Preparation and characterization of the nanocomposies SiO_2/-Bond hydrogensulphate (hydrogenselenate)

摘要

The nanocomposites representing interesting H-bond compounds (Na_3H(SO_4)_2,RbHSO_4,RbHSeO_4 and Rb_3H(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 temperaures of the nanocomposites were determinedusing DSC and compared with the T_C of the pure bulk active compounds. The shiftsof the T_C towards lower temperatures or the disappearingof the cerain effects in the case nanocomposites were observed. A possible explanation of the these phenomena was proposed using the analogy with the superparamagnetic compounds.