Charge homogeneity in synthetic fluorohectorite

Due to phase separation in the silicate melt, the synthesis of fluorosmecti tes ([Na-0.5](inter)[Mg2.5Li0.5](oct)[Si-4](O10F2)-O-tet) from the melt wit hout mechanical mixing yields an inhomogeneous material. Because of the sol id solution capability of the 2:1 layer silicate structure, the nonuniformi ty in chemical and mineral composition inevitably will lead to fluorosmecti tes that adopt a range of charge densities. This will be detrimental to man y possible applications due to the large influence of layer charge on the p roperties of clay minerals. The problem can be circumvented by rotating the crucible during synthesis in a horizontal mounting, which will continuousl y force mixing of the melt mechanically. The product obtained is homogeneou s at all length scales as judged by chemical analysis and its uniform intra crystalline reactivity. Noteworthy is its tendency to form regularly inters tratified intercalates of monolayers and bilayers upon alkylammonium exchan ge and of rectorite type phases upon partial K+ exchange. We expect that th e two dissimilar types of galleries, which are stacked in a regularly alter nating pattern, can be selectively addressed-leading to interesting interca lation materials.