P(Eu³⁺-co-MMA)功能微球材料的制备及应用研究

【作者】 李云；

【导师】 严长浩；

【作者基本信息】 扬州大学 ， 材料学， 2016， 硕士

【摘要】 单分散高分子微球具有尺寸均一、比表面积大、反应能力强等特点,活跃应用于涂料、分离材料等领域。其中,既具有高分子材料良好的加工成型性能,又能够达到荧光材料应用要求的高分子基荧光微球成为聚合物功能微球研究热点之一。传统荧光物质的研究主要集中于有机染料和荧光量子点,这类材料存在着荧光寿命短、易受干扰等缺点。近年来,具有特殊荧光性能的稀土材料广受关注,其荧光寿命长、发射光谱窄,检测灵敏度高,环境影响小。长程有序密堆结构的胶体晶体成功制备后,进一步将功能化微球进行有序组装成为高分子的发展方向,即通过纳米粒子的功能化来获得功能性的胶体晶体。本文围绕着单分散粒径窄分布的聚合物微球的制备,荧光微球的制备以及以基体纳米粒子自组装成有序功能性的胶体晶体展开了如下的工作：一、单分散聚甲基丙烯酸甲酯微球的制备以甲基丙烯酸甲酯(MMA)为单体,过硫酸钾(KPS)为引发剂,甲基丙烯酸(MAA)为稳定剂,乙烯基苯(DVB)为交联剂,制备了单分散的非交联／交联聚甲基丙烯酸甲酯(PMMA)微球。通过红外光谱(FT-IR)、扫描电子显微镜(SEM)、粉末X射线衍射仪(XRD)等分析了聚合物微球的组成、形貌,并研究了聚合反应和聚合机理等。结果表明：基于沸腾体系制备的聚甲基丙烯酸甲酯微球粒径均一,位于200-400nm之间,没有出现明显的团聚现象。对不同反应时间的聚合体系研究,提出无皂乳液聚合反应经历了“聚合-微囊-解离”等反应过程,有别于经典乳液聚合机理而又符合反应过程动力学理论。同时研究了聚合物微球的反应条件,使聚合物微球的粒径得以调控。二、Eu3+-co-PMMA共聚微球的制备以甲基丙烯酸甲酯(MMA)为单体,过硫酸钾(KPS)为引发剂,甲基丙烯酸(MAA)为稳定剂,十二烷基磺酸钠(SDS)为乳化剂,引入稀土三元配合物Eu(MAA)3phen为荧光物质,制备得到聚合物荧光微球。通过红外光谱(FT-IR)、电感耦合等离子体质谱(ICP-MS)分析了荧光微球的组成,结果表明甲基丙烯酸甲酯与稀土三元配合物是通过共聚的形式结合的；通过扫描电子显微镜(SEM)分析了共聚微球的形貌、粉末X射线衍射仪(XRD)分析了共聚微球的结晶结构,表明共聚微球为非晶结构,微球表面洁净,球形度好且粒径均一；通过紫外光谱、荧光光谱以及倒置荧光显微镜分析了共聚微球的荧光性能,表明共聚微球具有稀土的特征荧光(红色),且微球的荧光强度随着稀土配合物含量的增加而增强,没有发生浓度猝灭现象。三、胶体晶体微球的制备以单分散聚合物微球为基体,采用微流控法构筑长程有序的胶体晶体结构。通过扫描电子显微镜、3D激光共聚焦显微镜、偏光显微镜等分析了胶体晶体微球的结构色和微观结构。胶体晶体微球为有序的六方密堆积结构,且有序性从胶体晶体微球的表面延伸到内部；通过胶体晶体微球粒径分析,表明微流控法得到的胶体晶体微球具有较好的单分散性,制备的胶体晶体微球粒径范围较广；利用光纤光谱仪和金相显微镜,测得了不同结构色胶体晶体微球的反射波长,符合标准色度图的要求；倒置荧光显微镜表明由荧光微球的有序性组装得到的荧光功能性胶体晶体微球,特殊结构的作用使胶体晶体微球的荧光与稀土荧光存在着部分的不同,荧光性能均匀保留时间长；通过超声清洗仪分析了胶体晶体微球的力学性能,且随着处理温度的提高,胶体晶体微球的力学性能提高,为功能性胶体晶体材料的研究与应用提供基础性的理论研究。更多还原

【Abstract】 Monodisperse polymer microspheres with the advantages of uniform size, specific surface area and strong reaction performance are widely used in coating, separation materials and other fields, in which the fluorescent polymer microspheres have become an important part. The traditional fluorescent substances are mainly organic dyes and fluorescent quantum dots, and they often have the shortcomings of short fluorescence lifetime and easy to be disturbed. Recently, rare earth materials with special fluorescence properties have attracted more attention. Because of the longer fluorescence lifetime and narrow emission spectrum, the detection sensitivity is greatly improved. After successfully preparing the colloidal crystals, the functional microspheres are ordered assembly which becomes the development direction of the polymer fields. That is to say, the functional colloidal crystals are obtained by the functionalized of the microspheres. In this paper, we have prepared monodisperse polymer microspheres with narrow distribution, fluorescent microspheres and functional colloidal crystals. The contents are carried out mainly as follows:Firstly, preparation of monodisperse poly-methyl-methacrylate microspheresThe monodisperse non crosslinking/crosslinked poly-methyl-methacrylate microspheres have been synthesized with methyl methacrylate (MMA) as monomers, potassium sulfate (KPS) as initiator, methacrylic acid (MAA) as stabilizer, divinylbenzene (DVB) as cross-linking agent. The composition, morphology and polymerization mechanism of the poly-methyl-methacrylate microspheres are characterized by fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and powder X-ray diffraction (XRD). The results show that we could get poly-methyl-methacrylate microspheres with consistent particle size which located between 200nm to 400nm based on the boiling system. and the same time we can find no obvious aggregation. The reaction system are studied with different time, the soap-free emulsion polymerization reaction mechanism "Aggregation-Microcapsule-Dissociation" is put forward, which is different from the classical emulsion polymerization mechanism and meanwhile is in line with the theory of the reaction kinetics. At the same time, the reaction conditions of the polymer microspheres are studied, which make the particle size of the poly-methyl-methacrylate microspheres could be controlled.Secondly, preparation of Eu3+-co-PMMA copolymer microspheresThe fluorescent polymer microspheres have been prepared with methyl methacrylate (MMA) as monomers, potassium sulfate (KPS) as initiator, methacrylic acid (MAA) as stabilizer, sodium dodecyl sulfate (SDS) as emulsifier, rare earth (Eu(MAA)3phen) as fluorescent substance. By the means of fourier transform infrared spectroscopy (FT-1R), simultaneous thermal analysis (STA), coupled with inductively coupled plasma mass spectrometry (ICP-MS), it is indirectly proved that the methyl methacrylate (MMA) and the rare earth three element complex (Eu(MAA)3phen) is combination with copolymerization key (a form of covalent bond). The results of scanning electron microscopy (SEM), X-ray diffraction (XRD) indicate that Eu3+-co-PMMA fluorescent copolymer microspheres are amorphous structure with a clean surface which are in a good spherical shape and uniform particle sizes. Through the spectral analysis of ultraviolet spectrum, fluorescence spectrum and inverted fluorescence microscope, the Eu3+-co-PMMA copolymer microspheres present the characteristic fluorescence of rare earth, and the flourescent intensity enhances with the increase content of rare earth complexes, without the occurrence of the concentration quenching phenomenon.Lastly, preparation of colloidal crystal beadsBased on the monodisperse polymer microspheres, the long-range-ordering colloidal crystal structures are builded by the microfluidic method. The structure colour and microstructure of the colloidal crystal beads are analyzed through scanning electron microscopy,3D laser scanning confocal microscope and polarizing microscope, the observations show that the bead is in a good spherical shape, nanoparticles in the bead is arranged hexagonally and such ordering extends from the bead surface to the center. The analysis of particles sizes of colloidal crystals, the beads appeare in good dispersion by the microfluidic technique, and the range of the colloidal crystal beads are wider. The reflection wavelength of different structure colour colloidal crystal beads are measured by the optical microscope together with optical fiber spectrometer which meets the requirements of the standard color chart. The inverted fluorescence microscope indicates that the functional colloidal crystal microspheres show little difference between the rare earth fluorescent properties which roots in the special structure and it could be longer stayed. In order to improve the mechanical stability of the colloidal crystal beads, we heat treated them with different temperature. The ultrasonic cleaning instrument and nanoidentation confirm that with the increase of the treatment temperature, the mechanical properties of the collidal crystal beads improve, which provids basic research for the potential applications.更多还原