THE CHEMICAL-STATE OF SN IN SN-MONTMORILLONITE - A MULTINUCLEAR MAS NMR AND SN-119 MOSSBAUER SPECTROSCOPIC STUDY

The incorporation of Sn was attempted in-between the layers of Na-mont morillonite through the hydrolysis of (NH4)(2)SnCl6 in an aqueous envi ronment under reflux. Intercalation was successful and the resulting s tructure was characterized by X-ray fluorescence (XRF) spectroscopy, X -ray diffractometry (XRD), surface area (BET) and thermogravimetric me asurements, infrared (IR), Sn-119 Mossbauer and multinuclear (Al-27, S i-29 and Sn-119) magic angle spinning (MAS) spectroscopies. It was fou nd that the intercalated species was partially hydrated SnO2 which was kept between the layer with secondary forces: hydrogen bonds and van der Waals interactions. Upon heat treatment gradual and eventually com plete dehydration of the intercalated species occurred and the bare Sn O2 moved to the outer surface of the clay.