film: Graphene dispersion is ultrasonically atomized and sprayed onto a glass or flexible PET substrate. After low-temperature drying, a film with a sheet resistance <100 Ω/□ and a light transmittance >90% is formed, suitable for touch screens and flexible display devices;

◆Lithium-ion Battery Silicon-based Anode Coating: Nano-silicon particle dispersion is sprayed onto a copper foil substrate to form a uniform silicon-based coating (500 nm-2 μm thick), improving battery capacity and cycle stability.

2. Nanopowder Preparation

Application Scenarios:

◆Metal/Alloy Nanopowders (e.g., nano-silver, copper, nickel powder): used in conductive pastes, catalysts, and 3D printing raw materials;

◆Oxide Nanopowders (e.g., TiO₂, ZnO, Al₂O₃ powder): used in photocatalytic materials, ceramic raw materials, and coating additives;

◆Composite Nanopowders (e.g., Fe₃O₄@SiO₂, quantum dot powder): used in biosensing, fluorescent probes, and magnetic storage materials.

Technical Advantages:

◆ Uniform Powder Particle Size: Controllable droplet size results in a narrow particle size distribution (typically 10-100 nm);

◆ High Purity: Droplets react in the gas phase, avoiding the introduction of impurities as in traditional wet processing;

◆ Controllable Morphology: By adjusting the reaction temperature, carrier gas flow rate, and precursor concentration, nanopowders with different morphologies such as spherical, flake, and rod-shaped particles can be prepared.

Typical Case:

◆ Preparation of Nano-Silver Powder: Silver nitrate solution is mixed with a reducing agent (such as ethylene glycol), atomized, and then passed into a 300℃ reactor to reduce and generate spherical silver powder with a particle size of 20-50 nm, used in electronic pastes (such as LED packaging and photovoltaic cell electrodes).