| Summary: | 碩士 === 國立成功大學 === 材料科學及工程學系 === 102 === The phase behavior of a binary eutectic system of poly(9,9-di-n-octyl-2,7- fluorene) (PFO) and hexamethylbenzene (HMB) has been explored. During cooling from homogeneous molten state, a smectic phase of PFO developed epitaxially on HMB substrate. Upon further annealing at 120 °C, epitaxial organization results in the growth of β crystal. In order to decipher the route of molecular organization, this research advanced to elucidate involved epitaxial interactions through simulation and experimental approaches. Instead of the conventional packing tendency of fluorene backbones, the settlement of side chains within underneath lattice grooves of HMB contact plane emerged as an unexpected dominant epitaxial relationship. After adding 1 wt % of carbon nanotubes into this HMB/PFO binary system, the extent of coplanar conformation of backbone is reduced by involved interactions. As a result, the re-absorption of emitted blue light is lessened, leading to stronger blue emission. Furthermore, during the phase transition route of comb-like PFO, mixed nanotubes can be segregated into amorphous regions, resulting in oriented arrays of nanotube bundles within thin film. Not only the parallel orientation, the segregation distance between nanotube bundles can be adjusted also by the crystallization rate of PFO, which helps to enhance the use of carbon nanotube within polymeric thin film.
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