Achieving High Viscosity and Mica Suspension in Silicone Base using Oil-Fix S (Silica Dimethyl Silylate)

Based on the properties of Oil-Fix™ S (Silica Dimethyl Silylate), the low viscosity you are experiencing at 2% is highly likely due to insufficient shear, not a lack of heat.

Here is a breakdown of the requirements and a recommended procedure:

1. Shear vs. Heat Requirement

• High Shear is Essential: Oil-Fix™ S, like most silica gellants, requires high shear mixing to properly disperse the fine powder and break up the aggregates. This process allows the particles to fully swell and form the three-dimensional network necessary for gelling and achieving full viscosity. A standard paddle overhead mixer is typically not sufficient. You should use a high-speed propeller mixer (running at high RPM) or a homogenizer for this step.
• Heat is Recommended, Not Essential: Heat is not strictly required but is highly recommended. Applying gentle heat (e.g., 60-70°C) during the high-shear mixing process will significantly accelerate the gelling and ensure the gellant reaches its maximum viscosity more quickly and efficiently.

2. Recommended Procedure

To achieve the desired viscosity and suspension:

1. High-Shear Dispersion: Add the 2% Oil-Fix™ S to your silicone base. Mix with a high-shear mixer (homogenizer or high-speed propeller) for at least 15-30 minutes. If possible, apply gentle heat (60-70°C) during this mixing phase.
2. Check Viscosity: Stop mixing and allow the mixture to cool (if heated). The viscosity should increase significantly as the gel network forms.
3. Add Oils and Fragrance: Once the gel is formed, add the 1% Camellia oil, 0.5% Jojoba oil, and 0.3% fragrance. Mix until fully dispersed. The resulting gel structure will help stabilize these small amounts of non-silicone oils within the silicone base.
4. Add Mica: Finally, incorporate the mica. The high viscosity of the gel will be crucial for suspending the mica particles and preventing sedimentation.

3. Suitability for Your Goal

Oil-Fix™ S is the correct choice for gelling a silicone base and is perfectly suited for your goals:

• Suspending Mica: The resulting gel structure provides the necessary yield stress to hold solid particles like mica in suspension.
• Dispersing Oils/Fragrance: The product description confirms that Oil-Fix™ S is used to gel silicone oil. While the other types (O/W) are recommended for vegetable oils, the small total amount of Camellia oil and Jojoba oil (1.5% total) and fragrance will be effectively dispersed and stabilized within the highly viscous silicone gel.