二硫化钼基复合材料的制备及其摩擦学性能研究

发布时间：2018-01-11 10:30

本文关键词：二硫化钼基复合材料的制备及其摩擦学性能研究　出处：《江苏大学》2017年硕士论文　论文类型：学位论文

【摘要】：二硫化钼(MoS_2)作为典型的过渡金属化合物,具有特殊的层状结构,层与层间依靠及其微弱的范德华力相连接,在低应力载荷下就能发生滑移从而在金属摩擦面形成转移膜,因此具有优异的润滑性能,然而纯二硫化钼由于硬度低、结构松散和粘附强度差等因素使其很容易在低应力载荷下失效,因此需要制备复合材料来改善二硫化钼的抗磨性能。本论文通过简便的水热法制备出二硫化钼纳米片,并以其为载体引入氧化石墨烯、磁性纳米粒子、金属纳米粒子制备出氧化石墨烯-二硫化钼、铜-二硫化钼、四氧化三铁-二硫化钼以及铜-氧化石墨烯-二硫化钼复合材料,并将它们作为润滑添加剂研究其摩擦性能,具体工作内容如下:1.以氧化石墨烯、硫代乙酰胺和半胱氨酸为前驱体,在水热条件下制备出MoS_2-GO纳米复合材料,结果表明二硫化钼纳米片均匀负载于氧化石墨烯的表面,同时纳米片由4-7层的单分子层组成,鉴于纳米复合材料具有特殊的层状结构以及组分间的协同润滑作用,因此将MoS_2和MoS_2-GO纳米材料分别作为润滑油添加剂考察其摩擦性能,研究表明相比于MoS_2纳米添加剂,MoS_2-GO具有更优异的减摩和抗磨性能,当MoS_2-GO的质量比为1 wt%,达到最低的摩擦系数为0.0557。2.以二硫化钼纳米片为载体,六水合三氯化铁为铁源,乙醇和水混合溶液为溶剂,通过水热反应将粒径为15纳米的四氧化三铁纳米粒子负载到二硫化钼表面从而制备得到Fe_3O_4-MoS_2纳米复合材料,由于MoS_2易于在摩擦表面形成转移膜同时引入的磁性纳米粒子能够让生成的转移膜更加稳定,因此将其作为润滑添加剂研究其摩擦性能,实验结果表明当质量浓度比为1.5 wt%时能够达到最低摩擦系数为0.0565。3.以二硫化钼纳米片为载体,多巴胺为表面改性剂,醋酸铜为铜源,次亚磷酸钠为还原剂,通过化学还原反应成功制备Cu-MoS_2纳米复合材料,结果表明二硫化钼纳米片的表面吸附了一层多巴胺分子,使粒径为8-15纳米的铜金属粒子更加均匀的负载于纳米片表面,由于MoS_2在摩擦过程中易于成膜以及表面负载的金属纳米粒子起到微观轴承的作用,因此研究其摩擦性能,结果表明当0.5wt%的Cu-MoS_2作为润滑添加剂时具有最优异的摩擦性能,摩擦系数为0.0433。4.以二硫化钼-氧化石墨烯为载体,多巴胺为改性剂,醋酸铜为铜源,次亚磷酸钠为还原剂,通过水热还原反应将铜纳米粒子均匀负载在纳米复合材料表面,鉴于MoS_2和GO间的协同润滑以及在表面引入的金属粒子能够改变摩擦方式等因素,因此将其作为润滑油添加剂研究摩擦性能,结果表明当加入1 wt%的Cu-MoS_2-GO时,摩擦系数最低为0.0408。
[Abstract]:Molybdenum disulfide (MoS _ 2) as a typical transition metal compound, it has a special layered structure, which depends on the weak van der Waals force. Under low stress load slippage can take place to form a transfer film on the metal friction surface, so it has excellent lubricity, but pure molybdenum disulfide has low hardness. The loose structure and poor adhesion strength make it easy to fail under low stress load. In order to improve the antiwear performance of molybdenum disulfide, molybdenum disulfide nanocrystals were prepared by a simple hydrothermal method, and graphene oxide and magnetic nanoparticles were introduced as the carrier. The composites of graphene oxide molybdenum disulfide copper molybdenum disulfide iron trioxide molybdenum disulfide and copper graphene oxide molybdenum disulfide were prepared by metal nanoparticles. They were used as lubricating additives to study their tribological properties as follows: 1. Graphene oxide, thioacetamide and cysteine were used as precursors. MoS_2-GO nanocomposites were prepared under hydrothermal conditions. The results showed that molybdenum disulfide nanoparticles were uniformly loaded on the surface of graphene oxide, and the nanostructures were composed of 4-7 monolayer layers. In view of the special layered structure of nanocomposites and the synergistic lubrication between the components, MoS_2 and MoS_2-GO nano-materials were used as lubricating oil additives to investigate their friction properties. The results show that MoS2-go has better antifriction and antiwear properties than MoS_2 nano-additive MoS2-GO, when the mass ratio of MoS_2-GO is 1 wt%. The lowest friction coefficient was 0.0557.2. The molybdenum disulfide nanoparticles were used as the carrier, the ferric chloride hexahydrate as Tie Yuan and the mixed solution of ethanol and water as the solvent. Fe_3O_4-MoS_2 nanocomposites were prepared by hydrothermal reaction by loading 15 nanometer-sized iron trioxide nanoparticles onto the surface of molybdenum disulfide. Because MoS_2 is easy to form a transfer film on the friction surface and the magnetic nanoparticles can make the resulting transfer film more stable, it is used as a lubricating additive to study its tribological properties. The experimental results show that the lowest friction coefficient is 0.0565.3 when the mass concentration ratio is 1.5 wt%. Using molybdenum disulfide nanoparticles as the carrier, dopamine as the surface modifier, copper acetate as the copper source. Cu-MoS_2 nanocomposites were successfully prepared by chemical reduction reaction with sodium hypophosphite as reducing agent. The results showed that a layer of dopamine molecules was adsorbed on the surface of molybdenum disulfide nanoparticles. The copper particles with the particle size of 8-15 nanometers are more evenly loaded on the surface of the nanocrystals, because MoS_2 is easy to form film in the friction process and the metal nanoparticles loaded on the surface play the role of micro-bearing. The results show that 0.5wt% Cu-MoS_2 has the best friction performance when it is used as lubricating additive. The friction coefficient is 0.0433.4. MoS _ 2-graphene oxide is used as carrier, dopamine as modifier, copper acetate as copper source and sodium hypophosphite as reducing agent. Copper nanoparticles were uniformly loaded on the surface of nanocomposites by hydrothermal reduction reaction. Due to the synergistic lubrication between MoS_2 and go and the introduction of metal particles on the surface, the friction mode could be changed. The results show that the friction coefficient is the lowest 0.0408 when 1 wt% Cu-MoS_2-GO is added.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB33;TQ136.12

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