Thixotropy: no sagging and settling


A user-friendly applicable paint doesn't drip off the brush and doesn't run when it dries on vertical surfaces. At the same time, the coating should have a low viscosity due to the mechanical loading during the application process. Many coating systems owe this behavior - which the specialists call thixotropy—to the fumed silica AEROSIL®.

In a state of rest, the silica particles form a loose network: the coating is viscous. This network is destroyed when the coating is stirred, shaken, sprayed or painted, suddenly becoming considerably thinner. But as soon as it reverts to a state of rest, the molecules cluster into a network again. Based on this characteristic, AEROSIL® not only controls rheological behavior, but ensures that the heavier components of a liquid coating material don't settle during storage.

A comparison: paint without (left)
and with AEROSIL® (right)

More products by Evonik for paints and coatings: