Patent ID: 7758928

Claim:
A method of functionalizing a powdered substrate, which method comprises the following steps: i) passing a gas into a means for forming excited and/or unstable gas species; ii) treating said gas such that upon leaving said means the gas comprises excited and/or unstable gas species which are substantially free of electric charge at a temperature below 500° C.; iii) treating the powdered substrate with said excited and/or unstable gas species and a functionalizing precursor in a downstream region external to the means for forming excited and/or unstable gas, wherein neither the powdered substrate nor the functionalizing precursor have been subjected to steps (i) and (ii) and wherein said functionalizing precursor is introduced simultaneously with or subsequent to introduction of the powdered substrate; iv) collecting resulting functionalized substrate wherein the liquid and/or gas functionalizing precursor is an organopolysiloxane having viscosity from 0.65 to 1000 mPa.s.