石墨烯—聚多巴胺气相色谱固定相的研究

发布时间：2018-07-25 07:19

【摘要】：气相色谱分析中,选择性优良的固定相和有效的制柱方法是实现高效分离的关键。近年来,碳纳米材料受到了人们的广泛关注,其中,石墨烯(G)由于突出的热稳定性、特殊的结构及良好的吸附性能,有望用作新型毛细管气相色谱固定相。针对石墨烯纳米材料极易团聚等应用难点,本文引入聚多巴胺(PDA)预处理技术制备了石墨烯-聚多巴胺毛细管气相色谱柱(G-PDA@柱),并对其色谱性能和分离机理进行了探究。该方法在气相色谱研究方面尚未见其他报道。主要内容如下:(1)简要叙述了气相色谱固定相的发展现状,并介绍了石墨烯的结构、性质和应用现状以及多巴胺的发现、性质和发展前景。本课题对新型毛细管气相色谱固定相的研究具有重要意义。(2)利用多巴胺自聚合的特性和聚多巴胺涂层的黏附性作为新型粗糙化方法,以石墨烯为固定相,用静态法制备出G-PDA@柱。并以未经聚多巴胺粗糙化的石墨烯色谱柱(G@柱)和仅用聚多巴胺处理而未涂渍石墨烯固定相的聚多巴胺色谱柱(PDA@柱)为对照,通过对比电镜表征图证明了该制柱方法的可行性,并利用含烷、醇、醛的混样的分离证明了石墨烯的分离潜力。(3)对G-PDA@柱的性能评价和结果分析。通过测定麦氏常数表征固定相为弱极性,通过Golay曲线表征最佳柱效可高达3406塔板数/米。利用混合烷烃、混合醇、混合酯、混合醛、苯胺类、多环芳烃等不同极性混合物的分离表明G-PDA@柱对不同极性物质均可实现良好的分离。尤其针对烷烃、醇、苯胺等异构体的分离突出了石墨烯固定相在异构体分离中的应用,并通过对Grob试剂和不同取代基的苯系物的分离综合考察了G-PDA@柱对芳香族化合物的独特选择性和作用机理。最后探究了色谱柱的热稳定性和重复性,均获得优良结果,其中最高使用温度高达320℃。综上,本文利用聚多巴胺粗糙化的方法成功制备了G-PDA@柱,获得了良好分离性能。不仅为石墨烯用作气相色谱固定相的研究奠定了基础,更建立了新型制柱方法,对解决此类材料在色谱领域的应用难点提出了新的思路。
[Abstract]:In gas chromatographic analysis, good selectivity and effective column preparation are the key to achieve high efficiency separation. In recent years, carbon nanomaterials have attracted extensive attention. Among them, graphene (G) is expected to be used as a new capillary gas chromatographic stationary phase due to its outstanding thermal stability, special structure and good adsorption performance. In view of the difficulties in the application of graphene nanomaterials such as easy agglomeration, the graphene polydopamine capillary gas chromatographic column (G-PDA @ column) was prepared by using polydopamine (PDA) pretreatment technology, and its chromatographic properties and separation mechanism were investigated. This method has not been reported in gas chromatography. The main contents are as follows: (1) the development status of gas chromatographic stationary phase is briefly described, and the structure, properties and application of graphene are introduced, as well as the discovery, properties and prospect of dopamine. This paper is of great significance to the study of novel capillary gas chromatographic stationary phase. (2) G-PDA @ column was prepared by static method using the properties of dopamine self-polymerization and adhesion of polydopamine coating as a new roughening method. The feasibility of this method was proved by comparing the G@ column without roughening polydopamine with the PDA@ column which was treated only with polydopamine and uncoated graphene stationary phase. The separation potential of graphene was proved by the separation of alkanes, alcohols and aldehydes. (3) the properties of G-PDA @ column were evaluated and the results were analyzed. The stationary phase was characterized as weak polarity by measuring Mak's constant, and the best column efficiency could be as high as 3406 trays / m by Golay curve. The separation of mixed alkanes, mixed alcohols, mixed esters, mixed aldehydes, anilines and polycyclic aromatic hydrocarbons shows that the G-PDA @ column can achieve good separation of different polar substances. Especially for the separation of alkanes, alcohols, aniline and other isomers, the application of graphene stationary phase in isomer separation is highlighted. The unique selectivity and mechanism of G-PDA @ column to aromatic compounds were investigated by the separation of Grob reagent and benzene series with different substituents. Finally, the thermal stability and repeatability of the chromatographic column were studied. In conclusion, G-PDA @ column was successfully prepared by the method of polydopamine roughening, and good separation performance was obtained. It not only lays a foundation for the study of graphene as a stationary phase in gas chromatography, but also establishes a new method of column preparation, and puts forward a new idea to solve the difficulties in the application of this kind of materials in the field of chromatography.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O657.71

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