Wear resistant PTFE thin film enabled by a polydopamine adhesive layer

The influence of a polydopamine (PDA) adhesive layer on the friction and wear resistance of polytetrafluoroethylene (PTFE) thin films coated on stainless steel was investigated. The friction and wear tests were carried out using a ball on flat configuration under a normal load of 50 g, sliding speed of 2.5 mm/s, and stroke length of 15 mm. It is found that the PDA/PTFE film is able to withstand approximately 500 times more rubbing cycles than the PTFE film alone. X-ray photoelectron spectroscopy (XPS) results show that a tenacious layer of PTFE remains adhered to the PDA layer, which enables the durability of the PDA/PTFE film. Because of the relatively low thickness of the film, PDA/PTFE shows great potential for use in applications where durable, thin films are desirable.