Direct Conversion of Liquid Bio-Benzoxazine Precursor into Porous Graphene-Based Lubricant Additive by Laser Irradiation

Rapid heating is a facile and cost-effective approach to fabricate 3D graphene materials without using a heating furnace or gas resources. Nevertheless, the generated graphene products are usually supported on solid-state precursors, which brings difficulties in controlling their geometry and dimensions for satisfying various applications. Herein, we report a strategy of conversion of liquid bio-benzoxazine precursor into porous graphene via rapid laser irradiation for fabricating lubricant additives. The 3D porous laser-induced graphene (LIG) powder was used as an additive for polyalphaolefin (PAO4) lubricants, and their tribological behavior was investigated by the ball-on-disk linear reciprocating model. Besides, the effects of both additive concentrations and loads on friction-reducing and antiwearing were systematically evaluated. Taking advantage of the outstanding dispersion stability in oil, adding only 0.5 wt % of the 3D porous LIG additive into the PAO4 lubricant results in 52 and 97% decrease in terms of coefficient of friction and wear rate under a 2 N load, respectively. With unique graphene structural formation via rapid laser irradiation on liquid bio-benzoxazine, the obtained 3D porous LIG additive affords both filling and polishing effects in lubricants during friction. The achievements obtained in this work will pioneer a way for application of LIG technology in the tribological field.