Name: Fumed Silica Thixotropic Agent FS-200
Brand: Coatingsink
SKU: fumed-silica-thickener-fs200
Availability: InStock

Question 1

What is the mechanism by which fumed silica builds thixotropic structure?

Accepted Answer

Fumed silica primary particles (12 nm) aggregate into chains that form a three-dimensional hydrogen-bond network via surface silanol (Si-OH) groups. This network is reversibly broken under shear (application) and reforms at rest, giving the characteristic thixotropic recovery without permanent viscosity loss.

Question 2

How does the 200 m²/g BET grade compare to lower-surface-area fumed silicas for thickening efficiency?

Accepted Answer

Higher BET surface area means more silanol groups per unit mass, so FS-200 delivers stronger network formation and greater viscosity build at lower loading (typically 0.5–2.0 wt%) compared to 130 m²/g grades. This allows formulators to achieve equivalent anti-sag performance with less filler, which is important for gloss retention and film clarity.

Question 3

Can FS-200 be used directly in waterborne systems without pre-treatment?

Accepted Answer

As a hydrophilic grade, FS-200 disperses in aqueous media but requires high-shear incorporation (e.g., dissolvers at ≥ 2000 rpm or bead milling) to break down soft agglomerates and achieve full network formation. In solventborne or 100%-solids adhesive systems, a hydrophobic fumed silica grade is typically preferred for better compatibility and transparency.

SiO2 Content	≥ 99.8%
BET Surface Area	200 ± 25 m²/g
pH (4% dispersion)	3.7–4.7
Bulk Density (tamped)	~50 g/L
Average Primary Particle Size	12 nm

Fumed Silica Thixotropic Agent FS-200

Specifications

FAQ

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