| Summary: | 碩士 === 遠東科技大學 === 機械研究所 === 95 === In this study, a layered Calcium Silicate Z-Phase, Ca9Si16O40(OH)2．14H2O), has been prepared via a hydrothermal reaction and its interlamellar silylation reactions has been carried out. The silylation agents used were trimethyl chlorosilane, n-propyl-, n-butyl-, n-octyl-, n-decyl-, n-dodecyl-, and n-octadecyl-dimethyl chlorosilane. In the silylation process, it is not necessary to use the long-chain alkylammonium exchanged phase as a intermediate. But a direct process mixing layered calcium silicate, silane reagents, and DMF (assolvent) was used under a controlled condition to reach the goal. The Z-phase and silylated products were characterized by the PXRD, 29Si MAS NMR , TGA, , and elemental analyses. The obtained data can be used to calculate the ratio of silanes grafted on the available silicate sites and estimating the arrangement of the grafted organic chains in the interlayered space. Furthermore, the controlled acid-treatment of Z-Phase revealed that its interlayered calcium can be exchanged with proton with the thick calcium silicate layer largely remained. This state is designated as HX-Z-Phase, which is layered silicic acid but with calcium octahedral layer remained. With the aid of sodium hydroxide, the cetyldimethyl ammonium ions can be introduced into the interlayered space, which is similar to the organic ammonium exchanged clays.
Organically grafted Z-Phase (OGZ) can be dispersed easily in the oil-phase. Except for that, the modified phase has very good thermal stability based on TGA results. Combined these two features, OGZ was dissolved in a mixture that Ni nanoparticles (NPs) can be prepared by thermal decomposition. The in-situ formation of the nickel NPs in the presence of OGZ has carried out. The results show that nearly monodisperse nickel nanoparticle with size of 10 nm were packed orderly on the surface of the 8C-OGZ, while only small mount of Ni on the 1C-OGZ. The short carbon chain is not matched with the surfactant used in the synthesis, as a result the attachment of NPs is poor. However, TEM showed tiny NPs appeared on the interlayed space with a 1-nm increase in the d-spacing of the OGZ. Probably this is because the space is limited for growth and diffusion of precursor is inhibited.
|
|---|
