利用分子级助磨剂制备均匀小尺寸石墨烯及其润滑油添加剂应用

Molecular-scale grinding of uniform small-size graphene flakes for use as lubricating oil additives

目前研究者已开发出了多种石墨制备石墨烯的产业化制备方法,其中最为常用的是化学氧化还原法和插层解剖法。然而,实现径向尺寸小于1μm的石墨烯的低成本规模化制备始终是一个挑战,诸如纺织纤维、车用润滑油、高分子材料等,需要小尺寸石墨烯的应用领域的技术发展也因此受到限制。为此,本文提出了一种原位合成纳米助磨剂辅助的球磨方法,可以实现均匀小尺寸薄层石墨烯的低成本可控制备。此方法制备的石墨烯径向尺寸小于1μm,且该方法对石墨烯片的晶体结构破坏较小,面内几乎没有含氧官能团,因而石墨烯的基本物理属性没有遭到破坏。此外,利用处理过的小尺寸石墨烯作为润滑油添加剂,不仅可以解决目前石墨烯在润滑油中存在的分散稳定性差的问题,还能够降低27%以上的摩擦系数,减少38.8%以上的磨损。本文提出的这种小尺寸石墨烯制备方法简单、成本低廉、润滑应用效果显著,具有很大的应用潜力。

A variety of industrial preparation methods to obtain graphene from graphite have been developed,the most prominent of which are the chemical reduction of graphene oxide and intercalation-exfoliation methods.However,the low-cost,thin-layer,large-scale production of graphene with a radial dimension smaller than 1μm(SG)remains a great challenge,which has limited the industrial development and application of small-scale graphene in areas such as textile fibers,engine oil additives,and graphenepolymer composites.We have developed a novel way to solve this problem by improved ball milling methods which form molecularscale grinding aids between the graphite layers.This method can produce uniform,small-size(less than 1μm)and thin-layer graphene nanosheets at a low cost,while ensuring minimal damage to the internal graphene structure.We also show that using this SG as an additive in lubricating oil not only solves the current dispersion stability of graphene,but also reduces the friction coefficient by more than 27%and wear by more than 38.8%.The SG preparation method reported is simple,low-cost,and has a significant effect in lubricating applications,which is of great commercial value.