Silica Aerogel Powder — Hydrophobic Superinsulating Grade
SEMITECH Silica Aerogel Powder is a hydrophobic, amorphous silica aerogel in free-flowing powder form, delivering thermal conductivity of approximately 0.015 W/(m·K) at 25°C — approaching the theoretical insulation limit achievable by solid materials at atmospheric pressure. The aerogel's nanoporous open-cell structure (>85% porosity, primary particle size 5–20 nm) suppresses gas-phase thermal conduction below that of still air, making it the highest-performance thermal insulation filler commercially available.
The hydrophobic surface treatment (contact angle ≥145°) ensures moisture resistance, preventing the performance degradation that occurs with untreated hydrophilic aerogel in humid or wet installation environments. SEMITECH Silica Aerogel Powder is supplied in aggregate d50 5–50 μm for ease of handling and blending with binder systems.
Technical Specifications
| Properties and Test Methods | Unit | Typical Value | Standardization |
|---|---|---|---|
| Thermal conductivity at 25°C | W/(m·K) | ~0.015 | ASTM C518 |
| BET specific surface area | m²/g | 600–1000 | — |
| Apparent bulk density | kg/m³ | 50–150 | — |
| Primary particle size | nm | 5–20 | — |
| Aggregate median size d50 | μm | 5–50 | — |
| Porosity | % | ≥85 | — |
| Contact angle (hydrophobicity) | ° | ≥145 | — |
| Maximum service temperature | °C | 300 | — |
| SiO₂ content | % | ≥97 | — |
Application Suggestions
Aerogel Composite Blanket Manufacturing
Silica aerogel powder is the functional insulating filler in aerogel composite blanket products, where it is needled or impregnated into a fibrous batting (glass fiber, ceramic fiber, or polyester) binder matrix. Blankets incorporating aerogel powder achieve thermal conductivity values of 0.015–0.020 W/(m·K) — several times lower than conventional mineral wool blankets — enabling thinner insulation cross-sections for piping, equipment, and building envelope applications.
Thermal Insulation Paint and Coatings
In thermal insulation coating formulations, aerogel powder is dispersed in water-based or solvent-based binder systems at 10–30 Wt% loading to create thin-film insulating coatings for pipes, roofing, and industrial equipment. The nano-porous particle structure reduces the effective thermal conductivity of the coating well below that of equivalent ceramic microsphere formulations.
Lightweight Sandwich Panel Core
Aerogel powder can be incorporated into rigid foam or cementitious core materials in sandwich panel construction to significantly reduce thermal conductivity without the thickness penalties associated with conventional insulation cores. This is particularly relevant in cold-chain logistics panel construction and prefabricated building facade panels where space-to-performance ratio is critical.
PPE and Firefighting Apparel Insulation
The combination of low thermal conductivity, low weight, and hydrophobicity makes silica aerogel powder suitable as a component in high-performance insulating interlayers for firefighting turnout gear, industrial PPE, and extreme-cold protective apparel. Use in flexible textile composite form requires blending with fiber carriers.
Under-Floor and Cavity Wall Insulation Additive
As a loose-fill or slurry-injectable additive for retrofitting cavity walls and under-floor insulation in construction, aerogel powder significantly outperforms expanded perlite and mineral wool loose-fill on thermal resistance per unit thickness.
Technical Support & FAQ: Silica Aerogel Powder
+Q1: What are the key differentiators versus conventional insulation fillers?
Thermal conductivity of ~0.015 W/(m·K) at 25°C is approximately 4× lower than mineral wool (0.033–0.040 W/(m·K)) and 2× lower than EPS foam (0.030–0.035 W/(m·K)). The key mechanism is nanopore size (average 20–50 nm) — smaller than the mean free path of air molecules at atmospheric pressure, which suppresses gas-phase conduction. No other commercially available solid material approaches this performance level at ambient conditions.
+Q2: How does hydrophobic treatment affect performance?
The hydrophobic surface coating (contact angle ≥145°) prevents moisture absorption that would otherwise collapse the aerogel pore structure and degrade thermal performance. Hydrophobic aerogel maintains its insulation performance in humid environments and after water contact, unlike untreated hydrophilic aerogel which degrades rapidly on moisture exposure.
+Q3: What factors affect pricing?
Silica aerogel powder is a premium-priced material due to the supercritical drying or ambient-pressure drying process required in manufacture. Pricing depends on order volume, particle-size grade (finer grades carry a premium), and surface treatment specification. Contact info@semitechnm.com for a FOB Shanghai quotation.
+Q4: What are lead times and payment terms?
Standard lead time is 7–14 days from order confirmation. Payment terms: T/T, L/C, D/P. Free samples of 200g–1kg are available for formulation and thermal conductivity testing on request.
Packing & Storage Information
20′ FCL Container Silica aerogel powder is extremely low density (50–150 kg/m³) — volume rather than weight typically fills a container. Packed in 10 kg or 20 kg multi-wall bags with inner PE liner. A 20′ FCL holds approximately 2–4 MT depending on bulk density grade.
40′ HQ Container Approximately 4–8 MT in 10–20 kg bags. Compression-resistant outer packaging is specified to prevent bag damage during ocean freight.
Storage Conditions Store in a cool, dry warehouse away from open flame (aerogel powder is combustible at sufficient concentration). Keep sealed to prevent moisture ingress and airborne dust. Wear appropriate dust mask (FFP2) during handling. Shelf life is 24 months in original sealed packaging.