Preparation and Characterization of the Nanocomposites SiO 2 /H-Bond Hydrogensulphate (Hydrogenselenate)

The nanocomposites representing interesting H-bond compounds (Na 3 H(SO 4 ) 2 , RbHSO 4 , RbHSeO 4 , and Rb 3 H(SeO 4 ) 2 ) in the silica matrix were prepared by the sol-gel method. Resulting samples were characterised by X-ray diffraction, IR spectroscopy and electron microscopy. Transition temperatures of the nanocomposites were determined using DSC and compared with the T C of the pure bulk active compounds. The shifts of the T C towards lower temperatures or the disappearing of the certain effects in the case nanocomposites were observed. A possible explanation of these phenomena was proposed using the analogy with the superparamagnetic compounds.