▎ 摘　　要

The weak dispersion stability of graphene in water restricts its practical application as water-based lubricant additives. Herein, sulfonated graphene (SGO) with ultra-dispersive and superior lubrication performance was synthesized by means of sulfonating graphene oxide (GO). It was found that SGO was well dispersed in water. Besides, viscosity of water was enhanced by 25.8 % after adding 0.2 wt. % of SGO, which might be favorable to enhance film thickness between tribo-pairs. Furthermore, SGO lubrication contributed to significant reduction in friction coefficient (CoF) and wear scar diameter (WSD) by 74 % and 15.7 %, respectively. SGO exhibited the better lubricity in comparison to GO, which could be ascribed to that adsorption ability of -SO3H groups was stronger than that of -OH and -COOH groups.