Shanghai Semitech New Material Co., Ltd.
1628 Lijing Road, Lingang New Area, 200000, Shanghai, China.
Mobile:
+8615639100440
Email:
info@semitechnm.com
Core Advantages & Applications
Unique Physicochemical Profile
- High Purity & Fine Particle Size: Prevents contamination in sensitive electronic and ceramic applications.
- Positive Surface Charge: Unlike silica, fumed alumina naturally carries a positive charge, making it ideal for interacting with negatively charged surfaces.
- Thermal Stability: Maintains structural integrity and insulating properties at extreme temperatures.
Energy & Electronics
- Li-ion Battery Separators: Acts as a ceramic coating to significantly increase thermal stability and safety.
- Anode Modification: Improves conductivity and reversible capacitance in lithium batteries.
- Lighting Industry: Used in fluorescent coating powders to ensure uniform light output and reduce UV harm.
Coatings, Inks & Specialty
- Powder Flow & Anti-Caking: Improves flowability and charge ability for powder coatings and printing inks.
- Rheology Control: Acts as a highly effective thickening and thixotropic agent with high transparency in UV-curable systems.
- Specialty Binders: Essential for high-temperature refractory castables and insulation boards.
SemiAlu™ Technical Specifications
| Properties | Unit | SemiAlu Value | Testing Method |
|---|---|---|---|
| Specific Surface Area (BET) | m²/g | 100 ± 15 | GB/T 20020 |
| pH in 4% Dispersion | - | ≥ 3.9 | GB/T 20020 |
| Loss on Drying (@ 105°C × 2h) | % | ≤ 2.5 | GB/T 20020 |
| Loss on Ignition (@ 1000°C × 2h) | % | ≤ 2.0 | GB/T 20020 |
| Al₂O₃ Content (Ignited Material) | wt.% | ≥ 98.0 | GB/T 20020 |
| Tamped Density | g/dm³ | 50 - 80 | GB/T 20020 |
| Crystal Structure | - | Mixed crystal structure | GB/T 20020 |
Knowledge Base: Frequently Asked Questions
Expert answers to the most common queries regarding fumed aluminum oxide applications and formulation integration.
1. What is fumed alumina, and how does it differ from fumed silica?
Fumed alumina (aluminum oxide) is a high-purity synthetic oxide powder produced via flame hydrolysis. The primary difference is its positive surface charge. While fumed silica carries a negative charge, fumed alumina's positive charge makes it uniquely suited for interacting with negatively charged surfaces, improving dispersion in specific polymer matrices and powder coatings.
2. How does SemiAlu fumed aluminum oxide improve Li-ion battery performance?
In Li-ion batteries, SemiAlu is applied as a ceramic coating for separators, which drastically enhances thermal stability and prevents thermal runaway, thereby improving battery safety. Additionally, when applied to the anode, it helps improve conductivity and reversible capacitance.
3. Why is a positive surface charge important in fumed alumina applications?
The positive surface charge (indicated by a pH ≥ 3.9 in a 4% dispersion) allows fumed alumina to act as a highly effective anti-caking agent and flow aid. It enhances charge adsorption in melt-blown electret masterbatches and improves the triboelectric chargeability of powder coatings, leading to more uniform application.
4. Can high-purity fumed alumina be used as a flow aid and anti-caking agent?
Yes. Due to its superfine particle size, low bulk density (50-80 g/dm³), and high specific surface area (80±15 m²/g), fumed alumina is an exceptional flow aid and anti-caking agent. It prevents clumping in powder coatings, toners, and printing inks while simultaneously acting as a thixotropic thickening agent.
5. What are the key technical specifications of SemiAlu fumed aluminum oxide powder?
SemiAlu features a high purity (Al₂O₃ ≥ 98.0%), a specific surface area (BET) of 80±15 m²/g, and a mixed crystal structure. It exhibits excellent thermal stability with a loss on ignition of ≤ 2.0%, making it ideal for high-temperature refractory castables and specialty optical coatings.