| 초록 |
Free-standing and oriented periodic mesoporous organosilica (PMO) films with variable pore size have been synthesized at the air-water interface using cationic alkyltrimethylammonium surfactants (alkyl chain length from 12 to 18 carbon atoms) as structure-directing agent and 1,2-bis(triethoxysilyl)ethane as organosilica precursor for the first time. After hydrothermal reaction at 95 oC for 8 h, C12TA-PMO, C16TA-PMO, and C18TA-PMO films grown at the air-water interface have uniform thickness of ca. ~350 nm, ~670 nm, and ~400 nm, respectively. The films are continuous over the entire bulk depending on the size of the reaction bottle. From XRD pattern and TEM image, the PMO films with hexagonal symmetry were identified. It was confirmed by 29Si and 13C CP MAS NMR experiments that the organic-inorganic moiety (-Si-CH2-CH2-Si-) is the basic structural unit in the films. The pore diameter and the surface area of surfactant-extracted PMO films, e.g. C12TA-, C16TA-, and C18TA-PMO films, obtained from the N2 sorption isotherms were to be determined to be 24.3 Å, 26.4 Å, and 32.8 Å and 890.3, 917.7, and 811.0 m2g-1, respectively. The PMO films may have potential use in applications such as catalysis, sensing, and separation. |
