| Summary: | 碩士 === 中國文化大學 === 材料科學與製造研究所 === 88 === A comprehensive study on the synthesis, modification and characterization of mesoporous silica ropes has been made. In particular, the effects of related chemical and physical parameters, such as the reactant concentration, aging time, temperature and shearing flow, on the synthesis of the centimeter-sized, hexagonal-arrayed mesoporous molecular sieves have been investigated. It is found that the thermal and hydrothermal stability of these acid-made mesoporous silica can be markedly improved when subjected to further hydrothermal treatment under ammonia solution (pH > 10; 100℃). As a result, both the pore size distribution and structural ordering of the silica ropes are improved after the post-synthesis treatment.
The surface of the silica nanochannels were further modified by the silation of the as-synthesized mesoporous materials with various silane sources under ethanol solution at 70℃. Their surface properties were characterized by low temperature (77 K) N2 adsorption and by 29Si and 129Xe NMR spectroscopy.
|
|---|
