Using Disteardimonium Hectorite in Sunscreen Formulations

To create a gel texture and contribute to a mousse-like feel in a sunscreen formulation using Disteardimonium Hectorite, the typical usage rate is 0.1-10%. For a sunscreen, a range like 1-5% might be a good starting point depending on the desired thickness and suspension properties.

Regarding the mixing procedure, your observation that it didn't form a gel by just mixing in Dimethicone or Cyclopentasiloxane is correct. Disteardimonium Hectorite needs to be activated after being dispersed in the oil or silicone phase.

Here is the general procedure:

1. Disperse: Add Disteardimonium Hectorite to your oil or silicone phase (like Dimethicone, Cyclopentasiloxane, or other oils in your formula). Stir well to ensure it is fully dispersed. It will not thicken at this stage.
2. Activate: Add a small amount of a polar activator, such as ethyl alcohol or propylene carbonate, to the oil/silicone phase containing the dispersed Disteardimonium Hectorite. The activator helps the clay particles swell and build a gel structure. The amount of activator needed is typically around 30-50% of the weight of the Disteardimonium Hectorite, but you may need to experiment to find the optimal amount for your specific oil phase.
3. Mix/Shear: Apply high shear mixing (e.g., using a homogenizer or high-speed mixer) to the activated oil/silicone phase. This shear is necessary to properly develop the gel network and achieve the desired viscosity and suspension.
4. Emulsify: Once the activated and thickened oil/silicone phase is ready, you can proceed with your standard emulsification process by combining it with your water phase to form the sunscreen emulsion.

Using Disteardimonium Hectorite, especially when properly activated and sheared, helps stabilize emulsions, suspend solid particles (like UV filters), and provides a desirable thixotropic or shear-thinning property, which contributes to the mousse-like texture you are aiming for in a sunscreen that contains water.