改性氧化石墨的制备及在液体石蜡中的摩擦性能研究

发布时间：2018-06-22 16:05

本文选题：氧化石墨 + 有机硅烷　；参考：《东南大学》2016年硕士论文

【摘要】：摩擦和磨损是造成材料和能源耗损的主要方式。世界1/3以上的一次性能源的损耗都是由摩擦和磨损引起的。减少摩擦和磨损所带来的能源损耗迫在眉睫。据报道,纳米粒子具有良好的润滑性能,能够起到减摩抗磨作用。作为大规模制备石墨烯的初始材料,氧化石墨具有优良的理化性能,研究其及衍生物的摩擦性能具有一定的时代意义。本文采用改进Hummers方法制备氧化石墨,并使用两种具有不同烷基链长度的有机硅烷分子对其进行表面改性。利用傅立叶变化红外光谱、XRD、紫外光谱、扫描电镜等分析手段,对硅烷改性氧化石墨的结构与形貌进行表征。结果表明氧化石墨经过表面改性后的结构和形貌发生了明显的变化。通过四球试验方法,研究其在液体石蜡油中的摩擦性能。结果发现硅烷改性氧化石墨具有优异的摩擦性能,在较低浓度下能够明显提高基础油的减摩能力。而且,不同链长硅烷改性的氧化石墨之间的摩擦性能具有差别,归结于分散性的差异。分析推测其作用机理为：一方面,小尺寸的硅烷改性氧化石墨在基础油中稳定分散,容易进入金属接触区域；另一方面,在挤压和剪切应力下,氧化石墨从烷基链上脱落或卷曲,填补金属表面的洼坑,从而降低摩擦和磨损。利用一种压强辅助方法制备聚苯胺和聚苯胺-氧化石墨复合材料。同时在不同制备工艺条件下,合成出性能各异的纳米棒状聚苯胺。在四球摩擦机上,探究其作为液体石蜡添加剂时,浓度以及制备工艺对摩擦性能的影响。研究发现聚苯胺及其与氧化石墨的复合物具有良好的减摩特性。初步分析其作用机理为：首先,直径为70-80nm的棒状聚苯胺在摩擦过程中起到“微滚动轴承”的作用。其次,氧化石墨与聚苯胺在润滑时具有协同作用。在氧化石墨表面间的聚苯胺作滚动,促使氧化石墨的层间滑离更加容易,从而起到减摩抗磨作用。
[Abstract]:Friction and wear are the main ways to cause material and energy loss. More than a third of the world's disposable energy losses are caused by friction and wear. It is urgent to reduce the energy loss caused by friction and wear. It is reported that nanoparticles have good lubricity and can reduce friction and wear. As the initial material for the preparation of graphene on a large scale, graphite oxide has excellent physical and chemical properties. It is of great significance to study the friction properties of graphene and its derivatives. Graphite oxide was prepared by modified Hummers method and modified by two kinds of organosilane molecules with different alkyl chain lengths. The structure and morphology of silane modified graphite oxide were characterized by Fourier transform infrared spectroscopy (FTIR), UV spectroscopy and scanning electron microscope (SEM). The results show that the structure and morphology of graphite oxide have changed obviously after surface modification. The friction properties of the liquid paraffin oil were studied by four-ball test method. The results show that graphite oxide modified by silane has excellent friction property and can obviously improve the antifriction ability of base oil at lower concentration. Moreover, the tribological properties of graphite oxide modified by silane with different chain length are different, which can be attributed to the difference of dispersion. The mechanism is as follows: on the one hand, small size silane modified graphite oxide is stable and dispersed in the base oil, easy to enter the metal contact area; on the other hand, under extrusion and shear stress, Graphite oxide is removed or curled from alkyl chains to fill holes in metal surfaces, thus reducing friction and wear. Polyaniline and Polyaniline-graphite oxide composites were prepared by a pressure-assisted method. At the same time, nanorod Polyaniline with different properties was synthesized under different preparation conditions. In the four-ball friction machine, the effects of the concentration and the preparation process on the friction properties of paraffin were investigated when they were used as liquid paraffin additives. It is found that Polyaniline and its complex with graphite oxide have good antifriction properties. The mechanism is as follows: firstly, the rod-shaped Polyaniline with diameter of 70-80nm plays the role of "micro rolling bearing" in the friction process. Secondly, graphite oxide and Polyaniline have synergistic effect on lubrication. The rolling of Polyaniline on the surface of graphite oxide makes it easier to slip away from the layer of graphite oxide, thus reducing friction and antiwear.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB332

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