Sulfur-doped graphene oxide (SA-GO) prepared by sulfuration and alkylation of graphene oxide is applied as an efficient green anti-wear additive for harsh operation conditions of engines. X-ray photoelectron spectroscopy analysis reveals the sulfur content of octadecylamine-modified SA-GO (sulfuration follows alkylation) is increased by 79 times compared with the reverse process that alkylation follows sulfuration, suggesting the preparation route is a key factor of the sulfuration process. The higher sulfur content and -C-S-C- sulfur bonding constitution result better lubrication effect, while the investigation of chain length of alkylation modification and concentration of the alkylated sulfur-doped graphene oxide indicates the octylamine-modified SA-GO shows smaller diameter of wear scar within the concentration range between 1 × 10-4 and 2.5 × 10-4 wt%. The decrement percent of wear scar diameter is 43.2% in 928 lubrication oil and 17.2% in PAO4 oil while the SA-GO modified by octylamine is applied with the concentrations 2.5 × 10-4 wt% in PAO4 and 1 × 10-4 wt% in 928 oil, respectively. The sulfur content in oil samples is only 0.006~0.001 wt%, which is much lower than the sulfur content standard recommended by ILSAC that is 0.5 wt%. The research work indicates the SA-GO additive is more feasible for the pollution treatment which focuses the substantial reduction of sulfur content in lubrication oil on the premise of improving lubrication capability.

中文翻译：

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硫掺杂的烷基化氧化石墨烯作为高性能的润滑油添加剂。

通过氧化石墨烯的硫化和烷基化制备的硫掺杂氧化石墨烯（SA-GO）被用作有效的绿色抗磨添加剂，用于发动机的苛刻运行条件。X射线光电子能谱分析表明，十八烷基胺改性的SA-GO（烷基化后的硫化）的硫含量比烷基化后的硫化的逆过程增加了79倍，这表明制备路线是硫化过程的关键因素。较高的硫含量和-CSC-硫键构成可产生更好的润滑效果，而对烷基化改性的链长和烷基化的硫掺杂氧化石墨烯浓度的研究表明，辛胺改性的SA-GO显示出较小的磨损疤痕直径。浓度范围在1×10-4和2之间。5×10-4重量％。在928号润滑油中，磨损痕迹直径的减量百分比为43.2％，在PAO4油中为17.2％，而使用辛胺改性的SA-GO的浓度为PAO4中的2.5×10-4 wt％和1×10-4 wt％分别在928号机油中 油样中的硫含量仅为0.006〜0.001 wt％，远低于ILSAC建议的硫含量标准0.5 wt％。研究工作表明，SA-GO添加剂在提高润滑性能的前提下，着重于大幅降低润滑油中硫含量的污染处理更为可行。分别。油样中的硫含量仅为0.006〜0.001 wt％，远低于ILSAC建议的硫含量标准0.5 wt％。研究工作表明，SA-GO添加剂在提高润滑性能的前提下，着重于大幅降低润滑油中硫含量的污染处理更为可行。分别。油样中的硫含量仅为0.006〜0.001 wt％，远低于ILSAC建议的硫含量标准0.5 wt％。研究工作表明，SA-GO添加剂在提高润滑性能的前提下，着重于大幅降低润滑油中硫含量的污染处理更为可行。