The mechanism of ultraviolet bonding of perfluoropolyether lubricants

It has recently been reported that thin films of perfluoropolyethers can be bonded to a variety of substrates under illumination of 185 nm ultraviolet light. In this paper we examine the mechanism through which the bonding of the perfluoropolyethers to the substrate takes place. The perfluoropolyethers undergo dissociative electron attachment caused by photoelectrons that are generated by the interaction of the ultraviolet light with the substrate. This dissociative electron attachment results in the formation of a negative ion and a radical. It is suggested that subsequent radical propagation and termination steps then cross-link the perfluoro-polyether and bond it to the substrate. © 1993 IEEE