Intercalation of poly(oxyethylene) alkyl ether into a layered silicate kanemite

Poly(oxyethylene) alkyl ether (C_nEO_m) is intercalated into the interlayer space of a layered silicate kanemite by using layered hexadecyltrimethylammonium (C₁₆TMA) intercalated kanemite (C ₁₆TMA-kanemite) as the intermediate. C₁₆TMA-kanemite was treated with an aqueous solution of C₁₆EO₁₀, and the intercalation of C₁₆EO₁₀ was confirmed by the slight increase in the basal spacing (from 2.92 to 3.34 nm) with the increase in the carbon content, yielding C₁₆EO₁₀-C₁₆TMA- kanemite. The product was dispersed again in a C₁₆EO₁₀ aqueous solution, and then 1.0 M HCl was added to the suspension to remove C₁₆TMA ions completely. The basal spacing was further increased (from 3.34 to 5.52 nm) and the content of nitrogen was virtually zero, indicating further intercalation of C₁₆EO₁₀ molecules and complete elimination of C₁₆TMA ions simultaneously. Though C ₁₆EO₁₀ molecules are not directly intercalated into kanemite, the mutual interactions among C₁₆TMA ions, C ₁₆EO₁₀ molecules, and the interlayer silicate surfaces effectively induce the intercalation of C₁₆EO₁₀. C ₁₆EO₁₀-kanemite shows a reversible adsorption of n-decane and water owing to the hydrophobicity and hydrophilicity of C ₁₆EO₁₀, respectively, in the interlayer space. Layered C_nEO₁₀-kanemites (n = 12 and 18) were also synthesized in a manner similar to layered C₁₆EO₁₀-kanemite.