氧化石墨烯及其纳米复合物在油介质中的摩擦学研究

发布时间：2018-05-24 20:16

本文选题：氧化石墨烯 + 构效关系　；参考：《扬州大学》2017年硕士论文

【摘要】：摩擦磨损普遍存在于自然界中,给我们的生活和生产带来了巨大损失。润滑油是降低摩擦,减少磨损,延长机件寿命最为常见的润滑材料。为了提高润滑油的润滑性能,通常是在基础油中加入各种减摩、抗磨的添加剂。氧化石墨烯(GO)具有独特的二维片层结构,由于拥有超低的摩擦系数和超强的硬度特性,而且强的耐腐蚀和优异的抗氧化性能,成为了近年来摩擦学领域研究的热点材料之一。然而,GO要想实际应用于润滑油中作为减摩和抗磨添加剂使用,首先需要解决其在油介质中的分散性和透明性技术难题。本文主要探讨了(1)GO的尺寸与摩擦学性能构效关系;(2)GO表面改性技术开发及其分散性、透明性和摩擦学性能研究;(3)硼酸盐/GO纳米复合材料的制备及其摩擦学性能研究。通过控制Hummer法的氧化温度成功实现了 GO的尺寸控制,分别合成出平均尺寸为25 μm,22 μm 和 18 μm 的 GO-20,GO-27 和 GO-35 三种纳米片。运用 XRD、SEM、FT-IR、EDS、AFM等表征手段对三种GO纳米片进行了表征。结果发现,随着氧化温度的升高,GO纳米片的尺寸逐渐减小,并且发现C/O也随之减少。摩擦性能测试结果表明,G035基油的摩擦系数相比于GO20基油和G027基油分别降低18.5%和8.5%,而磨痕直径分别降低11.3%和5.2%。证明GO纳米片的尺寸越小,C/O 比越低,其减摩和抗磨性能越好,这是由于C/O低的GO纳米片表面含有更丰富的活性基团,有利于其在油介质中的分散性。为了改善GO在油介质中的分散性和透明性,我们采用可生物降解的油酸二乙醇酰胺硼酸酯(ODAB)作为改性剂,成功实现了 ODAB键合改性GO技术。运用FT-IR、XRD、UV-vis、Raman、TEM和XPS等一系列表征揭示了改性GO的结构,证明了 ODAB是通过脱水缩合生成酰胺的方式成功接支到了 GO纳米片表面。研究了改性GO在基础油中的分散性、和透明性,并考察了其摩擦性能。结果表明,改性后的GO纳米片在基础油中实现了高度分散,表现出优异的透明性,而且磨痕直径和平均摩擦系数相比于基础油分别下降了约42.0%和38.4%,展现出MGO优异的减摩和抗磨性能。为了进一步提升GO的摩擦学性能,我们通过一种液相超声混合剥离技术分别制备了硼酸钙(CB),硼酸镧(LB)和硼酸锌(ZB)与GO的纳米复合物。考察了物理砂磨,传统油酸(OA)改性及油酸二乙醇酰胺(OD)改性对复合物在油中分散性的影响。运用XRD、SEM、FT-IR、Raman、UV-vis、TEM、TGA、EDS等一系列表征揭示了复合材料的结构形貌。结果表明,CB/GO基油,OA-LB/GO基油和OD-ZB/GO基油相比于500 SN基础油,它的平均摩擦系数分别下降了 46.6%,30.8%和48.2%,而磨痕直径分别减小了 37.5%,44.3%和37.6%。这证明了复合材料出色的协同减摩抗磨作用。
[Abstract]:Friction and wear generally exist in nature, which bring great loss to our life and production. Lubricating oil is the most common lubricating material to reduce friction, reduce wear and prolong the life of machine parts. In order to improve the lubricating performance of lubricating oil, it is usually to add various antifriction and antiwear additives to the base oil. Graphene oxide (GOO) has a unique two-dimensional lamellar structure. Because of its ultra-low friction coefficient, super hardness, strong corrosion resistance and excellent oxidation resistance, it has become one of the hot materials in the field of tribology in recent years. However, in order to be used as antifriction and antiwear additive in lubricating oil, it is necessary to solve the technical problems of dispersion and transparency in oil medium. The relationship between the size and the tribological properties of HY1GGO surface modification technology and its dispersion, transparency and tribological properties are discussed in this paper. The preparation and tribological properties of borate / go nanocomposites are studied. The size control of go was successfully realized by controlling the oxidation temperature of Hummer method. Three kinds of GO-20 GO-27 and GO-35 nanocrystals with average sizes of 25 渭 m 22 渭 m and 18 渭 m were synthesized, respectively. Three go nanoparticles were characterized by means of XRDX SEMT-IR and EDSAFM. The results show that the size of go nanocrystals decreases with the increase of oxidation temperature, and the C / O decreases with the increase of oxidation temperature. The friction coefficient of G035-based oil was decreased by 18.5% and 8.5% than that of GO20 oil and G027-based oil, while the wear diameter was decreased by 11.3% and 5.2%, respectively. It is shown that the smaller the size of go nanoparticles, the better the antifriction and antiwear properties of go nanoparticles. This is due to the fact that there are more active groups on the surface of go nanocrystals with low C / O ratio, which is beneficial to their dispersity in oil medium. In order to improve the dispersity and transparency of go in oil medium, the biodegradable oleic acid diethanolamide borate ester (ODAB) was used as the modifier, and the ODAB bonding modified go technology was successfully realized. The structure of the modified go was revealed by a series of characterization, such as FT-IRDX, UV-visXPS and XPS. It was proved that ODAB was successfully connected to the surface of go nanoparticles by dehydration and condensation to form amides. The dispersion, transparency and tribological properties of modified go in base oil were studied. The results showed that the modified go nanoparticles were highly dispersed in the base oil and showed excellent transparency. Compared with the base oil, the wear scar diameter and the average friction coefficient decreased by 42.0% and 38.4%, respectively, showing the excellent antifriction and antiwear properties of MGO. In order to further improve the tribological properties of go, the nanocomposites of calcium borate (CBB), lanthanum borate (LB) and zinc borate (ZB) with go were prepared by a liquid phase ultrasonic mixing stripping technique. The effects of physical grinding, traditional oleic acid (OAA) modification and oleic acid diethanolamide (ODO) modification on the dispersion of the composite in oil were investigated. The structure and morphology of the composites were revealed by a series of characterizations such as XRDX SEMT-IRT Ramanum UV-vis-TEMN TGAEDS and so on. The results show that compared with 500SN base oil, the average friction coefficient of OA-LB / go base oil and OD-ZB/GO base oil decreases by 46.6% and 48.2%, respectively, while the diameter of wear marks decreases by 37.5% and 37.6%, respectively. This proves the excellent synergistic antifriction and antiwear effect of the composites.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE624.82;TQ127.11

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