聚合物修饰的石墨烯量子点的制备及应用研究

发布时间：2018-03-28 05:23

本文选题：石墨烯量子点　切入点：光催化性能　出处：《太原理工大学》2016年硕士论文

【摘要】：在全球经济大发展的前提下,能源短缺和环境污染已然成为社会发展的两大问题。在利用能源过程中带给环境的问题对社会的影响深远。各国政府都已经在新能源方面的研究中投入巨大精力,以期可以在清洁能源和环境污染治理方面做到有机结合,降低环境污染和提高社会生产效率,对人类久远的发展具有深远的实际意义。此时,能源丰富、无污染的太阳能进入研究者的视线。而目前,半导体量子点在紫外光下因其自身独特结构表现出优异的催化性能而引起了广泛研究,如何将其应用扩展到可见光范围是目前的研究热点。石墨烯量子点是当今的新型材料,其优异的光学性能和生物潜在应用引起了研究者的关注,以期它既可以光催化降解水中有机物,又同时可以对水中的污染微生物进行靶向治理。本文以柠檬酸为碳源,水热合成石墨烯量子点(graphene quantum dots,GQDs),并用聚乙烯亚胺(polyethylenimine,PEI)、聚乙二醇(polyethylene glycol,PEG)分别对GQDs进行修饰,得到GQDs-PEIs和GQDs-PEGs。采用傅里叶变换红外光谱、高分辨透射电子显微镜、荧光光谱仪和紫外可见光光谱仪对以上产物进行表面官能团、形貌、粒径和光学性质的分析。结果表明,GQDs的粒径均一(2-5 nm),具有大量含氧官能团,发蓝光,具有独立激发性能,聚合物修饰的GQDs发射光谱出现了不同程度的红移现象。研究了GQDs,GQDs-PEIs,GQDs-PEGs在生物方面的潜在应用,包括生物相容性应用和生物成像应用。细胞毒性的测试结果表明样品浓度在0-200μg/ml浓度区间内,细胞的成活率都在67%以上,间接说明GQDs,GQDs-PEIs,GQDs-PEGs对细胞的毒性较小;三个样品相比,在各个样品浓度下,细胞成活率从高到低依次是GQDs,GQDs-PEGs,GQDs-PEIs。生物成像方面,当把样品GQDs,GQDs-PEIs,GQDs-PEGs与MG-63细胞共同孵育6小时后,三者都能进入到细胞中,这为细胞中的生物成像、生物探针、生物载药提供了新的可能。同时通过亚甲基蓝可见光下光催化降解讨论材料的光催化性能。同等浓度下,对亚甲基蓝的降解速率从高到底依次是GQDs,GQDs-PEIs,GQDs-PEGs。分析原因是由于在光降解过程中,材料表面的含氧官能团产生氧自由基和羟基自由基氧化亚甲基蓝,从而使其降解。而GQDs-PEIs和GQDs-PEGs因聚合物的官能团与GQDs表面的含氧官能团结合,从而减缓了自由基在光下的生成。同等聚合物分子量下,PEI含有的大量氨基可以与GQDs结合,PEG只有聚合物末端羟基与GQDs结合,即GQDs-PEIs含有更多的石墨烯量子点,拥有更多的含氧官能团产生自由基。
[Abstract]:On the premise of the great development of the global economy, Energy shortage and environmental pollution have become two major problems of social development. The problems brought to society in the process of using energy have a profound impact on society. Governments of all countries have invested a great deal of energy in the research of new energy sources. With a view to achieving an organic combination of clean energy and environmental pollution control, reducing environmental pollution and improving social productivity, which is of far-reaching practical significance to the development of mankind for a long time. At this time, energy is abundant, At present, semiconductor quantum dots (QDs) have been widely studied because of their excellent catalytic properties due to their unique structure under ultraviolet light. How to extend its application to visible light is a hot topic. Graphene quantum dots (QDs) are new materials, and their excellent optical properties and potential biological applications have attracted the attention of researchers. So that it can not only photocatalyze the degradation of organic matter in water, but also can be targeted to treat the polluted microorganisms in water. In this paper, citric acid is used as carbon source. Hydrothermally synthesized graphene quantum dotsn GQDsn, GQDs was modified with polyethylene polyethylenimine (PEI) and polyethylene glycol polyethylene glycoline (PEG) to obtain GQDs-PEIs and GQDs-PEGs. Fourier transform infrared spectroscopy (FTIR) and high resolution transmission electron microscopy (HRTEM) were used to prepare GQDs-PEIs and GQDs-PEGs. The surface functional groups, morphology, particle size and optical properties of GQDs were analyzed by fluorescence spectrometer and UV-Vis spectrometer. The results show that the GQDs have a large number of oxygen functional groups, blue light and independent excitation property. In this paper, the potential biological applications of GQDs-PEIsa GQDs-PEGs have been studied. The results of cytotoxicity test showed that the survival rate of the cells was more than 67% in the concentration range of 0-200 渭 g/ml, which indirectly indicated that GQDsGQDs-PEIsa GQDs-PEGs was less toxic to the cells, compared with the three samples, the cytotoxicity of GQDs-PEGs to GQDs-PEGs was lower than that of GQDsGQDs-PEGs. In each sample concentration, the survival rate of GQDsGQDs-PEGsN GQDs-PEGsGQDs-PEIs. biological imaging, when the sample GQDsGQDs-PEGs GQDs-PEGs were incubated with MG-63 cells for 6 hours, all three could enter into the cells, which is the biological imaging of cells, biological probes, biological probes, biological imaging of the cells, biological probes, GQDs-PEGs, GQDs-PEGs, GQDs-PEGs, GQDs-PEGs, GQDs-PEGs, and GQDs-PEGs. Biologically loaded drugs offer new possibilities. At the same time, the photocatalytic degradation of materials is discussed under the visible light of methylene blue. The degradation rate of methylene blue is GQDsN GQDs-PEIsa GQDs-PEGs. The reason is that oxygen free radical and hydroxyl radical oxidize methylene blue are produced by oxygen-containing functional groups on the surface of materials during photodegradation. And GQDs-PEIs and GQDs-PEGs are bound by the functional groups of the polymers to the oxygen-containing functional groups on the surface of GQDs. This slows the formation of free radicals under light. At the same molecular weight, GQDs contains a large amount of amino acids that bind to GQDs only with the end hydroxyl of the polymer bound to GQDs, that is, GQDs-PEIs contains more graphene quantum dots. More oxygenated functional groups produce free radicals.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O613.71

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