Using high-resolution transmission electronic micrograph (HR-TEM) observation, one can clearly see the pore geometry of the MCM-41 and SBA-15 mesoporous silicas to determine that their pore shapes are hexagonal and round, respectively. With the perpendicular orientations of the nanochannels to the electron beam, parallel line images of the (100) and (110) repeating spacings were observed. In the SBA-15 mesoporous silicas, there are byproducts of the granular silica and disordered mesostructures, attributed to the weak hydrogen interactions between Pluronic 123 blockcopolymer and the silica species. There are also many different and significant +π disclination defects in SBA-15 and MCM-41 surfactant-silica composites. The SBA-15 with a thicker silica wall is more stable under irradiation by high-energy electron beams compared to MCM-41, which has thinner wall thickness. Some carbon nanostructure impurities were found in some carbon films on the metal grids.
All Science Journal Classification (ASJC) codes