Silica Dimethyl Silylate is a treated, hydrophobic fumed silica powder used in cosmetics to thicken oils, suspend pigments (prevent settling), control shine, and add a silky texture, forming clear gels in oil phases. It's a lightweight, absorbent powder that provides oil control, improves makeup payoff (like in lipsticks), and adds volume to dry shampoos, acting as a viscosity modifier, emulsifier, and anti-caking agent in various skincare, haircare, and makeup products.
Key Functions & Benefits
Thickening & Gelling: Creates transparent gels in oils (like mineral, castor, or plant oils) and thickens oil phases in emulsions.
Oil Control: Absorbs oil, making it great for mattifying products.
Pigment Suspension: Prevents makeup pigments from settling in liquid formulas.
Texturizing: Adds a silky, smooth feel and can provide grip in powders like dry shampoo.
Emulsifying: Helps stabilize oil-water mixtures.
Water Resistance: Can increase water resistance in balms and makeup.
How It's Used
Products: Found in lipsticks, powders, dry shampoos, skincare creams, and sunscreens.
Application: Added to the oil phase of formulations, typically at low usage rates (0.1% to 30%).
Handling: A light powder requiring a dust mask; shear mixing helps form uniform gels.
Ingredient Profile
Type: Synthetic, treated silica.
Appearance: Ultra-lightweight, fluffy white powder.
Properties: Insoluble in water, odorless, and hydrophobic (oil-loving).
Description
Silica Dimethyl Silylate is a hydrophobic (oil-loving) form of fumed silica that has been surface-treated with dimethyl silyl groups.
Compared to regular silica, it:
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Is water-repellent
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Has excellent oil-thickening and gelling ability
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Improves texture, stability, and suspension
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Reduces greasiness and tackiness
It appears as a very light, fine white powder with high surface area.
Common Uses
It is widely used in cosmetic, personal care, and pharmaceutical formulations, especially oil-based systems.
Typical applications include:
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Oil and anhydrous gels
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Creams and ointments
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Sunscreens
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Makeup (foundations, primers, lipsticks)
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Anti-caking agent in powders
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Suspension agent for pigments and actives
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Rheology modifier (thickener)
Usage Rate (Typical)
The amount depends on the viscosity and structure you want:
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0.2 – 1% → Light thickening, improved stability
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1 – 3% → Medium viscosity, suspension support
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3 – 7% → Strong oil gel formation (ointments, clear oil gels)
Most cosmetic formulas use 0.5 – 3%
How to Use (In Formulation)
Important: This material is dusty and very light—handle carefully.
For Oil-Based or Anhydrous Systems
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Pre-disperse into oils
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Slowly add Silica Dimethyl Silylate into the oil phase
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Use high shear mixing (homogenizer or fast propeller)
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Mix until fully wetted
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The oil will gradually thicken
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Add remaining ingredients
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Pigments, actives, fragrances, etc.
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For Emulsions (Creams/Lotions)
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Add to the oil phase before emulsification
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Disperse thoroughly before combining with the water phase
Key Benefits in Formulas
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Thickens oils without waxes
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Improves heat and storage stability
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Keeps pigments and actives evenly suspended
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Gives a silky, non-greasy feel
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Helps prevent oil separation