Selective fluorination of the interlayer surface of layered silicates

Abstract

Controllable fluorination of silicate materials has been hardly accomplished mainly due to the high reactivity of fluorinating substances. In this study, the introduction of fluorinating substances into the interlayer space of magadiite in neutral form was attempted to induce an in situ fluorination reaction preferably on the interlayer surface of layered silicates. Two types of fluorinating substances, inorganic ammonium fluoride salts and organic 4-tert-butyl-2,6-dimethylphenylsulfur trifluoride (Floulead), were successfully intercalated into the interlayer space of magadiite without any significant deterioration of the framework. Subsequent in situ fluorination reactions led to the preferred fluorination of the layered silanol groups that was envisioned successfully in the XRD pattern, FT-IR spectrum, TG/DTA curve, and cation exchange capacity. This study demonstrates that the silicate materials could be fluorinated selectively through intercalation and subsequent in situ localized reactions of various fluorinating substances.