【作者】 刘志辉；

【导师】 蒋富明；

【作者基本信息】 吉林大学 ， 无机化学， 2008， 硕士

【摘要】 近年来,随着汽车工业的发展,要求润滑油必须具有较好的燃油经济性。从这一观点出发,人们已对节能性润滑油做了大量的研究,主要是通过添加摩擦改进剂来降低摩擦。同时,改善材料的摩擦和润滑性能,不仅可以满足现代科学技术进步所需要的机械设备向高速、重载荷和高精度方向发展,而且还可以延长机器设备的使用寿命,对节约能源和环境保护都具有重大意义。本论文发展了化学方法制备纳米纳米硼酸铜的技术,利用各种控制方法和新的合成路线合成不同形貌的纳米材料。通过系统地研究工作,得到了许多有价值的结论和创新性的结果。纳米微粒具有小尺寸效应、比表面效应等很多常规材料所不具备的特殊性质,这些特殊性质使得纳米材料具有广泛的应用领域。目前纳米微粒作为润滑油添加剂已经引起许多科研工作者的兴趣,如何提高纳米微粒在润滑油中的稳定性、相溶性,已经成为该领域研究的热点和难点。目前将纳米添加剂用于改善润滑油性能已经取得了一些进展。进一步开展纳米微粒的制备及其应用于润滑油抗磨减摩性能研究,对于改善油品的性能和延长设备的使用寿命具有重要的意义。以硼砂和硫酸铜为主要原料,通过简单的液相法,首次一步原位制备出晶态疏水性的硼酸铜纳米片。用油酸作表面改性剂,降低了硼酸铜纳米粒子的表面能,提高了与基础油之间的相溶性。油酸是一种廉价的不饱和有机酸,含有羧基和碳碳双键两种官能团。在合成过程中,通过控制其生长条件实现了纳米粒子形貌控制,得到了疏水性的硼酸铜纳米片,其直径为100nm至200nm,厚度约为15nm。其中反应体系的pH、反应物的配比以及反应时间等对产物的疏水性影响非常大。通过热重和红外光谱分析表明,油酸中的羧基与硼酸铜表面富含的羟基发生键合作用,将油酸接枝在硼酸铜粒子表面上,疏水性硼酸铜的接触角高达112o。将疏水性的硼酸铜添加入到基础油中,由于其在基础油中分散性好,所以显著地降低了基础油的摩擦系数,并且摩擦系数波动非常微小。近年来,随着纳米技术的发展,复合材料由于其潜在的应用价值,已引起了科技界的广泛兴趣。复合材料纳米粒子代表了一类由两种不同成分和结构材料构成的新的结构单元。这类材料与他们的单组分的配对物相比,通常拥有改善的物理和化学性质,能创造多功能性复合纳米粒子。同时,复合材料的磁、光、机械、电、摩擦和催化性能可以通过控制复合材料粒子的结构、尺寸和组成得以实现。据我们所知,到目前为止还没有合成硼酸铜/二氧化硅复合纳米粒子的报道。我们首次直接在硼酸铜的表面通过自组装原位沉积一薄层致密的二氧化硅球。复合粒子中的二氧化硅壳为以无定形状态存在,具有单分散性和光滑的表面,其直径约30nm。内层硼酸铜以多晶态存在。硼酸铜的长度约1000nm,直径约100nm,并将其添加到基础油中,没能有效地降低基础油的摩擦系数。更多还原

【Abstract】 In recent years, the demand has been strong for improvement of the fuel economy of automobile engines. From the standpoint of engine oil formulations, a great deal of research effort has been devoted to the development of effective fuel-saving type lubricants and friction reduction by friction modifiers. Simultaneously, modifying the antiwear and lubricating property of material has an important effect on the saving of resources and environmental protection. It not only satisfies the tendency of higher speed, heavier load and higher accuracy of the machine demanded by modern scientific technology, but also lengthens the life of the machine. In this paper, we have focused on the control of the size and shape of nanoparticles by developing effective synthetic techniques of nanoparticles and copper borate nanoparticles. There are many valuable and innovative onclusions through systemic studies.Nanoparticles have many special properties,such as small particle size, high surface activity and high surface energy, which make them apply in extensive field. At present, as additives of lubricant nanoparticles arouse many researchers’interest. How to improve the stability and solubility of nanopaticles is the hot issue in the field of materials science. Now many kinds of nanoparticles have been prepared and tested as additives of lubricantion. More study on synthesis nanoparticles and applying it into wearing alleviation will be benefit to improve the use of the machine equipment efficiently and longer.The crystal and hydrophobic copper borate (Cu(BO2)2) nanosheets were successfully prepared by a wet method using Na2BB4O7 10H2O and CuSO4 5H2O as raw materials in situ aqueous solution, and oleic acid as the modifying surface agent. Surface energy of copper borate nanoparticles was reduced, and the comparability between copper borate nanoparticles and the base oil was enhanced. Oleic acid is a cheap unsaturation organic acid including carboxyl and C=C double bonds functional groups. It had been found that the as-prepared materials displayed nanosheet morphology with average diameters from 100 nm to 200 nm and the thicknesses about 15 nm. The reaction parameters including the pH of the solution, the mole ratios of Na2B4BO7 10H2O and CuSO4 5H2O and the reaction time played important roles on the formation of the hydrophobic copper borate. Oleic acid was bonded to copper borate surface with a covalent bond between carboxyl functional groups and hydroxy groups on the surface of copper borate nanoparticles. The presence of the oleic acid on the surface modified copper borate was confirmed by FTIR spectroscopy. The relative contact angle of the hydrophobic copper borate was increased to 112°. Moreover, the friction coefficient of the base oil was decreased by the addition of hydrophobic copper borate nanosheets and the fluctuation of the friction coefficient was very small.In recent years, advanced materials derived from composite particles are of extensive scientific and technological interests due to the ability to potential their properties with developments in nanotechnology. In this regard, nanoparticles with morphologies represent a new type of constructional unit consisting of two dissimilar compositional and structural domains. Such materials should have enhanced physical and chemical properties and a broader range of applications than their single-component counterparts. The structure, size, and composition of these particles can be easily altered in a controllable way to tailor their magnetic, optical, mechanical, thermal, electrical, tribological and catalytic properties. To the best of our knowledge, the synthesis of copper borate/silica nanoparticles has not been reported up to now. Our method involved the direct synthesis of copper borate and silica nanospheres coating was then deposited onto the copper borate surface through a self-assembly process. The as-prepared Cu(BO2)2/SiO2 materials have a rod–like shape with lengths of 1000 nm and diameters of 100 nm. The obtained SiO2 particles have perfect spherical shape with narrow size distribution (average diameters 30 nm).The friction coefficient of the base oil was not decreased by the addition of Cu(BO2)2/SiO2.更多还原