基于聚集诱导发光的纳米复合材料的荧光分析研究

发布时间：2018-03-01 17:50

本文关键词： 聚集诱导发光表面活性剂复合材料自组装成像分析　出处：《北京化工大学》2017年博士论文　论文类型：学位论文

【摘要】：利用聚集诱导发光(AIE)现象的光物理过程,以具有AIE特性的发光团为构筑单元,合成了一系列具有组装功能的AIE型发光材料。它们分别带有单电荷、双电荷和多电荷,可以进行自组装、插层组装以及层层组装,从而形成高效发光体系。此外,组装形式和组装单元的不同,使这些发光体系能够很好地用于成像分析和传感应用。对于带有单电荷的AIE型发光材料,本论文设计并合成了以四苯乙烯基团(TPE)为核的十二烷基磺酸钠表面活性剂(TPE-SDS)。通过对其表面活性、电导率变化、以及形成胶束前后光学性质的研究,证实TPE-SDS分子是AIE型阴离子表面活性剂。TPE-SDS分子在水溶液中可有序聚集自组装形成球形胶束产生高效发光,该现象可以通过荧光共聚焦成像技术直接观察到。随着体系中电解质浓度的增加,还可直接观察到TPE-SDS分子从球形胶束到棒状胶束、再到蠕虫状胶束的转变。另一方面,在助表面活性剂的帮助下,TPE-SDS分子在非极性溶剂中,可以自组装形成球形反胶束(即油包水微乳液滴)。该微乳液滴的大小与其荧光强度成反比关系。通过对微乳液滴几何模型的分析发现,微乳液滴表面的TPE-SDS分子间距离会随着微乳液滴的增大而增大,导致限制分子运动的能力减弱,这一发现与AIE的发光机理是一致的。本论文还合成出以TPE为核的十二烷基三甲基溴化铵阳离子表面活性剂(TPE-DTAB)。将TPE-DTA+阳离子通过离子交换的方式插入到蒙脱土(MMT)层间,制备出TPE-DTA+插层的有机改性蒙脱土(TPE-DTAB-MMT)。粉末X射线衍射技术、傅立叶变换红外技术和表面电势测量等表征可知,TPE-DTA+阳离子在蒙脱土层间具有多种有序的排布方式,使得蒙脱土颗粒疏水性增强。此外,在蒙脱土层间的TPE-DTA+阳离子,由于其分子运动能够被层间的二维限域空间有效抑制,从而减缓了非辐射衰减速率,得到较高的荧光量子产率。得益于TPE-DTAB-MMT颗粒的疏水性和高效发光特性,TPE-DTAB-MMT颗粒不仅能够在有机聚合物中良好分散以制备有机一无机复合材料,还可以通过荧光共聚焦成像技术直接观察到TPE-DTAB-MMT颗粒在复合材料中的三维分散度。与此类似,对于TPE-SDS修饰的水滑石颗粒在复合材料中的三维分散度也可同样成像分析。相比于电镜显微成像技术,基于构建高效发光填料(插层组装体)的荧光成像分析法具有其没有的优势,并且为有机—无机复合材料中无机填料的三维分散度评价的发展打开了新思路。对于带有双电荷的AIE型发光材料,可以在9,10-二苯乙烯基蒽(DSA)两端修饰两个磺酸根基团而形成BSDSA。通过与无机的水滑石(LDH)纳米片进行层层组装,进而得到主—客体杂化的BSDSA/LDH发光薄膜。此外,利用聚苯乙烯磺酸钠与BSDSA分子共组装,可以让LDH纳米片上下层间的BSDSA分子构象变得更加扭曲,从而实现发光颜色从黄色到绿色的调控。同时,得益于水滑石主体层板的刚性结构,BSDSA的分子内运动受到极大限制,从而得到较高的荧光量子产率。在25-85℃温度范围内,BSDSA/LDH发光薄膜会随着温度升高,而表现出荧光强度下降和发射波长蓝移的现象。这项工作中所构建的高效发光薄膜(层层组装体),能够衍生出大量的AIE-LDH发光薄膜,并对具有发光可调或可变特性的固态发光材料的发展起到一定的指导作用。相比于带有双电荷的BSDSA分子,具有AIE特性的荧光金纳米簇(Y-AuNCs)带有多电荷,更有利于静电层层组装。将石英片交替浸入到聚烯丙胺(PAH)溶液和Y-AuNCs溶液中,制备出具有黄色荧光的Y-AuNCs/PAH薄膜。另一方面,传统的非AIE型荧光金纳米簇(R-AuNCs)同样与PAH进行组装,可制备出具有红色荧光的R-AuNCs/PAH薄膜。通过薄膜的吸收光谱、发射光谱和稳态-瞬态荧光光谱对它们的光学性质进行表征。正如所料,在Y-AuNCs/PAH薄膜中,Y-AuNCs的荧光量子产率是溶液态的两倍。此外,组装5层的Y-AuNCs/PAH发光薄膜与组装25层的R-AuNCs/PAH发光薄膜相比,二者的荧光强度相当。基于这些现象,以Y-AuNCs/PAH发光薄膜为传感单元,R-AuNCs/PAH发光薄膜为参比单元,构筑复色发光薄膜,可以实现对爆炸物的比率荧光检测,检测限低至10-10M。
[Abstract]:The use of aggregation induced emission (AIE) light physical phenomenon, the light group with the characteristics of AIE as building blocks, a series of AIE type assembling function luminescent materials were synthesized. They are respectively provided with a single charge, double charge and charge, can self assemble, intercalation assembly and self assembly, thus forming high efficiency light emitting system. In addition, the assembly form and assembly unit is different, the light system can be well used for imaging and sensing applications. For the AIE type with a single charge of luminescent materials, this paper designed and synthesized four benzene vinyl group (TPE) twelve sodium dodecyl sulfonate surfactants (nuclear TPE-SDS). Based on its surface activity, conductivity, and optical properties of the micelles formed before and after, confirmed that the TPE-SDS molecule is AIE anionic surfactant.TPE-SDS molecules can self-assembly aggregation in aqueous solution The formation of spherical micelles have high luminescence efficiency, this phenomenon can be through confocal imaging directly observed. With the increase of electrolyte concentration in the system, but also can be directly observed TPE-SDS molecules from spherical micelle to rod, and then to change the wormlike micelles. On the other hand, in the cosurfactant under the help of TPE-SDS molecules in nonpolar solvents, can be self-assembled into spherical micelles (i.e. the microemulsion droplet). The size of the droplets and the fluorescence intensity is inversely proportional to the relationship. Through the analysis of the microemulsion droplet geometry model, TPE-SDS molecular micro emulsion droplets distance increases with the increasing of microemulsion drop, weakened the ability to limit molecular motion, and the luminescence mechanism of AIE this finding is consistent. This paper also synthesized with TPE core twelve alkyl three methyl bromide cationic surfactant ( TPE-DTAB). Insert the TPE-DTA+ cation by ion exchange method to montmorillonite (MMT) layer, preparation of Organic Modified Montmorillonite Intercalated TPE-DTA+ (TPE-DTAB-MMT). Powder X - ray diffraction, Fu Liye transform infrared technology and surface potential measurements showed that, TPE-DTA+ cation has a variety of orderly arrangement in the MMT, the montmorillonite particles increase the hydrophobicity. In addition, the TPE-DTA+ cation between montmorillonite, because its molecular motions can be two-dimensional confinement layer space effectively, thus slowing the rate of nonradiative decay, get higher fluorescence quantum yield. Thanks to the TPE-DTAB-MMT particle hydrophobicity and efficient luminescence properties TPE-DTAB-MMT, not only in organic polymer particles dispersed well prepared organic-inorganic composite materials in the system, but also through the fluorescence confocal imaging technique of direct observation The TPE-DTAB-MMT particles in the composite three-dimensional dispersion. Similarly, the TPE-SDS Modified Hydrotalcite particles in the composite dispersion can also be three-dimensional imaging analysis. Compared to the electron microscopic imaging technology, constructing efficient luminescence based on filler (intercalation assembly) fluorescence imaging analysis method has no the advantages, and opens up new ideas for the development of inorganic filler organic inorganic composite materials in the three-dimensional dispersion evaluation. For the AIE type with double charge luminescent materials, in 9,10- two styrene (DSA) modified anthracene ends two sulfonic acid groups formed by BSDSA. and inorganic nano hydrotalcite (LDH) film layer by layer, and then get the main object of BSDSA/LDH hybrid luminescent films. In addition, a total assembly using sodium polystyrene sulfonate and BSDSA molecules can make LDH nano sheet between the upper and lower BSDSA Conformation is more distorted, so as to realize the light color from yellow to green regulation. At the same time, due to the rigid structure of hydrotalcite main layer, the motion of BSDSA molecules is restricted greatly, resulting in higher fluorescence quantum yield. 25-85 degrees in the temperature range of BSDSA/LDH thin films as the temperature will rise, and show the fluorescence intensity decreased and the emission wavelength blue shift phenomenon. Efficient luminescent films constructed in this work (LbL assembly), can be derived from a large number of AIE-LDH luminescent films, and the development of solid state luminescent materials with light can be adjustable or variable characteristics play a guiding role. Compared to the BSDSA molecule with double the charge of the fluorescent gold nanoclusters with the characteristics of AIE (Y-AuNCs) with charge, more conducive to the electrostatic layer by layer assembly Quartz. Will alternately immersed into polyallylamine (PAH) solution and Y-AuNCs solution In the preparation of Y-AuNCs/PAH film with yellow fluorescence. On the other hand, non AIE type fluorescent gold nanoclusters (R-AuNCs) as the traditional assembly and PAH, prepared R-AuNCs/PAH films with red fluorescence. The absorption spectra of thin films, emission spectra and fluorescence spectra of steady-state transient optical properties of them respectively. As expected, in the Y-AuNCs/PAH film, the fluorescence quantum yield of Y-AuNCs is two times the solution state. In addition, the assembly of the 5 layer Y-AuNCs/PAH thin films with 25 layers of assembled R-AuNCs/PAH thin films compared to the fluorescence intensity of the two. Based on these phenomena, as the sensing unit with Y-AuNCs/PAH luminescence film, R-AuNCs/PAH light the film is a reference unit, build complex color luminescent films, can realize the ratiometric fluorescence detection of explosives, low detection limit to 10-10M.

【学位授予单位】：北京化工大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TB33;O657.3

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