【作者】 王萍萍；

【导师】 陈国华；

【作者基本信息】 华侨大学 ， 高分子化学与物理， 2005， 硕士

【摘要】 由于主链上π电子的高度离域,共轭聚合物呈现出良好的非线性光学性质、半导体特性以及掺杂态的金属导电性。共轭聚合物在半导体器件特别是在发光器件方面,具有广阔的商业应用前景,已成为近年来科技界研究的热点之一。共轭聚合物的发光性能与它自身链的形态有很大关系,这为纳米尺度内设计高分子链构造提供了广阔的空间。无机纳米微粒与共轭聚合物在光致、电致发光等方面极好的协同作用促使共轭聚合物/无机粒子纳米复合成为提高共轭聚合物光电性能的重要方法。 论文从球状SiO₂、多孔SiO₂、TiO₂、未改性Al₂O₃和改性Al₂O₃等纳米粒子中筛选出两种较为合适的纳米微粒:其一是在有机溶剂中分散性能良好的改性Al₂O₃,与聚芴复合制备PFO/Al₂O₃纳米复合材料;其二是具有多方晶系的TiO₂纳米微粒,共轭聚合物嵌入TiO₂纳米晶膜表面的孔道后,形成PFO/TiO₂纳米复合材料。 PFO/Al₂O₃纳米复合膜是通过聚合物溶液和纳米分散液的复合制备而成的一种新型材料。光致发光研究发现PFO/Al₂O₃纳米复合膜的荧光发射与纯PFO薄膜相比蓝移了22nm,Al₂O₃纳米片的隔离作用促使PFO的荧光发射从442nm迁移到420nm;PFO/Al₂O₃纳米复合膜的荧光蓝移程度与Al₂O₃纳米粒子的含量有关,随着Al₂O₃粒子比重的增加,复合膜的蓝移程度也在加大。制备的PFO/Al₂O₃纳米复合膜的热稳定性比纯共轭聚合物PFO膜好,Al₂O₃纳米片的引入抑更多还原

【Abstract】 Conjugated polymers have been intensively studied during the last two decades mainly due to their semiconductor-like optical and electronic properties. These organic materials have the capability to be processed on a variety of substrates as well as to allow a broad tunability of emission by controlling their chemical structure.There is strong dependence of optical properties of conjugated polymers on chain conformation, which opens room for the use of nanoscale architecture to control the polymer conformation. In particular, isolation of conjugated chains within inorganic materials plays an important role in improving optical and electronic properties of conjugated polymer due to the novel synergy effects.Among porous SiO₂, spheric SiO₂, TiO₂ , unmodified A1₂O₃ , modified Al₂O₃, two suitable nanoparticles were selected to incorporate with conjugated polymer （poly （9,9-dioctylfluorene）, PFO）. One of them is modified Al₂O₃, due to its excellent dispersion in organic solvent like CHCl₃, to fabricate PFO/Al₂O₃ nanocomposite; the other is porous TiO₂, due to its nanopores in TiO₂ crystalline film, to fabricate PFO/TiO₂ nanocomposite. Optical properties of both nanocomposites were investigated in detail.Nanocomposite film of PFO/Al₂O₃ has been prepared by blendingthe conjugated polymer solution with alumina nanoparticle dispersion in common organic solvent, investigated in terms of the optical properties. A blue shift of the photoluminescence （PL） spectrum for the fabricated PFO/AI2O3 nanocomposite film was observed as compared to the results obtained from the bulk PFO film, the maximum of the PL emission peaks occured at 442 nm in the bulk film while after the incorporation of the alumina nanoparticles the maximum appeared at 420 nm in the spectrum for PFO/AI2O3 nanocomposite film; the dependence of fluorescence blue shift of PFO on the concentration of AI2O3 was investigated; and the excimer formation that led to long wavelength tails was found to reduce in PFO/AI2O3 nanocomposite. All these results provide rich information for the conclusion that the isolation of the conjugated polymer chains by the flat rafts of alumina nanoparticles plays a key role for the obtained blue shift.PFO/T1O2 complex nanomaterial was successfully prepared through the adsorbing of polymer on the surface of nanocrystalline TiO2 film. The photoluminescence （PL） spectrum of the obtained nanocomposite showed 28 nm of red-shift, as compared to the bulk polymer film. The maximum of the PL emission peaks of the pure bulk polymer occured at 442 nm, while the maximal emission for nanocomposite film appeared at 470 nm. The adsorption of the conjugated polymer chains on the nanopores of TiC>2 film played a key role for the obtained red shift. Theobservation of phenomenon in PFO/TiO2 composite brought about the significant potential for modifying the optical emission properties of conjugated polymer by adsorption the polymer chains within inorganic nanostructure materials.Different inorganic particle has diverse effect on the emission of conjugated polymers. Controlling the chemical structure of polymer chains by the use of nanoscale architecture can be a fundamental solution to obtain the novel optical properties of conjugated polymers更多还原