Concentrated polymer brush (CPB) is the polymer film with a structure that possesses greatly extended polymer chains densely grafted to substrate. CPB is known to swell in good solvents, which have high affinity for the polymer. Swollen CPB by a good solvent shows excellent micro-tribological properties such as super lubrication with the extremely low friction coefficient (μ~10-4). However, macro-tribological properties of CPB surface on steel have not been explored sufficiently. In this study, macroscopic tribological properties of a CPB on rough steel were evaluated using a block-on-ring type tribo-tester under lubrication with an ionic liquid. The CPB showed a significant friction reduction effect with the low friction coefficient of 0.005 on macroscale
