Composition comprising: (a) one or more alkoxysilanes comprising solubilizing function(s) of formula (I) below, and/or hydrolysis products thereof and/or oligomers thereof: R 1 Si(OR 2 ) z (R 3 ) x (OH) y (I) in which: R 1 is a linear or branched, saturated or unsaturated C 1 -C 6 hydrocarbon-based chain, substituted with an amine group NH 2 or NHR, R being: ∘ a C 1 -C 20 , preferably C 1 -C 6 , alkyl group, optionally substituted with a group comprising a silicon atom, better still a (R 2 O) 3 Si-group, ∘ a C 3 -C 40 cycloalkyl or ∘ a C 6 -C 30 aromatic group. R 2 and R 3 , which may be identical or different, represent a linear or branched alkyl group comprising from 1 to 6 carbon atoms, y denotes an integer ranging from 0 to 3, z denotes an integer ranging from 0 to 3, and x denotes an integer ranging from 0 to 2, with z + x + y = 3, (b) one or more alkylalkoxysilanes of formula (III) below, and/or hydrolysis products thereof, and/or oligomers thereof: (R 4 ) m Si(OR 5 ) n (III) in which: R 4 and R 5 each represent, independently of one another, a C 1-6 , better still C 1-4 , alkyl group such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl, preferably methyl, ethyl and n-propyl, n ranges from 1 to 3, m ranges from 1 to 3, on condition that m+n=4. and (c) one or more surfactants, with a (a)/(b) weight ratio ranging from 0.5 to 10. (a) one or more alkoxysilanes comprising solubilizing function(s) of formula (I) below, and/or hydrolysis products thereof and/or oligomers thereof: R 1 Si(OR 2 ) z (R 3 ) x (OH) y (I) in which: R 1 is a linear or branched, saturated or unsaturated C 1 -C 6 hydrocarbon-based chain, substituted with an amine group NH 2 or NHR, R being: ∘ a C 1 -C 20 , preferably C 1 -C 6 , alkyl group, optionally substituted with a group comprising a silicon atom, better still a (R 2 O) 3 Si-group, ∘ a C 3 -C 40 cycloalkyl or ∘ a C 6 -C 30 aromatic group. R 2 and R 3 , which may be identical or different, represent a linear or branched alkyl group comprising from 1 to 6 carbon atoms, y denotes an integer ranging from 0 to 3, z denotes an integer ranging from 0 to 3, and x denotes an integer ranging from 0 to 2, with z + x + y = 3, R 1 is a linear or branched, saturated or unsaturated C 1 -C 6 hydrocarbon-based chain, substituted with an amine group NH 2 or NHR, R being: ∘ a C 1 -C 20 , preferably C 1 -C 6 , alkyl group, optionally substituted with a group comprising a silicon atom, better still a (R 2 O) 3 Si-group, ∘ a C 3 -C 40 cycloalkyl or ∘ a C 6 -C 30 aromatic group. ∘ a C 1 -C 20 , preferably C 1 -C 6 , alkyl group, optionally substituted with a group comprising a silicon atom, better still a (R 2 O) 3 Si-group, ∘ a C 3 -C 40 cycloalkyl or ∘ a C 6 -C 30 aromatic group. R 2 and R 3 , which may be identical or different, represent a linear or branched alkyl group comprising from 1 to 6 carbon atoms, y denotes an integer ranging from 0 to 3, z denotes an integer ranging from 0 to 3, and x denotes an integer ranging from 0 to 2, with z + x + y = 3, (b) one or more alkylalkoxysilanes of formula (III) below, and/or hydrolysis products thereof, and/or oligomers thereof: (R 4 ) m Si(OR 5 ) n (III) in which: R 4 and R 5 each represent, independently of one another, a C 1-6 , better still C 1-4 , alkyl group such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl, preferably methyl, ethyl and n-propyl, n ranges from 1 to 3, m ranges from 1 to 3, on condition that m+n=4. and R 4 and R 5 each represent, independently of one another, a C 1-6 , better still C 1-4 , alkyl group such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl, preferably methyl, ethyl and n-propyl, n ranges from 1 to 3, m ranges from 1 to 3, on condition that m+n=4. (c) one or more surfactants, with a (a)/(b) weight ratio ranging from 0.5 to 10. <EOS>