Unusual lift by shearing mesogenic fluids

The compounds hexakis- and pentakis[octylthio]benzene showing discotic phas es below room temperature were sheared in an oscillation mode under load be tween a cylinder and a disk of chromium steel at temperatures between 60 an d 120 degrees C. Surprisingly, after some initial wear friction coefficient s f decreased to values between 0.005 and 0.001, Under these conditions kno wn lubrication oils cause boundary friction with values some 100 times high er. The nonmesogenic compounds hexakis[2-ethylhexylthio]benzene and hexakis [2-octylthio]benzene behave like known oils. Possible reasons for this prom ising behaviour of the mesogenic compounds are discussed.