Aerogel insulation sheets are an efficient insulation material, mainly composed of silica aerogel, with extremely low thermal conductivity and excellent insulation performance. They can be widely applied in various fields.
The types of aerogel insulation sheets can be classified based on material composition, structural form, and functional characteristics. The following is a detailed analysis:
1. Classified by material composition
1.1 Silica (SiO₂) aerogel insulation sheets
Characteristics: The most common type, with a porosity of over 90%, low thermal conductivity (0.015–0.03 W/(m·K)), and a wide temperature tolerance range (-200°C to 650°C)
Disadvantages: High brittleness, requires fiber reinforcement to enhance strength
Applications: Pipeline insulation, building energy conservation, industrial equipment insulation (such as Aspen Aerogels' Pyrogel®)
1.2 Carbon-based aerogel insulation sheets
Characteristics: With graphene, carbon nanotubes, or carbon fibers as the framework, excellent electrical conductivity, high temperature resistance (up to 2000°C), but slightly higher thermal conductivity
Applications: High-temperature furnace linings, battery thermal management, electromagnetic shielding scenarios
1.3 Organic polymer aerogel insulation sheets
Materials: Polyimide (PI), polyurethane (PU), cellulose, etc. Characteristics: Good flexibility, can be bent, but poor thermal resistance (generally below 300°C)
Applications: Flexible electronic device insulation, clothing insulation, low-temperature environment insulation
1.4 Metal oxide aerogel insulation sheets
Materials: Oxides of aluminum (Al₂O₃), zirconium (ZrO₂), etc. Characteristics: High temperature resistance (above 1000°C), strong oxidation resistance, but higher density
Applications: Aerospace heat protection, nuclear reactor insulation layer
2. Classified by structural form
2.1 Pure aerogel sheets
Characteristics: No carrier, lightweight but poor mechanical properties, requires encapsulation for use (such as core material of vacuum insulation board)
2.2 Fiber-reinforced aerogel insulation sheets
Reinforcing materials: Glass fibers, ceramic fibers, carbon fibers or pre-oxidized fibers (such as Panox®) Characteristics: Enhanced tensile strength, can be processed into rolls or plates, suitable for complex shape encapsulation
Representative product: American Aspen Aerogels' Cryogel® (glass fiber reinforced)
2.3 Composite aerogel insulation sheets
Composite method: Combined with ceramic fiber felts, foam metals, or porous polymers
Characteristics: Combining insulation and structural support functions, such as aerogel/ceramic fiber composite felts used for high-temperature pipelines
3. Classified by functional characteristics
3.1 Hydrophobic aerogel insulation sheets
Processing method: Surface silane modification, contact angle > 150°
Applications: Damp environments (such as ships, cold storage), avoiding performance degradation due to water absorption
3.2 Hydrophilic aerogel insulation sheets
Characteristics: Used in scenarios requiring moisture absorption or phase change materials (PCM), such as temperature-regulating textiles
3.3 Flame-retardant aerogel insulation sheets
Modification method: Adding flame retardants (such as phosphorus-based compounds), passing UL94 V-0 certification
Applications: New energy vehicle battery packs, building fire isolation layer
4. Classified by preparation process
4.1 Supercritical drying aerogels
Characteristics: Complete pore structure, excellent performance, but high cost, long production cycle
4.2 Atmospheric drying aerogels
Characteristics: Optimized through sol-gel method, cost reduction, suitable for large-scale production, but slightly lower porosity
5. Future development trends
Multifunctional: Combining sensing, energy storage or self-cleaning functions
Cost reduction: Promoting optimization of atmospheric drying process and development of bio-based raw materials (such as cellulose)
Extreme environment suitability: High-temperature (>1500°C) or deep low-temperature (hydrogen storage) aerogels
6. Typical application scenarios
Industrial sector: Petrochemical pipelines, LNG storage tanks (SiO₂-based fiber-reinforced construction field: curtain wall insulation sandwich, energy-saving windows (transparent aerogel glass))
Aerospace sector: Thermal insulation for rocket engine nozzles (ZrO₂ aerogel)
New energy sector: Thermal insulation for new energy vehicle batteries (flame-retardant type), fireproof layer for high-speed train carriages