SILICAS COMPRISING PHOSPHONIC-ACID-MODIFIED SURFACES

摘要

The invention relates to a silica surface modification method which can be used, in particular, for the preparation of a silica grafted with hydrophobic chains R, in which: (A) a silica is treated in an aqueous medium with at least divalent metal cations that can bind to the surface thereof, typically type Al³⁺ aluminium cations; and subsequently (B) molecules of at least one phosphonic acid preferably having formula R-PO(-OH)₂, wherein R is a hydrophobic chain, are added to the aqueous medium obtained in step A. The invention also relates to the hydrophobised silicas obtained using said method and to the uses thereof, for example as a filler in silicon matrices.