【作者】 肖雨亭；

【导师】 黄晓华； 陈明清；

【作者基本信息】 江南大学 ， 化学工程与工艺， 2005， 硕士

【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微凝胶在化学,涂料,生物、医学领域具有引人注目的应用前景,在聚酰胺类高分子微凝胶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。本论文为探讨新型温敏性聚酰胺高分子微凝胶的新用途进行了尝试性工作。首先,选择N-异丙基丙烯酰胺(NIPAM)为基本单体,然后分别选择丙烯酸和苯乙烯作第二单体,与N-异丙基丙烯酰胺共聚,分别用乳液聚合法和无皂乳液聚合法合成了两种共聚微凝胶。以这两种共聚微凝胶作为配体,通过在温和反应条件下与铽(Tb)、铕(Eu)、钐(Sm)、镝(Dy)四种稀土元素离子以及α-噻吩甲酰三氟丙酮(HTTA)和邻菲啰啉(Phen)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微凝胶配合物,使用动态激光光散射、透射电镜、Zeta电位、紫外光谱、红外光谱及荧光光谱等研究手段对它们的粒子性质和光谱性质进行了表征,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。动态激光光散射和透射电镜表明,稀土离子的加入,并未对微凝胶的粒径和表面形态产生影响,Zeta电位、紫外光谱、红外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微凝胶中侧链酰胺基团或羰基上可配位原子作用,这两种作用方式都可以改变高分子的共轭结构,影响高分子的吸收和发射性质。荧光光谱证明含铽的微凝胶二元体系具有增强的稀土铽离子特征荧光发射峰,含铕的微凝胶二元体系仅有较弱的铕离子特征荧光发射峰,而其他稀土微凝胶二元体系仅有高分子配体自身荧光发射带。说明,在铽微凝胶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。在稀土微凝胶三元体系中,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P(NIPAM-co-AAc)-Tb(Ⅲ)-Phen、P(NIPAM-co-AAc)-Eu(Ⅲ)-TTA这两个三元体系均具有优异的发光性能,而且化学性质稳定,放置一段时间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纳米发光材料。更多还原

【Abstract】 Colloidal particles of temperature-responsive polymers with a submicrometer size range havebeen studied extensively. In this respect, hydrophilic-hydrophobic P(N-isopropylacrylamide)(PNIPAM) latex particles has increasingly attracted the interest of researchers in the field owing totheir temperature induced, dramatic and reversible volume changes in aqueous phase surroundingthe temperature of 32℃ , in which is called as the lower critical solution temperature (LCST),resulting in the corresponding large variation of the colloidal properties of the PNIPAM microgel,especially their particles size, electrophoretic mobility, colloidal stability etc. Therefore, theapplication of PNIPAM latex particles in general have mainly focused on the biomedical field fordiagnostic tests, control release, drug delivery system, chemical separation and coating additivesetc. On the other hand, some of lanthanide ions, especially Terbium and Europium, possessedgood luminescence characteristics (high color purity) based on the 4f electronic transitions, avariety of rare earth compounds activated by Terbium and Europium have been investigated forpractical application. In recent years, the lanthanide ion-containing polymers has been greatlystimulated many peoples to further efforts owing to their potential use in fluorescence and lasersystems, which the linear polymer were generally used as ligand in those researching systems. Itwas found that many researchers have reported on the preparation of the functional polymermicrogel, however, there have been only a few studies related to the study of the fluorescence ofpolymer microgel.In this paper, the preparation and spectral properties of copolymer microgels containing rareearth ions have been investigated. The objectives of this study were to synthesis the binary andternary compounds that not only possessed the outstanding luminescence behavior of rare earth ionsbut also kept the distinctive thermal properties of PNIPAM and its copolymers by adding four rareearth ions (Terbium, Europium, Samarium and Dysprosium) and two organic low molecular weightligands (phenanthroline, thenoyltrifluoroacetone) into the submicron NIPAM/AAc/St copolymermicrogels. At the first of all, The N-isopropylacrylamide and acrylic acid, styrene copolymermicrogels were prepared by two polymerization methods (emulsion polymerization andsurfactant-free emulsion polymerization). Secondly, several series of the complexes of microgelcontaining rare earth ions were prepared and characterized by Transmission Electron Micrography(TEM), Dynamic Laser Scattering (DLS), Zeta potential, Ultraviolet spectroscopy (UV-vis), Fouriertransform infrared transmission spectroscopy (FT-IR) and fluorescence spectroscopy. It would lay afoundation of the further investigation of the interaction of rare earth ions with copolymer microgel.The main results obtained are as follows:(1) The experimental results of TEM, DLS showed that the particle radium of the complex ofmicrogel containing rare earth ion has not been obviously changed after the rare earth ions addinginto copolymer microgel. The results from Zeta potential, UV-vis, and FTIR demonstrated that thereexist at least two interactions between the copolymer microgel and rare earth ion in these complexes,which one is coordination action, and another is electrostatic force. Nevertheless, both of themmaybe change the conformation and conjugated structure of these polymers, eventually leading tothe changes of their spectral properties.(2) The fluorescence emission spectra of Terbium (Europium) binary complexes show theirintensive characteristic emissions, indicating that there exists efficient energy transfer behaviorbetween Terbium (Europium) ion and copolymer microgel ligand. However, other binarycomplexes display merely emission bands of copolymer microgel ligands, indicating that the energylevels of triplet state of copolymer microgel ligands do not match the excited states of other rareearth ions. In ternary complexes, the characteristic emission intensities of rare earth ions weresignificantly increased by the introduction of low molecular weight ligands as a result of synergeticeffect between them. Especially, P(NIPAM-co-AAc)-Tb( Ⅲ )-Phen and P(NIPAM-co-AAc)-Eu(Ⅲ)-TTA are potential luminescent materials in respect that they could not only emit intensivemonochromatic light excited by UV light, but also have stable chemical characters.更多还原