基于光响应偶氮苯表面活性剂修饰石墨烯及其复合材料的制备研究
发布时间：2018-07-27 13:45
【摘要】：石墨烯作为二维SP2网络结构的碳材料,以其独特的物理化学性质被广泛关注。其优秀的导电、机械强度、电荷传输等性能使石墨烯材料广泛应用于光电设备。目前石墨烯功能化的主要方法是物理和化学方法改性,各种各样的有机或无机化合物添加到石墨烯表面。其中,大量研究工作集中在石墨烯复合材料组分之间的自组装、协同作用以及界面效应等。近些年,光响应石墨烯材料成为石墨烯材料发展的热点之一。一些重要的修饰方法(π-堆积和化学共价键作用)制备光响应石墨烯复合材料相继报道。由于其独特的光响应特性,该类材料在光电和能量储备等应用领域有潜在的应用价值。虽然这些光响应石墨烯复合材料已经报道,光响应分子结构变化引起石墨烯空间构象、微结构、光电子能量转变等科学问题仍然是重大挑战。因此,重点研究这些科学问题以及新的改性技术十分必要和关键。本论文通过小分子偶氮苯表面活性剂修饰石墨烯,制备出新型的光响应偶氮苯-石墨烯复合材料。同时进一步以该类偶氮苯表面活性剂作为稳定剂,制备出光响应偶氮苯-石墨烯-金纳米粒子复合材料。为光响应石墨烯材料的发展提供了一种崭新的改性技术。具体研究内容为:(1)偶氮苯表面活性剂采用有机合成和分子设计制备出光响应偶氮苯阳离子表面活性剂。对其化学结构和光致异构变化进行了表征。研究结果表明,偶氮苯表面活性剂在波长为350nm紫外光和455 nm的可见光诱导下具有光响应特性,其紫外可见吸收光谱(UV-Vis)能够可逆转变。此外,再次对偶氮苯表面活性剂进行分子结构设计,制备出双子型Gemini偶氮苯表变活性剂,为光响应石墨烯-金属纳米复合材料的制备提供稳定剂。(2)偶氮苯-石墨烯复合材料基于阳离子偶氮苯表面活性剂的电荷属性,通过离子键作用将阳离子偶氮苯表面活性剂(Azo C7NO)修饰到带负电荷的氧化石墨烯表面,制备出光响应偶氮苯-石墨烯复合材料(Azo-GO)。Zeta电位测试结果表明,该偶氮苯表面活性剂的引入改变了氧化石墨烯的表面电位,其表面电荷由负电位快速变为正电位。荧光光谱表明,该偶氮苯-石墨烯复合材料具有荧光性,证明Azo C7NO主要以离子键作用在氧化石墨烯上,而非常见的π-堆积(荧光猝灭),从而为光响应偶氮苯表面活性剂对石墨烯的修饰提供了理论支持。X射线衍射(XRD)、扫描电镜(SEM)、原子力显微镜(AFM)研究结果表明,本偶氮苯-石墨烯复合材料具有独特的自组装特性,主要由于静电作用使氧化石墨烯中的负电荷(羧基基团)抵消,使其羧基之间的静电排斥作用消失。此外,红外光谱(FTIR)、X射线光电子能谱(XPS)、热重(TGA)表明,复合材料中偶氮苯基团的接枝率为每71个石墨烯碳原子修饰一个偶氮苯分子,具有较高的接枝率。(3)偶氮苯-石墨烯复合材料光响应基于偶氮苯基团的光响应属性,对偶氮苯-石墨烯复合材料的光响应特性进行了研究。紫外可见吸收光谱(UV-Vis)表明,该偶氮苯-石墨烯复合材料具有光化学特性。X射线衍射(XRD)、原子力显微镜(AFM)以及拉曼光谱(Raman)表明,紫外光和蓝光诱导能够引起偶氮苯表面活性剂顺-反可逆异构以及亲疏水性的可逆转变,从而光控制该复合材料的自组装特性发生可逆变化。此外,电化学循环伏安(CV)研究结果表明,该复合材料的电化学性质同样能够被光可逆控制。在已经报道的偶氮苯-石墨烯复合材料中,通过π-堆积和共价键作用制备的复合材料,其光响应性质的变化主要是由于偶氮苯分子内部的空间异构变化。而本论文制备的偶氮苯-石墨烯复合材料的光响应性质的变化,主要由偶氮苯表面活性剂特有的光诱导分子极性和亲疏水的变化引起复合材料的自组装的转变来决定。该光控自组装现象是一种崭新的自装现象,对其进一步研究有可能为自组装理论提供介观范围内的研究实例和理论模型,促进自组装理论的发展。(4)光响应偶氮苯-石墨烯-金纳米粒子复合材料为进一步发展偶氮苯表面活性剂在石墨烯纳米复合材料的应用,从分子结构设计出发,制备出双子Gemini偶氮苯表面活性剂(Azo C10N2O2)。该类偶氮苯表面活性剂以偶氮苯为连接基团具有两个阳离子基团。因此,以Azo C10N2O2作为稳定剂通过静电作用来定位金属纳米粒子到石墨烯表面。同时,利用化学还原法一锅法制备出一种新型的光响应偶氮苯-石墨烯-金纳米粒子复合材料(Azo-RGO-GNP)。利用X射线衍射(XRD)、X射线光电子能谱(XPS)、热重(TGA)、透射电镜(TEM)和紫外可见吸收光谱(UV-Vis)对复合材料的结构和性质进行研究。研究结果表明,以Azo C10N2O2作为稳定剂可以使金纳米粒子均匀的分布在石墨烯表面,实现了准确定位。稳定剂中的偶氮苯基团使该复合材料具有光化学性质。通过该技术,首次合成光响应偶氮苯-石墨烯-金纳米粒子复合材料。此外,电化学循环伏安(CV)研究表明,该复合材料的导电性能同样可以通过光来控制。因此,该偶氮苯-石墨烯-金纳米粒子复合材料在光敏传感器以及电化学领域具有潜在的应用价值。
[Abstract]:Graphene, as a carbon material of two-dimensional SP2 network structure, is widely concerned with its unique physical and chemical properties. Its excellent conductivity, mechanical strength, charge transmission and other properties make graphene materials widely used in optoelectronic devices. The main methods of graphene functionalization are physical and chemical modification, a variety of organic or inorganic methods. Compounds are added to the surface of graphene. A large number of research work is focused on the self-assembly, synergism and interfacial effects of graphene composite components. In recent years, photoresponse graphene materials have become one of the hotspots of the development of graphene materials. Some important modified methods (PI accumulation and chemical covalent bond action) have been used to produce light response. Graphene composites have been reported successively. Due to their unique optical response characteristics, these materials have potential applications in the applications of photoelectric and energy reserves. Although these photoresponse graphene composites have been reported, the changes in the molecular structure of the photoresponse cause the space conformation, microstructures, photoelectron energy transformation and other science of graphene. The problem is still a major challenge. Therefore, it is necessary and key to focus on these scientific problems and the new modified technology. This paper has prepared a new type of photoresponse azobenzene graphene composite by modifying the graphene by the small molecular azobenzene surfactant, and further uses the azobenzene surfactant as a stabilizer. The photoresponse of azobenzene graphene gold nanoparticle composites provides a new modification technology for the development of photoresponse graphene materials. The specific contents are as follows: (1) azobenzene surfactants are prepared by organic synthesis and molecular design for the preparation of photoresponse azobenzene cationic surfactant. The results show that the azobenzene surfactant has the light response characteristics under the visible light of 350nm UV light and 455 nm, and the UV visible absorption spectrum (UV-Vis) can be reversible. In addition, the molecular structure of the double azobenzene surfactant is designed, and the double sub type Gemini couple is prepared. The azobenzene surface variable active agent provides a stabilizer for the preparation of photoresponse graphene metal nanocomposites. (2) the azobenzene graphene composite is based on the charge property of the cationic azobenzene surfactant, and modifies the cationic azobenzene surface active agent (Azo C7NO) to the surface of the negatively charged graphene oxide surface through the ion bond action. The results of.Zeta potential test of azobenzene graphene composite material (Azo-GO) showed that the surface potential of the azobenzene surfactant changed the surface potential of the graphene oxide, and the surface charge changed from negative potential to positive potential rapidly. The fluorescence spectrum showed that the azobenzene carbide composite was of a fluorescent property, which proved that Azo C7NO was the main factor. .X ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM) have been applied to the modification of graphene by the ionic bond on graphene oxide, which is a very visible pion accumulation (fluorescence quenching). The results of the atomic force microscopy (AFM) study show that the azobenzene graphene composite has a unique self composition. In addition, the infrared spectrum (FTIR), X ray photoelectron spectroscopy (XPS) and thermogravimetric (TGA) show that the grafting rate of azo phenyl group in the composites is modified for a azobenzene per 71 carbon atoms in the composite. Molecular, with high grafting rate. (3) photoresponse of azobenzene graphene composite is based on the optical response properties of azobenzene group, and the photoresponse characteristics of azobenzene graphene composite have been studied. The UV visible absorption spectroscopy (UV-Vis) shows that the azobenzene graphene composite has photochemical properties.X ray diffraction (XRD). Atomic force microscopy (AFM) and Raman spectroscopy (Raman) show that UV and blue light induction can cause the reversible and reversible isomerization of azobenzene surfactants and the reversible change of hydrophobicity, thus the self assembly of the composite is reversible. The results of the electrochemical cyclic voltammetry (CV) study show that the composite material is the composite. The electrochemical properties of the material can also be controlled by the light reversible control. In the reported azobenzene graphene composite, the properties of the composites prepared by the pion accumulation and covalent bond are mainly due to the spatial isomerization of azobenzene molecules. The azobenzene graphene composite prepared in this paper is prepared in this paper. The changes in the photoresponse properties are determined mainly by the change of the photoinduced polarity and hydrophobicity of azobenzene surfactants, which can lead to the self assembly of the composites. The light controlled self assembly is a new self-assembly phenomenon. The further study of it may provide a mesoscopic study of the self-assembly theory. Examples and theoretical models promote the development of self-assembly theory. (4) the application of azobenzene graphene gold nanoparticles composite material to further develop azobenzene surface active agent in the application of graphene nanocomposites. Based on the molecular structure design, a Gemini Gemini azobenzene surfactant (Azo C10N2O2) is prepared. The surface of this kind of azobenzene surface is prepared. The active agent has two cationic groups with azobenzene as the connecting group. Therefore, Azo C10N2O2 is used as a stabilizer to locate the metal nanoparticles to the surface of graphene by electrostatic action. At the same time, a new type of photoresponse of azobenzene graphene gold nanoparticle composite (Azo-RGO-GNP) is prepared by chemical reduction method. X ray diffraction (XRD), X ray photoelectron spectroscopy (XPS), thermogravimetric (TGA), transmission electron microscopy (TEM) and ultraviolet visible absorption spectroscopy (UV-Vis) are used to study the structure and properties of the composites. The results show that the gold nanoparticles can be evenly distributed on the surface of graphene with Azo C10N2O2 as a stabilizer, and a stable positioning agent is realized. The azobenzene group in the composite made the composite photochemical. By this technique, the first synthesis of azobenzene graphene gold nanoparticle composites was made for the first time. In addition, the electrochemical cyclic voltammetry (CV) study showed that the conductive properties of the composite could also be controlled by light. Therefore, the azobenzene graphene gold nanoparticle was obtained. Composite materials have potential applications in photosensitive sensors and electrochemistry.
【学位授予单位】：湖南大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TQ127.11;TB33
本文编号：2148018
[Abstract]:Graphene, as a carbon material of two-dimensional SP2 network structure, is widely concerned with its unique physical and chemical properties. Its excellent conductivity, mechanical strength, charge transmission and other properties make graphene materials widely used in optoelectronic devices. The main methods of graphene functionalization are physical and chemical modification, a variety of organic or inorganic methods. Compounds are added to the surface of graphene. A large number of research work is focused on the self-assembly, synergism and interfacial effects of graphene composite components. In recent years, photoresponse graphene materials have become one of the hotspots of the development of graphene materials. Some important modified methods (PI accumulation and chemical covalent bond action) have been used to produce light response. Graphene composites have been reported successively. Due to their unique optical response characteristics, these materials have potential applications in the applications of photoelectric and energy reserves. Although these photoresponse graphene composites have been reported, the changes in the molecular structure of the photoresponse cause the space conformation, microstructures, photoelectron energy transformation and other science of graphene. The problem is still a major challenge. Therefore, it is necessary and key to focus on these scientific problems and the new modified technology. This paper has prepared a new type of photoresponse azobenzene graphene composite by modifying the graphene by the small molecular azobenzene surfactant, and further uses the azobenzene surfactant as a stabilizer. The photoresponse of azobenzene graphene gold nanoparticle composites provides a new modification technology for the development of photoresponse graphene materials. The specific contents are as follows: (1) azobenzene surfactants are prepared by organic synthesis and molecular design for the preparation of photoresponse azobenzene cationic surfactant. The results show that the azobenzene surfactant has the light response characteristics under the visible light of 350nm UV light and 455 nm, and the UV visible absorption spectrum (UV-Vis) can be reversible. In addition, the molecular structure of the double azobenzene surfactant is designed, and the double sub type Gemini couple is prepared. The azobenzene surface variable active agent provides a stabilizer for the preparation of photoresponse graphene metal nanocomposites. (2) the azobenzene graphene composite is based on the charge property of the cationic azobenzene surfactant, and modifies the cationic azobenzene surface active agent (Azo C7NO) to the surface of the negatively charged graphene oxide surface through the ion bond action. The results of.Zeta potential test of azobenzene graphene composite material (Azo-GO) showed that the surface potential of the azobenzene surfactant changed the surface potential of the graphene oxide, and the surface charge changed from negative potential to positive potential rapidly. The fluorescence spectrum showed that the azobenzene carbide composite was of a fluorescent property, which proved that Azo C7NO was the main factor. .X ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM) have been applied to the modification of graphene by the ionic bond on graphene oxide, which is a very visible pion accumulation (fluorescence quenching). The results of the atomic force microscopy (AFM) study show that the azobenzene graphene composite has a unique self composition. In addition, the infrared spectrum (FTIR), X ray photoelectron spectroscopy (XPS) and thermogravimetric (TGA) show that the grafting rate of azo phenyl group in the composites is modified for a azobenzene per 71 carbon atoms in the composite. Molecular, with high grafting rate. (3) photoresponse of azobenzene graphene composite is based on the optical response properties of azobenzene group, and the photoresponse characteristics of azobenzene graphene composite have been studied. The UV visible absorption spectroscopy (UV-Vis) shows that the azobenzene graphene composite has photochemical properties.X ray diffraction (XRD). Atomic force microscopy (AFM) and Raman spectroscopy (Raman) show that UV and blue light induction can cause the reversible and reversible isomerization of azobenzene surfactants and the reversible change of hydrophobicity, thus the self assembly of the composite is reversible. The results of the electrochemical cyclic voltammetry (CV) study show that the composite material is the composite. The electrochemical properties of the material can also be controlled by the light reversible control. In the reported azobenzene graphene composite, the properties of the composites prepared by the pion accumulation and covalent bond are mainly due to the spatial isomerization of azobenzene molecules. The azobenzene graphene composite prepared in this paper is prepared in this paper. The changes in the photoresponse properties are determined mainly by the change of the photoinduced polarity and hydrophobicity of azobenzene surfactants, which can lead to the self assembly of the composites. The light controlled self assembly is a new self-assembly phenomenon. The further study of it may provide a mesoscopic study of the self-assembly theory. Examples and theoretical models promote the development of self-assembly theory. (4) the application of azobenzene graphene gold nanoparticles composite material to further develop azobenzene surface active agent in the application of graphene nanocomposites. Based on the molecular structure design, a Gemini Gemini azobenzene surfactant (Azo C10N2O2) is prepared. The surface of this kind of azobenzene surface is prepared. The active agent has two cationic groups with azobenzene as the connecting group. Therefore, Azo C10N2O2 is used as a stabilizer to locate the metal nanoparticles to the surface of graphene by electrostatic action. At the same time, a new type of photoresponse of azobenzene graphene gold nanoparticle composite (Azo-RGO-GNP) is prepared by chemical reduction method. X ray diffraction (XRD), X ray photoelectron spectroscopy (XPS), thermogravimetric (TGA), transmission electron microscopy (TEM) and ultraviolet visible absorption spectroscopy (UV-Vis) are used to study the structure and properties of the composites. The results show that the gold nanoparticles can be evenly distributed on the surface of graphene with Azo C10N2O2 as a stabilizer, and a stable positioning agent is realized. The azobenzene group in the composite made the composite photochemical. By this technique, the first synthesis of azobenzene graphene gold nanoparticle composites was made for the first time. In addition, the electrochemical cyclic voltammetry (CV) study showed that the conductive properties of the composite could also be controlled by light. Therefore, the azobenzene graphene gold nanoparticle was obtained. Composite materials have potential applications in photosensitive sensors and electrochemistry.
【学位授予单位】：湖南大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TQ127.11;TB33
【参考文献】
相关硕士学位论文 前1条
1 史会敏;石墨烯的制备及其性质研究[D];郑州大学;2010年
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