Patent ID: 8562728

Claim:
Process for preparing proton-conducting clay particles, successively comprising the following steps: a) providing clay particles in the form of a powder; b) activating the clay particles, by subjecting said particles to a gas plasma, said particles thus constituting activated particles; and c) contacting said activated particles with a solution comprising at least one compound comprising at least one group chosen from —PO 3 H 2 , —CO 2 H and —SO 3 H and salts thereof and comprising at least one group capable of grafting onto a surface of said activated particles, whereby proton-conducting clay particles in the form of a powder are obtained having on their surfaces at least one compound comprising at least one group chosen from —PO 3 H 2 , —CO 2 H and —SO 3 H and salts thereof, and wherein the at least one compound is grafted to the clay particles through covalent chemical bonds.