【作者】 曹敬煜；

【导师】 黄德欢；

【作者基本信息】 南昌大学 ， 材料学， 2010， 硕士

【摘要】 纳米粒子处于原子簇和宏观物体交界的过渡区域,具有小尺寸效应、表面效应、量子尺寸效应和宏观量子隧道效应,使其在结构、光电、磁学和化学性质等方面表现出特异性。大量研究表明,纳米粒子添加到润滑油中,可以提高润滑油的极压性能。纳米粒子润滑油添加剂的制备及纳米粒子在润滑油中稳定的分散是润滑油能够得到实际应用的前提。本文介绍了本课题选用作为润滑油添加剂的纳米铜和碳纳米管的特性、制备及应用,并对纳米粒子润滑油添加剂的发展现状作了综述和讨论。本文以自制甲酸铜为原料,在润滑油基础油的保护下,采用热分解方法成功制备出用作润滑油添加剂的纳米铜粉。本文还通过正交试验法研究了Cu2+的初始浓度、球磨时间、热分解温度以及搅拌速度对铜粉粒径的影响,并用XRD和TEM对纳米铜粉进行了粒径计算和形貌观察。测试结果表明：当制备工艺参数Cu2+的初始浓度0.33mol/L、球磨时间12h、热分解温度200℃、搅拌速度30 rad/min时,纳米铜颗粒粒径分布均匀,呈球形,表面未氧化,平均粒径为42nm。本文在纳米铜润滑油添加剂制备的基础上,将改性后的碳纳米管与甲酸铜混合球磨,在200℃下热解得到碳纳米管／纳米铜复合润滑油添加剂。首先,对碳纳米管的表面改性进行了研究,采用混酸回流与超声波振荡处理相结合的方法对碳纳米管进行纯化处理,并在此基础上通过酯化反应对碳纳米管表面进行功能化改性处理。由透射电镜检测结果可知,纯化处理后的碳纳米管的纯度得到了明显的提高。由红外检测结果分析可知,经过纯化处理后碳纳米管表面含有大量羧基和羟基官能团；酯化改性处理后的碳纳米管表面成功的接入了酯基长链烷烃分子基团。其次,对碳纳米管／纳米铜复合润滑油添加剂进行XRD、SEM测试和静置观察,测试和观察结果均表明,碳纳米管／纳米铜复合润滑油添加剂的分散稳定性明显优于纳米铜润滑油添加剂的分散稳定性。本文采用四球摩擦磨损试验机对添加了纳米铜润滑油添加剂和碳纳米管／纳米铜复合润滑油添加剂的甲基硅油进行了极压性能的测试。测试结果表明,添加了纳米铜润滑油添加剂的甲基硅油的最大无卡咬负荷PB值提高了98N,而添加了碳纳米管／纳米铜复合润滑油添加剂的甲基硅油的最大无卡咬负荷PB值提高了294N。得出了甲基硅油极压性能得到显著提高、抗磨性能亦将得到相应改善的结论。更多还原

【Abstract】 Nano-particles lie in the junction of the cluster and the macroscopic objects.It has the specific capacities in the structural, optical,electronic, magnetic and chemical properties with small size effect, surface effect, quantum size effect and macroscopic quantum tunnel effect. Numerous studies show that the extreme pressure of lubricating oil with the nano-particles additives can be improved. Preparation and stable dispersion of nano-particles in lubricating oil is the key of nano-particles as the lubricant additives.In the article, properties,preparation and application of copper nano-particles and carbon nanotube used in the research were described, and the recently development of nano-particles as the lubricant additives was summarized.In order to prepare the nanocopper particles,thermal decomposion of Cu(HCOO)2 in the basic-lubricating oil(150SN) under specified condition of temperature was applied by using self-made Cu(HCOO)2 as a raw material. Influence of the concentration of Cu2+,time of ball milling, temperature of thermal decomposion and the speed of the stir on the diameter of nanocopper particles were studied.XRD and TEM were used to characterize the size and structure of the nanocopper particles.Experimental results show that the nanocopper particles are with spherical geometry, their surfaces are not oxidized, and the particle sizes is about 42nm in average,when the concentration of Cu2+ is 0.33mol/L, time of ball milling is 12h, temperature of thermal decomposion is 200℃and the speed of the stir is 30rad/min. Though copper nano-particles had been dispersed evenly in the lubricating basic oil,the dispersed stability of the copper nano-particles in the lubricating basic oil was not good by the 1-2h standing observation. In order to solve the dispersion stability of the copper nano-particles in the lubricating oil, preparation and properties of MWNTs/copper nano-particles composite as the lubricant additive were studied.Firstly, MWNTs have been chemically purified and oxidized using a mixture of concentrated H2SO4/HNO3 mixture (volume ratio:3:1),and MWNTs were modified by the esterification. The result of TEM shows that the purity of MWNTs had been improved markedly by the treatment of the concentrated H2SO4/HNO3 mixture.The result of FT-IR shows that MWNTs were introduced with carboxyl groups which presented at the side wall defect sites and the open ends of oxidized MWNTs by the treatment of the concentrated H2SO4/HNO3 mixture,and MWNTs modified alkane were prepared by the esterification. Secondly, by the test of XRD and SEM, and the result of standing observation, the dispersed stability of MWNTs/copper nano-particles composite in the lubricating oil was better than the copper nano-particles’Two kinds of lubricant additives were added to the methyl silicone oil.The tribological property of the oil was evaluated using four-ball extreme pressure tester. The result of the test shows that the PB of methyl silicone oil with the copper nanoparticles was improved by 98N, and the PB of methyl silicone oil with MWNTs/copper nanoparticles composites was improved by 294N.更多还原