稀土聚酰胺类高分子配合物光谱性质研究
作者：蔡彦
院校:江南大学
关键字:聚酰胺,稀土,发光,能量传递
学位：硕士
专业:应用化学
摘要:
具有水溶性、温敏性、pH响应性和生理相容性等特性的聚酰胺类高分子在生物医学领域具有引人注目的应用前景，在聚酰胺类高分子中引入稀土离子可能赋予其更多的新特性，如发光、磁性、导电等。本论文为开发新型稀土聚酰胺类功能高分子材料进行了尝试性工作。 选择三种聚酰胺类高分子作为配体，分别是聚(N-乙烯基乙酰胺)(PNVA)、聚(N-乙烯基异丁酰胺)(PNVIBA)和聚(N-异丙基丙烯酰胺)(PNIPAAm)，通过在温和反应条件下与钐(Sm)、铕(Eu)、铽(Tb)、镝(Dy)四种稀土元素离子以及α-噻吩甲酰三氟丙酮(TTA)和三苯基氧化膦(TPPO)两种有机小分子配体反应，合成了一系列二元和三元稀土聚酰胺高分子配合物，使用紫外、红外、X射线光电子能谱及荧光光谱等研究手段对它们的光谱性质进行表征，探讨了反应条件、配合物中各组分比例对其光谱性质的影响规律。 紫外、红外和XPS光谱表明稀土离子可能通过配位键合和静电引力这两种方式与高分子侧链酰胺基团上可配位原子作用，这两种作用方式都可以改变高分子的构象和共轭结构，影响高分子的吸收和发射性质。 荧光光谱证明含铽的聚酰胺二元体系具有增强的稀土铽离子特征荧光发射峰，而其他稀土聚酰胺二元体系仅有高分子配体自身荧光发射带，说明在铽聚酰胺二元体系中高分子与稀土铽离子之间的能量传递效率高于其它二元体系。在稀土聚酰胺三元体系中，由于有机小分子第二配体的引入，高分子配体和小分子配体之间可能通过协同效应共同向稀土离子传递能量，可大大提高稀土离子特征荧光发射强度，特别是Eu(Ⅲ)-TTA-PNVA、Eu(Ⅲ)-TTA-PNVIBA这两个三元体系均具有优异的发光性能，吸收380nm紫外光后发射617nm高强度单色红光，而且Eu(Ⅲ)-TTA-PNVA三元体系化学性质很稳定，放置八个月后其发光强度几乎没有衰减，是一种有广泛应用潜力的稀土高分子发光材料。
Abstract:
Investigations pertaining to the polymer materials containing rare earth ions have intensified in recent years, mainly due to the potential of these widely useful materials for light-emitting devices, high magnetic materials etc. Moreover, polyamide polymers are also acquired a great importance for their wide applications in biomedical materials, pharmaceutical fields and analytical chemistry. However, researches concerning polyamide materials containing rare earth elements have not been reported until recently. In this paper, several series of binary and ternary polyamide complexes containing rare earth ions were synthesized for the first time by blending three polyamide polymers (poly N-vinylacetamide, poly N-vinylisobutyramide and poly N-isopropylacrylamide), four rare earth elements (Samarium, Europium, Terbium and Dysprosium) and two low molecular weight ligands (thenoyltrifluoroacetone, triphenylphosphineoxide) respectively. My researching focus was judging the formation of those complexes, developing conditions of doped rare earth ions, measuring spectral properties and luminescence behaviors of those materials by means of ultraviolet spectroscopy, Fourier transform infrared transmission spectroscopy, X-ray photoelectron spectroscopy and fluorescence spectroscopy and finally on theoretical analysis of experimental results. Their potential uses as novel luminescent materials were also discussed. The experimental results of UV, IR and XPS suggested that there exist at least two actions between the polyamide macromolecules and rare earth ions in these complexes. One is coordination action and another is electrostatic force. Although they are quite different in terms of intrinsic characters, both of them could change the conformation and conjugated structure of these polymers and further influence the properties of absorption and emission. The fluorescence emission spectra of terbium binary and ternary complexes show intensive characteristic emissions of terbium ions, indicating that there exists effective energy transfer behavior between terbium ion and polymer ligands. However, other binary complexes display merely emission bands of polymeric ligands, indicating that the energy levels of triplet state of polymer ligands do not match the excited states of other rare earth ions. In ternary complexes, the characteristic emission intensities of rare earth ions were greatly increased by the introduction of low molecular weight ligands as a result of synergetic effect between them. Especially, Eu (III)-TTA-PNVA and Eu (III)-TTA-PNVIBA are potential luminescent materials in respect that not only they could emit intensive monochromatic red light at 617 nm excited by UV light at 380 nm, but also they have stable chemical characters.