Studies On Molecular Sieve Host-Nanoguest Composite Materials

The nanosized and microsized MCM-41 molecular sieves were prepared by a hydrothermal method using tetraethyl orthosilicate as a silica source and cetyltrimethylammonium bromide as a structure-directing agent. (MCM-41)-cadmium (II) was prepared by ion-exchange and thioacetamide was used as the precusor of hydrogen sulfide for sulphidizing the (MCM-41)-cadmium (II) samples. The host-guest composite material (nanosized MCM-41)-rhodamine B (RhB) was prepared by liquid grafting method using RhB solution and the nanosized MCM-41 molecular sieve in water medium. By means of chemical analysis, powder X-ray diffraction, infrared spectroscopy, low-temperature nitrogen adsorption-desorption technique, solid state diffuse reflectance absorption spectroscopy and luminescence studies, the validity of the preparation methods was characterized. The results showed that the guests were sucessfully encapsulated in the channels of the molecular sieves and the frameworks of the molecular sieves in the prepared composite materials were intact. The prepared host-guest nanocomposite materials have the potentiality as luminescence materials.