Study Of Encapsulation Of DBS-Arsenazo, Cadmium Sulfide In Nanoscale SBA-15

Mesoporous molecular sieve and molecular sieve host-guest nanocomposite materials are of great research interests recently. Compared with other molecular sieves, SBA-15 has thicker walls, larger pores and better hydrothermal stability and thermal stability. In this thesis, nanoscale mesoporous SBA-15 molecular sieve was prepared in acidic medium by using triblock copolymers (EG20PG40EG20) as template, tetraethoxysilane as silica resource. Materials dibromo-p-sulfonic acid arsenazo (DBS-ASA) and cadmium sulfide were incorporated into the molecular sieve hosts by liquid-phase grafting and ion exchange-hydrothermal methods, respectively, to obtain host-guest nanocomposite materials (SBA-15)-(DBS-ASA) and (SBA-15)-CdS. Fourier transform infrared spectroscopy showed that the frameworks of the prepared host-guest nanocomposite materials were remained intact. Powder X-ray diffraction test results indicated that during the process of incorporation the frameworks of the molecular sieves were not destroyed and the crystalline degrees of the host-guest nanocomposite materials prepared were still remained highly ordered. Low-temperature nitrogen adsorption-desorption results showed that the surface area and the pore volume of the prepared host-guest composite materials decreased compared to those of the host molecular sieves, indicating that the guest has partially occupied the channels of the molecular sieves. Scanning electron microscopic studies indicated that the DBS-ASA and CdS had already located in the channels of the molecular sieves, respectively. The studies of luminous spectra showed that the post-encapsulation host-guest nonacomposite materials (SBA-15)-(DBS-ASA) and (SBA-15)-CdS have the properties of luminescence at 470 nm and 541 nm,respectively. The materials have the potential applied value in the field of luminescent materials.etc.