Method of preparing clay comprising the following steps: a) dissolving salts AB in a solvent in which A is a cation selected from aluminium, magnesium, calcium, zinc, manganese, iron, copper and mixtures thereof and B is an anion selected from chloride, sulphate, hydrogen carbonate, carbonate, phosphate, hydrogen phosphate, acetyl acetonate and mixtures thereof; b) adding at least one functional silane to the mixture obtained in step a); and c) adding a strong base to the mixture from step b), while stirring, at a temperature of less than 40°C; characterised in that said functional silane is a chemical compound having the general formula m -Si- p in which - each X is selected, independently, from a chlorine atom and a C 1 -C 4 alkoxy group; - each R is a group selected, independently, from acetoxy, alkyl, amine, aminoalkyl, aryl, diaminoalkyl, epoxy, fluoroalkyl, glycol, mercapto, silicic acid ester, silyl, ureide, vinyl and vinyl alkyl groups; - p is 2, 3 or 4; - m is 0, 1, 2; and - p+m=4, characterised in that step b) of the method of the invention comprises adding a mixture of at least one functional silane selected from hydrophilic silanes and at least one functional silane selected from lipophilic silanes, and said functional silanes having the formula are selected from (polyether)triethoxysilane, benzyltriethoxysilane, benzyltrimethoxysilane, benzyltriethoxysilane, 2-(bicycloheptyl)trichlorosilane, p-(t-butyl)phenethyltrichlorosilane, n-butyltrichlorosilane, t-butyltrichlorosilane, n-butyltriethoxysilane, t-butyltrimethoxysilane, (cyclohexylmethyl)trichlorosilane, cyclohexyltrichlorosilane, cyclohexyltrimethoxysilane, cyclooctyltrichlorosilane, cyclooctyltrimethoxysilane, cyclopentamethylenedichlorosilane, cyclopentyltrichlorosilane, cyclopentyltrimethoxysilane, n-decyltrichlorosilane, n-decyltriethoxysilane, n-decyltrimethoxysilane, docosyltrichlorosilane, docosyltriethoxysilane, dodecyltrichlorosilane, dodecyltriethoxysilane, dodecyltrimethoxysilane, dicosyltrichlorosilane, (heptadecafluoro-1,1,2,2-tetrahydrodecyl)trichlorosilane, (heptadecafluoro-1,1,2,2-tetrahydrodecyl)triethoxysilane, (heptadecafluoro-1,1,2,2-tetrahydrodecyl)trimethoxysilane, n-heptyltrichlorosilane, hexacosatrichlorosilane, n-hexadecyltrichlorosilane, hexadecyltriethoxysilane, hexyltrichlorosilane, hexyltrimethoxysilane, [hydroxyl(polyethyleneoxy)propyl]triethoxysilane(8-12 EO), isobutyltrichlorosilane, isobutyltriethoxysilane, isobutyltrimethoxysilane, isooctyltrichlorosilane, isooctyltriethoxysilane, isooctyltrimethoxysilane, 2-[methoxy(polyethyleneoxy)propyl]trimethoxysilane, methoxytriethyleneoxypropyltrichlorosilane, methoxytriethyleneoxypropyltrimethoxysilane, naphthylmethyltrichlorosilane, (1-naphthyl)triethoxysilane, (1-naphthyl)trimethoxysilane, nonafluorohexyltrichlorosilane, nonafluorohexyltriethoxysilane, nonafluorohexyltrimethoxysilane, n-octadecyltrichlorosilane, n-octadecyltriethoxysilane, n-octadecyltrimethoxysilane, n-octyltriethoxysilane, n-octyltrimethoxysilane, pentyltrichlorosilane, pentyltriethoxysilane, perfluoroalkylethyltriethoxysilane, phenyltrichlorosilane, phenyltrimethoxysilane, 3-phenoxypropyltrichlorosilane, 4-phenylbutyltrichlorosilane, 6-phenylhexyltrichlorosilane, 3-phenylpropyltrichlorosilane, phenyltrichlorosilane, phenyltriethoxysilane, phenyltrimethoxysilane, p-tolyltrichlorosilane, p-tolyltriethoxysilane, le p-tolyltrimethoxysilane, 7-(trichlorosilylmethyl)pentadecane, triacontyltrichlorosilane, triethoxysilylpropoxy(polyethyleneoxy)dodecanoate, (triethoxysilylpropyl)gluconamide, undecyltrichlorosilane, 3-aminopropyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and mixtures thereof. a) dissolving salts AB in a solvent in which A is a cation selected from aluminium, magnesium, calcium, zinc, manganese, iron, copper and mixtures thereof and B is an anion selected from chloride, sulphate, hydrogen carbonate, carbonate, phosphate, hydrogen phosphate, acetyl acetonate and mixtures thereof; b) adding at least one functional silane to the mixture obtained in step a); and c) adding a strong base to the mixture from step b), while stirring, at a temperature of less than 40°C; - each X is selected, independently, from a chlorine atom and a C 1 -C 4 alkoxy group; - each R is a group selected, independently, from acetoxy, alkyl, amine, aminoalkyl, aryl, diaminoalkyl, epoxy, fluoroalkyl, glycol, mercapto, silicic acid ester, silyl, ureide, vinyl and vinyl alkyl groups; - p is 2, 3 or 4; - m is 0, 1, 2; and - p+m=4,