Olefin Polymerization and Fluorescent Properties of Conjugated Polymers in Confined Space
Date Issued
2004
Date
2004
Author(s)
Lee, JunguHua
DOI
zh-TW
Abstract
This thesis is composed of three parts of research involving the chemsitry in confined space. In the first part: palladium and nickel diimine complexes were anchored on the surface of the silica particles and mesoporous channels for the catalysis of the polymerization of ethylene. The active polymerization palladium catalysts were generated in situ by combination of palladium precatalysts with NaBAr’4 and nickel catalysts with MAO. Effects of structure variations of the diimine ligand on catalytic activities, polymer molecular weights, and polymer microstructure were studied. The degree of branching in the polymers decreases with increasing ethylene pressure and with increasing temperature. The difference between silica and mesoporous support polymerization was discussed. In DSC analysis, one can find a good crystallinility of polyethylene from mesoporous support polymerization but not silica particles.
In the second part: conjugated polymer/silica nano composites with mesoscopic orderness were synthesized by self-assembly using polymerizable diacetylene’s organosilane molecules as organic source directing condensation with surfactant and TEOS. Effects of molecular size variations of the surfactant on pore size, surface area, and modified content are described. The surfactant with longer chain yielded the desired material with a larger pore size. Thermal polymerization of the incorporated diacetylene moiety resulted in polydiacetylene (PDA)/silica nanocomposites which show their fluorescence properties. The fluorescence intensity depends on the presence of surfactant or not inside the channels. The presence of surfactant in the channels can reduce the self-quenching to have a stronger intensity.
In third part: conjugated polymer or dye/silica thin film with mesoscopic orderness were synthesized by using the amphiphilic 1,2-dialkynylbenzene or dye molecules as described in the previous part. The self-assembly process readily incorporates the organic monomers uniformly. Polymerization of the incorporated 1,2-dialkynylbenzene resulted in the formation of polynaphthanlene/silica nanocomposites which were optically transparent. From the luminescence, it was found that the electron-donating group (-OCH3) would give a higher fluorescence intensity, while the electron-with donating group (-NO2) showed the negative effect. The surfactant containing dye moiety could be modulated by changing the surfactant/silicate acid (v/v) ratio to change the fluorescence intensity and the meso-structure.
Subjects
矽膠
中孔矽膠
聚雙炔
雙亞胺催化劑
薄膜
螢光
界面活性劑
聚乙烯
surfactant
mesoporous silica
thin film
silica gel
polydiacetylene
polyethylene
diimine catalyst
Type
thesis