关键词: 载银, 杂化材料, 红外光谱；热稳定性；热分析动力学

Abstract: Ag/MTES-SiO2 hybrid material was prepared by sol-gel method, in which AgNO3 was added into methyl-modified silica sol. According to XRD, FTIR spectra and TG-DTG analysis, the thermal stability of Ag/MTES-SiO2 hybrid material was discussed. The activation energies and frequency factors were figured out by using Coast-Redfern intergral method and Αchar differential method. The results show that, metallic nano-silver peaks can be clearly found in the silica materials calcined above 120°C. The metallic silver results from the reduction of AgNO3. The Si?CH3 vibrational bands disappear completely when the calcination temperature is increased to 600 ℃, which mineralized when the calcination temperature is further increased to 750 ℃. The introduction of Ag nanoparticles nearly has no influence on the thermal stability of －CH3 groups. As the calcining temperature is increased, the diffraction peaks of metallic silver in intensity and the tendency of silica particles to form crystals increase. The metallic silver results from the reduction of AgNO3. There are four steps in the thermal decomposition of Ag/MTES-SiO2 materials in N2 atmosphere, with different mechanism functions. The activation energies are 71.92、125.78、235.73 and 417.37 kJ?mol?1, and the frequency factors are 1.18×109、7.14×1010、8.35×1013 and 1.16×1020 s?1 for the four steps, respectively.

Key words: Silver loaded, Hybrid material, Infrared spectra；Thermal stability；Thermal analysis kinetics