Photo-induced grease/oil switched lubricant for friction regulation

Abstract

AbstractControllable friction regulation has drawn much interest in both scientific and industrial fields. And there have been many researches on friction regulation by many physical fields and chemical factors. Photo-sensitive materials are promising because it is relatively easy to change their properties compared with others. Here, a new kind of photo-induced grease/oil switched lubricant is designed and shows great reversibility under ultraviolet (UV) and visible (Vis) irradiation. Its viscosity can change more than 50 times under different irradiation, and the coefficients of friction (COFs) obviously increase under Vis irradiation and decrease under UV irradiation, which performs better than those of the common grease. According to the experimental results, the phenomena are contributed to the break and reconstruction of the three-dimensional network inside the lubricant. With a switchable grease/oil state under different irradiation, this work provides a new principle for designing a smart lubricant with controllable friction regulation.