摘要 |
Fine particle silica, especially fumed silica (FS), is interacted, in aqueous medium, with a substantially crystalline mixed metal layered hydroxide (MMLH) of the formula shown below to form a novel adduct, MMLH-SiO2, as an aqueous gell which is shear-thinning and which has rapid gelation times, the said MMLH comprising the general formula LimDdT(OH)(m+2d+3+n.a)(An)a.qH2O(I) where: m is from zero to about 1; D represents divalent metal ions; d is from zero to about 4; T represents trivalent metal ions; A represents monovalent or polyvalent anions or negative-valence radicals other than OH-ions; a is the number of ions of A; n is the valence of A; n-a is from zero to about -3; q is zero or more; (m+d) is greater than zero; and (m+2d+3+n.a) is equal to or greater than 3.
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